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). Here, S100A8 is linked to systemic lupus erythematosus.