Vaccine and Infectious Disease Division

The effect of antiviral compounds on human herpesvirus-8 replication

Human herpesvirus-8 (HHV-8) is a human oncovirus and the key pathogenic agent in certain cancers: Kaposi sarcoma, primary effusion lymphoma and certain types of multicentric Castleman disease. Healthy individuals generally control HHV-8 infection and have no symptoms, but immunosuppressed populations, such as those with AIDS or following tissue transplants, are at high risk of developing symptomatic infection. In vitro studies have suggested that antiviral medications can inhibit HHV-8 replication, but little data exist on their efficacy in controlling infection in humans. A recent report authored by former VIDD senior fellow in Infectious Disease Dr. Ashok Cattamanchi (currently an attending physician at Fairfax Inova Hospital), VIDD associate member Dr. Amalia Magaret, VIDD associate member Dr. Corey Casper, VIDD member Dr. Anna Wald, Center President and Director Dr. Larry Corey and colleagues analyzed data from three recent antiviral clinical trials aimed at controlling HIV-1 and/or HSV-2 replication in HIV-infected men with valacyclovir or famciclovir, and determined whether these treatments or highly active antiretroviral therapy (HAART) had any impact on HHV-8 replication.

 

The researchers analyzed daily mouth and throat swabs collected from 58 study participants who were dually infected with HIV-1 and HHV-8, for a total of 6036 swabs. From these samples, they detected HHV-8 in 19% of the swabs, with a fairly uniform distribution among placebo and drug arms of the studies. However, after adjusting for HIV viral load and HAART treatment, they found significant reductions in HHV-8 shedding frequency when patients were treated with valacyclovir (18% reduction) or famciclovir (30% reduction). HAART use was associated with a dramatic, 89% reduction in HHV-8 shedding. These findings suggest that it would be worthwhile to comprehensively study the effect of antivirals and HAART treatment on preventing or treating HHV-8-associated disease, perhaps in combination with chemotherapy.

Cattamanchi A, Saracino M, Selke S, Huang ML, Magaret A, Celum C, Corey L, Wald A, Casper C.  Treatment with valacyclovir, famciclovir, or antiretrovirals reduces human herpesvirus-8 replication in HIV-1 seropositive men.  J Med Virol. 2011 Oct;83(10):1696-703.