 Inclusion criteria: Patients satisfying the ACR Criteria for RA24 and having received a prescription of Adalimumab from a rheumatologist at the Centre hospitalier universitaire de Sherbrooke. Patients having received other anti-TNF therapies are eligible only after 5 half-lives of the previous medication. Patients must be willing to sign an informed consent. Concomitant medication other than anti-TNFs and other biologicals is allowed and the treating rheumatologist can adjust it on the best interest of the patients. This study has, thus, no impact on the routine treatment of the patients. Concomitant medication will be recorded and considered in the final analysis. 