A randomized prospective controlled trial of oral acyclovir versus oral ganciclovir for cytomegalovirus prophylaxis in high-risk kidney transplant recipients

Background. Posttransplantation cytomegalovirus (CMV) infection remains a significant cause of morbidity in kidney transplant recipients. We performed a randomized prospective controlled trial of oral acyclovir versus oral ganciclovir for CMV prophylaxis in a group of renal allograft recipients considered at high risk for CMV disease due to the use of OKT3 induction therapy. Methods. A total of 101 recipients of cadaveric (83) and zero haplotype-matched live donor (18) kidney transplants were entered into the trial. A total of 22 D-R- patients received no prophylaxis. Twenty-seven D+R-, 29 D+R+, and 23 D-R+ patients were randomized to receive 3 months of either oral acyclovir (800 mg q.i.d.) or oral ganciclovir (1000 mg t.i.d.). Doses were adjusted according to the level of renal function, The D+R- patients were also given CMV immune globulin biweekly for 16 weeks. Surveillance blood cultures were obtained at transplantation, at months 1, 2, 3, and 6, and when clinically indicated. The primary study end points were time to CMV infection and disease the first 6 months after transplantation. Results. The mean follow up was 14.4 months. Both agents were well tolerated, and no drug interruptions for toxicity occurred, CMV was isolated in 14 of 39 (35.9%) acyclovir-treated and 1 of 40 (2.5%) ganciclovir-treated recipients by 6 months (P=0.0001). Symptomatic CMV disease occurred in 9 of 14 (64%) of the acyclovir patients,two with tissue-invasive disease. Infection rates for acyclovir vs. ganciclovir, respectively, stratified by CMV serology were: D+R-, 54 vs. 0%, P=0.0008; D+R+, 43 vs. 6.6%, P=0.01; D-R+, 8.3 vs. 0%, P=NS. No patient developed CMV infection while taking oral ganciclovir, however three delayed infections occurred 2-7 months after finishing therapy. Each patient had been previously treated for acute rejection. Conclusions. Oral acyclovir provides effective CMV prophylaxis only for recipients of seronegative donor kidneys. Oral ganciclovir is a superior agent providing effective CMV prophylaxis for recipients of seropositive donor kidneys. Recipients who are treated for acute rejection are at risk for delayed CMV infection during the first posttransplantation year.