LAUSR

To evaluate the vaccine response of treatment-naive juvenile idiopathic arthritis (JIA) patients who were fully vaccinated against Hepatitis B Virus (HBV) and then compare their antibody status with healthy controls. In this multicenter study, initial visit hepatitis B surface antigen (HbsAg) and anti-hepatitis B surface antibody (anti-Hbs) titers of 262 treatment-naive JIA patients who were followed up regularly between May 2015 and October 2019 were evaluated retrospectively from patients’ medical records and compared with 276 healthy peers. Both HbsAg and anti-Hbs antibody titers were tested by the ELISA technique. Anti-HBs titers ≥ 10 IU/L were considered as reactive indicating seroprotection against HBV. In the JIA group, seropositivity rate was 59.1% while 72.9% of the control group were immune against HBV (p = 0.002). The median titer for anti-Hbs was 14 (range: 0–1000) IU/L in the patient group and 43.3 (range: 0–1000) IU/L in the control group (p = 0.01). Neither JIA patients nor healthy controls were positive for HbsAg. Patients with JIA vaccinated according to the national vaccination schedule were evaluated at their first visit in pediatric rheumatology outpatient clinics for anti-Hbs presence and it was found that they have lesser seroprotectivity than their age and sex-matched routinely vaccinated, healthy peers. So, to complete missing vaccines and booster vaccine doses, assessing the immune status of the patients at the time of diagnosis against HBV should be in the check-list of physicians dealing with pediatric rheumatic diseases.