Pharmacogenetics in treatment of rheumatoid arthritis.

Over the last decades important progress is being made regarding disease modifying anti-rheumatic drugs (DMARDs) in the treatment of rheumatoid arthritis (RA). Nevertheless, a substantial part of the patients fail to achieve a good response and/or experience toxicity, which limits further treatment leading to progression of inflammation and destruction of joints. These high interindividual differences in drug response gave rise to the need for prognostic markers in order to individualize and optimize therapy with these antirheumatic agents. Besides demographic and clinical factors, studies in the research field of pharmacogenetics have reported potential markers associated with clinical response on treatment with methotrexate and TNF inhibitors. However, publicized conflicting results and underlying interpretation difficulties inhibit drawing definitive conclusions. Presently, clinical implementation of pharmacogenetics as an important step for individualizing drug therapy in RA is not feasible yet. Replication and prospective validation in large patient cohorts are required before pharmacogenetics can be used in clinical practice. This review provides the current state of art in genotyping RA patients as a potential guide for clinical decision making.