We have studied in peripheral blood (PB) and synovial fluid (SF) of 31 patients diagnosed with rheumatoid arthritis (RA), the expression of CD5 and CD23 antigens on B cells, and the levels of soluble CD23 (sCD23), interleukin-4 (IL-4) and tumour necrosis factor alpha (TNF-alpha). We have also correlated the results with the disease activity index.
CD5+ B cells are expanded in SF and, moreover, show higher expression of CD23 than CD5 - B cells. Twelve patients had detectable levels of IL-4 in plasma and 10 in SF (nine patients in both samples); the absence of IL-4 was related to a higher expression of CD23 on CD5 + B cells and with higher levels of sCD23. A negative correlation was found in SF between TNF-alpha and sCD23 levels.
There is no correlation between disease activity index and the different parameters studied (expression of CD5 and CD23 on B cells, sCD23, IL-4 and TNF-alpha levels) either in plasma/PB or in SF.