1. Signed Written Informed Consent. Before any study procedures are performed,subjects will have the details of the study described to them, and they will be given a written informed consent document to read. Then, if subjects consent to participate in the study, they will indicate that consent by signing and dating the informed consent document in the presence of trained study personnel.
4. For preclinical cohort: Individuals with positivity for ACPA or IgM/IgA RF without clinical signs of arthritis, whose positivity is not related to other concomitant pathologic conditions.
5. For naive to treatment cohort: RA patients without previous exposure to conventional DMARDs or biologic/targeted synthetic-DMARDs.
6. For resistant to treatment cohort: RA patients with failure to previous conventionalDMARDs for inadequate response or side effects.
7. For remission RA cohort: RA patients in sustained clinical and ultrasound remission as stated in section 3.3.1.
8. For healthy control cohort: Healthy donors will be aged from 18 to 70 years.
You may not be if
1. Severe and uncontrolled infections such as sepsis and opportunistic infections.
2. Patients who are currently included in any interventional clinical trial in RA.
