The Expression And Clinical Significance Of Anti-MICA Antibodies In Renal Allografts

【Objective】The aim of our study is to explore the dynamic changes of anti-MICA antibodies in renal allografts and its clinical significance.【Methods】40 recipients who were followed-up by pretransplantation, posttransplantation 1 month, 3 months, 6 months, 1 year, 2years, and 3years between January 2007 and January 2010. Each patient had one serum sample taken. MICA antibodies were detected by using Flow PRATM beads. Monitor adverse events and allograft function. Selected 7 cases with MICA antibodies and used recombinant MICA antigens to remove serum MICA antibodies by specific immune adsorption. Discuss the influence of specific immune adsorption on the removal of the body levels of MICA antibodies.【Results】(1) Among 40 patients, the patients of MICA(+) were 8 cases (20.0%), HLA(+) were 2 cases,HLA(-)MICA(-) were 30 cases (75.0%) by pretransplantation; (2) There were no obvious differences for stored MICA antibodies between positive patients and negative patients in the aspects of sex, blood transfusion history, CDC, cold ischemia time and the use of immunosuppressive agents(P > 0.05); (3) 35 of 40 patients received a dynamic followed-up after renal transplantation. 8 of the 35 patients were MICA(+) before transplantation, in which 2 cases of antibody changed after transplantation. 27 of the 35 patients were MICA(-) before opreation, in which 1 case generated new MICA antibody after operation; (4)Clinical analysis showed that 5 out of 9 patients(55.6%)of MICA(+) group developed adverse events, while 5 out of 26 patients(19.2%)of MICA(-) group developed adverse events (P = 0.045). There is statistic significance of the episode of adverse events between MICA(+) group and MICA(-) group; (5)The serum creatinine levels of MICA(+) group patients were higher than MICA(-) group patients at time point of 6 month and 12 month(P value was 0.049 and 0.042, respectively); (6)Specific immune adsorption can significantly reduce the levels of serum MICA antibodies.【Conclusions】1. The presence of MICA antibodies was clinically relevant with the chronic decline of renal allograft function. Whether patients with MICA antibodies before renal transplantion or not, periodic dynamic monitor MICA antibodies after renal transplantation will good for reduce renal function damage and take effective therapy for decreasing the occurrence and development rejection on renal allograft. 2. Specific immune adsorption can reduce the levels of serum MICA antibodies, suggesting that immune adsorption methods have potential application in clear MICA antibodies stored in patients.