RESUMEN
Objective To study T lymphocyte subsets and expression of costimulatory molecule CD154 on T-cells in peripheral blood from patients with ankylosing spondylitis and their changes after treated with Enbrel. Methods Sixty-six patients with AS(39 active and 27 inactive, 35 axial and peripheral joint involvement and 31 axial involvement only), 30 patients with rheumatoid arthritis(RA), 30 healthy volunteers were analyzed. The expression of CD154 on CD3+ T cell as well as T-cells subsets were evaluated using flow cytometry respectively. The changes of the expression of costimulatory molecule CD154 in 39 active AS patients(Enbrel treatment or placebo treatment) were observed in a randomized, double-blind, placebothan that of healthy volunteers, and CD154 expression on CD3+ T cells in peripheral blood in AS patients was on CD3+ T cells in the peripheral blood of active AS or AS patients with peripheral joint involvement were significantly higher than those in inactive or axial involvement only AS patients(P＜0.05), and CD154 on CD3+ placebo, in AS patients group, there was significant reduction in CD154 expression on CD3+ T cells in Enbrel group at week 6(P＜0.05), there was no significant difference between Enbrel group and healthy volunteers at week 6(P＞0.05). Conclusion T lymphocyte subsets are significantly abnormal and CD154 is overexpressed on T-cells in peripheral blood of patients with AS. A six-week course of treatment with Enbrel in active AS can induce a down-regulation of the expression of CD154 on T cells.