Background:QuantiFERON-cytomegalovirus (QFT-CMV) is a standardized assay for the evaluation of cytomegalovirus-specific cell-mediated immunity (CMV-CMI).
Objectives:The purpose of this study was to assess the evolution of CMV-CMI posttransplant and the clinical utility of QFT-CMV for the prediction of postprophylaxis CMV disease in CMV-seronegative recipients of CMV-seropositive donor kidneys (D+R− KTRs).
Methods:601 adult CMV D+R− kidney transplant recipients (KTRs) received letermovir or valganciclovir prophylaxis for 28 weeks in a phase 3, double-blind, multicenter trial (ClinicalTrials.gov NCT03443869). QFT-CMV was performed at a central laboratory by masked personnel at transplant, 12, 28, and 52 weeks posttransplant. Investigators assessed CMV disease through week 52. Sensitivity, specificity, and positive and negative predictive values (PPV, NPV) at week 28 were used to evaluate the clinical utility of QFT-CMV.
Results:Positive QFT-CMV results (pooled) were detected: baseline–1.2%, week 12–2.6%, week 28–7.7%, and week 52–28.9%. The distribution of positive results with letermovir and valganciclovir was comparable, except at week 28 (letermovir 2.2% and valganciclovir 12.8%). Postprophylaxis CMV disease by week 52 occurred in 18.3% (84/460) of evaluable participants: 12.5% (4/32) of participants with a positive, 17.5% (66/377) with a negative, and 27.5% (14/51) with an indeterminate result at week 28 (p = not significant for all comparisons). QFT-CMV sensitivity, specificity, PPV, and NPV were 8.3%, 94.3%, 87.5%, and 17.5%, and were similar when pooling indeterminate and negative results and within the letermovir and valganciclovir study arms.
Conclusions:Among adult CMV high-risk D+R− KTRs who received prophylaxis, CMV-CMI by QFT-CMV increased over time. The result at the end of prophylaxis had limited clinical utility for identifying the risk for subsequent CMV disease.