Assessment of the level of vaccine-induced anti-HBs antibodies in children with inflammatory systemic connective tissue diseases treated with immunosuppression

OBJECTIVES: Protective vaccinations are the most effective method of prevention of type B virus hepatitis. The aim of the study was to determine whether in children receiving immunosuppressive therapy due to inflammatory systemic connective tissue diseases the protective concentration of the anti-HBs antibodies produced after vaccination against type B virus hepatitis in infancy is maintained. MATERIAL AND METHODS: The concentration of anti-HBs antibodies was assessed in the sera of 50 children with inflammatory connective tissue diseases – 37 girls (74%) and 13 boys (26%), aged 1.5–17.5 years – during the immunosuppressive treatment, which lasted at least 6 months. The control group consisted of 50 healthy children – 28 girls (56%) and 22 boys (44%) aged 2–17 years. All children were vaccinated in infancy with Engerix B vaccine according to the 0–1–6 months schedule. The antibody concentration of ≥ 10 mIU/ml in patients is regarded as protective. RESULTS: No protective antibody concentrations were found in 25 cases (50%) in the group of diseased children and only in 2 children in the control group (4%). CONCLUSIONS: The concentration of vaccine-induced antibodies should be assessed in children with inflammatory systemic connective tissue diseases and, in case of the absence of a protective concentration, revaccination should be started. The use of glucocorticosteroids, synthetic and biological disease-modifying antirheumatic drugs is no contraindication to vaccination against hepatitis B.