Discordance in cytomegalovirus viremia in kidney recipients from the same donor is associated with the worst outcomes.

Background: Cytomegalovirus (CMV) is a common viral infection in kidney transplant recipients (KTR) that has been associated with negative outcomes. The effect on outcomes of concordance versus discordance in CMV between two different recipients of kidneys from the same donor is largely unknown. Methods: We reviewed all adult deceased donor kidney transplant recipients (DDKTs) for which both kidneys were transplanted to two different recipients at our center between 2014 and 2019. Recipient pairs from each donor were divided into groups based on concordance or discordance for the development of CMV viremia between the pair; concordant no CMV (cc‐no‐CMV) if neither KTR developed CMV, concordant CMV (cc‐CMV) if both KTRs developed CMV. The discordant group was then further divided based on the individual development of CMV (dc‐CMV) or lack of development of CMV (dc‐no‐CMV). Patient mortality and death‐censored graft failure (DCGF) were outcomes of interest. Results: Of 578 KTRs, 67% were cc‐no‐CMV, 5% were cc‐CMV, 14% were dc‐no‐CMV, and 14% dc‐CMV. Some of the baseline characteristics differ among the groups including a higher prevalence of high‐risk serostatus (D+/R‐) in cc‐CMV (32%) and dc‐CMV (32%). In multivariate analysis, with reference to cc‐no‐CMV, dc‐CMV was associated with increased risk for DCGF (HR 3.13, 95% CI 1.58–6.19), and so was delayed graft function. Factors associated with increased risk of mortality were advanced recipient age and DGF. cc‐CMV was neither associated with mortality nor DCGF. Conclusions: These findings support that in certain contexts, CMV viremia has adverse allograft outcomes, and this is highlighted when illustrated via discordance in CMV between pair kidneys from the same deceased donor. [ABSTRACT FROM AUTHOR]