Gregory P. Bisson, MD, MSCE

Associate Professor of Medicine and Epidemiology

Dr. Bisson is committed to using clinical and translational research to answer important questions in Human Immunodeficiency Virus (HIV) infection and tuberculosis (TB); he focuses primarily on the application of epidemiologic methods to the study of the natural history and treatment of clinically important HIV-associated infections. Dr. Bisson led one of the first published studies from HIV-infected patients living in Africa,which documented the deleterious effects of greater out-of-pocket costs of antiretroviral therapy (ART) regimens on patient outcomes. He was lead author on a study that demonstrated the limitations of the use of World Health Organization (WHO)-advocated CD4 count changes, for evaluating HIV treatment failure in resource-limited settings. In addition, a study Dr. Bisson conducted with multiple collaborators from South Africa indicated that monitoring adherence to ART was more accurate than monitoring CD4 count changes in individuals receiving HIV treatment in resource-limited settings; the approach was described in an accompanying editorial in PLoS Medicine as a "paradigm shift" in preventing HIV drug resistance.

His current research ongoing in the sub-Saharan African country of Botswana focuses on delineating causal mechanisms whereby patients with advanced HIV do poorly after ART initiation. The phenomenon of “early mortality” after ART initiation is common among individuals with advanced HIV in many resource-limited settings, yet the effectiveness of ART in patients who suffer early mortality is unknown. Dr. Bisson’s multi-year prospective cohort study of early response to ART and risk of early mortality, recently completed in Botswana, demonstrated how very early virologic and detailed pathogen-specific cellular immune responses relate to risk of early mortality in patients with advanced HIV and active TB. In addition, he has led randomized clinical trials that demonstrated that empiric TB treatment lacks efficacy in HIV/TB and that early ART initiation in adults with HIV and Cryptococcal meningitis (CM) has potentially harmful effects. 

Dr. Bisson is a faculty member of the Department of Medicine's Infectious Disease Division. He has received multiple grants for his research, including a K23 Mentored Career Development Award, a National Research Science Award (F32), a K12 Career Development Award in Translational Research, a Center for AIDS Research (CFAR) Developmental Core Pilot award, a Doris Duke Charitable Foundation award on Operations research on AIDS Care in Afirca (ORACTA), a Doris Duke Clinical Scientist Development Award (2008), multiple Research Project Grants (RO1) and a planned UH3 grant (2017) evaluating imatinib for treatment of drug-resistant TB. Dr. Bisson was the first research scientist at Penn to begin formal research studies in Botswana. He contributed to the creation of the research component of Penn’s main international research program – the Botswana-UPenn Partnership.