Anti-MICA antibodies: production path and impact on therapeutic efficacy after renal transplantation with acute rejection

Abstract

Objective To investigate the production path of major histocompatibility complex class Ⅰ chain-related gene A(MICA) antibodies and the impact on the therapeutic efficacy after acute rejection in renal transplantation recipients.Methods Luminex flow cytometry was used to detect antiMICA antibodies and the antibody specificity in 157 pre-transplant kidney transplant recipients randomly selected.The clinical data were collected,anti-MICA antibody production pathway and immunoglobulin types were analyzed,and the impact of IgM anti-MICA antibody and IgMI In 89 recipients having no sensitized experience,MICA antibodies were positive in 26 recipients (29.2％ ) (P＞0.05).In 45 anti-MICA antibody-positive recipients,the anti-MICA antibodies type was IgM in 26 cases having no sensitized experience; and that was IgG and IgM complex in 19 cases having sensitized experience.In 38 antiMICA antibody-positive recipients undergoing kidney transplantation,7 out of 22 IgM anti-MICA antibodies recipients had AR (31.8％) that was reversed by methylprednisolone pulse therapy,and 7out of 16 IgM&IgG complex anti-MICA antibodies recipients had AR (43.8％) and treated with methylprednisolone pulse therapy:reversion in 3 recipients (42.9％),and the graft function loss in 4 recipients.The AR incidence was not associated with the two immunoglobulin types of MICA antibodies(P＞0.05),but there was significant difference in the reversal rate of AR (P＜0.05).Conclusion For non-allergenic history recipients,there exists the classic “natural antibodies” pathway in the production of the anti-MICA antibodies whose immunoglobulin type was IgM.In addition,the reversal effect of AR in recipients with IgM anti-MICA antibodies was much better.We need to attach importance to IgM&IgG complex anti-MICA antibodies for the pre-transplant anti-MICA antibodies in renal transplant recipients,because their AR treatment outcome is poor. Key words: Kidney transplantation; Graft rejection; MICA; Treatment outcome