Longitudinal Epigenome-Wide Analysis of Kidney Transplant Recipients Pretransplant and Posttransplant.

Introduction: Kidney transplantation remains the gold standard of treatment for end-stage renal disease (ESRD), with improved patient outcomes compared with dialysis. Epigenome-Wide Association Analysis (EWAS) of DNA methylation may identify markers that contribute to an individual's risk of adverse transplant outcomes, yet only a limited number of EWAS have been conducted in kidney transplant recipients. This EWAS aimed to interrogate the methylation profile of a kidney transplant recipient cohort with minimal posttransplant complications, exploring differences in samples pretransplant and posttransplant.

Methods: We compared differentially methylated cytosine-phosphate-guanine sites (dmCpGs) in samples derived from peripheral blood mononuclear cells of the same kidney transplant recipients, collected both pretransplant and posttransplant ( = 154), using the Infinium MethylationEPIC microarray (Illumina, San Diego, CA). Recipients received kidneys from deceased donors and had a mean of 17 years of follow-up.

Results: Five top-ranked dmCpGs were significantly different at false discovery rate (FDR) adjusted  ≤ 9 × 10; cg23597162 within , cg25187293 within , cg17944885, located between and cg14655917 located between and and cg09839120 located between and .

Conclusion: Five dmCpGs were identified at the generally accepted EWAS critical significance level of FDR adjusted ( ) ≤ 9 × 10, including cg23597162 (within ) and cg17944885, which have prior associations with chronic kidney disease (CKD). Comparing individuals with no evidence of posttransplant complications ( = 105) demonstrated that 693,555 CpGs (89.57%) did not display any significant difference in methylation (  ≥ 0.05), thereby this study establishes an important reference for future epigenetic studies that seek to identify markers of posttransplant complications.