Background. Kidney injury molecule-1 (KIM-1) and osteopontin (OPN) play important roles in immune regulation. We hypothesized that serum KIM-1 and OPN might serve as biomarkers for predicting early acute rejection after kidney transplantation (KTx). Methods. We conducted a single-center study of 155 subjects, who were classified into acute rejection group (ARG, n=32), non-rejection group (NRG, n=45) and healthy controls (HC, n=78). The serum samples from patients were collected at day 0, 1, 4, 7, 14, 21, and 28 after KTx. Once acute rejection was developed, the samples were collected on anti-rejection treatment days 0 (before treatment was given), 1, 4, 7 and on the end of anti-rejection treatment. Serum KIM-1 and OPN levels were measured by Luminex. Results. The pre-transplant levels of serum KIM-1 and OPN in all KTx recipients were higher than those of HC (P<0.01). Compared with NRG, ARG showed significantly high serum levels of KIM-1 on day 0 (pre-KTx) and on the 1st, 4th, and 7th post-KTx days, and significantly high OPN levels on day 0 and the 7th day. Kaplan-Meier survival analysis showed that the higher levels of KIM-1 on day 0, the 1st and 4th days and OPN on day 0 and the 7th day were significantly associated with the lower probabilities of rejection-free survival. ROC analyses highlight the superiority of KIM-1 on the 1st day and OPN on the 7th day over those on other post-KTx days in prediction of acute rejection episodes. Multivariate logistic analysis revealed that the serum KIM-1 levels on the 1st post-KTx day and the OPN level on the 7th day were independent and powerful predictors of acute rejection episodes An optimal predictive model was built by combining KIM-1 on the 1st day and OPN on the 7st day, and this model had the highest AUC (0.922). Conclusions. This study was the first to demonstrate that serum KIM-1 and OPN may be the promising and elegant markers for prediction of early acute kidney allograft rejection. Our results might help stratify the “immunological risk” to better adapt the strategy of prevention in transplanted patients or to initiate a treatment regimen before tissue injury occurs.

This work was supported by the National Natural Science Foundation of China (No. 81270829, 81270548, 81102247).

« Back to 2013 American Transplant Congress