Perelman School of Medicine at the University of Pennsylvania

Lo Re Research Group

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Research Focus

Dr. Lo Re’s research program focuses on evaluating the epidemiology of acute and chronic liver diseases, especially among patients with HIV and chronic viral hepatitis infections. His research focuses on the examination of the epidemiology of chronic viral hepatitis infection, particularly HIV/hepatitis B and C coinfection, the evaluation of outcomes of new antiviral therapies for chronic viral hepatitis, and assessment of the hepatic safety of medications in patients with chronic liver disease. A recent addition to his research program is the evaluation of the epidemiology of COVID-19.

Methodologic Work to Validate Liver-Related Events Within Electronic Health Databases

Dr. Lo Re has conducted validation studies to ascertain end-stage liver disease (i.e., hepatic decompensation, hepatocellular carcinoma) events within electronic health data. Since this represents the most important outcome of chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections, the development and validation of algorithms to identify these endpoints within large electronic health databases has led to the conduct of important epidemiologic studies by Dr. Lo Re examining incidence rates of end-stage liver disease by HIV status, determining the impact of HIV viral suppression on hepatic decompensation, evaluating determinants of end-stage liver disease in HIV/HCV-coinfected patients, and examining outcomes of liver complications. Dr. Lo Re has also led scientific workgroups within the FDA’s Mini-Sentinel Initiative, Veterans Health Administration, and Kaiser Permanente Northern California to identify and validate severe acute liver injury and acute liver failure events. This work led to the first population-based study evaluating the incidence of drug-induced acute liver failure, the development of prognostic models estimating the risk of acute liver failure in patients with drug-induced liver injury, and comparative safety studies evaluating the risk of severe liver injury in users of antiretrovirals and antifungals.

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Epidemiology of Drug-Induced Liver Injury and Acute Liver Failure

Dr. Lo Re received R01 funding from the Agency for Healthcare Research and Quality to evaluate the impact of drug-induced liver disease in HIV-infected and uninfected patients. He recently published a seminal paper in Gastroenterology that reported the incidence, etiologies, characteristics, and outcomes of drug-induced acute liver failure. Subsequent studies have led to the development of prognostic models to identify drug-induced liver injury patients at high-risk of acute liver failure and have evaluated the risk of acute liver injury associated with antiretroviral and antifungal medications. 

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Incidence and Determinants of Liver Complications in HIV, HCV, and HIV/HCV Coinfection

Dr. Lo Re has applied the novel methodology described above to identify end-stage liver disease events to produce a seminal study published in Annals of Internal Medicine that demonstrated that despite effective antiretroviral therapy, HIV/HCV-coinfected patients had significantly higher rates of hepatic decompensation compared to those with chronic HCV alone. Notably, HIV/HCV patients who maintained suppressed HIV RNA throughout their follow-up still had higher rates of decompensation than those with chronic HCV alone, suggesting that HIV viral suppression with antiretroviral therapy is not sufficient to reduce rates of end-stage liver disease to those of HCV-monoinfected patients. Subsequent studies evaluated risk factors for the high rate of liver complications in HIV/HCV patients, including non-hazardous alcohol use, uncontrolled HBV, race, obesity, and diabetes mellitus. Recently, Dr. Lo Re has evaluated the impact that medications have on liver disease progression in HIV/HCV, using marginal structural models to determine the risk of hepatic decompensation associated with current and cumulative use of antiretroviral and non-antiretroviral medications. He has also developed prognostic models to estimate the risk of end-stage liver disease in HIV/HCV patients. He has a pending R01 grant from NCI that will extend the above work and evaluate novel mechanisms for hepatocellular carcinoma development in HIV.

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Pharmacoepidemiologic Studies of Chronic HCV Infection

Dr. Lo Re’s background in pharmacoepidemiology has allowed him to make important contributions on adverse effects of anti-HCV therapies, adherence to HCV treatment, and access to the new direct-acting antiviral therapies. Early studies highlighted the risk of significant weight loss and anemia due to pegylated interferon and ribavirin therapy among HIV/HCV patients. Dr. Lo Re then developed methods to measure adherence to anti-HCV agents using pharmacy refill measures and used this methodology to produce an important paper, published in Annals of Internal Medicine, which evaluated the relationship between antiviral adherence and virologic response, changes in adherence over time, and determinants of non-adherence.

In addition, Dr. Lo Re’s team was the first to evaluate the HCV continuum of care via a meta-analysis of existing data, showing the drop-offs in each step of the HCV care cascade over time. Policy makers and the Institute of Medicine have cited this article as helping to determine where to allocate health care resources for the goal of elimination of chronic HCV in the US. Finally, research by Dr. Lo Re has recently found that a significant disparity in access to direct-acting antiviral-based HCV treatments exists, with nearly half of US Medicaid beneficiaries from four states denied access to these therapies. These findings were recently presented as a late-breaking oral abstract at The Liver Meeting 2015 and were reported in the national news and highlighted in a health segment by National Public Radio.

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Epidemiologic Studies of HIV/HBV Coinfection

Dr. Lo Re has also focused on evaluating the epidemiology of HIV/HBV coinfection. He conducted a cohort study that determined that over half of HIV/HBV patients in the Delaware Valley region treated with anti-HBV active antiretroviral therapy failed to achieve HBV DNA suppression. He has a R21 grant from NIAID to examine the risk of liver complications (i.e., hepatic decompensation and hepatocellular carcinoma) associated with detectable HBV and HIV viremia among HIV/HBV-coinfected patients.

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Epidemiologic Studies of COVID-19


View a complete publication listing in PubMed.