Detection of Diagnosis Escape Variants of Hepatitis B Virus-impact on Viral Load

Abstract

© 2011, INASL 11 Conclusion: The prevalence of positive serological markers for HBV and HCV was as per the national prevalence. Conflict of Interest: None Oral Plenary Session Detection of Diagnosis Escape Variants of Hepatitis B Virus-impact on Viral Load P Balkumar Reddy*, RM Mukherjee*, J Aparna*, PN Rao**, S Mitnala*, R Gupta**, DN Reddy** *Asian Health Care Foundation, **Asian Institute of Gastroenterology, Somajiguda, Hyderabad, India Background/Objective: Hepatitis B virus (HBV) DNA in serum is measured by real time polymerase chain reaction (PCR) assay as viral load—a marker in guided antiviral therapy. Being quasispecies in nature, HBV produce replication variants, which whether escape detection by the commercially used diagnostic PCR assays and thus alter the burden of viral load has not been elucidated. We evaluated an in-house nested PCR assay to detect diagnosis escape variants (DEV) of HBV undetected by commercially available real time PCR assay. Methods: Sera of HBsAg +ve subjects (n = 178) were screened for HBV DNA by a commercially available real time TaqMan based PCR and an in-house nested PCR assay followed by direct sequencing and densitometric quantification of amplicons to obtain viral load. Serum ALT, hepatitis B virus e antigen (HBeAg) and antibody (anti-HBe) status were evaluated by standard biochemical and ELISA procedures. Result: The in-house assay detected 80% of real time PCR positive samples of which, 79.7% had single band (858 bp) and 20.3% showed mixed type (858 bp ± 192 bp). Among 70 real time PCR negative subjects, 5.7% were positive by the in-house assay having 192 bp amplicon containing A1762T and G1764A mutations with variable viral load. Conclusion: Viral load estimated on 858 bp product only showed conformity with real time assay while inclusion of 192 bp product increased the total viral load which might have significance in determining rapid or sustained virological response (RVR/SVR) in treated subjects. Detection of DEV, particularly in real time PCR negative subjects, warrant customization of the in-house assay to real time format for better diagnosis and management of HBV infection. Conflict of Interest: None Low Prevalence of Hepatitis B and Hepatitis C Infection in Western India D Amarapurkar*, N Patel** *Bombay Hospital and Medical Research Centre, Mumbai, Maharashtra, India **Jivandeep Hospital, Anand, Gujarat, India Introduction: Prevalence rates of hepatitis B viral infection (HBV) in India vary from 3% to 12%, which falls in intermediate prevalence zone. Prevalence of hepatitis C viral infection (HCV) in India varies from 0.3% to 4% among blood donor population. Previous data from western India suggests HBV prevalence of 1.6–5.9% and HCV prevalence of 0.2–15.9%. Most of these data are almost 10 years old, and most are based on select population. We aimed to study HBV and HCV recent prevalence from multiple sources. Methods: Data on prevalence of HBV and HCV was collected prospectively from multiple sources like: general population, blood donor population, hospital attending population, and liver clinic population. Results: HBV prevalence was as follows: general population data: 166/17581 (0.94%); blood donor data: 2039/172316 (1.18%); hospital attending population: 133/13177 (1%); liver clinic data: 2637/12251 (21.5%). HCV prevalence was as follows: general population: 1/2388 (0.04%); blood donor data: 666/171306 (0.38%); hospital attending population: 12/2597 (0.46%); liver clinic data: 916/12251 (7.4%). Conclusion: In Western India, there is very low prevalence of HBV and HCV; making it a low prevalence area. Conflict of Interest: None 03_JCEH-Abstract.indd 11 3/18/2011 11:13:03 AM