Establishment of Platelet Antigen and Antibody Tests by Mixed Passive Hemagglutination with Frozen-stored Platelets / 대한수혈학회지

ABSTRACT

BACKGROUND: Platelet antigen and antibody tests have been used in platelet immunological disorders, such as neonatal alloimmune thrombocytopenia (NAIT) and post-transfusion purpura (PTP). Mixed passive hemagglutination (MPHA) method has several advantages, including frozen preservation of platelets, ability to differentiate between anti-HLA and platelet-specific antibodies, and quick and easy interpretation without expensive equipment. In this study, we intended to develop the MPHA method using indicator cells of anti-Rh(D) sensitized group O, Rh+ RBCs. METHODS: We made indicator cells sensitized with anti-Rh(D) with various strengths (1:32 to 1:256) and determined the optimal strength. We determined the sensitivity of the MPHA and compared the results using flow cytometry. We observed the changes of the reaction according to the storage time of indicator cells. RESULTS: The optimal sensitization strengths of the indicator cells were 1:192 and 1:256. MPHA showed strong positive results with 1:8,192 diluted positive control, while the detection limit of flow cytometry was 1:128. Until the second week (mean 16 days), the indicator cells showed good results comparable to those of fresh ones. CONCLUSION: We developed the MPHA method using indicator cells of anti-Rh(D) sensitized group O, Rh+ RBCs. We produced the indicator cells in our own laboratory and obtained platelet panels with rare antigen typing using frozen-stored platelets. This technology will be used effectively for detection of platelet antigens and identification of platelet antibodies and also for platelet crossmatching.