2957 Retrospective Review of Patients With Chronic Hepatitis B in Las Vegas, Nevada

Abstract

INTRODUCTION: The estimated annual incidence of clearance of Hepatitis B surface antigen (HBsAg) is 1–2% in Asian populations. The spontaneous seroclearance of HBsAg in patients with chronic Hepatitis B infection in the Western world is seldomly reported. HBsAg loss is a relatively rare outcome in the natural history of chronic Hepatitis B. Aim of this study was to assess the incidence of spontaneous seroconversion of Hepatitis B surface antigen and the natural development of immunity to HBV virus as evidenced by development of Hepatitis B surface antibody (HBsAb) in a US-based outpatient population. METHODS: Electronic medical records from January 2010 to May 2019 at a large outpatient community-based Gastroenterology practice were retrospectively reviewed. Seroconversion of HBsAg and appearance of HBsAb were recorded. Serologic markers for Hepatitis B infection, AST, ALT, and alpha fetoprotein levels were also recorded. RESULTS: A total of 263 charts were reviewed. One hundred seventy nine (179/263; 68%) of these patients had a positive HBsAg upon referral. Fifty five had a history of Hep B treatment; 124 (124/179; 69%) were treatment-naïve. Forty six (46/179; 26%) had chronic active Hepatitis B, and seventy three (73/179; 40%) were lost to follow up. Five (5/179; 2.7%) patients seroconverted to negative HBsAg. Four of these patients subsequently developed immunity as evidenced by the appearance of HBsAb (4/179; 2.2%). Sixty seven (67/263; 25.5%) of all referred patients had immunity to Hepatitis B through natural infection. Thirteen (13/263; 4.9%) patients had incomplete serologies; 4 (4/263; 1.5%) patients were caught in the “window period” with both negative HBsAg and HBsAb. All four patients who had a documented loss of HBsAg were male, Asians (Filipino), aged 48-65 years. The average time from referral to HBsAg clearance was 8-9 years. None of the 4 patients had a positive Hepatitis delta agent, concomitant infection with Hepatitis C, or elevated AFP. CONCLUSION: Chronic HBV infection poses a significant socio-economic burden specially among immigrant communities from endemic geographic regions. Continued adherence to CDC guidelines for HBV screening should be encouraged among high risk patient populations. Further race/ethnicity and community based studies on the natural history of chronic HBV infection will further increase knowledge of disease prevention and cure.