Changes in Plasma Human Immunodeficiency Virus Type 1 RNA Associated with Herpes Simplex Virus Reactivation and Suppression

Changes in Plasma Human Immunodeficiency Virus Type 1 RNA Associated with Herpes Simplex Virus Reactivation and Suppression Timothy Schacker 0 1 Judith Zeh 0 Huilin Hu 0 4 Mary Shaughnessy 0 2 Lawrence Corey 0 2 3 0 Received 8 May 2002; revised 12 August 2002; electronically published 22 November 2002. The institutional review board of the University of Washington approved this study. Financial support: National Institutes of Health (grants AI30731 and AI01338) and the AIDS Clinical Trial Group (grant 2-U01-A127664-06) 1 Department of Medicine, University of Minnesota, Minneapolis; Departments of 2 Program in Infectious Diseases, Fred Hutchinson Cancer Research Center , Seattle 3 Microbiology, University of Washington 4 Present affiliation: Novartis Pharmaceuticals , East Hanover , New Jersey. University of Minnesota , Box 250, 516 Delaware St. SE, Minneapolis, MN 55455 In early trials of antiretroviral therapy, acyclovir was associated with increased survival by an unknown mechanism. The hypothesis that subclinical herpes simplex virus (HSV) reactivation was associated, in vivo, with increased plasma human immunodeficiency virus (HIV) RNA and suppression with a reduced plasma HIV RNA load was investigated. HSV cultures were performed daily on HSV-2-positive/HIV-positive patients, and plasma HIV-1 RNA loads were measured at regular intervals. A subset of patients prior to, during, and after HSV suppression with high-dose acyclovir was measured to determine whether HSV suppression was associated with a decrease in HIV replication. Most (25/27 HSV-2-positive/HIV-positive persons) reactivated HSV. Total HSV shedding rate was strongly correlated with plasma HIV1 RNA load (R p 0.54; P p .004), and the plasma HIV-1 RNA level at a given CD4 cell count was 48% lower when treated with acyclovir. These data indicate that frequent mucosal HSV reactivation influences HIV replication in vivo and daily HSV suppression may be important in the management of HSV-positive/HIV-positive persons. - Herpes simplex virus (HSV) is a significant pathogen in persons infected with human immunodeficiency virus (HIV). It was one of the first opportunistic infections affecting immunocompromised homosexual men [1]. Seroepidemiologic studies have established that HSV is among the most common viral infections in persons with HIV-1 infection [28]. Over 60% of persons who are at risk for HIV-1 are HSV-2 seropositive, including men who have sex with men and injection drug users [912]. It has recently been shown that, in developing countries, HSV2 infection is even more prevalent than in the United States or Europe. Among adults 130 years old, rates of HSV-2 infection in the Central African Republic, Tanzania, South Africa, Zambia, Kenya, Uganda, and Zimbabwe are 82%, 60%, 82%, and 74%, respectively [2, 1316]. The role that HSV-2 infection plays in HIV disease progression is still controversial. Several studies have demonstrated that high doses of acyclovir (3.2 g/day), when administered in combination with zidovudine, provided a survival benefit for persons who were randomized to receive acyclovir [17, 18]. The mechanism for this reduction in mortality was unclear, with many authorities feeling that this was related to acyclovirs action on reducing cytomegalovirus (CMV) reactivation [19]. However, a retrospective survey of acyclovir use suggested lower doses, which were effective only against a-herpes viruses such as varicella-zoster virus (VZV) and HSV, were also associated with a survival benefit [20], and a recent meta-analysis found that 7 of 8 studies showed a survival benefit for HIV infected persons receiving acyclovir. Overall, the odds ratio (OR) for acyclovir treatment reducing mortality was 0.78 (95% confidence interval [CI], 0.650.93) [21]. Acyclovir has no effect on HIV replication [22]. The decreased mortality associated with its use may be through its suppression of replication of the a-herpes viruses, HSV-1, HSV-2, and VZV. A suggested mechanism for suppression affecting HIV survival is a direct effect of specific HSV proteins on genes regulating the rate of HIV-1 replication [23]. In vitro, the HSV immediate early gene coding for ICPO and ICP27 HSV have been shown to transactivate the long-terminal repeat portion of the HIV genome [2426], and coinfection of MT-4 cells with HSV and HIV can lead to increased replication of HIV [27, 28]. An in vivo demonstration of this phenomenon may be the observation that keratinocytes, observed to be coinfected with both HSV-1 and HIV, show increased numbers of HIV virions, compared with those cells infected only with HIV [29]. Our group has demonstrated the presence of high titers of HIV-1 virions in mucosal HSV-2 infection and that mucosal variants may subsequently appear in plasma [30]. These data suggest that frequent HSV reactivation may influence the replicating pool of HIV-1 and influence disease progression. One of the concerns that has arisen about the importance of HSV reactivation as a factor in HIV-1 disease pathogenesis is the relatively low frequency of clinical expression of HSV in the HIV-positive subjects [31]. However, we have recently shown that, when samples are collected daily, HSV-2 may be cultured on 5%10% of days in immunocompetent persons and HSV DNA detected on 120% of days [32, 33]. Among HIV1infected persons studied, HSV can be detected on 10% of days by culture and on up to 40%50% of days using HSV polymerase chain reaction (PCR) [34-36]. Given the seroepidemiologic studies suggesting HSV is a nearly universal pathogen among HIV-1 infected persons and the in vitro and in vivo data suggesting a significant interaction between these 2 pathogens that may impact the natural history of HIV infection, we wanted to examine the association between clinical and subclinical HSV reactivation and HIV-1 RNA levels in plasma and determine if suppression of HSV alters plasma HIV 1 RNA levels. Methods Patient Selection HSV seropositive HIV-infected persons were recruited into these protocols between 1994 and 1996. Eligibility criteria included serum antibodies to HSV-2 or both HSV-1 and -2, demonstrated by Western blot, age 118 years, detectable HIV-1 RNA in plasma at entry, and no history of anti-HSV therapy or changes in antiretroviral therapy within 2 weeks of study entry. There were no restrictions because of sex, race, or stage of HIV-1 infection. All patients were monitored at the University of Washington Virology Research Clinic, Seattle. At entry, each subject completed a standardized interview to record history of prior HSV recurrences and frequency and type of past antiviral therapy for both HSV and HIV-1. Protocol Descriptions Study 1: Assessment of plasma HIV-1 RNA during and between sequential HSV reactivations. This protocol involved monthly visits to the clinic for routine medical and genital examinations. Blood samples to measure CD4 T cell count and plasma HIV-1 RNA loads were collected at each visit. Patient (...truncated)