AIM In the general population, proteinuria is associated with progression to kidney failure, cardiovascular disease, and mortality. Here, we analyzed the effects of proteinuria on outcomes in kidney transplant recipients.

METHODS We performed a retrospective, multi-centre cohort study involving 2047 recipients to evaluate the effects of post-transplant proteinuria on adverse cardiovascular events, graft failure, and mortality. Patients were classified into two groups according to their levels of proteinuria: patients without proteinuria (<150 mg/day, n = 1113) and proteinuric patients (≥ 150 mg/day, n = 934). Multivariate Cox hazard model was conducted with using the maximal proteinuria as time-varying covariate.

RESULTS During a median 55.3-month (range, 0.6-167.1) follow-up, there were 50 cases of major adverse cardiac events (cardiac death, nonfatal myocardial infarction, or coronary revascularization), 115 cases of graft failure, and 52 patient deaths. In multivariate Cox regression with time-varying covariate, proteinuric recipients were significantly associated with major adverse cardiac events (hazard ratio [HR] 8.689, 95% confidence interval [CI] 2.929-25.774, P < 0.001) compared to those without proteinuria. Recipients with proteinuria showed significantly higher incidences of acute rejection (23.1% vs. 9.4%, P < 0.001) and graft failure rate (HR 6.910, 95% CI 3.270-14.601, P < 0.001). In addition, mortality rate was also significantly higher in patients with proteinuria (HR 6.815, 95% CI 2.164-21.467, P = 0.001).

CONCLUSION Post-transplant proteinuria correlates with adverse cardiovascular events, graft failure, and mortality. Therefore, proteinuria should be evaluated and managed to improve the outcomes of renal recipients.