Background Biologic therapy for rheumatic diseases (RD) and inflammatory bowel disease (IBD) has been associated with increased risk of reactivation of latent infections such as hepatitis B (HB). However, the actual risk of HB reactivation is still unclear, especially in low-endemic countries such as Portugal.
Objectives To evaluate the serologic HB profile of rheumatic and IBD patients exposed to biologics in two centres. To characterize and assess the incidence of HB reactivation in patients with evidence of past HB infection.
Methods We collected available HB serology of rheumatic patients that ever started biological therapy at our departments. We reviewed the clinical course to identify reactivation cases, defined as raising transaminases, de novo detection of AgHBs and/or positive viral load. Anti-HBc positive patients were studied as to clinical and treatment characteristics.
Results We identified 934 patients with available data on HB serologies (710 RD, 224 IBD) that corresponded to a cumulative biologics exposure of 3904.4 patient-years. All of the patients were AgHBs negative, 72 (8.5%) were anti-HBc positive and viral load was undetectable in every case (Figure 1). In the anti-HBc positive subpopulation, two thirds were females, median age at biologic start was 54.1 years (interquartile range [IQR] 41.3-60.6) and median disease duration was 6.6 years (IQR 3.3-11.1). Sixty-one had a RD diagnosis (9.8% of total; 31 rheumatoid arthritis [10.9%], 12 ankylosing spondylitis [6.9%], 10 psoriatic arthritis [11.2]) and 11 had IBD (5.0% of total; 10 Crohn's disease [5.7%], 1 ulcerative colitis [2.5]). Amongst anti-HBc positive patients, the most frequent initial biologic was infliximab (38.9%), followed by etanercept (31.9%), adalimumab (12.5%), golimumab (5.6%), tocilizumab (5.6%) and rituximab (5.6%). Only 5.6% eventually stopped biologic treatment during follow-up. Forty-four patients (61%) were concomitantly treated with methotrexate (69% of RD and 18% of IBD patients), 43 (60%) with other DMARDs (56% of RD and 82% of IBD patients) and 51 (71%) were on corticosteroids (71% of RD, 73% of IBD patients). No patient received prophylactic antiviral therapy and there was only one case of HB reactivation, a Crohn's disease patient with prior history of acute HB, anti-HBc/anti-HBs positive and initially treated with adalimumab plus azathioprine. She was switched to infliximab because of poor response and at the time she had lost anti-HBs positivity while maintaining anti-HBc. Severe HB reactivation ensued after 13 months of treatment, infliximab was stopped and anti-viral therapy started with a favorable outcome.
Conclusions In our cohort of 934 rheumatic and IBD patients, anti-HBc positivity was infrequent, viral load undetectable and there were no chronic HB cases. There was one case of HB reactivation in a anti-HBc+/anti-HBs- patient treated with infliximab. In a low incidence setting, HB reactivation following biologic therapy is likely to be a much rarer event than what has been previously reported.
Disclosure of Interest None declared