Nonalcoholic fatty liver disease (NAFLD) is a spectrum of liver conditions associated with fat accumulation that ranges from benign, non-progressive liver fat accumulation to severe liver injury, cirrhosis, and liver failure. The spectrum of NAFLD encompasses simple nonalcoholic steatosis (nonalcoholic fatty liver [NAFL]) and nonalcoholic steatohepatitis (NASH) in which there is evidence of hepatocellular injury and/or fibrosis. NAFLD is the most common liver disease in adults and the second leading cause for liver transplantation in the U.S. The natural history of NAFLD in the general population has been well described. The NASH Clinical Research Network (NASH CRN) was established by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) in 2002 to further the understanding of the diagnosis, mechanisms, progression and therapies of NASH. This effort has resulted in numerous seminal studies in the field. However, NASH CRN studies have systematically excluded persons living with HIV (PLWH) , as NAFLD in PLWH was thought to be different from that in the general population due to HIV infection, antiretroviral therapy (ART), concomitant medications and co-infections. This resulted in major knowledge gaps regarding NAFLD in the setting of HIV infection. Thus, the natural history of NAFLD in PLWH is largely unknown. The goal of this ancillary study of NAFLD and NASH in Adults with HIV (HIV NASH CRN), is to conduct a prospective, observational, multicenter study of NAFLD in PLWH (HIV-associated NAFLD).
NAFLD is the most prevalent of all liver disorders and is the most common cause of chronic aminotransferase elevations in the U.S. With the availability of highly effective ART, chronic liver disease has become a leading cause of non-AIDS related morbidity and mortality in PLWH. NAFLD is projected to become the leading cause of liver disease in the aging HIV population. While there is evidence that both Hepatitis B and Hepatitis C infection follow an accelerated course in PLWH, it is unknown if NAFLD is also accelerated in PLWH. Unlike NAFLD in the general population, there is a significant lack of characterization of the natural history of NAFLD in PLWH. This prospective observational study of PLWH with NAFLD will examine the natural history of HIV-associated NAFLD. It will also test the accuracy of non-invasive assessments of advanced fibrosis in detecting histologically confirmed advanced fibrosis in PLWH, and establish a robust biospecimen bank (plasma, serum, genomic DNA, and urine; peripheral blood mononuclear cells (PBMCs) and stool at select sites).