Risk of Cytomegalovirus Viremia Following Transplantation of Hepatitis C-Viremic Donor Kidneys Into Uninfected Recipients: A Multi-Center Retrospective Cohort Study.

Background: Several studies have suggested an increased risk of cytomegalovirus (CMV) viremia among Hepatitis C virus (HCV)-uninfected recipients of kidney transplants from HCV-RNA+ deceased donors (HCV D+/R-), but these studies featured small sample sizes and limited ability to address confounding variables.

Methods: We assembled a retrospective cohort of adult kidney transplant recipients at five US centers between 4/1/2015 and 12/31/2020 to determine the association between HCV D+/R- transplants and the outcomes of CMV viremia (> 1000 IU/mL), death-censored graft failure, and mortality in the first posttransplant year compared to HCV D-/R- transplants. We generated highly similar matched cohorts of HCV D+/R- and HCV D-/R- recipients based on attributes that affect the risk of CMV viremia. We matched exactly on center, CMV donor/recipient serostatus, and antibody induction therapy.

Results: The cohort comprised 275 HCV D+/R- recipients with a mean age of 52.5 years (SD = 10.7); 19% were CMV D+/R-, and 74% received anti-thymocyte globulin induction. With variable ratio matching, 267 HCV D+/R- recipients were matched to 996 HCV D-/R- recipients. CMV viremia occurred in 15% of HCV D+/R- and 11% of HCV D-R- recipients. In Cox regression, transplantation with an HCV-RNA+ donor kidney was not associated with a significantly higher risk of CMV viremia (HR 1.3, 95% CI 0.89-1.92) or death-censored graft loss (HR 0.61, 95% CI 0.31-1.2).

Conclusion: The risk of CMV viremia was not significantly increased among HCV D+/R- kidney recipients. Future studies should examine associations between donor-derived HCV infection and clinical outcomes of CMV syndrome and disease.