S2680 Serum Cystatin C Is Better Predictor of Renal Dysfunction Among African American Patients Undergoing Liver Transplant Evaluation

Introduction: In patients with portal hypertension and sarcopenia due to end stage liver disease (ESLD), accurate assessment of renal function is critical for management of volume status and for prognosis models such as MELD score. While Serum Cystatin C (normal range 0.6-1.2 mg/dl) is a more reliable determinant of GFR than serum Creatinine, it is not known whether it is useful among African American patients with ESLD. This study aims to explore the predictive value of Cystatin C among African Americans (AA) undergoing liver transplant evaluation. Methods: Cystatin C was measured in all consecutive patients undergoing Liver Transplant Evaluation and we studied serum creatinine (SCr), serum cystatin C (CysC), MELD 3.0 and MELD Cystatin C (MELD Cy). MELD Cy was obtained by substituting the value of CysC for creatinine in the MELD 3.0 calculation. We compared the MELD 3.0, MELD Cy, SCr based GFR (CKD EPI) and eGFR (CKD EPI) based on SCr and CysC for AA. A cohort of White patients who underwent liver transplant evaluation at the same period were used as control. Paired t-test was used to compare the eGFR and MELD scores. Results: Records of 90 patients (20 AA and 70 Whites) with ESLD were accessed. Among both AA and Whites, the CysC was higher compared to SCr measured on the same day reflecting the value of CysC in assessing renal dysfunction in patients with ESLD and loss of muscle mass in both ethnicities. Mean SCr and CysC among Whites were 1.01 mg/dl (±0.44) and 1.78 (±0.67) and among AA were 1.302 mg/dl (±1.81) and 1.71 (±0.82), respectively. Similarly, eGFR based on SCr with CysC was significantly lower than eGFR based on SCr in both ethnicities (57.1 ± 21.2; 81.9 ± 26.9; P-value < 0.005 for Whites, 60 ± 22.9; 78.7 ± 29; P-value 0.03 for African Americans). However, MELD Cy resulted only in a modest increase from MELD 3.0 in AA (21.25 ± 6.8; 19.1 ± 6.5; P value 0.328) compared to Whites (22.4 ± 6.7; 18.6 ± 5.8; P value < 0.005). Conclusion: CysC is a more accurate predictor of renal dysfunction in both AA and Whites with decompensated Cirrhosis. While MELD Cy offers gains in MELD score models, in both ethnicities, impact of MELD Cy is higher among Whites compared to AA. Future prognostic models in ESLD should incorporate Cystatin C instead of Serum creatinine.