On further investigation, patients are found to have thrombocytopenia, with platelet counts often below 20,000/μL; MAHA, evidenced as numerous schistocytes on a peripheral blood smear; and elevated lactate dehydrogenase (LDH). Serum creatinine concentration is elevated if there is renal involvement, and urinalysis may be normal or reveal RBCs and mild proteinuria. Prothrombin and partial thromboplastin times, as well as levels of individual clotting factors, should be normal in both TTP and HUS and can help facilitate the distinction from disseminated intravascular coagulation (DIC).