CD40LG and systemic lupus erythematosus: In SLE, the serum or plasma levels of platelet associated molecules, such as HMGB1, S100A8/A9, sCD40L, and CCL5 as well as platelet derived PMPs harboring IgGs have been shown to correlate with the SLE disease activity index (SLEDAI) score (105, 110, 124, 209, 210).