Introduction: Cytomegalovirus (CMV) is the most common viral infection after kidney transplantation, and is associated with significant morbidity and potential mortality. Taking into account the interaction of the virus with the host's immune system, recent studies showed that specific CMV CD8+ T lymphocytes play a protective role against viral reactivation. The QuantiFERON®-CMV (QF-CMV) is a technique that monitors interferon gamma (INF-γ) released in response to CMV epitopes. The aim of this study was to evaluate the frequency of CMV-seropositive patients with reactive and non-reactive QF-CMV and their follow up after kidney transplantation, evaluating the frequency of viral replication and treatment necessity.

Methods: We studied 98 renal transplant recipients who had collected the QF-CMV test in the pretransplant moment. CMV seropositive patients were classified according to the QF-CMV result in reactive (≥ 0.2 IU/mL) or non-reactive (< 0.2 IU/mL). After transplant patients were submitted to the center's usual preemptive treatment, followed-up with qPCR.

Results: 78,6% of the patients were QF-CMV reactive. Time to viremia was shorter in non-reactive QF-CMV patients (68.2 ±15.39 days vs. 135.96 ±28.62 days (p= 0.009). Twenty-nine patients needed CMV treatment, 9 (47.4%) were non-reactive QF-CMV and 20 (26.3%) were reactive (p= 0.075). Time to treatment was shorter in non-reactive QF-CMV patients (p=0.004).

Conclusion: 78.6% of our sample was QF-CMV reactive, there was no difference in the overall need for treatment between patients, but in the reactive group it was earlier than in the non-reactive group.