Impact of high body mass index on allograft outcomes in kidney transplant recipients with presensitization to human leukocyte antigen

Background: This study aimed to investigate whether high body mass index (BMI) and presensitization to human leukocyte antigen (HLA) in kidney transplant recipients (KTRs) affected allograft outcomes. Methods: From January 2010 to December 2018, 1,290 kidney transplantations (KTs) were performed at the Seoul St Mary’s Hospi-tal. Of these, 682 cases of ABO-compatible living donor KT patients were enrolled. They were divided into four groups (low BMI-non-sensitized, high BMI-non-sensitized, low BMI-sensitized, and high BMI-sensitized) according to the median BMI value (22.7 kg/m²) and HLA presensitization status (anti-HLA antibody mean fluorescence intensity > 3,000). Short-term and long-term allograft outcomes were compared between groups. Results: In the high BMI-sensitized group, the decline in allograft function was higher than that in the other three groups. Death-cen-sored graft loss (DCGL) rates were highest in the high BMI-sensitized group (4 of 21 [19.0%], p = 0.04). In the multivariable Cox regression hazard regression model analysis, the hazard ratio (HR) for DCGL was intensified when high BMI and presensitization statuses were combined (HR, 3.75; p = 0.03); these statuses significantly interacted with each other (p-value for interaction = 0.008). Conclusion: Our results suggest that presensitization to HLA and high BMI might have an interactive adverse impact on allograft outcomes in KTRs.