Detection of clinically relevant platelet antibodies in the Asian population

Background The detection and identification of the clinically relevant platelet antibodies are important for the diagnosis and management of the affected patients with immune thrombocytopenia. Aims The aim of this study was to investigate the characteristic of clinically relevant platelet antibodies in the Asian population, and to evaluate the ability of platelet immunology laboratories in Asia to detect and identify these platelet antibodies. Methods Total of 635 cases that were diagnosed and studied as NAITP, PTR and PTP by Asian platelet laboratories were reviewed for the clinical and experimental data from the publications. Results Except the anti-HLA and unknown-specificity antibody, the most frequently identified platelet antibody was anti-CD36 (18/635, 18·35%), and then anti-HPA-3 and anti-HPA-4 (each 5/635, 0·78%), and anti-HPA-5 (4/635, 0·62%). Only two cases of anti-HPA-1 antibodies (2/635, 0·31%) were reported. In 274 cases, including four cases contained anti-HLA antibody, the laboratories could not identify the specificity of platelet antibodies. The methods of detection and identification of antiplatelet antibody, such as monoclonal antibody immobilization of platelet antigens (MAIPA), mixed passive hemagglutination assay (MPHA), platelet immunofluorescence test (PIFT), modified antigen-capture ELISA (MACE) and solid-phase red-cell adherence (SPAA), have been used in Asian laboratories. Conclusion With an increasingly heterogeneous patient population in Asia, diagnostic laboratories should be aware of the ethnic origin of a particular patient to consider the possibility of immunization to antigens. The most important clinical relevant platelet antibodies implicated in immune-mediated thrombocytopenia among the Asian population are anti-CD36, then anti-HPA-3, anti-HPA-4 and others.