FRI0155 Prevalence of hbv infection and risk of reactivation on biologic treatment: a population-based observational study of rheumatoid arthritis subjects in a northern italy area

Background The introduction of biologic agent9s treatment in rheumatic diseases dramatically changed their outcome, but raised some concerns about infections recrudescence. Due to the prevalence of hepatitis B virus (HBV) among Italian general population (2–6%), the possibility of a disease reactivation in case of an immunosuppressive treatment has to be considered. Objectives Aim of this prospective, population-based observational study was to assess the prevalence of HBV (both in chronic carriers and recativated) rheumatoid arthritis (RA) patients in our setting; to verify if these findings were in line to the Italian and European-reported data; finally, to evaluate the final outcome of HBV RA subjects. Methods We enrolled the totality of RA patients treated by biologics and, therefore, consulting our Unit at least every 12 weeks, from December 2015 to January 2017. According to the current (ACR/EULAR and AASLD) guidelines, every subject was screened for HBV before starting biologic treatment. Descriptive statistics was performed. Acute infection; previous (resolved) infection; inactive and active carrier; and vaccine-immunized subjects were defined according to Tab. I. Results A totality of 265 RA patients (female 56.3%; male 43.7%; mean age 36+/-20 years) underwent biologic treatment after succeeding the screening (HBsAg+ subjects were excluded). The huge majority of them (82%) was treated by TNF-alpha inhibitors (TNFi), since the remaining received biologic agents with different mechanisms of action. We overall detected 33 (12.5%) inactive carriers, for whom HBsAg and HBV DNA periodical monitoring was suggested; in 3 of them (1.1% of the study population), HBV DNA became detectable, with a low viral load ( In occasion of the screening, we observed 6 (2.3%) HBV-immunized (due to vaccine) and 6 (2.3%) previously infected (HBcAb+) patients: for the first ones no action is required, since the latter were put on standard prophylaxis before undergoing biologic agent and monitored. One of them (0.38%) developed, after 6 months of treatment, HBV reactivation with high-level (>2000 UI/ml) detectable DNA and liver enzymes elevation (>normality x3). She was therefore stopped from receiving biologic agent and put on entecavir 1 mg daily. Conclusions Our prospective, population-based observational study, performed in a first-level referring Hospital in a highly populated area, suggests some considerations. In a way, our data reported a significantly higher prevalence of HBV infection “contact” among our RA population, in comparison to the general one (p Disclosure of Interest None declared