In a previous study of 31 ADAMTS13-deficient TTP patients, 9 had other autoimmune co-morbid conditions, including non-destructive polyarthritis, Raynaud’s phenomenon, autoimmune endocrinopathies, discoid lupus and systemic lupus erythematosus (SLE) [12]. This evidence concerns the gene ADAMTS13 and thrombotic thrombocytopenic purpura.