RBC destruction caused by a micropore blood filter

Two infants who received whole blood filtered through commercially available woven stainless steel micropore filters experienced a sudden onset of hemoglobinuria. The plasma hemoglobin level in one child was 200 mg/dL. To investigate whether filters might lead to RBC destruction, we experimentally quantitated filter-induced hemolysis using standard conditions. Our studies in vitro show that hemolysis decreases with increased speed to transfusion. Hemolysis is particularly extensive with blood stored more than 14 days, but measurable hemolysis occurs with blood stored for as little as one day.