Acute kidney injury and chronic kidney disease after liver transplant: A retrospective observational study

Background and rationale: Chronic kidney disease remains an important risk factor for morbidity and mortality among LT recipients, but its exact incidence and risk factors are still unclear. Material and methods: We carried out a retrospective cohort study of consecutive adults who underwent liver transplant (January 2009–December 2018) and were followed (at least 6 months) at our institution. CKD was defined following the Kidney Disease: Improving Global Outcomes (KDIGO) 2012 Clinical Practice Guidelines. Long-term kidney function was classified into 4 groups: no CKD (eGFR, ≥60 mL/min/1.73 m2), mild CKD (eGFR, 30–59 mL/min/1.73 m2), severe CKD (eGFR, 15–29 mL/min/1.73 m2), and end-stage renal disease (ESRD). Results: We enrolled 410 patients followed for 53.2 ± 32.6 months. 39 had CKD at baseline, and 95 developed de novo CKD over the observation period. There were 184 (44.9%) anti-HCV positive, 47 (11.5%) HBsAg positive, and 33 (8.1%) HBV/HDV positive recipients. Recipient risk factors for baseline CKD were advanced age (P = 0.044), raised levels of serum uric acid (P < 0.0001), and insulin dependent DM (P = 0.0034). Early post-transplant AKI was common (n = 95); logistic regression analysis found that baseline serum creatinine was an independent predictor of early post-LT AKI (P = 0.0154). According to our Cox proportional hazards model, recipient risk factors for de novo CKD included aging (P < 0.0001), early post-transplant AKI (P = 0.007), and baseline serum creatinine (P = 0.0002). At the end of follow-up, there were 116 LT recipients with CKD – 109 (93.9%) and 7 (6.1%) had stage 3 and advanced CKD, respectively. Only two of them are undergoing long-term dialysis. Conclusion: The incidence of CKD was high in our cohort of LT recipients, but only a slight decline in kidney function over time was recorded. Prevention of post-transplant AKI will improve kidney function in the long run. We need more studies to analyze the function of kidneys among LT recipients over extended follow-ups and their impact on mortality.