Soluble Tim-3/Gal-9 as predictors of adverse outcomes after kidney transplantation: A cohort study

Background: In our previous study, serum soluble T-cell immunoglobulin and mucin structure-3 (sTim-3) and galactosin-9 (sGal-9) were found to be associated with renal function after kidney transplantation. However, it is unclear whether these two indicators can predict adverse outcomes after transplantation. Methods: Ninety-one recipients of kidney transplantation were enrolled and divided into a stable group and an adverse outcome group (consisting of biopsy-proven rejection, graft loss, death and clinically diagnosed rejection). The expression levels of sTim-3 and sGal-9 before (pre-Tim-3 and pre-Gal-9) and one month after transplantation (post-Tim-3 and post-Gal-9) were measured by ELISA. Results: The level of pre-Tim-3 was significantly higher in the stable group than in the adverse outcome group [median (range), 2275 (840-4236) pg/mL vs. 1589 (353-3094) pg/mL, P = 0.002]. The level of post-Gal-9 was significantly lower in the stable group than in the adverse outcome group [median (range), 4869 (1418-13080) pg/mL vs. 6852: (4128-10760) pg/mL, P = 0.003]. The areas under the curve (AUCs) for pre-Tim-3 and post-Gal-9 were 0.737 (P = 0.002) and 0.751 (P = 0.003), respectively, better than AUC of post-eGFR (0.633) (P = 0.071), according to the receiver operating characteristic (ROC) curve. Through Cox regression analysis, including pre-Tim-3, post-Gal-9, post-eGFR, sex, age, BMI of recipients and donors, pre-Tim-3 and post-Gal-9 were independent risk factors for adverse outcomes after kidney transplantation (P = 0.016, P = 0.033, respectively). Conclusion: Serum sTim-3 and sGal-9 can predict adverse outcomes within two years after kidney transplantation.