title: Anti-leucocyte antibodies in platelet apheresis donors with and without prior immunizing events: implications for TRALI prevention.
abstract: OBJECTIVE
  Transfusion-related acute lung injury (TRALI) prevention strategies in platelet (PLT) apheresis donors focus on identifying antileucocyte antibody-positive donors. The use of microbead based assays for screening purposes is hampered by the lack of a consensus cut-off for TRALI prevention and the undefined role of anti-leucocyte antibodies in never-alloexposed donors. This study evaluated anti-leucocyte antibody assays in PLT apheresis donors with and without prior immunizing events with special focus on microbead assay cut-offs, antibody specificities and their potential significance in never-alloexposed donors.
  
  
  METHODS
  Blood samples of male and female PLT apheresis donors with and without history of prior immunization were tested for anti-leucocyte antibodies.
  
  
  RESULTS
  Of 262 female and 118 male PLT apheresis donors, 37·4% had prior immunizing events. Fifty-eight of 238 (24·4%) donors without prior immunizing event had anti-HLA antibodies confirmed in microbead single antigen assay (mean fluorescence intensity (MFI) >500). Even with a cut-off MFI >3000, anti-HLA antibodies were detected in 10·6% of female and 4·3% of male donors without history of immunization. Of the antibody specificities found, 6 of 17 (35·3%) anti-HLA-A, 4 of 8 (50·0%) anti-HLA-B and 4 of 6 (66·6%) anti-HLA class II antibodies have been detected in donors associated with TRALI cases in the literature.
  
  
  CONCLUSIONS
  Platelet apheresis donors without history of immunization have anti-leucocyte antibodies that potentially can cause TRALI. In our opinion, this cohort should be included in screening strategies for TRALI prevention. As references and consensus cut-offs have not yet been established, it is premature to use microbead assays as standard for donor screening.
authors.affiliation: Regional Blood Transfusion Service of the Swiss Red Cross, Basel, Switzerland; Regional Blood Transfusion Service of the Swiss Red Cross, Aarau, Switzerland.
authors.forename: J-P
authors.initials: JP
authors.lastname: Sigle
authors.forename: J
authors.initials: J
authors.lastname: Thierbach
authors.forename: L
authors.initials: L
authors.lastname: Infanti
authors.forename: M
authors.initials: M
authors.lastname: Muriset
authors.forename: G
authors.initials: G
authors.lastname: Hunziker
authors.forename: K
authors.initials: K
authors.lastname: Chassot
authors.forename: C
authors.initials: C
authors.lastname: Niederhauser
authors.forename: P
authors.initials: P
authors.lastname: Gowland
authors.forename: A
authors.initials: A
authors.lastname: Holbro
authors.forename: K
authors.initials: K
authors.lastname: Sunic
authors.forename: A
authors.initials: A
authors.lastname: Buser
authors.forename: S
authors.initials: S
authors.lastname: Fontana
mesh_terms: D055371:Acute Lung Injury / Q000276:immunology* / Q000517:prevention & control*; D000328:Adult; D000906:Antibodies / Q000097:blood* / Q000276:immunology; D000918:Antibody Specificity / Q000276:immunology; D001782:Blood Donors; D001792:Blood Platelets / Q000276:immunology; D046148:Donor Selection / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006680:HLA Antigens / Q000276:immunology*; D006801:Humans; D007114:Immunization; D008297:Male; D008863:Microspheres; D017713:Platelet Transfusion / Q000009:adverse effects*; D010983:Plateletpheresis
chemical_list: D000906:Antibodies; D006680:HLA Antigens
keywords: apheresis platelets; donors; transfusion-related acute lung injury