ADAMTS13 and thrombotic thrombocytopenic purpura: The activity of A disintegrin and metalloproteinase with thrombospondin motifs 13 (ADAMTS13), a factor related to thrombotic thrombocytopenic purpura (TTP), was 78.52% (>10%, reference range: 42.16%–126.37%), and the patient tested negative for ADAMTS13 antibodies, ruling out TTP.