Immunogenicity - implications for rheumatoid arthritis treatment

Biologic agents used to treat rheumatoid arthritis are in- trinsically immunogenic, as they represent complex proteins which are manufactured outside of the recipient of the drug. This is true for chimeric antibodies, humanized antibod- ies, and for fusion proteins. The emergence of antibodies against biologic agents (AAB) will influence both short and long-term efficacy of these agents and may also play a role in adverse events such as infusion reactions. For patients who fail an initial biologic agent or for those who initially respond but lose efficacy, knowledge of whether an AAB is present will allow the clinician to more effectively choose the best agent to which the patient can be switched. The pres- ence of rising ANA titers or antibodies to double stranded DNA may be a good marker for the emergence of AABs. Concurrent use of non-biologic DMARDs at appropriate doses is critical to prevent the evolution of AABs and to ensure long-term efficacy of the biologic agent.