Rheumatoid arthritis (RA) is a systemic autoimmune disease, with chronic inflammation of synovial peripheral joints as the most prominent feature. The serum amyloid A (SAA) is one of the major acute phase proteins (APP), however its use in the clinical laboratory routine is uncommon. OBJECTIVE: The aim of this work was to analyze the usefulness of SAA in the evaluation of RA clinical activity. METHODS: We studied 113 patients diagnosed with RA according to the criteria of the American College of Rheumatology. The disease activity was evaluated by the Disease Activity Score (DAS) according to the European League Against Rheumatism. RESULTS: SAA presented positive correlation, statistically significant, with C-reactive protein (CRP), as well as α-1-acid glycoprotein (AGP) and DAS. The results demonstrated that SAA presented a higher sensibility in relation to other APP in the determination of the inflammatory activity on RA patients. SAA also shows a good capability to discriminate the groups of moderate and high activity of DAS. As DAS doesn't measure only the inflammatory behavior of RA, the determination of APP is of great usefulness for the activity characterization of this illness. CONCLUSIONS: Our data suggest that SAA can be of great value in the determination of the RA inflammatory activity.
Rheumatoid arthritis; acute phase proteins; serum amyloid A protein; Disease Activity Score (DAS)
