Platelet refractoriness (PR) due to HLA alloimmunization is a common and serious complication of patients receiving long-term packed red blood cell and platelet transfusions. Although most alloimmunized patients will respond to HLA-matched platelets, 20-50% of patients will remain refractory even to matched platelets. Several measures have been reported to overcome this complication, such as intravenous immunoglobulins (IVIG), plasma exchange (PE), protein A column therapy, or rituximab. We report a woman with acute myeloid leukemia secondary to myelodysplastic syndrome who was diagnosed with PR because of HLA alloimmunization. Due to difficulties in finding HLA-compatible platelet donors by cross-reactive groups in our panel of HLA-typed platelet donors, the patient received treatment with rituximab, PEs and IVIG. With this treatment strategy, the presence of HLA antibodies decreased from a panel-reactive antibody (PRA) of 89-0%. This allowed the performance of hematopoietic progenitor cell transplantation with random donor platelets. Rituximab, PE, and IVIG may be an option to overcome severe PR due to poly-specific HLA alloimmunization.
Keywords: HLA alloimmunization; intravenous immunoglobulins; plasma exchange; platelet refractoriness; rituximab.