Serum levels of soluble CD40 ligand at flare and at remission in patients with systemic lupus erythematosus.

sCD40L plays a biologically active role, with decreased levels at flare at low SLEDAI scores. At high SLEDAI scores there are mechanisms that involve platelets and that are inhibited by high doses of prednisone that lead to increased serum values of sCD40L at flare.