Taner, Timucin

Background: Steatotic grafts are increasingly being used for liver transplant (LT); however, the impact of graft steatosis on renal function has not been well described. Methods: A total of 511 allografts from Mayo Clinic Arizona and Minnesota were assessed. We evaluated post-LT acute kidney injury (AKI) patterns, perioperative variables and one-year outcomes for patients receiving moderately steatotic allografts (>30% macrovesicular steatosis, n = 40) and compared them to non-steatotic graft recipients. Results: Post-LT AKI occurred in 52.5% of steatotic graft recipients versus 16.7% in non-steatotic recipients (p < 0.001). Ten percent of steatotic graft recipients required new dialysis post-LT (p = 0.003). At five years, there were no differences for AKI vs. no AKI patient survival (HR 0.95, 95% CI 0.08–10.6, p = 0.95) or allograft survival (HR 1.73, 95% CI 0.23–13.23, p = 0.59) for those using steatotic grafts. Lipopeliosis on biopsy was common in those who developed AKI (61.0% vs. 31.6%, p = 0.04), particularly when the Model for End-Stage Liver Disease (MELD) was ≥20 (88.9%; p = 0.04). Lipopeliosis was a predictor of post-LT AKI (OR 6.0, 95% CI 1.1–34.6, p = 0.04). Conclusion: One-year outcomes for moderately steatotic grafts are satisfactory; however, a higher percentage of post-LT AKI and initiation of dialysis can be expected. Presence of lipopeliosis on biopsy appears to be predictive of post-LT AKI.

T cell–mediated rejection (TCMR) is common after liver transplantation (LT), and it is often thought to have a minimum impact on outcomes. Because alloimmune response changes over time, we investigated the role of the timing of TCMR on patient and allograft survival and examined the risk factors for early and late TCMR. We reviewed protocol liver biopsies for 787 consecutive LT recipients with an 8.6‐year follow‐up. The incidence of early TCMR (≤6 weeks after LT) was 33.5% with nonalcoholic steatohepatitis patients having the lowest incidence. Younger recipient age (P < 0.01), number of human leukocyte antigen mismatches (P < 0.01), and use of deceased donor allografts (P = 0.01) were associated with increased risk of early TCMR, which had no impact on allograft (hazard ratio [HR], 1.02; 95% CI, 0.79‐1.32; P = 0.89) or overall survival (HR, 1.03; 95% CI, 0.78‐1.34; P = 0.86). Late TCMR (>6 weeks after LT) was less common (17.7%) and was associated with different risk factors. The majority of late TCMR (56.2%) episodes had no antecedent early TCMR, although moderate‐to‐severe early TCMR (HR, 2.85; 95% CI, 1.55‐5.23; P < 0.01) and steroid resistance (HR, 3.62; 95% CI, 1.87‐6.99; P < 0.01) were associated with late TCMR. Late TCMR increased risk of mortality (HR, 1.89; 95% CI, 1.35‐2.65; P = 0.001) and graft loss (HR, 1.71; 95% CI, 1.23‐2.37; P = 0.001). Thus, these data suggest that the timing and histologic grade of TCMR determine its impact on patient and allograft survival. Early mild TCMR episodes after LT do not adversely impact patient or allograft survival provided that they are adequately treated. The occurrence of late TCMR carries deleterious effects with increased longterm risk of graft loss and decreased survival. Patients with moderate‐to‐severe early TCMR are at an increased risk for late TCMR and warrant closer clinical follow‐up.