Cell-mediated Immunity to Guide Primary Prophylaxis for CMV Infection in Organ Transplant Recipients: A Multicenter Single-arm Prospective Study

Background. There are few interventional studies using CMV cell-mediated immunity (CMI) to guide antiviral prophylaxis. We assessed the Quantiferon-CMV (QTF-CMV) assay to guide CMV prophylaxis duration in high-risk organ transplant recipients. Methods. A single-arm, multicenter, prospective interventional study including high-risk kidney, pancreas, liver, and heart transplant recipients who were either donor CMV-seropositive, recipient-seronegative (D + /R – ) or recipient-seropositive with antithymocyte globulin (R + /ATG) induction. CMI testing was performed using the QTF-CMV assay at months 3, 4, 5, and 6 posttransplant. Prophylaxis was discontinued for a positive CMI but continued for a negative result up to a maximum of 6 mo. The primary endpoint was CMV viremia ≥1000 IU/mL up to 1 y posttransplant. Results. One hundred eight patients were included, comprising kidney (n = 89), kidney-pancreas (n = 7), liver (n = 10), and heart (n = 2) transplants. Eighty-nine patients (82.4%) completed the study protocol (n = 39 D + /R – and n = 50 R + /ATG). In the D + /R – group, only 1 of 39 patients (2.6%) had a positive QTF-CMV result. In the R + /ATG group, 33 of 50 patients (66%) had a positive QTF-CMV result before 6 mo, allowing for early discontinuation of prophylaxis (28 at month 3, 4 at month 4, and 1 at month 5). During the follow-up, CMV viremia ≥1000 IU/mL occurred in only 4 of 33 patients (12.1%) who discontinued prophylaxis early compared with 6 of 17 patients (35.3%) with negative QTF-CMV results and continued prophylaxis (hazard ratio 0.31; 95% confidence interval, 0.09-1.09; P = 0.07). No R + patient developed CMV disease. Conclusions. QTF-CMV-guided prophylaxis appears useful in R + patients who may benefit from a tailored duration of prophylaxis. This strategy does not appear to be useful in D + /R – patients.