OBJECTIVETo investigate the effect of prolactin on CD40 and CD154 expressions on the surface of peripheral blood mononuclear cells in patients with systemic lupus erythematosus (SLE) and explore the role of prolactin in the pathogenesis of SLE.

METHODSThe serum prolectin level was detected in 30 SLE patients and 20 healthy volunteers, from whom peripheral blood mononuclear cells (PBMCs) were also isolated to examine the expressions of CD40 and CD154 using flow cytometry.

RESULTSCD154 significantly increased on the PBMCs in SLE patients with high serum prolectin level in comparison with that in patients with normal prolactin level or the normal controls (P<0.05). When the PBMCs were incubated with recombinant human prolactin, CD154 expression was significantly increased in SLE patients with normal serum prolactin level (P<0.05), but not in the normal control group (P>0.05). Incubation of the PBMCs in the presence of bromocriptine did not result in significantly decreased CD154 expression in SLE patients irrespective of the prolactin level, nor was significant difference found in CD40 expression on the surface of PBMCs between SLE patients and the normal controls(P>0.05).

CONCLUSIONProlactin plays an important role in the pathogenesis of SLE by increasing CD154 expression on the PBMCs, and bromocriptine produces no significant inhibitory effect on either endogenous or exogenous prolectin.