Non-Renal Factors Associated with Simultaneous Liver-Kidney Transplant in Patients with End-Stage Liver Disease and Stage 3-5 Chronic Kidney Disease Not Requiring Dialysis

Abstract

We aimed to identify the non-renal risk factors for simultaneous liver-kidney transplantation (SLKT) vs. liver transplantation alone (LTA) in end-stage liver disease (ESLD) patients with estimated glomerular filtration rate (eGFR) <60 ml/min, not on dialysis. Using organ procurement and transplantation network data, we studied adult ESLD patients who received deceased-donor SLKT or LTA in July 2002-Mar 2016 with a 4-point modification of renal disease (MDRD) equation-estimated glomerular filtration rate (eGFR) stratified into chronic kidney disease stage 3 (CKD-3): 30-59 ml/min, CKD stage 4 (CKD-4): 15-29 ml/min, and CKD stage 5 (CKD-5): <15 ml/min) and not on maintenance dialysis (NOD). The outcome of the study was identification of non-renal risk factors predicting likelihood of SLKT vs. LTA. We reported the odds ratio (OR) and 95% confidence interval (CI) for SLKT vs. LTA associated with important clinical variables. Strong non-renal (non-creatinine-associated) risk factors for SLKT were WL-time >2 yrs. and 1-2 yrs. (OR = 3.80, CI = 2.94-4.91; OR = 3.20, CI = 2.58-3.97; respectively), African American or Hispanic recipient race/ethnicity (OR = 2.93, CI = 2.45-3.51; OR = 1.46, CI = 1.24-1.72; respectively), liver repeat transplant (OR = 1.66, CI = 1.39-1.99), and diabetes (OR = 1.53, CI = 1.36-1.72). Factors associated with lower likelihood of SLKT were donor age >60 years (OR = 0.25, CI = 0.19-0.32), female recipient sex (OR = 0.48, CI = 0.43-0.54), hepatocellular carcinoma (OR = 0.53, CI = 0.35-0.81), and transplant center procedure volume tercile ranks 3<sup>rd</sup> (OR = 0.74, CI = 0.62-0.89) and 2<sup>nd</sup> (OR = 0.78, CI = 0.64-0.95). Model for end-stage liver disease scores have varying associations with SLKT vs. LTA, depending on calculation time: at wait listing or transplant. CKD-5 and -4 at wait listing (WL) and transplant were the risk factors with highest point estimates for SLKT vs. LTA. In patients with ESLD and CKD stage 3-5, not on dialysis, strong non-renal risk factors favoring SLKT versus LTA include: prolonged waitlist time, African American or Hispanic race/ethnicity, previous liver transplant, and diabetes. Some novel associations found between risk factors and likelihood of SLKT need further study for confirmation. Lack of uniform criteria for SLK allocation during the period studied is a major limitation of the study.