Reduced IgG titers against pertussis in rheumatoid arthritis: Evidence for a citrulline-biased immune response and medication effects.

Background: The antibody response to pertussis vaccination in rheumatoid arthritis is unknown, a concerning omission given the relatively low efficacy of the pertussis vaccine, a rise in pertussis infections, and a general increased susceptibility to infection in rheumatoid arthritis. Additionally, the contributions from an intrinsically dysregulated immune system in rheumatoid arthritis and immune-suppressing medications to the response to pertussis vaccination is poorly defined. This study examines antibody titers against pertussis in vaccinated rheumatoid arthritis patients and controls as well as evaluates potential contributions from demographic factors, immune suppressing medications, and reactivity against citrullinated pertussis.