ANTI-TNF-ALPHA INHIBITS THE ANTIBODY RESPONSE TO INFLUENZA VACCINATION

Background: TNF-alpha blocking agents (TBA) are successful in the treatment of autoimmune disorders such as rheumatoid arthritis and Crohn''s disease. Influenza vaccination is advised annually for patients using immunosuppressants, including anti-TNF-alpha. However, the antibody response to influenza vaccination in patients treated with anti-TNF-alpha is unknown.Objectives: To evaluate the effectiveness of influenza vaccination in patients using TNF-alpha blocking agents.Methods: We studied 113 patients with rheumatoid arthritis (71%), Crohn''s disease (19%) and other autoimmune disorders (10%) and 18 age- and gender matched healthy controls. All patients were treated with immunosuppressive therapy such as methotrexate, prednisone, azathioprine and/or anti-TNF-alpha.Sixty-five patients (58%) were treated with one of the TNF-alpha blocking agents infliximab, etanercept or adalimumab at the time of vaccination or had been 2 months prior to the study entry (TBA+ group). The remaining 48 patients received similar immunosuppressive therapy but no anti-TNF-alpha (TBA- group).All study subjects were vaccinated in the fall of 2003 with a trivalent subunit influenza vaccine (Influvac™ 2003/04) at days 0 and 30. Virus specific serum antibody titers were determined in a hemagglutination inhibition (HI) assay on days 0, 30 and 60.Results: The antibody response to H3N2 was significantly impaired (p <0.05) in the TBA+ group, as compared with the TBA- group and controls. The geometric mean titres in the three groups were 17, 24, 38 before vaccination and 84, 208 and 261 at day 30 (postvaccination). Protective HI titres (i.e. ≥40) at day 30 were observed in 79%, 85% and 94% of the patients in the TBA+, TBA- group and controls, respectively.Conclusion: TNF-alpha blocking agents significantly reduce the antibody response upon vaccination against influenza. However, the proportion of patients achieving a protective titre was substantial, about 80%, endorsing the recommendation for annual vaccination of these patients against influenza.Citation: Ann Rheum Dis, volume 64, supplement III, year 2005, page 181Session: Rheumatoid arthritis – Clinical aspects