Human neutrophil antibodies in a blood donor population: a lookback study

Background and Objectives Human neutrophil antibodies (HNA) have been associated with severe transfusion‐related acute lung injury (TRALI). We identified HNA antibodies in a blood donor population and performed an observational lookback on patients who received products from these donors to determine whether TRALI was associated with these transfusions. Materials and Methods Human neutrophil antibodies were determined in 1171 blood donors (388 non‐transfused males, 390 human leucocyte antigen (HLA) antibody–negative females and 393 HLA antibody–positive females) for IgG and IgM antibodies using a flow cytometric assay. Selected positive samples had a monoclonal antibody immobilization of granulocyte antigen (MAIGA) and neutrophil genotyping performed to confirm specificity. Lookback was performed on patients receiving blood from donors with positive samples by extracting recipient data from hospital medical records. An expert panel of three pulmonary critical care physicians reviewed the summarized data and assigned a diagnosis of TRALI, possible TRALI, cannot distinguish between TRALI and TACO, TACO and other. Results Eight donors had HNA antibodies of which five contributed to this lookback (3‐HNA‐specific antibodies, 2‐HNA non‐specific antibodies). Seventy‐six blood products were transfused from these donors into individual patients. One patient developed TRALI that was associated with a donor with a non‐specific HNA antibody as well as class‐I and class‐II HLA antibodies. Conclusion The incidence of TRALI in this lookback was low and combined with low frequency of HNA antibodies in the donor population suggests not screening donors for HNA antibodies at this time is acceptable.