Antigen-Specific Antibody Response in Juvenile-Onset SLE Patients Following Routine Immunization with Tetanus Toxoid

Background: Infection is now the most common cause of morbidity in Systemic Lupus Erythematosus (SLE). There is lack of information regarding the specific antibody forma-tion in response to vaccines in young SLE patients. Objective: To determine the efficacy of anti-tetanus antibody response in young patients with SLE. Methods: Forty SLE pa-tients with mean age of 14.1 years (range: 7-21) and 60 age and sex matched normal con-trols were enrolled in this study over a period of one year. Diagnosis was made according to the ACR criteria and disease activity was determined based on SLE Disease Activity Index (SLEDAI). All patients and controls had received the complete schedule of tetanus vaccinations consisting of three primary doses and two boosters by the age of six. Serum immunoglobulins and anti-tetanus antibody titers were determined by Nephelometry and ELISA. Anti-tetanus antibody levels greater than 0.1 IU/ml have been suggested as pro-tective. Results: In all of the patients and controls anti-tetanus antibody titer was > 0.1 IU/ml. IgG, IgA, and IgM levels were in the normal range for their age. Mean disease ac-tivity score was 4.9 (range: 0-16). There was no association between SLEDAI score and anti-tetanus antibody response. Conclusion: School age onset and immunosuppressive therapy does not seem to interfere with development of consistent immunity to tetanus vaccine in young SLE patients.