title: The value of crossmatch tests and panel tests as a screening tool to predict the outcome of platelet transfusion in a non-selected haematological population of patients.
abstract: OBJECTIVE
  Alloantibodies against platelets can be detected by using different laboratory tests. Most of these tests, which use panel cells or antigens as a target, perform poorly in non-selected haematological patients. In relation to these tests, a crossmatch test of transfused platelets and patient's serum may be viewed as the standard and may be superior in predicting donor platelet destruction by alloimmunization.
  
  
  METHODS
  In 95 randomly selected thrombocytopenic patients with haematological malignancies, who were receiving leucodepleted blood products, 184 serum samples were studied in an in vitro crossmatch test by using the technique of the platelet immunofluorescence test (crossmatch-PIFT), in an in vivo crossmatch test detecting in vivo binding of immunoglobulins to transfused platelets according to the PIFT technique (in vivo-PIFT), in the indirect PIFT using five random donors as a target (panel-PIFT) and in an enzyme linked immunosorbent assay using immobilized human leucocyte antigens (HLAs) of 100 standardized donors (ELIHLA). The results of all these methods were related to the recovery at 1 and 16 h post-transfusion.
  
  
  RESULTS
  The results of the crossmatch-PIFT were not associated with platelet recovery at 1 and 16 h after transfusion. Even in a subgroup of patients, in whom predefined clinical factors were excluded, no association with platelet recovery was found. The results of the crossmatch-PIFT correlated with those of the in vivo-PIFT (P = 0.02); however, 35 (19%) discrepant results were identified between these tests. The results of the crossmatch-PIFT were not related to the panel-PIFT (P = 0.25), but did relate to those of the ELIHLA (P = 0.02), still revealing 36 (20%) discrepant results. None of the in vivo-PIFT, the panel-PIFT or the ELIHLA was associated with platelet recovery after 1 h, whilst only a positive panel-PIFT was associated with poor platelet recovery at 16 h after transfusion (P = 0.03).
  
  
  CONCLUSIONS
  In a population at low risk for alloimmunization, the correlation of test outcome and platelet recovery is poor. None of these crossmatch tests or screening tests was identified as superior to any other in this population.
authors.affiliation: Department of Hematology, Erasmus Medical Center, Rotterdam, the Netherlands. levin@xs4all.nl
authors.forename: M-D
authors.initials: MD
authors.lastname: Levin
authors.forename: B
authors.initials: B
authors.lastname: van der Holt
authors.forename: J C
authors.initials: JC
authors.lastname: de Veld
authors.forename: J W
authors.initials: JW
authors.lastname: Gratama
authors.forename: W
authors.initials: W
authors.lastname: de Vries
authors.forename: M B
authors.initials: MB
authors.lastname: van't Veer
mesh_terms: D000937:Antigen-Antibody Reactions; D001788:Blood Grouping and Crossmatching / Q000379:methods*; D001792:Blood Platelets / Q000276:immunology; D019337:Hematologic Neoplasms / Q000150:complications / Q000628:therapy; D006801:Humans; D007136:Immunoglobulins / Q000276:immunology; D007519:Isoantigens; D017713:Platelet Transfusion / Q000379:methods*; D011237:Predictive Value of Tests; D011379:Prognosis; D013921:Thrombocytopenia / Q000628:therapy; D016896:Treatment Outcome
chemical_list: D007136:Immunoglobulins; D007519:Isoantigens