AB0336 Hepatitis b virus reactivation in rheumatoid arthritis patients with hbsag-negative/anti-hbc-positive status
Authors: C.-H. Ho, M.H.A. Leung
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Hepatitis B virus (HBV) reactivation in rheumatoid arthritis (RA) patients with positive hepatitis B surface antigen (HBsAg+) is one of the treatment-related complications. The risk of reactivation in patients with negative hepatitis B surface antigen but positive anti-hepatitis B core antibody (HBsAg+/anti-HBc-) is less well defined compared to their HBsAg +counterparts. <h3>Objectives</h3> This retrospective, single centre study aimed to study the prevalence of HBV reactivation (defined as HBV DNA becoming detectable) among RA patients with HBsAg+/anti-HBc +status, and to investigate any factors predicting reactivation. <h3>Methods</h3> RA patients attending the rheumatology specialist clinic in a local tertiary hospital between 1st January 2011 and 31st December 2016 were included if they had of<sup>1</sup> HBsAg-/anti-HBc +status and<sup>2</sup> undetectable HBV DNA at baseline. Demographic data, clinical parameters including treatments for RA and any use of antiviral prophylaxis, and laboratory results including anti-hepatitis B surface antibody (anti-HBs) and serial HBV DNA levels were obtained. Chi-square (or Fisher exact test if number was less than 5) was used for analysis of categorical variables. Student's t-test and Mann Whitney test were used for analysis of parametric and non-parametric continuous variables respectively. <h3>Results</h3> Majority (80%) of the 107 included patients included were female and the mean age was 62.5-year-old (SD 12.09). All the patients were receiving disease modifying anti-rheumatic durgs (DMARDs), 43% of which (n=46) were on biological therapy (with or without concomitant synthetic DMARDs) and the remaining (n=61) were only on conventional synthetic DMARDs (8 on monotherapy, 53 on combination therapy). As antiviral prophylaxis was not mandatory in HBsAg-/anti-HBc +patients according to local guideline, only 13 patients (12.1%) were on antiviral cover (12 on entecavir and 1 on lamivudine). Ten patients (9.3%) experienced HBV reactivation during their disease course. Three of them were on antiviral prophylaxis and four had positive anti-HBs. All of these reactivations were only transient low-grade viraemia with HBV DNA level &lt;20 IU/ml. Spontaneous resolution of viraemia in less than 12 months' time were observed in all of these patients. None of the reactivation resulted in any adverse clinical event including acute hepatitis, hepatic failure or mortality. Among all synthetic and biological DMARDs, only the use of methotrexate was found to be a significant predictor of HBV reactivation (p&lt;0.05). Other parameters including age, the lack of antiviral prophylaxis, negative anti-HBs status and anti-HBs titre did not predict HBV reactivation. <h3>Conclusions</h3> HBV reactivation among RA patients with HBsAg-/anti-HBc +status and undetectable HBV DNA at baseline was infrequent. Reactivation may occur in patients with positive anti-HBs or on antiviral prophylaxis, but was unlikely to be associated with adverse clinical outcome. The use of methotrexate was a predictor of HBV reactivation in these patients. <h3>References</h3> [1] Mod Rheumatol2018Jan 22:1–6. [2] Clin Exp Rheumatol2017Sep–Oct;35(5):831–836. <h3>Disclosure of Interest</h3> None declared