Successful management of alloimmunized patients by transfusing HLA compatible and crossmatched platelets

An average of three (range 0-22) perfect matches for 65 patients could be found in 1490 filed HLA-typed donors. It could increase to 8.7 (0-45) if strong cross-reactive antigens were added. Three methods of platelet crossmatching, i.e, lymphocytotoxicity test (LCT), platelet suspension immunofluorescence test (PSIFT) and solid phase red cell adherence test (SPRCA), were used to search for compatible donors. Forty episodes of apheresis platelet transfusion were evaluated in seven patients. Using one-hour posttransfusional corrected count of increment (CCI), greater than 7500 microliters as a guideline to assess the reliability of these three methods, we found that the efficiency of PSIFT, LCT and SPRCA were 67.5%, 97.5% and 97.5% respectively. Retrospectively, we did the HLA-A, B typing of those matched donors. There was no significant difference in CCI among different HLA match grades. The concordance of LCT and SPRCA was 100%, indicating that all the antibodies were of HLA specificity and there was no platelet specific antibody. We concluded that HLA donor-file and platelet crossmatching technique could be used together in selecting suitable donors for alloimmunized patients.