OBJECTIVE The aim of this study was to compare the efficacy and safety of two subsequent CMV prophylaxis regimens for prevention of cytomegalovirus (CMV) infection and disease in our kidney transplant recipients (KTRs). METHODS In an historic-cohort of KTRs, two CMV prophylaxis protocols were compared: short protocol in which CMV IgG seronegative recipients (R-) of CMV IgG seropositive donors (D+) received valganciclovir for 3 months post-transplant (group 1: 2005 - 2010); and expanded protocol in which prophylaxis for high-risk recipients was extended to 6 months, and a 3-month prophylaxis for D+/R+ and D-/R+ was introduced (group 2: 2011 - 2016). Incidences of CMV viremia, disease, and adverse events were assessed 12 months after transplant. RESULTS Of 457 KTRs, 167 received short (group 1) and 290 expanded (group 2) CMV prophylaxis. The incidence of CMV viremia was significantly lower in group 2 than in group 1: 17.6% vs. 29.2%, respectively (p = 0.001). The incidence of CMV disease was 5.2% in group 2 vs. 10.2% in group 1 (p = 0.04). After comparing group 2 and group 1 according to the risk of CMV infection, incidences of CMV viremia were 50% vs. 47.4% in D+/R- (p = 0.79), 3.1% vs. 5.7% in D-/R+ (p = 0.05), and 9.7% vs. 23.6% in D+/R+ (p = 0.0004). The incidence of neutropenia was 41.7% in group 2 and 33.5% in group 1 (p = 0.09). CONCLUSIONS The results show a significant reduction of CMV viremia in D+/R+ and D-/R+ KTRs after introduction of 3-month prophylaxis with valganciclovir. Extension of CMV prophylaxis to 6 months in D+/R- was not associated with reduction in CMV viremia at 12 months after transplant.
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