A-281 Analysis of Concurrent HBV Surface Antigen and HBV DNA Test Results

Abstract

Abstract Background HBV surface antigen (HBsAg) is the serological hallmark of both acute and chronic infection. HBV DNA levels are monitored clinically in chronic HBV patients to evaluate HBV replication, candidacy for antiviral therapy and monitor patients on therapy. Although HBsAg has an intrinsic association with HBV DNA, it does not necessarily correlate with HBV DNA, especially in the natural course of infection. This study evaluates concurrent HBsAg and HBV DNA testing with a focus on natural infection serological markers such as detection of HBV core antibody (HBcAb), HBV e antigen (HBeAg), and HBV e antibody (HBeAb). Methods Clinical laboratory results from 1604 specimens tested over one year for both HBsAg and HBV DNA were analyzed. The HBsAg test is a qualitative assay, but concurrent quantitative HBV DNA results were available. HBV DNA results spanned the measurable range of the assay (lower limit-of-detection: 3.5 IU/mL, lower limit-of-quantitation: 10 IU/mL). HBsAg-positive/HBV DNA-negative results were further investigated to clarify under what circumstances such discordant results are more likely to be observed. Results HBsAg-positive and HBV DNA-negative results, which accounted for approximately 18% of the data set (284 out of 1604 samples), are more likely to occur when the specimen is HBeAg-negative (Table). A limitation of this study is a lack of information regarding treatment status of the study population. Additionally, HBsAg can persist during HBV treatment. This discordance between HBsAg and HBV DNA test results could also be due to increased integration of HBV into the host genome that produces HBsAg in the absence of measurable viral load in treatment-naïve individuals. Conclusion HBsAg-positive and HBV-DNA negative discordance is most often seen when HBeAg is negative.