AB0659 EXTREMELY LOW FREQUENCY OF CHRONIC HEPATITIS B INFECTION IN SYSTEMIC LUPUS ERYTHEMATOSUS

Background There are few studies evaluating the frequency of chronic hepatitis B virus (HBV) infection in systemic lupus erythematosus (SLE) patients (1). Objectives Aim of this study is to determine the HBV seroprevalence in SLE patients and to compare it with normal population and patient control groups (rheumatoid arthritis and spondyloarthritis). Methods HBV serology tests [hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (HBsAb), hepatitis B core antibody (HBcAb)] performed during the diagnosis of 278 SLE patient and the control group [consist of 125 rhomatoid arthritis (RA) and 125 spondhyloarthritis patient (SpA)] were analyzed retrospectively between 2005-2022 in two different centers. Patients with SLE responding to the 2019 ACR/EULAR criteria were included. HBV serology characteristics of SLE patients were compared with those of the normal population and control groups. The categorical data were presented as numbers (in percent). The chi-square test or Fisher’s exact test was used to analyze the categorical variables. We compared 95% confidence intervals (95% CI) for the HBV infection rate of each variable; 95% CI which did not overlap were considered as statistically significant. Statistical significance was considered as p<0.05. Results HBsAg was positive in 2/278 (0.7%) in SLE patients, 6/125 (4.8%) in RA patients, and 9/125 (7.2%) in SpA patients. HBsAg positivity rate in SLE patients was lower than two different national normal population analysis [%4, (218/5960), %4,57, p=0,008] and RA (p=0,019) and SpA patients (P=0,003) (2,3). HBcAb positivity rate in SLE patients (%15) was significantly lower than both normal population (%30.6) and RA (%42.7) and SpA (%30.6) patients (Table 1). Analysis of SLE patients clinical outcomes showed that less oral ulceration (5/38 vs 57/210, p=0.067) and skin lesions (18/38 vs 140/208, p=0.018) occured in the HBcAb positive patients compared to negative patients. There was no relationship between other clinical findings and the HBcAb positivity. The HBcAb positive SLE patients were older than negative patients (51±10 vs 42±13, p<0.001). Conclusion The positivity rate of HBsAg and HBcAb was lower in SLE patients than both normal population and other inflammatory disease subgroups such as SpA or RA. Lower HBsAg and HBcAb seroprevelance in SLE patients compared to normal population and also to other inflammatory diseases (SpA and RA), maybe due to specific protective mechanisms in SLE pathogenesis (like the association of familial mediterrenian fever and pestilence). This mechanism can be explained with the high interferon levels in SLE patients. To properly understand these mechanisims we need more prospective and molecular studies. References [1]X Chen, L Hong, W Zhang et al. Hepatitis B Virus Infection Rate and Distribution in Chinese Systemic Lupus Erythematosus Patients. Med Sci Monit. 2015; 21: 1955–1959. [2]N Tozun, O Ozdogan, Y Çakaloglu, et al..Seroprevalence of hepatitis B and C virus infections and risk factors in Turkey: a field work TURHEP study. Clin Microbiol Infect. 2015 Nov;21(11):1020-6. [3]M Toy, FO Önder, T Wörmann, et al. Age- andregion-specifichepatitis B prevalence in Turkey estimated using generalized linear mixed models: a systematic review. BMC Infect Dis. 2011 Dec 12;11:337. Disclosure of Interests None declared