Role of rheumatoid factor isotypes and anti-citrullinated peptide antibodies in the differential diagnosis of non-selected patients with inflammatory arthralgia.

Background/objectives: Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by swelling, tenderness and destruction of synovial joints, leading to severe disability and premature mortality. The aim of the study was to determine the diagnostic accuracy of the 3 isotypes of rheumatoid factor (RF), anti-citrullinated peptide antibodies (ACPA) and the combination of both, for the diagnosis of rheumatoid arthritis (RA) in non-selected patients with inflammatory arthralgia.

Methods: We include 129 patients with inflammatory Arthalgia from a third level reference Center of rheumatic diseases in Monterrey, México.