Extended Low-Dose Valganciclovir Is Effective Prophylaxis Against Cytomegalovirus in High-Risk Kidney Transplant Recipients With Near-Complete Eradication of Late-Onset Disease

Background. Cytomegalovirus (CMV)-seronegative kidney transplant (KTx) recipients of organs from CMV-seropositive donors (D+/R-) are at increased risk for CMV infection. Despite valganciclovir (VGCV) prophylaxis (900 mg daily for 200 days), late onset CMV (LO-CMV) occurs at excessive rates. VGCV-associated cost and toxicities remain problematic. Methods. We retrospectively evaluated 50 D+/R- adult KTx recipients from August 2008 to August 2014 who received low-dose VGCV (450 mg daily) prophylaxis for an extended duration. The primary outcome was occurrence of CMV disease. Results. All patients received depletion induction and underwent ABO-compatible KTx. Mean prophylaxis and follow-up durations were 22.8 and 40.7 months, respectively. Eight patients developed CMV: 5 breakthrough cases (1 case of colitis [2%] and 4 cases of infection [8%]) and 3 cases of LO-CMV (1 syndrome [2.9%] and 2 cases of infection [5.7%]). On logistic regression, longer duration of VGCV prophylaxis was protective against CMV infection or disease (P =.044; odds ratio, 1.12 [95% confidence interval, 1.03-1.29]). None of 19 recipients with prophylaxis for >= 12 months developed LO-CMV compared with 3 of 16 recipients with prophylaxis for <12 months (18.8%) (P =.086). Four patients had recurrence of CMV, and 1 patient developed resistance. CMV was not responsible for graft or patient loss and did not affect survival. Conclusions. Low-dose VGCV is an effective prophylaxis for D+/R- KTx recipients despite depleting induction. Longer prophylaxis is more protective, and receiving VGCV for >= 12 months nearly eradicated LO-CMV without increasing antiviral resistance.