Pretransplant risk stratification for early survival of renal allograft recipients

Abstract

Background: Baseline comorbidities influence patient outcomes in renal transplantation. Identification of high-risk recipients for patient death and early allograft loss might lead to superior stratification.

Material and methods: In this retrospective study, risk stratification models were developed in a cohort of 392 kidney transplant recipients and validated in an independent cohort to predict short-term (2 year) outcomes.

Results: Peripheral arterial disease [OR 7·7 (95% confidence interval (CI): 2·45-24·60); P < 0·001], use of oral anticoagulation [OR 18·68 (95% CI: 3·77-92·46); P < 0·0001], smoking [OR 5·15 (95% CI: 1·67-15·84); P = 0·004], recipient age > 60 years [OR 7·28 (95% CI: 2·33-22·69; P = 0·001)], serum albumin < 40 g/L [OR 5·08 (95% CI: 1·82-14·19); P = 0·002], serum calcium ≥ 2·42 mM [OR 6·47 (95% CI: 1·37-30·58); P = 0·02] living donation [OR 2·95, (95% CI: 0·31-28·29); P = 0·34)] and previous haemodialysis [OR 3·33, (95% CI: 0·39-28·11); P = 0·27)] were included in the model. The validated model discriminated between low- (< 3 points) and high-risk recipients (> 8·5 points) with mortality rates of 0% vs. 54%. The comparison of the model with the Charlson comorbidity index (CCI) yielded significantly better receiver operating characteristic (ROC) areas (Novel Score ROC: 0·87 vs. CCI: 0·72, P = 0·0012). Early allograft loss was associated with presensitization [OR 3·02 (95% CI: 1·29-7·09); P = 0·011] and presence of hepatitis C antibodies [OR 2·42 (95% CI: 1·09-5·34); P = 0·029]. A risk model (ROC: 0·62) for allograft loss could not be developed.

Conclusion: Risk stratification based on the novel score might identify high-risk recipients with disproportional risk of early patient death and lead to optimized strategies.

Keywords: Mortality; renal transplantation; risk model; survival.