Clinical relevance of antibodies associated with rheumatoid arthritis

Abstract

Rheumatoid Arthritis (RA) is an inflammatory, systemic, polyarticular and autoimmune disease. Several antigens and their immunogenicity, including cartilage components, stress proteins, enzymes, nuclear proteins, as well as citrullinated and carbamylated proteins, have been characterized in this pathology. The pathogeny is really complex, and there are immunologically relevant epitopes that fluctuate throughout the disease. This makes it difficult to apply adequate therapy, even when early diagnosed. Currently, RA is diagnosed based on the criteria proposed by the American College of Rheumatology (ACR) in 2010 and the European League Against Rheumatism Collaborative Initiative. These criteria take into account the clinics of the patient, acute phase reactants (erythrocyte sedimentation rate, C reactive protein) and serological markers: rheumatoid factor (RF) and antibodies against cyclic citrullinated peptide (a-CCP). Both antibodies have been studied for years, demonstrating their association with pathogenesis, as well as prognosis, diagnosis and follow-up of RA. On the other hand, anti-carbamylated protein (anti-CarP) antibodies have been described in association with RA since 2010. Studies in a-CARP have shown that they are related to early diagnosis (years before the onset of symptoms), early prognosis, and progression of the disease. The fact that these antibodies are present in a-CCP-negative patients would indicate that the use of both markers together with RF could increase the specificity of early diagnosis.