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Pilot study: "Identification of anti-citrullinated protein antibodies in ‪CFS‬" plus call for funds

Dolphin

Senior Member
Messages
17,567
Results of pilot study: "Identification of anti-citrullinated protein antibodies in ‪CFS‬"

http://immunedysfunction.org/future15.html

The Vermont ‪#CFIDS‬ Association aka ImmuneDysfunction.org wants to raise $27000 to do a larger study (see link)

I think it would probably be better if people don't try to convert the image file into text for posting elsewhere as:
(i) perhaps they will want to publish it;
(ii) it could get separated from the call for funds for a larger study.
 

A.B.

Senior Member
Messages
3,780
An anti-citrullinated protein antibody (ACPA) was detected in roughly a third of the ME/CFS patients, advancing the possibility that citrullination of a protein or family of proteins may underlay the physical and cognitive disabilities in some CFS/ME patients. However, this pilot study was limited by the small number of samples tested (50), requiring additional tests with larger sample sets (e.g., 250 or 500 samples) for confirmation and validation.

So... anti-citrullinated protein antibodies are frequently found in other diseases, reliable tests exist for measuring these antibodies for the purpose of diagnosing rheumatoid arthritis... and nobody has thought about ruling out this possibility in ME/CFS before this study?
 
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Snow Leopard

Hibernating
Messages
5,902
Location
South Australia
Positives: 7/25 patients, 2/25 controls in the pilot study...

https://en.wikipedia.org/wiki/Anti–citrullinated_protein_antibody

In a comparative study (in 2007), various detection kits had a sensitivity between 69.6% and 77.5% and a specificity between 87.8% and 96.4%

Target citrullinated antigens in RA, including fibrinogen, deiminated Epstein-Barr Virus Nuclear Antigen 1 and vimentin...

See also:
https://en.wikipedia.org/wiki/Citrullination

Additional edit:
What drives deimination?

There seems to be some discussion of deimination of small cyokines (chemokines) such as CXCL8, CXCL10, CXCL11 and others.

What about deimination of GPCRs? Does this serve any functional purpose or would it only happen by accident?
 
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Messages
2,087
One of the things that is suggestive and intriguing about this study, but far from proven to be important, is that a third of patients is about the proportion of Rituximab patients who respond and we have not yet found any antibody to investigate. Depending on where the research goes this could prove interesting.

I thought it was closer to two thirds response for rtx.
 

Gijs

Senior Member
Messages
690
There are several positive antibodies found in CFS patients. What is causing this. Could it be due to impaired function of B cells? In that case, I think that EBV -living in B cells- may be a major player.
 

Bob

Senior Member
Messages
16,455
Location
England (south coast)
One of the things that is suggestive and intriguing about this study, but far from proven to be important, is that a third of patients is about the proportion of Rituximab patients who respond and we have not yet found any antibody to investigate. Depending on where the research goes this could prove interesting.
I seem to remember the Norway rituximab studies having a two-thirds response rate overall and roughly a 50% response rate when compared to the control group. But my memory is bad.
 

alex3619

Senior Member
Messages
13,810
Location
Logan, Queensland, Australia
I seem to remember the Norway rituximab studies having a two-thirds response rate overall and roughly a 50% response rate when compared to the control group. But my memory is bad.
They have identified possible autoantibody mechanisms in roughly half the responders, which leaves half completely unaccounted for. The finding in the paper in this thread potentially, and this is not proven at all, may account for that other half.
 

alex3619

Senior Member
Messages
13,810
Location
Logan, Queensland, Australia
I'm puzzled as to how this finding relates to what seems to be Fluge and Mella's view that citrulline might be useful in treatment. See their patent application:

http://wames.org.uk/cms-english/2015/04/fluge-mellas-patent-application-for-a-cfs-treatment/
Patent applications typically cover a range of options. They seek to secure rights before the research is finalized. Citrulline, by itself, and citrullilne modified proteins, are not the same thing. One does have to wonder though what conditions would permit citrulline to worsen the protein damage.
 

Bob

Senior Member
Messages
16,455
Location
England (south coast)
They have identified possible autoantibody mechanisms in roughly half the responders, which leaves half completely unaccounted for. The finding in the paper in this thread potentially, and this is not proven at all, may account for that other half.
Ah, I see what you mean now. Thanks for clarifying, Alex.
 

Jonathan Edwards

"Gibberish"
Messages
5,256
@Jonathan Edwards, any thoughts on this pilot study?
Scroll down to read paper:
http://immunedysfunction.org/future15.html

It would be easy to replicate in all ME/CFS service units and it would be worth checking out. I would like to see the actual readings for each patient before commenting on the data. Two positives in 25 controls is not quite as expected. One would have thought they would make sure the controls did not have RA in advance! The description of the study seems a bit naive but there is no harm in that if the results are repeatable. I would be a bit surprised if a third of patients with ME had ACPA since ACPA would be a pretty standard screen for someone with fatigue and limb pain these days.
 

SOC

Senior Member
Messages
7,849
I would be a bit surprised if a third of patients with ME had ACPA since ACPA would be a pretty standard screen for someone with fatigue and limb pain these days.
Interesting point. This should have been picked up if ME patients are routinely tested. Let's do a casual poll... Who has had an ACPA screen as part of their ME assessment? Is the test more commonly given in some countries than others?

I have not had this test and I am in the US.
 

A.B.

Senior Member
Messages
3,780
I don't think I've had this test. I've had a couple for rheumatoid arthritis (waaler rose and rheumatoid factor) but these don't detect anti-citrullinated protein antibodies right?