Hi I know there are quite a few conflicting results regarding protein level of IL-10 in PBMC's etc. in ME. But what I found interesting, in the context of myself being a very partial Rituximab responder: Inhibition of interleukin 10 by rituximab results in down-regulation of bcl-2 and sensitization of B-cell non-Hodgkin's lymphoma to apoptosis. http://www.ncbi.nlm.nih.gov/pubmed/11297268 I had several periods only lasting for the most part of a day at a time where practically all symptoms seemed to normalise (even sleep, a symptom I have found very hard to manipulate other than through sedation, reduction neuroexcitation etc.) Infact the time I felt best whilst undergoing B cell depletion was when I acquired a bout of Bronchitis. Quite possibly Th1 cytokines were more able to manifest during a period of reduced IL-10 secretion So in theory: (-) IL-10 --> (+) PBMC response to TLR agonist challenge (LPS etc.) --> (+) Th1 production (enabling presentation of physical manifestations of infection - of which I am from the subgroup that hardly ever catches any flu) I also wonder if some IL-10 disturbance could be having implications on Circadian Rhythm: http://www.ncbi.nlm.nih.gov/pubmed/11353686 Cytokine- and microbially induced sleep responses of interleukin-10 deficient mice.