RESUMO
Rheumatoid arthritis [RA] is a chronic inflammatory disease of unknown etiology characterized by an erosive proliferative synovitis. Since the etiology of RA remains obscure, rheumatoid disease activity can only be evaluated by indirect laboratory measures. Despite the intensive efforts to make the clinical assessment more objective by applying numerical grades and indices, a relevant, reliable and reproducible method to quantitate rheumatoid activity is still needed. The pathogenesis of RA is complex involving many cells and cytokines. Neopterin, a pyrazino-pyrimidine derivative from gua-nosine triphosphate, was found to be an excellent biochemical marker for the invivo activation state of cell-mediated immunity. The aim of the present work was to study the monocyte/macrophage activation in RA patients by measuring neopterin concentration in serum and synovial fluid to test the efficacy of this new biochemical parameter in reflecting rheumatoid disease activity. 47 RA patients and 25 controls were included in this study Neopterin as well as other routine laboratory investigations were performed on the serum and synovial fluid [when applicable]. The results of this work showed that serum neopterin is significantly higher in RA patients than normal controls. Both serum and synovial fluid neopterin correlated strongly with the activity of the disease. Serum levels increased significantly as the disease becomes more active. If has been concluded that neopterin measurement can be used as a parameter of rheumatoid disease activity