The Diagnostic Value of Anti-Cyclic Citrullinated Peptide Antibodies, Adenosine Deaminase Activity and Other Potential Biomarkers for Predicting and Monitoring Rheumatoid Arthritis

The aim of this study was to investigate the presence of anti-cyclic citrullinated peptide antibodies (anti-CCP2) in RA and non-RA patients and to evaluate the combination of these auto-antibodies with some other markers such as RF and CRP. We examined the enzymatic activity of ADA in RA patients without therapy and RA patients treated with methotrexate. Therefore, the aim of this study was also to assess the possibility of introducing these biochemical parameters in the diagnosis and monitoring of the RA patients in this region. Serum antibodies directed to cyclic citrullinated peptide were analyzed using an anti-CCP2 antibody ELISA. Serum ADA activity was measured by a spectrophotometer using adenosine as substrate (Giusti method). Rheumatoid factor (IgG-RF) was analyzed using a latex agglutination test. Serum CRP was measured by an immunoturbidimetric assay. The measurement of anti-CCP2 by itself, is useful for the diagnosis of RA for its high sensitivity and specificity, however, a combined use of anti-CCP2 with RF is much more useful. Serum ADA activity can be used as a biochemical marker of inflammation in RA. Measuring CRP in the RA patients has no diagnostic value. Cilj rada je bio utvrđivanje prisustva anticikličnih citruliniranih peptidnih antitela (anti-CCP2) kod pacijenata sa i bez reumatoidnog artritisa (RA) i poređenje tih auto-antitela s drugim markerima kao što su reumatoidni faktor (RF) i C-reaktivni protein (CRP). Određivana je katalitička aktivnost adenozin deaminaze (ADA) u serumima pacijenata sa reumatoidnim artritisom, bez terapije i sa terapijom metotreksatom. Cilj rada bio je i utvrđivanje mogućnosti uvođenja navedenih biohemijskih parametara u dijagnostikovanje i praćenje reumatoidnog artritisa u našu regiju. Anti-CCP2 su analizirana ELISA testom, katalitička aktivnost ADA određivana je spektrofotometrijskom metodom uz adenozin kao supstrat. RF je određivan Latex testom. CRP je meren imunoturbidimetrijskom metodom. Određivanje anti-CCP2 je korisno u dijagnostikovanju RA zbog visoke osetljivosti i specifičnosti, međutim, kombinovano određivanje anti-CCP2 sa RF je mnogo korisnije. Katalitička aktivnost ADA u serumu može da se koristi kao marker upalnog procesa u RA. Određivanje CRP u serumu pacijenata sa RA nema dijagnostički značaj.