Exploring Disease-Specific Waitlist Outcomes in Simultaneous Liver-Kidney Transplantation

The current allocation system does not account for liver etiology in simultaneous liver-kidney transplantation (SLKT). This study aims to assess differences in waitlist outcomes among major liver disease groups (alcohol-related liver disease [ALD], metabolic dysfunction-associated steatohepatitis [MASH], hepatitis C virus infection, and biliary diseases) in SLKT using Organ Procurement and Transplantation Network (OPTN) registry. In total, 4,846 adult SLKT candidates listed between January 2018 and March 2024 were enrolled. Patients with MASH had worse waitlist 1-year mortality compared to ALD adjusted for patient characteristics at listing (HR 1.300, 95% CI 1.059-1.597, p = 0.012), whereas the 1-year SLKT probability was comparable. When patients were categorized by MELD score at listing (6-20, 21-29, and ≥30), patients with MASH had significantly higher 1-year waitlist mortality compared to those with ALD in the middle MELD score group (HR 1.365, 95% CI 1.008-1.834, p = 0.044). Prior to the allocation policy change in 2020, patients with MASH experienced higher waitlist mortality compared to ALD, however, this disparity was not observed following the policy change. Waitlist outcomes varied significantly depending on the etiology in SLKT. The revised 2020 allocation policy may be temporally associated with changes in mortality disparities across different liver etiologies.