Background Rituximab (RTX), an anti-CD20 monoclonal antibody, is an effective treatment for Rheumatoid arthritis (RA), targeting B cells. However, the safety of this drug in hepatitis B surface antigen (HBsAg) negative/anti-hepatitis B core antigen (anti-HBc) positive carriers is still unknown. The purpose of our study is to evaluate the risk of HBsAg seroreversion in this kind of patients.
Objectives The purpose of our study is to evaluate the risk of HBsAg seroreversion in this kind of patients.
Methods We retrospectively reviewed 310 RA patients treated in 5 italian outpatient rheumatologic Clinics with RTX from August 2006 to December 2011. 35 (11,2%) were HBsAg negative/anti-HBc positive patients and they did not undergo antiviral prophylaxis. Complete serological panel for HBV status before starting RTX infusions and adequate post-treatment follow-up were available. All patients (75% female, median age 60 years, median disease duration 8 yrs, 100% serum HBV DNA negative by sensitive PCR assay, 87% anti-HBs positive) has been treated with one or more disease-modifying anti-rheumatic drugs (83% MTX, 26% CYS, 80% PDN, 8% LEF, 6% AZA) and were eligible for RTX therapy according to international guidelines. The median period of RTX administration was 3 cycles (range: 1-8) and the therapy was ongoing at the end of observational period in 76% of cases. All patients were laboratory and clinically evaluated every three months. Serum HBsAg and serum HBV DNA were assessed in all patients every 6 months or in case of alanine aminotransferase (ALT) elevation and at the end of the follow-up period.
Results The median follow-up time was 45 months (range: 12-80). In this period 27% of patients had anti-HBs titer decrease (2 patient with a complete lost of anti-HBs levels). Only one patient (3%) had an increase of serum HBV DNA (from undetectable to 24 and 44 IU/mL, 1 week apart) without either HBsAg seroreversion or ALT increase. This virological breakthrough occurred 5 months after the first cycle of RTX and required Lamivudine treatment which successfully suppressed viral replication in 4 weeks. One patient (3%) had an ALT flare, not related to HBV reactivation.
Conclusions The retrospective review of our multicentre experience suggest that an adequate monitoring of HBsAg and HBV DNA levels in RA patients HBsAg negative/anti-HBc positive, as recommended by international guidelines, allows us to avoid the antiviral prophylaxis during RTX treatment.
Disclosure of Interest None declared