Utilization of a CMV T Cell Immunity Assay to Guide Secondary Prophylaxis in Solid Organ Transplant Recipients

Secondary prophylaxis following treatment of CMV infection in solid organ transplant recipients (SOTRs) may be considered in high-risk SOTRs, although utilization criteria are not well described. The addition of CMV-specific T-cell immunity assay testing may help guide selection of SOTRs for secondary prophylaxis.

All SOTRs at a single center with CMV T-cell assays obtained during secondary prophylaxis between January 2020 and August 2023 were reviewed. CMV antiviral secondary prophylaxis discontinuation rates and subsequent need for antiviral therapy re-initiation were recorded. Positive predictive and negative predictive values of the assay, as well as the association between absolute lymphocyte count (ALC) and CMV T cell assay variables, were assessed.

CMV T-cell assay results in 32/78 (41%) SOTRs showed adequate response. Secondary prophylaxis was discontinued in 27 (84.4%) with adequate and 13 (28.2%) with inadequate T-cell response (p < 0.005). CMV DNAemia requiring re-initiation of CMV therapy occurred in 2/27 (7.4%) of the adequate and 3/13 (23.1%) of the inadequate response cohorts (p = 0.056), demonstrating a PPV and NPV of 92.6% and 23.1%, respectively, with 71.4% sensitivity and 60% specificity. When combined with ALC > 0.5 10⁹/L at time of assay, an adequate T cell assay response was significantly associated with no CMV reactivation (n = 0/22, p < 0.001).

In this exploratory population, the combination of an adequate CMV T-cell assay with adequate ALC was strongly predictive of no CMV reactivation. Further investigation into the predictive characteristics of a CMV T-cell assay combined with ALC and other patient-specific factors may optimize its clinical application.