[The expression and significance of costimulatory molecule in peripheral blood B lymphocytes in rheumatoid arthritis].

OBJECTIVE: To research the mechanisms of immune function disorder in the patients with rheumatoid arthritis (RA). METHODS: Monoclonal antibodies against CD(80), CD(86), CD(40) were used for flow cytometry and expression of costimulatory molecule CD(80), CD(86), CD(40) on peripheral blood B lymphocytes was studied in patients with RA, and healthy human were used as control groups. We also used enzyme linked immunosorbent assay to detect the cytokines level of Th1 cell including interleukin (IL)-2, interferon-gamma and those of Th2 cell including IL-6, IL-10. These samples are serum and synovial fluid of patients with RA, respectively. RESULTS: Compared with control group, the expression of CD(86) on peripheral blood B lymphocytes in patients with RA was obviously decreased (P < 0.01), the expression of CD(40) was also significantly increased (P < 0.05). No statistically significant differences in CD(80) positive peripheral blood B lymphocytes between RA group and control group were observed. Comparing with control group, the level of IL-2 and interferon-gamma in serum and synovial fluid of patients with RA are obviously increase (P < 0.01 or P < 0.05). While, the level of IL-6 and IL-10 are decrease (P < 0.01 or P < 0.05). CONCLUSIONS: The disorder expression of costimulatory molecule CD(86), CD(40) on peripheral blood B lymphocytes may be associated closely with the imbalance of Th1/Th2 cytokines level in patients with RA. These will give us a new idea on the therapeutic strategy of RA.