Background: Hepatitis B virus (HBV) infection is prevalent in many parts of the world, especially in South East Asia, and
reactivation of HBV can occur after patients receive immunosuppressive agents. Systemic Lupus Erythematosus (SLE) is one of the most important autoimmune diseases because of its high morbidity and mortality rates. Most SLE patients need corticosteroid and immunosuppressive drugs as a treatment regimen; however, there are conflicting recommendations for screening for HBsAg in patients undergoing immunosuppressive therapy and diverse theories about the impact of chronic HBV infection on clinical manifestations of SLE and its activity. As there is no data on the prevalence of HBV infection in Thai SLE patients,the primary objective of this study was to determine the prevalence of chronic HBV infection in Thai SLE patients, and its secondary aim was to determine the impact of HBV infection in SLE patients.
Material and Method: A cross-sectional study was conducted between November 2013 and February 2014 to determine the
prevalence of HBV infection in Thai SLE patients in Rajavithi Hospital. All participants were screened for Hepatitis B surface
Antigen (HBsAg). Clinical manifestations of SLE such as arthritis, rash, nephritis, lupus nephritis, were recorded, and
abnormal laboratory investigations, including serological tests, were noted, together with details of all medications used.
Data of SLE patients with HBsAg positive were compared with those of HBsAg-negative patients.
Results: One hundred and thirty-four Thai SLE patients were included in the study, and the prevalence of HBV infection in
these patients was 1.5% (2/134), which is lower than in the Thai general population. No differences were found between
clinical manifestations of SLE, abnormal laboratory investigations, and treatments of patients with HBsAg positive SLE patients and those of HBsAg-negative patients. Neither HBsAg-positive SLE patients nor those who were HBsAg negative had cirrhosis or hepatocellular carcinoma. Neither group had evidence of acute transaminitis during their disease course, even though one patient had high HBV viremia and had not received any antiviral prophylaxis.
Conclusion: The results showed that the prevalence of chronic HBV infection in SLE patients was lower than in the general
population. Even though they had received high doses of corticosteroid and immunosuppressive agents, no HBV reactivation was found in these SLE patients with chronic HBV infection.

Keywords: Systemic lupus erythematosus, Hepatitis B virus, Prevalence, Impacts