Prevalence and Clinical Course of Chronic Hepatitis B Infection in Patients With Inflammatory Bowel Disease and Rheumatologic Disease on Immunosuppressive Therapy

The incidence of inflammatory bowel disease (IBD) has been increasing in Hong Kong. The management of inflammatory bowel disease involved the use of immunosuppressant, however, the use of immunosuppressant in patients with hepatitis B infection has been associated with hepatitis B reactivation. It is estimated that around 7% of the Hong Kong population is infected with HBV. The information on the prevalence of hepatitis B in IBD patients in Hong Kong is lacking. Moreover, limited information is available on the effect of different immunosuppressive regimens given for longer periods of time in lower doses in patients with chronic HBV infection and IBD. There is therefore a need to determine the incidence and predictive factors for HBV reactivation in these patients.

Rheumatologic diseases, including systemic lupus erythematous, rheumatoid arthritis, psoriasis and anklyosing spondylitis are inflammatory conditions which commonly affect the locomotors system as well as other organs. Epidemiological data from China have suggested that patients with ankylosing spondylitis have a higher risk of hepatitis B infection; while the rates of hepatitis B for those with rheumatoid arthritis, and other spondyloathropathies are similar to that of the general population. However, there are no such local data in Hong Kong aspect.

This study aims to determine the prevalence of HBV infection in patients with IBD and rheumatologic disease, and to assess the impact of immunosuppressive therapy on viral load and clinical course of IBD patients.