Expanding the Liver Fibrosis Screening Pool to Kidney Transplant Clinics May Identify Frequently Missed Patients With Significant to Advanced Fibrosis

Introduction: Non-alcoholic fatty liver disease (NAFLD) is a silent epidemic strongly associated with chronic kidney disease (CKD). Recently, screening guidelines have been created to guide physicians in screening patients with NAFLD risk factors for significant liver fibrosis, however, patients with CKD are not currently included in the high-risk groups recommended for screening. Therefore, we aimed to evaluate the risk of liver fibrosis in patients with CKD undergoing renal transplantation. Methods: We performed a retrospective cohort study of patients who underwent kidney transplantation at our institution between January 2015 and December 2015. We excluded patients who had undergone simultaneous liver-kidney transplant. Pre-transplant demographic, laboratory, and abdominal imaging data were collected in addition to 5-year post-transplant mortality. Liver fibrosis risk pre-transplant was predicted using the Fibrosis-4 (FIB-4) index to categorize patients into low (< 1.3), indeterminate (1.3-2.67), and high-risk ( >2.67) categories. Descriptive statistics were used for univariate and multivariate analysis. Results: 200 patients met the inclusion criteria. Demographic data across FIB-4 categories is shown in Table 1. Those at high risk of advanced fibrosis were older, had a higher prevalence of type 2 diabetes (T2DM), higher aspartate aminotransferase and alanine aminotransferase values, and lower platelet counts. Of those at indeterminate to high risk, 26% patients had abdominal imagining and 2.4% patients had hepatology evaluation. Five-year mortality after renal transplant was significantly different between those in the indeterminate (33.9%) and high-risk (29.4%) categories compared to those at low risk for advanced fibrosis (13.6%) (P = 0.0002) (Figure 1). Conclusion: Patients with CKD who undergo kidney transplant have a significant risk for liver fibrosis. Given the thorough current pre-transplant assessment protocols, pre-kidney transplant clinics may be a useful avenue to target for screening. Further studies to evaluate if CKD is an independent risk factor for liver fibrosis should be performed in a prospective, larger-scale manner. Table 1. - Demographic Data Across Fibrosis Risk Categories Low risk (FIB-4 < 1.3, n = 118) Indeterminate (FIB-4 1.3-2.67, n = 65) High Risk (FIB-4 >2.67, n = 17) P-value %Female 118 (41.5%) 18 (27.69%) 7 (41.2%) 0.17 %White 44 (37.29%) 25 (38.46%) 8 (47.0%) 0.38 HTN 95 (81.20%) 55 (84.62%) 15 (88.24%) 0.69 HLD 38 (32.48%) 30 (46.15%) 8 (47.06%) 0.14 T2DM 29 (24.79%) 31 (47.69%) 11 (64.71%) 0.0003 Age 42 (11.4) 56 (9.6) 62 (5.6) < 0.001 BMI 28.4 (5.3) 28.9 (4.7) 27.4 (4.9) 0.53 AST(U/L) 16.3 (7.0) 19.1 (7.2) 40 (39.7) < 0.001 ALT(U/L) 16.4 (11.4) 16.6 (10.4) 41.8 (73.3) 0.0002 Albumin(g/dL 5.7 (18.1) 4.7 (4.2) 4.1 (0.4) 0.82 Platelet(x103/μL) 231(232) 155 (41) 136(39) 0.009 Figure 1.: Evaluation for Liver Fibrosis in Kidney Transplant Clinic.