Table 1. Definitions of transplant-associated thrombotic microangiopathy [7].

	O-TMA [7]	CTN-TMA [5]	IWG-TMA [6]
Normal coagulation assaysa	Yes	Yes	Yes
Schistocytosis	≥ 2/HPF	≥ 2/HPF	≥ 8/HPF
Increase in serum LDH	Yes	Yes	Yes
Concurrent renalb and/or neurologic dysfunction without other explanations		Yes
Negative Coombs test	Yes	Yes
Thrombocytopeniac	Yes		Yes
Decrease in hemoglobin concentration	Yes		Yes
Decrease in serum haptoglobin	Yes		Yes

LDH = lactate dehydrogenase. ^aProthrombin time and activated partial thromboplastin time; ^bdoubling of serum creatinine from baseline or 50% decrease in creatinine clearance from baseline; ^cde novo, prolonged, or progressive thrombocytopenia (platelet count < 50,000/µL or > 50% reduction.