Table 1.

Diagnostic criteria for TA-TMA

Clinical/laboratory findingBMT-CTN criteria32IWG-EBMT criteria5Overall TMA criteria33Refined TMA criteria34
Normal coagulation assays*YesYesYesNR
Schistocytosis>2 per HPF on PS>8 per HPF on PS>2 per HPF on PSYes
Increase in serum LDHYesYesYesYes
Decrease in serum haptoglobinNRYesYesNR
Negative Coombs testYesNRYesNR
Renal and/or CNS involvementYesNRNRNR
ProteinuriaNRNRNRRandom urinalysis proteinuria concentration ≥30 mg/dL
HypertensionNRNRNR3-18 y: BP at 95th percentile value for age, sex, and height; >18 y: BP ≥140/90 mm Hg
Terminal complement assayNRNRNRElevated plasma concentration of sC5b-9
  • Doubling of serum creatinine from baseline (baseline creatinine before hydration and conditioning) or 50% decrease in creatinine clearance from baseline.

  • BP, blood pressure; BMT-CTN, Blood and Marrow Transplant Clinical Trials Network; CNS, central nervous system; HPF, high-power field; IWG, International Working Group; LDH, lactose dehydrogenase; PS, peripheral smear.

  • * Coagulation assays included prothrombin time and activated partial thromboplastin time.

  • De novo, prolonged, or progressive thrombocytopenia (platelet count 50 × 109/L or 50% reduction from previous counts).

  • Parameters of severity of TMA, according to Jodele et al.34