We assessed whether the addition of anti-tumor necrosis factor (TNF) agent to methotrexate (MTX) therapy might alter the response of patients with rheumatoid arthritis (RA) to pneumococcal vaccination.
Seventy patients with early RA (n = 20, 36, and 14 in the infliximab 3 mg/kg plus MTX, infliximab 6 mg/kg plus MTX, and placebo plus MTX groups, respectively) were included in an analysis of patients enrolled in an ASPIRE substudy. Patients received 0.5 ml pneumococcal vaccine (Pneumovax) 34 weeks after initiation of study treatment; patient sera were collected 4 weeks later (week 38). Antibody responses were tested using enzyme immunoassay methods for reactivity to a panel of 12 serotypes of the pneumococcal vaccine.
No significant difference in response to Pneumovax was observed between the infliximab plus MTX and placebo plus MTX groups. Roughly 80%-85% of patients responded to at least one serotype; however, only 20%-25% of patients in the different treatment groups responded to at least 6 different serotypes. Comparable proportions of patients in the 3 treatment groups responded to an increasing number (> or = 1 to > or = 6) of different serotypes. Patients < 45 years of age and those receiving oral corticosteroids generally appeared to respond better than those age 45 to 65 years and those not receiving oral corticosteroids.
All treatment groups in this study had lower responses to vaccine than would be expected in the normal population. However, the addition of the anti-TNF agent infliximab to MTX therapy did not appear to affect the response of patients with RA to pneumococcal vaccination.