AUTOANTIBODIES DETECTION IN AN EARLY ARTHRITIS CLINIC: DIAGNOSTIC VALUE FOR RHEUMATOID ARTHRITIS?

C. Resende , A. Hernandez , J.M. Tarrio , S. Muñoz , R. Alvarez-Doforno , S. Ramiro , M. Lozano , D. Pascual-Salcedo , A. Balsa , E. Martin-Mola Unit of Rheumatology, Hospital Santa Maria, Lisboa, Portugal, Service of Rheumatology, Service of Immunology, Hospital Universitario La Paz, Madrid, SpainObjectives: To investigate the value for the diagnosis of rheumatoid arthritis (RA), in an early arthritis of the detection of the following autoantibodies: rheumatoid factor (RF), anti citrullinated peptide antibodies (anti-CCP), antikeratin antibodies (AKA), antiperinuclear factor (APF) and anti-RA33.Methods: We studied 141 patients with arthritis of less than 6 months of duration (43 RA and 98 with other pathologies). Osteoarthritis, microcristalines, infectious and traumatic causes as well as juvenile arthritis were excluded. In the baseline visit, serum was extracted and the presence and title of RF, AKA, anti-CCP, anti-RA33 and APF were determined. Their presence was later correlated with the clinical diagnosis.Results: In RA, RF was present in 32 (74,4%) patients, anti-CCP in 30 (73,2%), AKA and APF in 21 (48,8%) and RA33 in 10 (23,3%) patients. In the 11 patients who were RF negative anti-RA33 was present in 3 and APF, AKA and t anti CCP in 2 patients. The combination of some of them (APF, AKA or anti-CCP) was present in 4 patients (36,4%). The patients with higher titles of RF had higher frequency of AKA, FAP, anti CCP and RA33 (p <0,05 in all cases).All the antibodies were significantly associated with the RA diagnosis, but the RF O.R. 68,4 (95% IC 20,3 - 229,9) and the anti CCP O.R 45,8 (95% IC 14 - 142,3) were the most significant. All combinations of antibodies were associated with but none was better than isolated RF. By logistical regression analysis for steps with the diagnosis of RA like dependent variable, the RF and the anti CCP were the only ones that entered in the pattern.Conclusion: RF was the autoantibody with more value for the diagnosis of the RA, followed by the anti CCP. No autoantibodies combination was better than isolated RF determination.Citation: , volume , supplement , year 2003, page Session: Rheumatoid arthritis – Clinical aspects