Patients with active systemic lupus erythematosus (SLE) or considerable cumulative tissue damage may have reduced ADAMTS-13 levels potentially mediated by ADAMTS-13 autoantibodies.22 Decreased ADAMTS-13 activity in combination with increased VWF levels potentially demonstrates thrombotic risk in active SLE with aPLs.23 This evidence concerns the gene ADAMTS13 and systemic lupus erythematosus.