Transfusion of ABO-Incompatible HLA-Matched Platelets as Support for Patients with Acute Myeloid Leukaemia Undergoing Chemotherapy

Background: ABO-incompatible human leukocyte antigen (HLA)-matched platelets are used to manage thrombocytopenic patients with anti-HLA-A and/or anti-HLA-B (HLA-A/B) antibodies when ABO-identical donors are not available. This study assessed the effectiveness of ABO-incompatible HLA-matched platelets in an unselected group of patients with acute myeloid leukaemia (AML) undergoing cytotoxic chemotherapy. Material and Methods: The study cohort consisted of 12 AML patients undergoing cytotoxic chemotherapy and administered HLA-matched single donor platelet transfusions. Patients positive for anti-HLA-A/B antibodies were defined as candidates for HLA-matched platelet transfusion. The effectiveness of platelet transfusions was determined by measuring corrected count increments (CCIs). Results: The 12 patients received a total of 128 HLA-matched platelet transfusions. The median CCIs 1 hour after ABO-minor and -major incompatible HLA-matched transfusions were 11.4 (range: 3.2-24.9) and 12.4 (range: 3-37), respectively. There were no significant differences in 1- and 24-hour CCIs among ABO-identical and ABOminor and major incompatible transfusions. Discussion: ABO-incompatible HLA-matched platelets are effective in supporting thrombocytopenic AML patient’s positive for anti-HLA-A/B antibodies and undergoing cytotoxic chemotherapy.