Cytomegalovirus Infection Is Associated with Development of Chronic Lung Allograft Dysfunction

BACKGROUND: Cytomegalovirus (CMV) is the major and most common opportunistic infection complicating lung transplant (LTX). The aim of this study was to analyse the epidemiological aspects of CMV infection in lung transplant patients subject to a pre-emptive anti-CMV approach and to study the impact of this infection on lung transplant outcome, in terms of onset of chronic lung allograft dysfunction (CLAD). METHODS: This single-centre retrospective study enrolled 87 LTX patients (median age 55.81 years; 41 females, 23 single LTX, 64 bilateral LTX). All patients were managed with a pre-emptive anti-CMV approach. The incidences of the first episode of CMV infection, 1, 3, 6 and 12 months after LTX, were 12.64%, 44.26%, 50.77% and 56.14%. A median interval of 41 days elapsed between LTX and the first episode of CMV infection. The median blood load of CMV-DNA at diagnosis was 20,385 cp/ml; in 67.64% of cases, it was also the peak value. Patients who had at least one episode had shorter CLAD-free survival. Patients who had three or more episodes of CMV infection had the worst outcome. RESULTS: CMV infection was confirmed to be a common event in lung transplant patients, particularly in the first three months after transplant. It had a negative impact on transplant outcome, being a major risk factor for CLAD. The hypothesis that lower viral replication thresholds may increase the risk of CLAD is interesting and deserves further investigation.