torsdag den 26. december 2013

Ny viden om hvordan B celler kan aktiveres ved autoimmun sygdom

B celler også kaldet B lymfocytter er en del af immunforsvaret. B celler kan danne antistoffer, som er en særlig type proteiner, immunoglobuliner. Disse immunoglobuliner kan genkende og binde sig til bakterier eller virus. Herved aktiveres andre dele af immunforsvaret, som angriber og eliminerer mikroorganismerne.

Denne mekanisme spiller også en rolle ved autoimmun sygdom. Her er antistoffet fejlagtigt blevet rettet mod kroppens eget væv, og immunforsvaret angriber så dette væv. Der er efterhånden identificeret mange forskellige slags auto-antistoffer i forskellige sygdomme. Disse kan anvendes som biomarkører, dvs. man kan udtage en blodprøve og påvise auto-antistoffet som tegn på sygdommen.

Statens Serum Institut har en liste over de auto-antistoffer, som anvendes som biomarkører til diagnosticering af sygdom:

Autoantistoffer

Efterhånden som forskningen skrider frem, identificeres flere og flere autoantistoffer. Herved kan årsagen til sygdomme afsløres – sygdomme, hvor man ikke tidligere har kendt og forstået sygdomsmekanismen.

Et eksempel på en sygdom, hvor man er ved at finde ud af, at autoantistoffer kan spille en rolle, er Postural ortostatisk takykardi syndrome (POTS). POTS omfatter forstyrrelser i det autonome nervesystem, og man har observeret, at POTS f. eks. kan opstå efter virussygdom eller HPV vaccine. I USA har man hos 10-15% af en gruppe POTS patienter påvist antistoffer mod acetylcholin receptor (ganglionic α3-AChR antibodies). Der er hos nogle POTS patienter også påvist andre autoantistoffer. Læs mere i den norske lægehåndbog: Autonome nevropatier (kroniske).


Regulering af B celler


Regulering af kroppens B celler er meget vigtig. B cellerne skal fungere effektivt, således at infektioner bliver bekæmpet, men B cellerne må ikke komme ud af kontrol og danne auto antistoffer.

På B cellerne findes en receptor, der hedder FcγRIIb (CD32B). Den sørger for at nedregulere dannelsen af immunoglobulin, så immunforsvaret ikke bare ”kører derudaf”.

Der findes flere forskellige slags Fcγ receptorer, som regulerer forskellige slags immunceller. Men indtil nu har man kun kendt til én Fcγ receptor på B celler. Imidlertid har et forskerhold fra University of Alabama at Birmingham opdaget én til Fcγ receptor på B celler. Den hedder FcγRIIc, og den virker aktiverende på B celler. Omkring 15% af verdens befolkning har denne receptor på deres B celler.

Denne genetiske variation – at have en opregulerende receptor på B celler – kan måske give en bedre evne til at bekæmpe infektioner, men således også have den ulempe, at man bliver mere sårbar over for muligheden for at udvikle autoimmun sygdom.

Forskerne bag opdagelsen kunne se, at mennesker med denne receptor producerede flere antistoffer efter vaccination. Ligesom forskerene kunne se, at den genetiske variation havde betydning for risikoen for udvikling af den autoimmune sygdom lupus.

Viden om denne receptor åbner op for, at man kan undersøge om der er sammenhæng til, hvorfor mennesker med autoimmune sygdomme responderer forskelligt på medicin som TNF alfa hæmmere og Rituximab. Og muligheden for at man kan udvikle ”skrædder-syet” behandlinger til patienter på baggrund af deres genetiske B-celle profil.

Læs mere: Newly identified immune receptor may activate B cells in autoimmunity

Forskerne bag opdagelsen har søgt patent for de behandlingsmuligheder opdagelsen bringer med sig: PROCESS FOR REGULATING IMMUNE RESPONSE . Patent application number: 20110268753.

Jeg tænker videre, at det var en oplagt idé at undersøge de unge kvinder, der har fået bivirkninger efter HPV vaccine, for om de har den aktiverende B celle receptor?

Ligesom det kunne være en oplagt mulighed også at undersøge for receptoren hos de ME/CFS patienter, som har fået Rituximab, og de der har prøvet TNF alfa hæmmere. Kunne Fc receptorer forklare forskellen mellem de der responderer, og de der ikke responderer på forskellige typer behandling?

Der er SÅ stor økonomisk og menneskelige gevinst, hvis man kunne finde mere viden til både at forebygge og behandle autoimmune sygdomme. Her er en oplagt mulighed for et forskningsprojekt i B celle regulering.


Yderligere viden:


Den videnskabelige artikel om B celle receptoren:
Allelic-Dependent Expression of an Activating Fc Receptor on B Cells Enhances Humoral Immune Responses

Den store danske, Gyldendals åbne encyklopædi om immunforsvarets celler:
Immunologi

Artikel fra ugeskrift for læger af professor Klaus Bendtzen
Medfødt immunitet, autoimmunitet og autoinflammation

Blog indlæg:
POTS, ME/CFS, HPV vaccine bivirkninger og autoimmunitet

Viden om ganglionic (α3) acetylcholine receptor (AChR):
Autoimmune Autonomic Neuropathy



tirsdag den 24. december 2013

The NO/ONOO cycle - disrupted endothelial caveolae?

Given the focus on endothelial dysfunction (read previous posts) perhaps it is time to take another look at Martin Palls old hypothesis about the NO/ONOO cycle:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome as a NO/ONOO- Cycle Disease

Nitric oxide synthase partial uncoupling as a key switching mechanism for the NO/ONOO– cycle

Martin Palls NO/ONOO- cyklus (på dansk/in Danish)

And his latest paper:

The NO/ONOO-Cycle as the Central Cause of Heart Failure


..if there is a peroxynitrite (ONOO- ) problem in ME/CFS – do ME/CFS patients have disrupted endothelial caveolae – as in this paper?

Peroxynitrite Disrupts Endothelial Caveolae Leading to eNOS Uncoupling and Diminished Flow-Mediated Dilation in Coronary Arterioles of Diabetic Patients:

  • Peroxynitrite (ONOO) contributes to coronary microvascular dysfunction in diabetes mellitus (DM).
  • NO-mediated coronary flow-mediated dilatation (FMD) was significantly reduced in DM patients, which was restored by ONOO scavenger.
  • The researchers propose, that ONOO selectively targets and disrupts endothelial caveolae, which contributes to NO synthase uncoupling, hence reduced NO-mediated coronary vasodilation in DM patients.

…and may an ONOO scavenger help ME/CFS patients?


(Remember: Flow-mediated dilatation (FMD) is a test for assessing endothelial dysfunction, and a study, Large and small artery endothelial dysfunction in chronic fatigue syndrome, showed FMD was significantly lower in ME/CFS patients.)

Some ME/CFS patients say vitamin B12 (cobalamin) helps, and others say it makes no difference. I do not know what to believe, but something I do know, is that the biochemistry behind this is very complicated. I found this paper: 

And then there is folic acid and eNOS activity: 

Folic Acid Reverts Dysfunction of Endothelial Nitric Oxide Synthase


...I fear that vitamins alone can't fix the broken cycle in ME/CFS, but let us hang in there and follow the research about it!!! 

I do believe we are getting closer to answers and a treatment!

søndag den 15. december 2013

Endothelial dysfunction and HSP60 antibodies – pieces to the ME/CFS puzzle?

Endothelial dysfunction – ME/CFS

Vascular endothelial dysfunction has been measured directly in ME/CFS patients. This information is from: International Journal of Cardiology, 2012 Feb 9; 154(3):335–6

ME Research UK has described the study here: Large and small artery endothelial dysfunction in chronic fatigue syndrome

This study is indeed interesting, because endothelial dysfunction in ME/CFS patients is also discussed in this presentation from the Research Council of Norway made by Øystein Fluge and Olav Mella from Haukeland University Hospital: B-lymfocytt deplesjon og sykdomsmekanismer ved kronisk utmattelsessyndrom/ myalgisk encephalopati (ME/CFS)


ME/CFS - HSP60

Hsp60 is of  interest in ME/CFS because of this recent study Epitopes of Microbial and Human Heat Shock Protein 60 and Their Recognition in Myalgic Encephalomyelitis:

"When evaluated with 61 other ME and 399 non-ME samples (331 BD, 20 Multiple Sclerosis and 48 Systemic Lupus Erythematosus patients), a peptide from Chlamydia pneumoniae HSP60 detected IgM in 15 of 61 (24%) of ME, and in 1 of 399 non-ME at a high cutoff (p<0.0001). IgM to specific cross-reactive epitopes of human and microbial HSP60 occurs in a subset of ME, compatible with infection-induced autoimmunity."

ME Research UK has described the study here: Immune responses to HSP60


HSP60 - endothelial cells – autoimmunity - inflammation seem to be connected

Modulation of endothelial cell damages by anti-Hsp60 autoantibodies in systemic autoimmune diseases

and

Chlamydia heat shock protein 60 decreases expression of endothelial nitric oxide synthase in human and porcine coronary artery endothelial cells

Endothelial dysfunction and HSP60 antibodies are found in Behçet's disease and Ankylosing spondylitis. Endothelial dysfunction may also be involved in the pathobiology of depression. So, endothelial dysfunction and HSP60 antibodies are not unique for ME/CFS, but perhaps it can help us to put the pieces together and understand the disease.

Let us look at my “pieces to the ME/CFS puzzle”:


ME/CFS - autoimmune thyroiditis – endothelial dysfunction - HSP60

From this German report "Characterization of phenotypic and functional Immune status of patients with Chronic Fatigue Syndrome": Charakterisierung des phänotypischen und funktionellen Immunstatus bei Patienten mit Chronischem Erschöpfungssyndrom, we can read that (my translation):

“Our analyzes have shown that an increased prevalence (approximately 11%) of autoimmune thyroiditis (Hashimoto's thyroiditis) is present in CFS patients. In contrast, the prevalence of autoimmune thyroiditis in the normal population is about 1.5 -2% . This finding suggests involvement of autoimmune processes in the pathogenesis of CFS. It is a primary thyroid hypothyroidism, which belongs to the most common consequences of an autoimmune disease.”

The endothelial dysfunction:

Low-grade systemic inflammation causes endothelial dysfunction in patients with Hashimoto'sthyroiditis

And there is a HSP60 connection:

Elevated blood Hsp60, its structural similarities and cross-reactivity with thyroid molecules, and its presence on the plasma membrane of oncocytes point to the chaperonin as an immunopathogenic factor in Hashimoto's thyroiditis


ME/CFS – POTS – endothelial dysfunction(?) - HSP60

ME/CFS and Postural Orthostatic Tachycardia Syndrome (POTS) are two diseases which very often occur together. One study showed that 27% of ME/CFS patients had POTS. A second study showed that 64% of a group of POTS patients also met the criteria for ME/CFS. Orthostatic intolerance can be a part of an autonomic dysfunction (like POST) is in a study shown to occur in 95% of ME/CFS patients.

Like ME/CFS, POTS is suspected to be an autoimmune disease. In this article, Autoimmunoreactive IgGs against cardiac lipid raft-associated proteins in patients with postural orthostatic tachycardia syndrome, we find (on page 6, table 3) HSPD1 60 kDa heat shock protein as a “suspect” for a possible autoimmune attack.

And links about ME/CFS/POTS, endothelial function and blood flow:

In ClinicalTrials.gov Identifier: NCT01308099 we find this project: Assessment of Vascular Endothelial Function in Postural Tachycardia Syndrome The hypothesis of the study is: Patients with POTS will have vascular endothelial dysfunction compared with control subjects.

Flow-mediated vasodilation and endothelium function in children with postural orthostatic tachycardia syndrome: In conclusion, augmented Flow Mediated Dilation and abnormal function of vascular endothelium may play an important role in POTS in children.

Decreased microvascular nitric oxide-dependent vasodilation in postural tachycardia syndrome: One variant of postural tachycardia syndrome (POTS), designated low-flow POTS, is associated with decreased peripheral blood flow related to impaired local vascular regulation. The data suggest that flow-dependent nitric oxide release is reduced in low-flow POTS. This may account for local flow regulation abnormalities.



lørdag den 14. december 2013

Caveolae, endothelium and NO production

The Research Council of Norway has this presentation from Øystein Fluge and Olav Mella:

B-lymfocytt deplesjon og sykdomsmekanismer ved kronisk utmattelsessyndrom/ myalgisk encephalopati (ME/CFS)

It is in Norwegian, but page 26 and 28 are in English. 

The hypothesis is about endothelial dysfunction in ME/CFS, and as you can see from page 28 nitric oxide (NO) production in the caveolae is of relevance. 

I have written about Endothelial dysfunction in ME/CFS – and cytochrome CYP2C9, but to find out what is the disease mechanism in ME/CFS, I think we have to learn more about what is going on in the caveolae. Therefore I have searched for some articles about the caveolae and NO production. So, this is not about ME/CFS - this is basic knowledge about caveolae, nitric oxide and nitric oxide synthesis:

Regulation of eNOS in caveolae from: Nitric oxide signaling specificity — the heart of the problem

Caveolins and the regulation of endothelial nitric oxide synthase in the heart

Nitric oxide synthases: regulation and function

Model for TRPC5-mediated feedback of Ca2+ and NO signaling in endothelial cells and attenuation of Ca2+ entry through TRPC6 by NO in smooth muscle cells


And we also need to look into the connection between nitric oxide and the mitochondria: 
Nitric oxide in skeletal muscle: role on mitochondrial biogenesis and function

torsdag den 12. december 2013

ME/CFS - possible disturbance to amino acid and nitrogen metabolism?

Production of nitric oxide (NO) - nitric oxide synthase (NOS)

In my previous post  Endothelial dysfunction in ME/CFS – and cytochrome CYP2C9, we learned from wikipedia, that endothelial dysfunction is commonly associated with decreased NO bioavailability, which is due to impaired NO production by the endothelium and/or increased inactivation of NO by reactive oxygen species.

We can learn more from wikipedia about the production of Nitric oxide (NO) and Nitric oxide synthase:

The endothelium (inner lining) of blood vessels uses NO to signal the surrounding smooth muscle to relax, thus resulting in vasodilation and increasing blood flow.

NO is produced by the three calcium/calmodulin controlled isoenzymes called nitric oxide synthases (NOS), all present in skeletal muscle, but named because of the tissues from where they were first purified (neuronal and endothelial), but all three types of NOS are expressed in the skeletal muscle:
  • Neuronal NOS (nNOS) 
  • Endothelial NOS (eNOS) 
  • Inducible NOS (iNOS) - is mainly expressed during inflammatory responses
NOS generates NO upon the conversion of the amino acid L-arginine to L-citrulline and it is regulated by multiple mechanisms.

Arginine can also be converted to the amino acid ornithine:

arginine + O2  →  citrulline + nitric oxide (NO)
arginine  → ornithine + urea

Further details and fine figures, please, read this article: Enzymes of Arginine Metabolism

What does the litterature have to say about the levels of these amino acids in ME/CFS patients?


Arginine, citrulline and ornithine in ME/CFS patients

From this article NMR metabolic profiling of serum identifies amino acid disturbances in chronic fatigue syndrome we learn:

ME/CFS patients have reduced levels of glutamine and ornithine = possible disturbance to amino acid and nitrogen metabolism

"Identified metabolites that were found to be significantly altered between the groups were subjected to correlation analysis to potentially elucidate disturbed metabolic pathways. Our results showed a significant reduction of glutamine (P=0.002) and ornithine (P<0.05) in the blood of the CFS samples. Correlation analysis of glutamine and ornithine with other metabolites in the CFS sera showed relationships with glucogenic amino acids and metabolites that participate in the urea cycle. This indicates a possible disturbance to amino acid and nitrogen metabolism."

And from this article Levels of Nitric Oxide Synthase Product Citrulline Are Elevated in Sera of Chronic Fatigue Syndrome Patients:

ME/CFS patients have elevated levels of citrulline

"Serum levels of citrulline, a product of nitric oxide synthase activity, were measured in 36 CFS patients and 16 controls to determine whether synthase activity may be elevated in CFS patients. Serum citrulline levels were found to be significantly elevated in CFS patients and, in addition, there was a trend towards higher levels in CFS patients with stronger symptoms. These results provide support for the view that nitric oxide synthase activity tends to be elevated in CFS patients, thus supporting a prediction of the elevated nitric oxide/peroxynitrite theory of CFS etiology."

It would be reallye nice to have these results replicated in a new study - all parameters measured at the same time in the same study! And if someone follow this idea, please look at the NK cells too!

Because of this article Decreased nitric oxide-mediated natural killer cell activation in chronic fatigue syndrome says:  "...These results demonstrate that the L-Arg-induced activation of NK activity is mediated by NO and that a possible dysfunction exists in the NO-mediated NK cell activation in CFS patients."

tirsdag den 10. december 2013

Endothelial dysfunction in ME/CFS – and cytochrome CYP2C9

Endothelial dysfunction in ME/CFS

Vascular endothelial dysfunction has been measured directly in ME/CFS patients. This information is from: International Journal of Cardiology, 2012 Feb 9; 154(3):335–6

ME Research UK has described the study here: Large and small artery endothelial dysfunction in chronic fatigue syndrome :

  • Flow‐mediated dilatation was assessed using ultrasound to measure the percentage increase in brachial artery diameter during the hyperaemia following 5 minutes of ischaemia in 30 ME/CFS patients and 27 healthy controls. 
  • In addition, post‐occlusive reactive hyperaemia was assessed in 9 ME/CFS patients and 9 healthy controls using laser Doppler flowmetry to measure the increase in forearm skin microcirculation after 5 minutes of ischaemia.
  • Flow‐mediated dilatation was significantly lower in the ME/CFS group than in the control group.
  • Post‐occlusive reactive hyperaemia in the forearm microcirculation was also significantly lower in ME/CFS patients.

(Read more about the measurement technique: Measurement of endothelial function by brachial artery flow-mediated vasodilation and Post occlusive reactive hyperemia (PORH))


This study is indeed interesting, because endothelial dysfunction in ME/CFS patients is also mentioned in this presentation from Øystein Fluge from Haukeland University Hospital: B-lymphocyte depletion with Rituximab induction and maintenance in ME/CFS. A multicenter, randomised, double-blinded and placebo-controlled study.

Wikipedia about Endothelial dysfunction:

  • In human vascular diseases, endothelial dysfunction is a systemic pathological state of the endothelium (the inner lining of blood vessels) and can be broadly defined as an imbalance between vasodilating and vasoconstricting substances produced by (or acting on) the endothelium.
  • Endothelial dysfunction can result from and/or contribute to several disease processes, as occurs in hypertension,hypercholesterolaemia, diabetes, septic shock, Behcet's disease, and it can also result from environmental factors, such as from smoking tobacco products and exposure to air pollution
  • Nitric Oxide (NO) reduction is considered the hallmark of endothelial dysfunction. A key and quantifiable feature of endothelial dysfunction is the inability of arteries and arterioles to dilate fully in response to an appropriate stimulus that stimulates release of vasodilators from the endothelium like NO. Endothelial dysfunction is commonly associated with decreased NO bioavailability, which is due to impaired NO production by the endothelium and/or increased inactivation of NO by reactive oxygen species.

Cytochrome P450 2C9

The human body is designed with redundancy - when a function fails, then another function will support or take over.

In this study an inhibition of nitric oxide synthase (NOS) occurs and nitric oxide production is compromised, then a CYP-dependent vasodilator mechanism is been observed :

Cytochrome P450 2C9 plays an important role in the regulation of exercise-induced skeletal muscle blood flow and oxygen uptake in humans

(So if vasodilation is somehow impaired in ME/CFS patient, I hypothesize that the use of Cytochrome P450 2C9 (CYP 2C9) could be a useful redundancy???)

But “too much vasodilation” can be damaging, if it is after lack of oxygen in the tissue – like reperfusion injury in myocardial infarction (heart attack).

Wikipedia about reperfusion injury:
  • Reperfusion injury is the tissue damage caused when blood supply returns to the tissue after a period of ischemia or lack of oxygen. The absence of oxygen and nutrients from blood during the ischemic period creates a condition in which the restoration of circulation results in inflammation and oxidative damage through the induction of oxidative stress rather than restoration of normal function.

This article, Fundamentals of Reperfusion Injury for the Clinical Cardiologist, informs “Decreasing reperfusion injury via modulation of nitric oxide bioavailability is an active area of research.“

You could get the thought that the other redundancy system might also be a target of modulation. And this is in fact the case:

Inhibition of cardiac cytochrome P450: a new approach to cardiac ischaemia and reperfusion damage:

“Inhibition of CYP2C9 is a promising approach for the treatment of myocardial infarction, and should be further developed.”

CYP2C9 is drug-metabolizing cytochrome, and the inhibition in this study was done be giving the antibiotic chloramphenicol.

There are different genetic types of CYP2C9, and people with certain types of CYP2C9 is poor drug metabolizers. This article Cytochrome P450 2C9-CYP2C9 gives the information that, the haplotypes CYP2C9*2 and CYP2C9*3 have decreased metabolism for some drugs.

But what happens in the endothelial cells in people with CYP2C9*2 and CYP2C9*3 ?

From this article, CYP2C9*2 and CYP2C9*3 Alleles Confer a Lower Risk for Myocardial Infarction, we get the information:

  • Both the CYP2C9*2 and theCYP2C9*3 allele lead to decreased enzyme activity.
  • Endothelial cells synthesize and release endothelium-derived hyperpolarizing factor (EDHF), which causes hyperpolarization of underlying vascular smooth muscle cells via activation of Ca2+-activated K+ channels.
  • Decreased concentrations of CYP2C attenuate EDHF-mediated vascular response in porcine coronary artery endothelial cells.
  • The researchers hypothesized that reduced CYP2C9 activity attributable to genetic alterations may modulate vascular function and influence the risk of vascular disease.
  • But, in the present study, a protective effect was observed. This was surprising because one would have expected carriers of CYP2C9 mutant alleles to exhibit reduced CYP2C9 metabolic capacity, leading to decreased endothelial EDHF synthesis and an increased risk for Myocardial Infarction. However, CYP enzymes also contribute to oxidative stress through the formation of oxygen radicals in the vasculature.

Endothelial dysfunction in ME/CFS - and cytochrome CYP2C9

Let us take this knowledge a little further in a hypothesis.

If ME/CFS patients have endothelial dysfunction and reduced decreased NO bioavailability, - do they need to borrow a little redundancy from a ”strong” CYP2C9?

But what if ME/CFS patients have decreased CYP2C9 enzyme activity?

Both the CYP2C9*2 and theCYP2C9*3 allele lead to decreased enzyme activity.

ME/CFS patients is known to have low tolerance for drugs, and some patients also have the co-morbidity Mutiple Chemical Sensitivity (MCS). Do CYP2C9*2 and the CYP2C9*3 occur more frequently in ME/CFS/MCS?

This study, Xenobiotic Sensor- and Metabolism-Related Gene Variants in Environmental Sensitivity-Related Illnesses: A Survey on the Italian Population, compared the frequency of gene polymorphisms of selected cytochrome P450 (CYP) metabolizing enzymes in the three cohorts of 156 diagnosed MCS, 94 suspected MCS, and 80 FM/FCS patients:
  • The researchers found significantly higher frequency of polymorphisms CYP2C9*2, CYP2C9*3, CYP2C19*2, CYP2D6*4 and CYP2D6*41 in patients compared with controls. 
  • Moreover, the compound heterozygosity for CYP2C9*2 and *3 variants was useful to discriminate between either MCS or FM/CFS versus suspected MCS.

…we need more research in this area!

And I need more pieces to the puzzle...

If ME/CFS patients have endothelial dysfunction and reduced decreased NO bioavailability,  Why do patients not have hypertension?

And if  NO bioavailability and if  EDHF endothelium-dependent relaxation both are compromised in ME/CFS patients - do they get hypertension?

Most ME/CFS patients I know have normotension or hypotension. And where do POTS fit in? Is it the blood-regulation there has gone wrong, and not the "tension"?

Can someone help me to an answer?

Wikipedia on EDHF and hypertension: In mice lacking both eNOS and COX-1, EDHF-mediated response appeared to compensate the absence of endothelial NO in females but not in males. In female mice, the deletion of eNOS and COX-1 did not affect mean arterial blood pressure, while males become hypertensive. In accordance with this study, EDHF has been suggested to be more important in female arteries to confer endothelium-dependent dilatation, while NO played a predominant role in arteries from males.

Is the answer in the caveolae?


Is the answer an auoimmune reaction against the caveolae?

Autoimmunoreactive IgGs against cardiac lipid raft-associated proteins in patients with postural orthostatic tachycardia syndrome










fredag den 6. december 2013

ME/CFS – forskellige holdninger til diagnosticering og behandling

I Norge forsætter afprøvning af Rituximab til behandling af patienter med Myalgic encephalomyelitis (ME). Ligesom man forsøger at afdække den immunologiske og muligvis autoimmune sygdomsmekanisme, der invaliderer patienterne. Det er et storstilet projekt til over 20 millioner kroner, der sættes i gang:

B-lymphocyte depletion with Rituximab induction and maintenance in ME/CFS. A multicenter, randomized, double blind, placebo-controlled study

ME kaldes også for Chronic Fatige Syndrome (CFS), og i Danmark er det blevet oversat til kronisk træthedssyndrom. Imidlertid er betegnelsen ”funktionel lidelse” i stedet ved at vinde indpas. Og behandling er kognitiv terapi. Men er ME, CFS, kronisk træthedssyndrom og funktionel lidelse det samme? Og kan lidelsen behandles både med en medicin som Rituximab, der fjerner B cellerne fra blodet og med kognitiv terapi? Og hvordan diagnosticerer man sygdommen?

Forskere, patientforeninger og patienter er ikke enige om diagnosekriterier og behandling af sygdommen. Hvad der det der foregår?

Jeg vil i det følgende prøve at gøre rede for situationen - set fra mit hjørne.


Diagnosekriterier og diskussionen om hvilke kriterier er de rette

Diagnosekoden er: WHOs diagnosekode ICD-10 G93.3. Postviral fatigue syndrome, Benign myalgic encephalomyelitis

Der har været og er megen diskussion om rette diagnostiske kriterier til ME/CFS. Wikipedia giver et overblik: Clinical descriptions of chronic fatigue syndrome

Fukuda kriterierne 1994: The Chronic Fatigue Syndrome: A Comprehensive Approach to Its Definition and Study

De canadiske kriterier 2003: Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome: Clinical Working Case Definition, Diagnostic and Treatment Protocols

NICE guidelines 2007: National Institute of Health and Clinical Excellence, NICE clinical guideline 53

En oversigts artikel over NICE kriterier: Diagnosis and management of chronic fatigue syndrome or myalgic encephalomyelitis (or encephalopathy): summary of NICE guidance

De internationale konsensuskriterier 2011: Myalgic encephalomyelitis: International Consensus Criteria

En god artikel, der sammenligner diagnosekriterierne og sætter dem op i overskuelige tabeller er denne: The role of clinical guidelines for chronic fatigue syndrome/myalgic encephalomyelitis in research settings


Hvilke diagnosekriterier benyttes i Danmark?

Der er ikke enighed mellem myndigheder, forskere og patienter om anvendelse af diagnosekriterier i hverken Danmark eller udland.

Der er heller ikke enighed om brugen af betegnelserne Myalgic encephalomyelitis, Chronic Fatigue Syndrome eller kronisk træthedssyndrom. Og somme tider kommer begrebet kronisk træthed også ind i forvirringen.

Hertil kommer begreberne funktionelle lidelser og Bodily Distress Syndrome, som også omfatter G93.3 ME. Af denne artikel: ”Fink P, Rosendal M., Dam M, Schröder A. Ny fælles diagnose for funktionelle sygdomme. Ugeskr Laeger 2010 14;172(24):1835-38” fremgår det, at der sættes lighedstegn mellem G93.3 ME og betegnelsen kronisk træthedssyndrom, og at diagnosen foreslås omklassificeret.

Så spørgsmålet er om det er samme lidelse med mange navne, eller om det er flere tilstande, der blandes sammen?

Ser man på benyttede diagnosekriterier i Danmark, finder man dette:

Århus Universitetshospital, Infektionsmedicinsk afdeling Q. har en diagnosevejledning, der er baseret på Fukuda: 1.18.1 Kronisk træthedssyndrom, version 1

Neurolog Finn Somnier fra Statens Serum Institut henviser til NICE guidelines: Diagnosing chronic fatigue syndrome (CFS)

Ved forespørgsler til folketinget om ME/CFS henvises der til Sundhedsstyrelsen, som henviser til NICE guidelines generelt: Sundheds- og Forebyggelsesudvalget 2011-12 SUU Alm.del endeligt svar på spørgsmål 183

Dansk Selskab for Almen Medicin har følgende vejledning om funktionelle lidelser, hvoraf der fremgår forskningsbaserede diagnosekriterier: Funktionelle lidelser


Hvilke diagnosekriterier benyttes i Norge?

Det norske helsedirektorat har nedenstående vejledning. På side 22 står der: ”Selv om vi ikke vet om det ene diagnosesettet er bedre enn et annet, har vi valgt å beskrive og anbefale noen diagnosesett”: Pasienter med CFS/ME: Utredning diagnostikk, behandling, pleie og omsorg

Man kan også finde de internationale konsensus kriterier fra 2011 oversat til norsk på det norske helsedirektorats hjemmeside: Diagnosekriterier - Det foreligger flere ulike diagnostiske kriterier for CFS/ME. De ulike kriteriene benyttes til både forskning og diagnostikk

Olso Universitetssygehus har denne vejledning. Her er der taget udgangspunkt i de canadiske diagnosekriterier: Veileder i forbindelse med utredning på sykehus av pasienter der man mistenker Myalgisk encefalopati (ME)/ Kronisk utmattelsessyndrom (CFS)


Hvilke diagnosekriterier benyttes i USA?

Hvis man kigger bredt på artikler, der omhandler forskning i ME/CFS, er der igennem de sidste årtier benyttet flere forskellige diagnosekriterier, som grundlag for forskning. En meget stor andel af forskningen er baseret på Fukuda kriterierne.

Og det er også Fukuda 1994, som man finder på Centers for Disease Control and Prevention: CFS Case Definition

Imidlertid er der blevet skrevet et guideline, som er blevet anerkendt af National Guideline Clearinghouse. Og denne guideline anbefaler brugen af de canadiske kriterier 2003: Chronic fatigue syndrome/myalgic encephalomyelitis. A primer for clinical practitioners

På U.S. Department of Health and Human Services hjemmeside finder man Chronic Fatigue Syndrome Advisory Committee (CFSAC). Denne ekspertgruppe kommer med forskellige anbefalinger vedrørende ME/CFS. I deres sidste anbefaling Highest Recommendations from the Chronic Fatigue Syndrome Advisory Committee beder de om, at Primeren bliver stillet bredt til rådighed.

Department of Health and Human Services har andre planer. De vil få en arbejdsgruppe til at starte forfra og definere ME/CFS diagnosekriterier. Dette har fået en række ME/CFS forskere og fortalere til at skrive et brev til sundhedsmyndighederne An open letter to the Honorable Kathleen Sebelius, U.S. Sercretary og Health and Human Services og beder om, at de canadiske diagnosekriterier tages i anvendelse.


Hvorfor så megen diskussion om diagnosekriterier?

Rette diagnose er selve fundamentet for korrekt behandling af en patient, og grundlaget for at forskningen i ME/CFS bliver valid.

Kritikken der rettes mod Fukuda kriterierne er, at de er så bredt defineret, at der er risiko for, at der fejlagtigt kan medtages patienter med andre diagnoser.

Som det fremgår af det åbne brev til Health and Human Services, så er det obligatorisk, at ME/CFS patienter har post-exertional malaise (PEM) ifølge de canadiske kriterier. Dette er ikke obligatorisk i Fukuda kriterierne.

Kardinal-symptomet i ME/CFS er, at patienterne oplever en opblussen af deres sygdom efter motion/aktivitet, som overskrider deres individuelle tolerance grænse. Dette fænomen er yderst karakteristisk for sygdommen, og det er oven i købet meget let målbart. Det er derfor foreslået, at man anvender en 2 dages motionstest som diagnostisk værktøj. Dette fremgår af denne pressemeddelese: Has Workwell Foundation Identified a Diagnostic Biomarker for Chronic Fatigue Syndrome?

Den videnskabelige artikel er her: Discriminative Validity of Metabolic and Workload Measurements for Identifying People With Chronic Fatigue Syndrome

Et godt eksempel på, at forskning først bliver valid, når man er klar over forskellen på anvendelsen af diagnosekriterier fremgår af artiklen: Immune Abnormalities in Patients Meeting New Diagnostic Criteria for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis. Her fremgår det tydeligt, at det er en anden immunologisk profil, der tegner sig, når man skelner mellem patienter diagnosticeret efter CDC 1994 (Fukuda) kriterier og de nye snævre ICC kriterier.

Denne artikel Contrasting Chronic Fatigue Syndrome versus Myalgic Encephalomyelitis/Chronic Fatigue Syndrome konkluderer ligeledes, at man får fat i en mindre og mere syg patientgruppe, når de canadiske kriterier anvendes i stedet for Fukuda kriterierne.


Er kognitiv terapi og gradueret motion rette behandling af ME/CFS patienter?

Diskussion om rette diagnosekriterier fører os videre til diskussionen om rette behandling.

ME/CFS patienters tolerance af motion/aktivitet, og gradueret træning som behandling er omdrejningspunkt for en vedvarende diskussion. Anbefaling af den graduerede motion kan bl.a. findes i den tidligere nævnte NICE guideline. Og rapport over den skade, som gradueret motion kan forvolde, er samlet her: Reporting of Harms Associated with Graded Exercise Therapy and Cognitive Behavioural Therapy in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Ligesom der for nylig er udgivet denne pressemeddelelse: INCORRECT GOVERNMENT INFORMATION COULD BE HURTING CHRONIC FATIGUE SYDROME PATIENTS

Motion hjælper på en meget lang række sygdomme, og hvis en patientgruppe udvalgt efter Fukuda kriterier fejlagtigt omfatter patienter andre diagnoser, vil forskning i gradueret træning på denne patientgruppe give misvisende forskningsresultater.

Enkelte læger tror sommetider, at ME/CFS patienter har ”motionsfobi” eller ikke er klar over, at det er forbundet med henfald af muskelmasse, øget risiko for blodpropper og andre sundhedsrisici ved længere tids sengeleje/inaktivitet. ME/CFS patienter er fuldt klar over dette. Og det er hos de fleste forbundet med stor sorg, at de har måttet opgive sportsaktiviteter og reducere almen aktivitet til et minimum. I ME/CFS patient-netværk et det en kendt ting, at patienterne prøver at holde sig fysisk i gang, så vidt det overhovedet er muligt for dem. Modstanden mod gradueret motion som behandling skyldes, at det er afprøvet af patienterne, og det ikke har hjulpet dem. Tværtimod.

Som det fremgår af denne spørgeskemaundersøgelse Patient Survey Results for FDA Drug Development Meeting for ME and CFS, så det er fænomenet “pacing”, der hjælper ME/CFS patienter. Pacing er beskrevet på side 21 i ME/CFS: A Primer for Clinical Practitioners

Med hensyn til kognitiv terapi til ME/CFS, så fremgår det af de tidligere omtalte NICE guidelines, side 190: “CBT or psychological approaches to CFS/ME do not imply that symptoms are psychological, ‘made up’ or in the patient’s head. CBT is used as part of the overall management for many conditions, including cardiac rehabilitation, diabetes and chronic pain.”

Der er bred enighed i patient-netværk om, at psykologisk hjælp til at leve med svær sygdom, er et virkeligt godt redskab. Desværre møder ME/CFS patienter sommetider den opfattelse, at kognitiv terapi skal ændre deres fejlagtige tanker om, at de er syge. Og at ”terapi er kurativ”.

ME/CFS er en alvorlig sygdom, og der findes ikke en behandling mod den. Derfor har de amerikanske myndigheder U. S. Food and Drug Administration (FDA) iværksat et initiativ ”Patient Focused Drug Development”, der skal hjælpe med at skaffe behandling til patienterne: FDA Workshop on Drug Development for Chronic Fatigue Syndrome (CFS) and Myalgic Encephalomyelitis (ME)

En behandling som har skabt håb for de mange alvorlig syge ME/CFS patienter er Rituximab.


Håbet om at bliver rask og få sit liv tilbage – er Rituximab en behandlingsmulighed?

Det vakte megen opsigt, da de norske kræftforskere Olav Mella og Øystein Fluge i 2011 publicerede en artikel om, at kræftmidlet Rituximab havde hjulpet 2 ud af 3 ME/CFS patienter: Benefit from B-Lymphocyte Depletion Using the Anti-CD20 Antibody Rituximab in Chronic Fatigue Syndrome. A Double-Blind and Placebo-Controlled Study

De norske TV2 nyheder bragte følgende indslag (youtube):

ME - research by Mella and Fluge - Part1

ME - research by Mella and Fluge - Part 2

Idet Rituximab fjerner B cellerne fra blodet har medicinen også en effekt på autoimmune sygdomme. Der blev nedsat en international arbejdsgruppe, der forsøger at afklare om ME/CFS er en autoimmun sygdom. Clinical Autoimmunity Working Group

Olav Mella og Øystein Fluge har modtaget midler til at iværksætte en større afprøvning af Rituximab. Den norske ME syge læge Maria Gjerpe, som selv blev rask af Rituximab behandling, gjorde en stor indsats for at hjælpe med at samle penge ind til det videre studie. På sin blog beskriver hun om planerne for det videre ME Rituximab behandlings studie: Rituximab – update fra Haukeland

Det skal understreges, at Rituximab er en medicin, der kan give alvorlige bivirkninger. Og det er også set, at enkelte ME/CFS patienter ikke tåler medicinen. Tysklands meget kendte ME patient, den tidligere fodboldspiller Olaf Bodden kunne ikke tåle medicinen (tysk youtube):

Olaf Bodden: Eine prominente Stimme im Kampf gegen ME / CFS

Der er nødvendigt at samle mere viden om ME/CFS og behandling med Rituximab. Den viden kommer ikke af sig selv. Det er vigtigt at flere lande samarbejder omkring disse kliniske afprøvninger. Senest er UK også ved at iværksætte et Rituximab behandlingsforsøg: UK Rituximab Trial


Hvorfor gør patientforeninger indsigelser mod betegnelsen funktionelle lidelser og mod behandlingen?

Ovenstående afsnit fører os frem til forståelsen af, hvorfor ME/CFS patienter er imod betegnelsen funktionelle lidelser/bodily distress syndrome og mod behandlingen kognitiv terapi/gradueret motion.

Af denne artikel One single diagnosis, bodily distress syndrome, succeeded to capture 10 diagnostic categories of functional somatic syndromes and somatoform disorders fremgår det, at der indgår 54 CFS patienter i diagnosekonveterings-undersøgelsen. Det er ikke lykkedes for patientgruppen at finde mere fyldestgørende dokumentation for at anvende denne forskningsbaserede diagnose.

Hvordan skal en så bred diagnose som funktionelle lidelser kunne anvendes, når der skal udvælges patienter til klinisk afprøvning af medicin som Rituximab, Ampligen (rintatolimod) og lignende typer medicin? Når flere ME/CFS forskere verden over lægger vægt på, at post-exertional malaise er kardinalsymptomet og snævre ME/CFS kriterier skal anvendes, skaber det utryghed, at danske psykiatere gør diagnosekriterierne så brede, at de kan rumme omkring 300.000 danskere.

ME/CFS patienter er syge i forskellig grad, desværre ender mange med at miste erhvervsevnen. Sundhedssystemet fremstiller det som om der eksisterer et behandlingstilbud til ME/CFS patienter i form af kognitiv terapi.

Hverken indenlandske eller udenlandske patientnetværk er bekendt med ME/CFS patienter, som er blevet helbredt af kognitiv terapi og gradueret træning. Der er derimod kendskab til flere patienter som har fået forværret deres tilstand af genoptræningsforsøg.

ME/CFS patienter er imod aktiviteterne omkring funktionelle lidelser og kognitiv terapi/gradueret træning, fordi de faglige og økonomiske ressourcer i stedet kunne anvendes målrettet til at støtte op om det internationale arbejde for at afdække sygdomsmekanismen og finde en behandling til ME/CFS.


Links med indsigelser mod betegnelsen funktionelle lidelser

Et detaljeret indblik i hvad de enkelte patientforeninger har af indsigelser til funktionelle lidelser, fremgår af høringssvarene: DSAMs vejledning om funktionelle lidelser - høringssvar

Patienternes frustration over situationen har medført en stribe af henvendelser til politikerne. Her er et lille udpluk af dokumenter fra Folketingets hjemmeside:

2012-13 Alm. del Bilag 306 Henvendelse af 17/5-13 fra Hanne Holst Rasmussen vedr. Forskningsklinikken for Funktionelle Lidelsers rubricering af fysiske lidelser som psykiatriske lidelser

2012-13 Alm. del Svar 651 SUU alm. del - svar på spm. 651 om kommantar til henvendelse af 17/5-13 fra Hanne Holst Rasmussen vedr. Forskningsklinikken for Funktionelle Lidelsers rubricering af fysiske lidelser som psykiatriske lidelser, fra ministeren for sundhed og forebyggelse

2012-13 Alm. del Svar 994 SUU alm. del - svar på spm. 994 om at den forskning, der foregår på Forskningsklinikken for Funktionelle Lidelser, ikke kommer patienterne til skade, fra ministeren for sundhed og forebyggelse

2012-13 Alm. del Svar 995 SUU alm. del - svar på spm. 995 om, hvordan forskningen kan foregå på hovedfunktionsniveau, når Forskningsklinikken samarbejder med og underviser læger og andet personale indenfor mange forskellige specialer på landsplan (udfra TERM-modellen), fra ministeren for sundhed og forebyggelse

2012-13 Alm. del Svar 996 SUU alm. del - svar på spm. 996 om, hvordan Forskningsklinikken for Funktionelle Lidelsers forskning i så vid udstrækning kan implementeres i praksis over hele landet m.v., fra ministeren for sundhed og forebyggelse

2012-13 Alm. del Svar 997 SUU alm. del - svar på spm. 997 om at Forskningsklinikken f.eks. ikke ser ud til at have held med at øge erhvervsevnen synderligt hos dem, der får diagnosen funktionelle lidelser, fra ministeren for sundhed og forebyggelse

2013-14 Alm. del Bilag 125 Henvendelse af 12/11-13 fra Gruppen 'Menneskesynet bag term-modellen og lægekonsulenternes arbejde' vedr. funktionelle lidelser


Hvordan kommer vi videre herfra ?

Dialog.

En mulighed kunne være, at der blev etableret en arbejdsgruppe bestående af læger/forskere med forskellige indgangsvinkler til sygdommene kaldet funktionelle lidelser, repræsentanter fra  patientforeninger og evt. regionerne/sundhedsstyrelsen. Dagsorden for gruppen skal være at etablere en god dialog, hvor parterne lytter til hinanden og sætter sig ind i problematikken.

Arbejdsgruppen skal have til opgave sammen at kigge på eksisterende viden om diagnosticering og behandling af sygdommene. Den nyeste forskning skal også gennemgås i fællesskab. Ud fra dette skal det sikres, at patientgrupperne får en behandling, der i videst muligt omfang bringer dem tilbage til et godt helbred.

International Consensus Primer for Medical Practitioners har samlet viden fra megen forskellig forskning, som kunne inspirere til at afprøve behandlingsformer for ME/CFS patienter under kontrollerede kliniske forhold.

Det kunne ligeledes være en opgave for arbejdsgruppen, at der lægges en plan for at tage avancerede teknologier (fx Omics, QTL) i brug for at karakterisere patientgrupperne og afdække sygdomsmekanismer. Danmark råder over mange dygtige forskere, og det kunne være spændende om disse lagde sig forrest i feltet med henblik på at finde biomarkører og behandlingsmetoder til sygdommene.

Med hensyn til ME/CFS kunne man invitere de norske forskere til Danmark, så de kan fortælle mere detaljeret om deres utrolige opdagelser, og der kunne udveksles viden med danske forskere.

National Centre for Neuroimmunology and Emerging Diseases ved Griffith University i Australien er meget langt fremme med forskning i ME/CFS. De har lige afholdt The 2nd international symposium for Chronic Fatigue Syndrome/Myalgic encephalomyelitis. Det kunne være en oplagt mulighed for et par danske forskere at tage på studietur til Griffith og hente inspiration til dansk forskning.

Mht til diagnoseværktøjer, så er der intet til hinder for i en periode at benytte flere diagnose-værktøjer samtidig, og herved høste mere viden om overlap og forskelle i sygdomskarakteristika. 

Kognitiv terapi og mindfulness meditation er fremragende værktøjer, og den udenlandske immunologiske forskning viser gode resultater. Hvorfor ikke forene det bedste fra begge verdener?


List of ME/CFS articles

I have listed some of the latest ME/CFS articles that I find interesting:

Epitopes of Microbial and Human Heat Shock Protein 60 and Their Recognition in Myalgic Encephalomyelitis


Immune Abnormalities in Patients Meeting New Diagnostic Criteria for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis


Myalgic encephalomyelitis/chronic fatigue syndrome and encephalomyelitis disseminata/multiple sclerosis show remarkable levels of similarity in phenomenology and neuroimmune characteristics


Comorbidity of postural orthostatic tachycardia syndrome and chronic fatigue syndrome in an Australian cohort


A multidisciplinary approach to study a couple of monozygotic twins discordant for the chronic fatigue syndrome: a focus on potential salivary biomarkers


The Emerging Role of Autoimmunity in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome(ME/cfs)


In myalgic encephalomyelitis/chronic fatigue syndrome, increased autoimmune activity against5-HT is associated with immuno- inflammatory pathways and bacterial translocation


Analysis of Neutrophil Function in Severe and Moderately Affected Chronic Fatigue Syndrome Subjects


T Cell Dysregulation in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis


Assessment of Natural Killer Cell Receptors and Activity in Severe and Moderate Chronic Fatigue Syndrome


The role of Dendritic Cells and Monocytes in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis


Characterising eye movement dysfunction in myalgic encephalomyelitis/chronic fatigue syndrome



Cerebral vascular control is associated with skeletal muscle pH in chronic fatigue syndromepatients both at rest and during dynamic stimulation


Chronic fatigue syndrome with history of severe infection combined altered blood oxidant status, and reduced potassium efflux and muscle excitability at exercise


Differing leukocyte gene expression profiles associated with fatigue in patients with prostate cancer versus chronic fatigue syndrome


Patient Survey Results for FDA Drug Development Meeting for ME and CFS, April 25-26, 2013



lørdag den 12. oktober 2013

DDPIV/CD26, CXCL12 and CXCR4

CD26: Dipeptidyl Peptidase DPPIV known as adenosine deaminase complexing protein 2 or CD26 is an enzyme expressed on the surface of most cell types and is associated with immune regulation, signal transduction and apoptosis. CD26 has a key role in immune regulation as a T cell activation molecule and in immune-mediated disorder.

CXCL12: Stromal-derived-factor-1, SDF-1 also known as C-X-C motif chemokine 12, CXCL12 or Pre-B-Cell Growth-Stimulating Factor. A CXC chemokine that is chemotactic for T-lymphocytes and monocytes. Often induced by proinflammatory stimuli such as lipopolysaccharide, TNF, or IL1.

CXCR4: CXCR-4 is an alpha-chemokine receptor specific for stromal-derived-factor-1 (SDF-1 also called CXCL12), a molecule endowed with potent chemotactic activity for lymphocytes.

Interaction between DPPIV CD26, CXCL12 and CXCR4 is involved in inflammatory diseases.

This was studied in an experimental model of arthritis. Murine antigen-induced arthritis (AIA) induction led to reduced plasma DPPIV CD26 activity. And in CD26-deficient mice, the severity of AIA was increased. CD26-deficient mice exhibited increased levels of circulating active CXCL12, associated with increased numbers of CXCR4-positive cells infiltrating arthritic joints. Decreased circulating CD26 levels in arthritis may influence CD26-mediated regulation of the chemotactic CXCL12/CXCR4 axis.

CD26-deficient mice:
· reduced plasma DPPIV activity↓
· exhibited increased levels of circulating active CXCL12 ↑
· associated with increased numbers of CXCR4-positive cells infiltrating arthritic joints ↑

Reference: Circulating CD26 is negatively associated with inflammation in human and experimental arthritis:


What has that got to do with ME/CFS? The answer is:

Dipeptidyl peptidase IV/CD26 has been evaluated as a biomarker for ME/CFS.

Biomarkers in chronic fatigue syndrome: evaluation of natural killer cell function and dipeptidyl peptidase IV/CD26:
In the present study, we found the density of DPPIV/CD26 on lymphocyte surfaces and the concentration of the enzyme in plasma is reduced in CFS subjects, compared to controls. We hypothesize that this reduction is due to chronic lymphocyte activation in CFS patients. The present study adds to the evidence of loss of innate immune function and chronic immune activation, resulting from the long term presence of antigenic stimulus, either self or foreign.

ME/CFS:
· Density of Dipeptidyl Peptidase DPPIV/CD26 on lymphocyte surfaces ↓
· And concentration of the enzyme in plasma ↓
· CXCR4 up-regulated ↑


An up-regulation of CXCR4 in ME/CFS has been shown in other studies:
A gene signature for post-infectious chronic fatigue syndrome

Gene Expression Subtypes in Patients with Chronic Fatigue Syndrome/Myalgic Encephalomyelitis

Assessment of a 44 Gene Classifier for the Evaluation of Chronic Fatigue Syndrome from Peripheral Blood Mononuclear Cell Gene Expression


The latest Light study Differing leukocyte gene expression profiles associated with fatigue in patients with prostate cancer versus chronic fatigue syndrome showed that mRNA expression for CXCR4 for CFS patient was elevated in relation to healthy controls, but it was not statistic significant. It would be interesting to repeat this Light study with patients after exercise, because exercise-elicited endogenous cortisol effectively augments CXCR4 expression on T lymphocytes. Reference: Cortisol-induced CXCR4 augmentation mobilizes T lymphocytes after acute physical stress


A potential up-regulation of CXCR4 in ME/CFS is worth keeping an eye on because the CXCL12-CXCR4 signaling is involved in both B cell development and development of plasmacytoid dendrite cells:

The Earliest Stages of B Cell Development Require a Chemokine Stromal Cell-Derived Factor/Pre-B Cell Growth-Stimulating Factor

Development of plasmacytoid dendritic cells in bone marrow stromal cell niches requires CXCL12-CXCR4 chemokine signaling


CXCL12-CXCR4 signaling is also involved in NK development, but it must be noted that nothing is simple in the human body. IL-15 is also involved in NK cell function, and IL15 is low in ME/CFS patients. So how all these factors affect the immune system and the dysregulated NK cells in ME/CFS is not easy to understand:

Differential chemotactic receptor requirements for NK cell subset trafficking into bone marrow

CXCL12-CXCR4 chemokine signaling is essential for NK-cell development in adult mice

Mechanistic Model of Natural Killer Cell Proliferative Response to IL-15 Receptor Stimulation


Synovial fluid is a lubricating, nourishing material present in many joints of the body. CXCL12 mediates desensitization of neutrophil respiratory burst in the synovial fluid from Rheumatoid Arthritic Patients.
Reference: Stroma Cell-Derived Factor 1α Mediates Desensitization of Human Neutrophil Respiratory Burst in Synovial Fluid from Rheumatoid Arthritic Patients


Preliminary data from CFS subjects showed differences in neutrophil function based on respiratory burst and phagocytic activity when compared to the control group. These results suggest that differences in neutrophil function in CFS patients may contribute to CFS related immune dysfunction.
Reference: Analysis of Neutrophil Function in Severe and Moderately Affected Chronic Fatigue Syndrome Subjects

This is something I would like to know more about, so...


Let us look for more studies on CD26/CXCR4…

Remember the cancer study: Chronic fatigue syndrome and subsequent risk of cancer among elderly US adults? ME/CFS was associated with an increased risk of non-Hodgkin lymphoma (NHL).

This study Dipeptidyl peptidase IV: serum activity and expression on lymphocytes in different hematological malignancies showed: Significantly decreased serum DPPIV activity and a significant decrease in the percentage of: CD26 + lymphocytes, CD26 + overall white blood cells and lymphocytes in patients with NHL in comparison to healthy controls. The obtained results in the study indicate that immune disturbances that can occur in hematological malignancies might be related to the decreased expression and activity of CD26/DPPIV.

This knowledge has already come to use in this article, Targeting the CD20 and CXCR4 pathways in non-hodgkin lymphoma with rituximab and high-affinity CXCR4 antagonist BKT140: Chemokine axis CXCR4/CXCL12 is critically involved in the survival and trafficking of normal and malignant B lymphocytes. Findings suggest the possible role of CXCR4 in NHL progression and response to rituximab and provide the scientific basis for the development of novel CXCR4-targeted therapies for refractory NHL.

Data show that Cyclophilin (CYPA) has a critical role in CXCR4 signaling involved in cell proliferation and migration. Reference: Cyclophilin A Is Required for CXCR4-mediated Nuclear Export of Heterogeneous Nuclear Ribonucleoprotein A2, Activation and Nuclear Translocation of ERK1/2, and Chemotactic Cell Migration

And Cyclophilin A is up-regulated in ME/CFS:
A multidisciplinary approach to study a couple of monozygotic twins discordant for the chronic fatigue syndrome: a focus on potential salivary biomarkers

Aberrant CXCR4/CXCL12-mediated inflammatory respons is found in several disorders, such as systemic lupus erythematosus, uveitis, multiple sclerosis and inflammatory bowel diseases. Reference: Involvement of CXCR4/CXCR7/CXCL12 Interactions in Inflammatory bowel disease

And dipeptidyl peptidase IV CD26 is reduced in tissue and plasma in active Crohn's disease. This is unlikely to represent simple downregulation induced by inflammation since the key proinflammatory cytokine strongly upregulated DP4 expression in Caco-2 cells.
Reference: Dipeptidyl peptidase-4 expression is reduced in Crohn's disease
Reference: Dipeptidyl peptidase IV (DP IV, CD26) in patients with inflammatory bowel disease

Data suggest that simultaneous targeting of CXCR4 and CXCR3 may be of benefit in the treatment of the CNS autoimmune disease.
Reference: Antagonism of the chemokine receptors CXCR3 and CXCR4 reduces the pathology of experimental autoimmune encephalomyelitis

This knowledge has led to a Patent application TREATMENT OF AUTOIMMUNE DISEASE where the invention provides methods for identifying a patient suffering from and/or susceptible to autoimmune disease who might be likely to respond to treatment with CXCL12 and/or CXCR4 antagonists. The present invention provides novel CXCL12 and/or CXCR4 antagonists, methods of identifying novel CXCL12 and/or CXCR4 antagonists, and methods involving the use of these in the treatment of autoimmune disease.

The patent application include

Dysautonomia malfunction of the autonomic nervous system, including such disorders as postural orthostatic tachycardia syndrome (POTS); though dysautonomia appears to have multiple causes, post-viral autoimmune damage appears to be a frequent cause.

and

Chronic fatigue immune disorder whose primary symptom is usually intense fatigue; dysfunction syndrome though the syndrome likely has multiple causes, some (CFIDS) maintain that autoimmune damage to the brain stem is the principal mechanism in a significant subset of cases.

Note that POTS is mentioned! And this article suggest that this chemokine CXCR4 may contribute to autonomically mediated pathophysiological events:CXCR4 receptors in the dorsal medulla: implications for autonomic dysfunction

Oxygen availability is a determinant parameter in the setting of chemotactic responsiveness to CXCL12. Low oxygen concentration induces high expression of CXCR4 in different cell types (monocytes, monocyte-derived macrophages, tumor-associated macrophages, endothelial cells, and cancer cells), which is paralleled by increased chemotactic responsiveness to its specific ligand. CXCR4 induction by hypoxia is dependent on both activation of the Hypoxia-inducible factor 1 α and transcript stabilization. In a relay multistep navigation process, the Hypoxia–Hypoxia-inducible factor 1 α–CXCR4 pathway may regulate trafficking in and out of hypoxic tissue microenvironments.
Reference: Regulation of the Chemokine Receptor CXCR4 by Hypoxia

And it is hypothesized that autonomic dysfunction/cerebral hypoxia could be involved in ME/CFS. Postural Orhtostatic Tachycardia Syndrome (POTS) is a very common ME/CFS co-morbidity, and POTS-patients are markedly sensitized to hypoxia when upright.
Reference: Brain dysfunction as one cause of CFS symptoms including difficulty with attention and concentration
Reference: Baroreceptor unloading in postural tachycardia syndrome augments peripheral chemoreceptor sensitivity and decreases central chemoreceptor sensitivity


Chemokines are also involved in pain. Increased signaling by CXCL12 and its receptor, CXCR4, has been shown to contribute to chronic pain behavior. Activation of another chemokine CCR2 by monocyte chemoattractant protein-1 MCP-1 elicits membrane depolarization, trigger action potentials and sensitizes nociceptors via transactivation of transient receptor potential channels TRPA1 and TRPV1.
Reference: Chemokines as pain mediators and modulators.

...there are many puzzle pieces to keep an eye on! Which pieces belong to the ME/CFS puzzle and which pieces do not fit in?







søndag den 6. oktober 2013

P2X7 in ME/CFS and other diseases

I have previously referred to articles about TRPA1 involvement in inflammation, vasodilation, central sensitization and hypothesized that TRPA1 has a role in ME/CFS/POTS/MCS/pain and more.

TRPA1 is of course only a small part of what is affected in the human body during these diseases. Many other receptors must also be involved. The latest article from Light et al mentions higher expression of P2RX7, so let us take a closer look at the P2X7 receptor.

The P2X7 receptor (P2X7R) is a nonselective cation channel that is activated by extracellular ATP and triggers the secretion of several proinflammatory substances, such as IL-1β, IL-18, TNF-α, and nitric oxide.

Quotes from P2X7 articles:

Following the activation of P2X7R through high concentrations of and/or prolonged exposure to ATP, a large conductance channel is elicited, which leads to dynamic changes in the membrane potential that include an intracellular potassium efflux. This cationic efflux induces inflammasome complex assembly and subsequent pro-caspase-1 maturation into caspase-1 through the NOD-like receptor protein (NLRP3). Caspase-1 plays a key role in the cleavage of pro-IL-1β to form mature IL-1β, which plays a principal role in nitric oxide synthase (NOS), cyclooxygenase-2, and tumor necrosis factor-alpha (TNF-α) activities
Reference: Physiological Roles and Potential Therapeutic Applications of the P2X7 Receptor in Inflammation and Pain

The expression of the purinergic, P2X7 receptor (P2X7R), is known to be enhanced in many brain pathologies where presence of activated microglia is a concurrent feature. This review focuses on the links between P2X7R expression and microglial activation and proliferation. The P2X7R is identified as a key player in the process of microgliosis, where by driving microglial activation, it can potentially lead to a deleterious cycle of neuroinflammation and neurodegeneration.
Reference: Microglia: Proliferation and activation driven by the P2X7 receptor

P2X7 is involved in central sensitization. Purinergic signaling, involving P2X4, P2X7 and P2Y12 receptors, plays a central role in the recruitment and activation of microglia, which have emerged as key regulators of central sensitization.
Reference: Pain hypersensitivity mechanisms at a glance
Reference: Central sensitization of nociceptive neurons in rat medullary dorsal horn involves purinergic P2X7 receptors
Reference: P2X(7) inhibition in stellate ganglia prevents the increased sympathoexcitatory reflex via sensory-sympathetic coupling induced by myocardial ischemic injury


Lipid rafts are important in the control of nociceptor excitability – P2X7 is associated with lipid rafts

Lipid rafts are microdomains of the plasma membrane highly enriched in cholesterol and sphingolipids. Lipid rafts tune the spatial and temporal organisation of proteins and lipids on the plasma membrane. They are thought to act as platforms on the membrane where proteins and lipids can be trafficked, compartmentalised and functionally clustered.
Reference: Association between tetrodotoxin resistant channels and lipid rafts regulates sensory neuron excitability

Reference: Palmitoylation of the P2X7 receptor, an ATP-gated channel, controls its expression and association with lipid rafts
(Palmitoylation is the covalent attachment of fatty acids, such as palmitic acid, to cysteine and less frequently to serine and threonine residues of proteins, which are typically membrane proteins.)

Caveolae are a special type of lipid raft

It has recently been shown in epithelial cells that the ATP-gated ion channel P2X7R is in part, associated with caveolae and colocalized with caveolin-1. In the present study of the mouse heart, we show for the first time, using immunohistochemistry and cryoimmunoelectron microscopy, that P2X7R is expressed in atrial cardiomyocytes and in cardiac microvascular endothelial cells, but not in the ventricle cardiomyocytes. In cardiac tissue homogenates derived from caveolin-1 deficient mice (cav-1-/-), an increase of the P2Xrx7 mRNA and P2X7R protein (80 kDa) was found, particularly in atrial samples.
Reference: Increased P2X7R expression in atrial cardiomyocytes of caveolin-1 deficient mice

Some guessing:
Some ME patients have POTS. POTS patients may have autoimmunoreactive IgGs against proteins associated with caveolae structure. Cavelolin-1 is a protein in the caveolae. Increased P2X7R expression is found in atrial cardiomyocytes of caveolin-1 deficient mice. ME patients show increased P2RX7 expression.

P2X7 and motor neruron death/cell death:

Here we found that P2X(7) receptor activation in spinal cord astrocytes initiated a neurotoxic phenotype that leads to motor neuron death
Reference: Extracellular ATP and the P2X7 receptor in astrocyte-mediated motor neuron death: implications for amyotrophic lateral sclerosis

P2X7-induced motor neuron death was dependent on neuronal nitric oxide synthase-mediated production of peroxynitrite, p38 activation, and autocrine FAS signaling. Taken together, our results indicate that motor neurons are highly sensitive to P2X7 activation, which triggers apoptosis by activation of the well-established peroxynitrite/FAS death pathway in motor neurons.
Reference: P2X7 receptor-induced death of motor neurons by a peroxynitrite/FAS-dependent pathway

A cytofluorometric assay demonstrated that P2X7 activation induced ROS formation in EOC13 cells, via a mechanism independent of Ca2+ influx and K+ efflux. Cytofluorometric measurements of Annexin-V binding and 7AAD uptake demonstrated that P2X7 activation induced EOC13 cell death. The ROS scavenger N-acetyl-L-cysteine impaired both P2X7-induced EOC13 ROS formation and cell death, suggesting that ROS mediate P2X7-induced EOC13 death. In conclusion, P2X7 activation induces the uptake of organic cations, ROS formation, and death in EOC13 microglia.
Reference: P2X7 Receptor Activation Induces Reactive Oxygen Species Formation and Cell Death in Murine EOC13 Microglia

Let us keep an eye on P2X7 and ME/CFS research to find out what the higher expression of P2RX7 actually means in ME/CFS.

Update: 
Surface expression of P2X7R on PBMC in patients with pSS was significantly higher than controls, suggesting P2X7R may contribute to the complex pathogenesis of pSS and also anxiety and/or depression.
Reference: The expression of P2X7 receptors on peripheral blood mononuclear cells in patients with primary Sjögren's syndrome and its correlation with anxiety and depression

tirsdag den 24. september 2013

Transducer and amplifier in ME/CFS/MCS/pain?

From the world of electronic device we know the terms “transducer” and “amplifier”:

A transducer is a device that converts a signal in one form of energy to another form of energy. Energy types include (but are not limited to) electrical, mechanical, electromagnetic (including light), chemical, acoustic or thermal energy. Reference: Transducer

An amplifier is an electronic device that increases the power of a signal. It does this by taking energy from a power supply and controlling the output to match the input signal shape but with a larger amplitude. In this sense, an amplifier modulates the output of the power supply. Reference: Amplifier

The electronic device is connected by wires.

There are also “transducers”, “amplifiers” and “wires” in the human body:

Various environmental stimuli exist that initiate signal transmission processes in multicellular organisms; examples include photons hitting cells in the retina of the eye, and odorants binding to odorant receptors in the nasal epithelium. The sensory transduction is the conversion of a sensory stimulus from one form to another. Transduction in the nervous system typically refers to stimulus alerting events wherein a physical stimulus is converted into an action potential, which is transmitted along axons towards the central nervous system where it is integrated. A receptor cell converts the energy in a stimulus into a change in the electrical potential across its membrane. It causes the depolarization of the membrane to allow the action potential to be transducted to the brain for integration. Reference: Signal transduction Transduction (physiology)

The human “transducers” are the sensory receptors and the human “wires” are called neurons, axons and sensory fibers/ afferent nerve fibers. Just outside the spinal cord, thousands of afferent neuronal cell bodies are aggregated in a swelling in the dorsal root known as the dorsal root ganglion. Reference: Wikipedia.

When a ME patient no longer can tolerate sunlight, soft music, the smell of toothpaste or the weight from a blanket something must be wrong with the transducers, the amplifiers and/or the wires.

To understand the disease and the symptoms we must locate and identify the problem in the transducers, the amplifiers and/or the wires in the body.

Is there a defective amplifier in the dorsal root ganglion? In the brain? Is it out of order because of an autoimmune attack? An autoimmune attack on a receptor? Is there a domino effect involved?

I am looking for answers. Am I getting closer? Is TRPA1 involved? TRPA1 amplifies pain and inflammation. What amplifies light, sound, odor and touch?

TRPA1 - A Transducer and Amplifier of Pain and Inflammation

Excessive activation of TRPA1 and TRPV1 by ROS may induce central sensitization – does it concern ME?

Is TRPV4 involved? TRPC3? P2X3? Articles from a google-brainstorm on the subject:

Neuronal IL-17 receptor upregulates TRPV4 but not TRPV1 receptors in DRG neurons and mediates mechanical but not thermal hyperalgesia
(remember Ian Lipkin’s results: IL-17 is up-regulated in spinal cord fluid in ME/CFS patients)

Transient receptor potential canonical 3 (TRPC3) is required for IgG immune complex-induced excitation of the rat dorsal root ganglion neurons

Lipid rafts control P2X3 receptor distribution and function in trigeminal sensory neurons of a transgenic migraine mouse model

P2X3 receptor: a novel ‘CASKade’ of signaling?

Identification of voltage-gated K+ channel beta 2 (Kvβ2) subunit as a novel interaction partner of the pain transducer Transient Receptor Potential Vanilloid 1 channel (TRPV1)

Mechanism of sodium channel NaV1.9 potentiation by G-protein signaling

TRPC3 and TRPC6 are essential for normal mechanotransduction in subsets of sensory neurons and cochlear hair cells

Potentiation of acid-sensing ion channel activity by the activation of 5-HT₂ receptors in rat dorsal root ganglion neurons

Methods of antagonizing signal transduction in dorsal root ganglion cells