I disagree. I don't think that studying the immune system (and potential autoimmunity) and pathogens such as XMRV need to be mutually exclusive. There are a lot of questions that have yet to be answered about both subjects and abandoning one in favor of the other is in my opinion shortsighted.
For instance: How does autoimmunity explain ME/CFS?
To me autoimmunity is the most elegant explanation. It would explain the autoantibodies found in ME/CFS, it would explain the female/male ratio, it would explain the improvement after rituximab administration and it would also somewhat unify the viral/toxin origin with the psychological origin. I believe both can trigger an autoimmune condition
How does it explain outbreaks and transmission between people which has been reported for years?
How does it explain the common symptoms and signs of ME/CFS (PEM, NK cell abnormalities, T cell abnormalities).
Very simple, different pathogens may cause immune dysregulation that ultimately may result in ME/CFS. Actually the autoimmune hypothesis makes the most sense in all these outbreaks. ME/CFS is associated with many different pathogens (EBV, HHV6, enteroviruses, Giardia) so there has to be a common pathway that leads to these symptoms. I believe Lipkin said the same in his WPI talk.
Do these things respond to Rituxan as well, or do people just "feel better"?
Mella and Fluge said today that all symptoms improved in rituximab responders. No effect on NK and T cells though, but I don't know what kind of testing they did.
How does it explain Dr. Snyderman's response to ARVs?
Obviously it could be all placebo, but Jay Levy said there is evidence ARVs 'calm down' the immune system. Also don't forget there are anecdotal reports that ARVs had no effect on symptom improvement.
How does it explain the re-activation of other (mostly intracellular) pathogens?
We don't know, but we also don't know if pathogen activation really plays a role in the majority of ME/CFS patients. Studies are very conflicting.
Consider this: just because a drug that has been used "off label" for some "autoimmune" diseases seems to have an effect on ME/CFS symptoms doesn't mean that ME/CFS therefore must also be autoimmune. Thats a logical fallacy. In fact, we might as well also consider that ME/CFS is actually cancer because Rituximab was originally developed as a drug for cancer... Or that its actually HIV because Ampligen was originally tried for HIV... etc.. you see my point. Shouldn't we approach this finding with Rituxan with the same high burden of proof as we did other findings (HHV6, XMRV, etc.)?
You're right that the Rituximab reponse doesn't
prove that ME/CFS is an autoimmune condition, but it does
suggest so. If it was a merely a viral condition with viruses 'hiding' in B-cells the response should be much sooner. The rituximab response combined with other evidence gives validity to the autoimmune hypothesis and it would be a shame if we didn't explore this further.
Also, they were able to execute a study with Rituxan (which has lots of potential side effects - some of them fatal) and yet despite a lot of smoke about retroviruses and reports of response to ARVs, nobody has done a trial with them? Surely the side effect profile of ARVs is not bad compared to Rituxan. Certainly there are millions of people taking them, so the effects are well known. Perhaps XMRV proper isn't going to lead anywhere, but if we are trying Rituxan and getting a response (but we don't know why) we might as well try ARVs and see if we can get the same thing. The results might be interesting - and they could actually converge.
Even if you could explain all of this, "autoimmunity" does not occur in a vacuum. Its clearly triggered by something. So I really don't think looking at the immune system or "pathogens" separately is really an option. The goal should be to find a root cause and arrive at the simplest answer to the question. To do so, they need to look at the big picture and figure out how it all fits together. You can't do that by picking and choosing.
I disagree. The safety profile of rituximab definetely doesn't compare to the daily horrors of ME/CFS and I have no doubt I'd take it as soon as it becomes available to me. Wether the side effect profile of ARVs is better compared to rituximab is irrelevant at this point in time. There is no evidence of retroviral involvement in ME/CFS so it makes no sense to do a trial.