P150 Risk of hepatitis flare in patients with previous hepatitis B virus exposure amongst inflammatory bowel disease patients: results from a territory-wide Hong Kong IBD Registry study

J.W.Y. Mak, T.C.F. Yip, H.M. Lam, T.Y. Cheng, S.H. Wong, F.K.L. Chan, S.C. Ng, V.W.S. Wong, G.L.H. Wong

The Chinese University of Hong Kong- Prince of Wales Hospital, Department of Medicine and Therapeutics, Hong Kong, Hong Kong- China

Background

Biological therapies, thiopurines and steroid are commonly used in the treatment of inflammatory bowel disease (IBD) and may cause hepatitis B virus (HBV) reactivation. However, their exact risk of hepatitis B flare in patients with previous HBV exposure is poorly defined. We aim to study the risk of hepatitis flare in IBD patients with previous HBV exposure.

Methods

Patients were identified from a territory-wide Hong Kong IBD Registry. IBD patients who were negative for HBsAg and received biological therapies or thiopurines or steroids from 1 January 2000 to 30 June 2019 were included. Patients who were positive for total antibody to hepatitis B core antigen (anti-HBc) and/or hepatitis B surface antigen (anti-HBs) were defined to have previous HBV exposure. Primary endpoint was development of hepatitis flare (alanine Aminotransferase [ALT) >80U/L).

Results

Total 369 patients fulfilled the inclusion criteria and were classified into three groups: anti-HBs positive only (n = 246); anti-HBs and anti-HBc positive (n = 78) and anti-HBc positive only (n = 45). Median follow-up duration was 60 months (Interquartile range: 32.7–60 months). Seventy-six IBD patients (20.6%) developed hepatitis flare. Cumulative incidence of hepatitis flare were 13.2%, 18.3% and 22% at 12 months, 36 months and 60 months respectively. Use of thiopurine [adjusted hazard ratio (aHR) 2.56; 95% Confidence Interval (CI) 1.54 – 4.26, p < 0.001]and ever exposure to steroid [aHR 2.73; 95% CI 1.30–5.72; p = 0.008] were risk factors for hepatitis flare after adjustment of baseline ALT level. The use of biological therapy was not associated with risk of hepatitis flare [aHR 1.79; 95% CI 0.79–3.99; p = 0.14]. Ever exposure to steroid was associated with increased risk of hepatitis flare irrespective of the peak dose (<20mg prednisolone daily, 20-40mg daily or >40mg daily) [aHR: 2.34–4.18]. Fifteen patients (4.1%) developed severe icteric hepatitis flare (ALT > 120U/L and bilirubin >38 mmol/L). Cumulative incidence of severe icteric hepatitis flare were 2.7%, 7.2% and 8.4% at 12 months, 36 months and 60 months respectively.

Conclusion

Amongst IBD patients with previous HBV exposure who were treated with biological therapy, thiopurines or steroid, 20.6% developed hepatitis flare. The use of thiopurine and ever exposure to steroid were risk factors for hepatitis flare. The use of biological therapy was not associated with risk of hepatitis flare.