Parikh Laboratory

Dr. Parikh has worked in the HIV/AIDS field since 1998, focusing on RNA quantitation, mechanisms of drug resistance, and HIV prevention. The Parikh lab has expertise in virology and molecular biology in the context of clinical and translational research. Currently, a major focus of the laboratory’s work is developing sensitive assays for nucleic acid detection from a variety of clinical sample types. Dr. Parikh currently serves as the Associate Director of the Virology Core for the Microbicide Trials Network {MTN) and the Project Lead for the USAID funded Global Evaluation of Microbicide Sensitivity (GEMS) Project. In these capacities, her lab confirms virologic endpoints and performs drug resistance testing for studies, provides technical and troubleshooting assistance in virology-related issues to trial sites throughout Africa, provides policy recommendations related to HIV drug resistance, and develops state-of-the-art virologic methods to address research questions in clinical trials.

Contributions to Science

Mechanisms of HIV-1 Resistance to Antiretroviral Agents

Focus on elucidating the mechanisms of how specific mutation and mutation combinations in the HIV-1 reverse transcriptase gene cause resistance to nucleoside reverse transcriptase inhibitors. Through these studies, the K65R mutation could not co-exist with thymidine analog mutations in the same viral genome, and these data had implications on which combinations of antiretroviral agents would be optimal for therapy.

Tenofovir for HIV Prevention

A topical gel containing tenofovir that was applied daily completely protected macaques from vaginal SHIV infection. The tenofovir gel as well as oral tenofovir and oral TDF/FTC was evaluated in a large safety and efficacy trials for which Dr. Parikh was protocol virologist and confirmed all study endpoints. We found that the rate of resistance was low in women who seroconverted in the VOICE trial.

Biomarkers

The Parikh lab has investigated the detection of Y chromosome DNA in genital tract specimens using quantitative real-time PCR as a biomarker for unprotected sex. With a team of collaborators, they showed that women often underreport unprotected sexual activity in clinical trials, and that an objective biomarker of unprotected sex is an important tool for interpreting behavioral data in HIV prevention studies.