title: Transfusion-related alloimmune neutropenia with no pulmonary complications: one donor-five cases.
abstract: BACKGROUND
  Neutrophil alloantibodies are well-known triggers of transfusion-related acute lung injury (TRALI) and also cause immune neutropenia. Alloimmune neutropenia due to transfusion is an isolated phenomenon that is only rarely identified. Its incidence is specified in the literature as being less than one in 10,000 transfused plasma-containing units. We expect that this phenomenon is underreported.
  
  
  METHODS
  We observed five cases of alloimmune neutropenia with no respiratory complications with only one case initially reported as a suspected transfusion reaction. The other four cases were detected in the course of the subsequent lookback investigation.
  
  
  RESULTS
  The first case was reported as a potential transfusion reaction when a female patient showed a decrease in the white blood cell count after a platelet (PLT) transfusion. Examinations of the donor blood revealed an antibody against the human neutrophil antigen HNA-1b; the recipient was typed HNA-1b positive and HNA-1a negative. After examining the blood counts of other patients who previously received PLT concentrates from the same donor, we identified four other patients with an unreported decrease in the leukocyte and/or granulocyte count of more than approximately 50% after transfusion.
  
  
  CONCLUSIONS
  HNA antibodies are generally regarded as potential triggers of TRALI. Here we describe an HNA antibody that reproducibly caused transfusion-related neutropenia only without pulmonary complications. Factors predisposing patients to TRALI development are widely discussed. Our case suggests that antibody characteristics are also relevant in the development of TRALI. Current measures to prevent TRALI should also prevent transfusion-related alloimmune neutropenia.
authors.affiliation: Department of Transfusion Medicine and Hemostaseology.
authors.forename: Barbara
authors.initials: B
authors.lastname: Hauck-Dlimi
authors.affiliation: Department of Pediatrics, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Renate
authors.initials: R
authors.lastname: Ruppel
authors.affiliation: Department of Transfusion Medicine and Hemostaseology.
authors.forename: Robert
authors.initials: R
authors.lastname: Zimmermann
authors.affiliation: Department of Transfusion Medicine and Hemostaseology.
authors.forename: Julian
authors.initials: J
authors.lastname: Strobel
authors.affiliation: German Red Cross Blood Service West, Hagen, Germany.
authors.forename: Angelika
authors.initials: A
authors.lastname: Reil
authors.affiliation: Department of Transfusion Medicine and Hemostaseology.
authors.forename: Reinhold
authors.initials: R
authors.lastname: Eckstein
authors.affiliation: Department of Transfusion Medicine and Hemostaseology.
authors.forename: Juergen
authors.initials: J
authors.lastname: Zingsem
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001782:Blood Donors; D005260:Female; D006801:Humans; D007518:Isoantibodies / Q000097:blood*; D007519:Isoantigens / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009503:Neutropenia / Q000097:blood / Q000175:diagnosis / Q000276:immunology*; D017713:Platelet Transfusion / Q000009:adverse effects*; D065227:Transfusion Reaction / Q000097:blood / Q000175:diagnosis / Q000276:immunology*
chemical_list: D015415:Biomarkers; D007518:Isoantibodies; D007519:Isoantigens; C067704:neutrophil-specific antigen NA1, human