Hla-Matched Platelet Transfusion Experience Using A Hospital-Based Small Pool Of Hla-Typed Donors

Patients with platelet refractoriness as a result of HLA alloimmunization are generally given HLA-matched platelets. However, HLA-matched platelets of A or Bu (higher grade) match are frequently unavailable from a small-sized donor pool. We have evaluated HLA-matched transfusion effect using a hospital-based small donor pool of 450 HLA typed donors. For 16 patients showing platelet refractoriness to random donor platelets (1hr corrected count increment, CCI <5,000) and evidence of HLA alloimmunization (% panel reactive antibody greater than or equal to50%), 82 single-donor platelets from 62 apheresis donors were transfused. HLA compatible donors were selected based on HLA match and patients' HLA antibody specificities. In majority of the cases (13 patients and 56 donors), HLA (lymphocyte) crossmatch (XM) was done before pheresis, and if possible XM-negative donors were selected. In 76% of the total transfusions, effective platelet increment (1hr CCI ! 5,000) was obtained with a mean of 16,802. HLA XM (NIH method)-negative patients showed significantly higher platelet increment compared with XM-positive patients (22,546 vs 1.0,905; P<0.001.). Because of a small pool. size, less than 10% (8/82) of the transfusions were from A/BU grade match. Although A/BU match platelets showed higher CCI (23,853), by selection of HLA compatible donors according to patient's HLA antibody if specificities, effective platelet increment was also obtained in lower grade matches, i.e., BX (15,225) and C/D (16,006).