[The rapid cytofluorometric indices of lymphocyte functional activity in rheumatoid arthritis and systemic lupus erythematosus].

As many as 49 patients with rheumatoid arthritis (RA), 16 with systemic lupus erythematosus (SLE) and 40 healthy persons were examined for functional parameters of freshly isolated peripheral lymphocytes with the aid of quantitative cytofluorimetry designed by the authors. Proliferative function was estimated according to the RNA/DNA ratio in nuclear chromatin, suppressor function to the early processes of mitogenin-induced activation of B cells in the presence of prednisolone, and immunoglobulin-synthesizing function was assessed by the mean level of Ig in B cells of the population. It has been established that lymphocytes from the healthy persons are primarily in a state of rest (G0), have low B activation and high suppressor function (SF). In RA, lymphocytes, mainly B cells, are in a state of spontaneous activation (G1--S--G2) related to the degree of SF decrease. In 1/3 of patients, moderately decreased SF (to 70% of normal) controls the early processes of mitogen-dependent B activation, whereas in 2/3 of patients, a more pronounced decrease of SF (to 40% of normal) combines with hyperactivation of B cells. SLE is characterized by higher, as compared with RA, proliferative and Ig-synthesizing activity of B cells combined with a decrease of SF (to 45% of normal). High correlations have been shown: a direct one between nuclear chromatin activation and Ig-synthesis in the B cell and a reverse one between these processes and SF. The conclusion has been made that the immune status in patients with RA and SLE is marked by hyperactivation of B cells and SF decrease.