I have the same question as Nielk in the post above.I missed the reference to the B cell measurements. To be honest nobody else has found this sort of result with B cells and also the measurements used are inappropriate so one cannot really make much of it. I don't think this gives any indication of 'B cell immunodeficiency' or has anything to do with rituximab.
What caught my interest in the study, though methodological questions arises, was the very good subjective result from supplementing with folate in the folinic form, in (extremely) high doses, 25 mg 3-4 times a day for 1-2 months.
"Thirty-four patients (81 %) reported significant subjective improvement with increased energy level and reduced pain within 2 months (Table 1). No patient reported side effects from folinic acid. Responses were documented in all CFS patients regardless of their co-morbidities or EBV antibody status (Table 4)."
Earlier in the text: " Folate metabolism plays a central role in human leucocyte development and function (30-33). It is therefore plausible that the inappropriate antibody responses of CFS patients are in part owing to an underlying folate deficiency". Would be interesting to get your comments on this; if the first statement is medical consensus?
Sorry @Nielk to be a little off topic, but your link brought up folate deficiency and folate metabolism in CFS again.
@Jonathan Edwards, I cross-posted. I will read your reply to Nielk. Thanks.