title: Flow-cytometric approach to the prompt laboratory diagnosis of TRALI: a case report.
abstract: OBJECTIVE
  Transfusion-related acute lung injury (TRALI) is a rare but serious complication which can occur after transfusion of blood components. In this report we describe our flow-cytometry approach to the laboratory diagnosis of a case of TRALI in a recipient of fresh frozen plasma containing human leukocyte antigen (HLA) class II antibodies.
  
  
  METHODS
  The post-transfusion reaction work-up included the direct and indirect Granulocyte Immunofluorescence Test (GIFT) on the recipient's neutrophils collected before and after the reaction and on the serum from the recipient and from all implicated donors; flow-cytometry bead-based screening and identification assay for HLA class I and II antibodies in donor sera and flow cytometry cross-matching on T and B patient's lymphocytes. Finally, we investigated the reactivity of one donor serum, containing HLA class II antibodies, with the patient's neutrophils activated in vitro to induce expression of HLA class II.
  
  
  RESULTS
  We found an increased level of IgG bound on patient's granulocytes collected after TRALI, in the absence of detectable granulocyte and HLA class I antibodies in the five implicated donors. One of them showed HLA-DR 1 and -DR 51 antibodies, which determined a positive cross-match with patient's B lymphocytes and in vitro activated granulocytes. Both HLA class II antigens were present in the recipient and absent in the donor.
  
  
  CONCLUSIONS
  In some pathological conditions, HLA class II antibodies can react with activated granulocytes expressing HLA-DR antigens, and activate TRALI reaction. HLA class II antibodies screening and flow cytometry cross-matching techniques should be added to the current diagnostic algorithm of TRALI.
authors.affiliation: Servizio Autonomo per il Prelievo e Trapianto di Organi e Tessuti, IRCCS Ospedale Maggiore Policlinico, Milan, Italy. lauraporr@libero.it
authors.forename: Laura
authors.initials: L
authors.lastname: Porretti
authors.forename: Elena
authors.initials: E
authors.lastname: Coluccio
authors.forename: Daniele
authors.initials: D
authors.lastname: Prati
authors.forename: Maria B
authors.initials: MB
authors.lastname: Colombo
authors.forename: Raffaella
authors.initials: R
authors.lastname: Lopa
authors.forename: Pietro
authors.initials: P
authors.lastname: Tombolini
authors.forename: Antonella
authors.initials: A
authors.lastname: Ambrosone
authors.forename: Loretta
authors.initials: L
authors.lastname: Crespiatico
authors.forename: Mario
authors.initials: M
authors.lastname: Scalamogna
authors.forename: Paolo
authors.initials: P
authors.lastname: Rebulla
mesh_terms: D000368:Aged; D005434:Flow Cytometry; D006801:Humans; D055370:Lung Injury; D008297:Male; D065227:Transfusion Reaction