A new transfectant panel cell line-based MoAb-independent antigen capture assay system for detection of CD36 antibody.

BACKGROUND AND OBJECTIVES: CD36 antibody (Ab) causes several disorders: neonatal alloimmune thrombocytopenia, platelet transfusion refractoriness and non-haemolytic transfusion reactions. However, there is no gold-standard test for CD36 Ab. MATERIALS AND METHODS: We developed a transfectant panel cell line-based MoAb-independent antigen capture assay system for detection of CD36 Ab and compared it with the monoclonal antibody-specific immobilization of platelet antigens (MAIPA) system in terms of sensitivity and specificity. RESULTS: Our new system was characterized by (1) gene-transfected cell lines, but not panel platelets; (2) not being hampered by HLA Abs; and (3) no need to use CD36 MoAbs to ensure the antigen specificity of this detection system. In addition, it showed a much better receiver operating characteristic curve than the MAIPA system. CONCLUSIONS: The present results indicate that our new system permits highly sensitive and specific detection of CD36 Ab.

Establishment of a cell line panel as an alternative source of platelet antigens for a screening assay of anti-human platelet antibodies.

BACKGROUND: A panel of platelets expressing various human platelet antigens (HPAs) for a platelet antibody screening assay is difficult to prepare because some antigens are rarely expressed. Therefore, an alternative method without using platelets would be helpful in detecting HPA antibodies. This study describes the establishment of cell lines that stably express specific HPAs and their application for detecting specific antibodies. METHODS: Wild-type ß3, HPA-1b, -6b, -7b and -7 variant cDNA as well as wild-type αIIb and HPA-3b cDNA were individually co-transduced with wild-type αIIb and ß3 cDNA in the K562 cell line. We performed an immunobead monoclonal antibody immobilisation of platelet antigens (MAIPA) assay to evaluate this cell line panel for antibody detection using identified sera containing HPA antibodies, whose specificities had been determined by the mixed passive haemagglutination test. RESULTS AND CONCLUSION: Of the 12 sera containing HPA-1a (n = 2), HPA-3a (n = 6), HPA-6b (n = 3) or HPA-7 variant (n = 1) antibodies, all antibodies were detected and determined by our new method, except for two HPA-3a antibodies. One of the two antibodies was also negative for conventional platelet MAIPA, suggesting that the cell line panel might be used as an alternative source of platelet antigens in the MAIPA assay.