Use of long-term suppressive acyclovir after hematopoietic stem-cell transplantation: Impact on herpes simplex virus (HSV) disease and drug-resistant HSV disease

Abstract

The effect that long-term use of suppressive acyclovir (ACV) has on both overall herpes simplex virus (HSV) disease and ACV-resistant HSV disease was examined in 3 consecutive cohorts of hematopoietic stem-cell transplant (HCT) recipients (n = 2049); cohort 1 received ACV for 30 days after HCT, cohort 2 received it for 1 year after HCT, and cohort 3 received it for an extended period (i.e., >1 year) if the patient's immunosuppression continued after 1 year. The 2-year probability of HSV disease was 31.6% (95% confidence interval [CI], 28.0%-35%) in cohort 1, 3.9% (95% CI, 2.7%-5.2%) in cohort 2, and 0% in cohort 3 (P < .001). ACV-re-sistant HSV disease developed in 10 patients in cohort 1 (2-year probability, 1.3% [95% CI, 0.8%-2.7%]), in 2 patients in cohort 2 (2-year probability, 0.2% [95% CI, 0%-0.8%]; P = .006), and in 0 patients in cohort 3 (cohort 2 vs. cohort 3, P = .3). Long-term use of suppressive prophylactic ACV appears to prevent the emergence of drug-resistant HSV disease in HCT. © 2007 by the Infectious Diseases Society of America. All rights reserved.