Background: Following abdominal solid organ transplant (aSOT), valganciclovir (VGC) is recommended for cytomegalovirus (CMV) prophylaxis. This agent is associated with efficacy concerns, toxicity, and emergence of ganciclovir resistance. Objective: To evaluate the incidence of high-dose acyclovir (HD-A) prophylaxis failure in seropositive aSOT recipients (R+). Methods: This was a retrospective, single-center study of R+ transplanted without lymphocyte-depleting induction between January 1, 2000, and June 30, 2013, discharged with 3 months of HD-A prophylaxis (800 mg 4 times daily). The primary outcome was incidence of prophylaxis failure. Secondary outcomes were incidence of biopsy-proven tissue-invasive disease and prophylaxis failure for each allograft subgroup. Results: A total of 1525 patients met inclusion criteria: 944 renal (RTX), 108 simultaneous pancreas-kidneys (SPK), 462 liver (LTX), and 11 pancreas (PTX) transplant recipients. The composite rate of HD-A prophylaxis failure was 7%; incidence of tissue-invasive disease was 0.4%. Failure rates were 4.5%, 6.1%, 11%, and 20% in the RTX, SPK, LTX, and PTX populations, respectively; tissue-invasive disease rates were 0.2%, 0%, 0.7%, and 10%. Failure occurred more frequently in the LTX and PTX populations ( P < 0.0001, HR = 2.6; P = 0.04 HR = 4.4). Incidence of tissue-invasive disease was minimal and not different in the RTX, LTX and SPK populations ( P = 0.34). When evaluating recipients of seronegative allografts (D−), the composite failure rate was 3.4% with no significant difference between allograft subgroups ( P = 0.45). Conclusion: HD-A may be a reasonable prophylaxis alternative for D−/R+ recipients, in the absence of lymphocyte-depleting induction, if low incidence viremia is tolerable. Future studies are needed to determine the long-term impact of CMV viremia in the setting of this prophylaxis approach.
