[Soluble CD40 ligand in systemic lupus erythematosus and antiphospholipid syndrome]

To investigate a clinical role of soluble (s) CD40 ligand in systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS).

A serum concentration of sCD40 ligand was measured with enzyme immunoassay (Bender Medsystems, Austria) in 21 patients with primary antiphospholipid syndrome (PAPS), in 25 patients with secondary APS (SAPS) associated with SLE, in 92 SLE patients and in 16 healthy donors.

A sCD40 ligand concentration in sera of SAPS and SLE patients was significantly higher than in donors. Significant differences by the ligand level between the above patients were not seen. In PAPS sCD40 ligand concentration was normal. Elevated serum concentration of the ligand was observed in 9.5% patients with PAPS, 54.0%--with SAPS, 73.9%--with SLE. This rise in SLE and SAPS was not related with the disease activity or renal damage. Hyperexpression of the ligand in APS was associated neither with thromboses nor with a high concentration of IgG/IgM antibodies to cardiolipin. A direct correlation occurred between sCD40 ligand level and platelet count. In SLE and SAPS elevation of the ligand level correlated with increased thickness of carotid artery intima-media complex, hypercholesterinemia and diastolic dysfunction of left ventricular myocardium.

Hyperexpression of sCD40L in SLE and SAPS is associated with developing cardiovascular diseases and atherosclerosis.