SUBSTANCE-P IN THE SERUM OF PATIENTS WITH RHEUMATOID-ARTHRITIS

Serum substance P was assayed in rheumatoid arthritis patients and hea lthy controls to evaluate whether neurogenic inflammation with substan ce P release is significant in rheumatoid arthritis. A very sensitive competitive immunoenzymetric assay was used. Mean serum substance P le vel was significantly higher in rheumatoid arthritis patients than in controls and was not correlated with disease duration, morning stiffne ss duration, Thompson's articular index, Larsen's radiographic score, or the following laboratory indices of inflammation: erythrocyte sedim entation rate, C-reactive protein, and alpha 1-acid glycoprotein. Neur ogenic inflammation with substance P release may contribute significan tly to the pathogenesis of rheumatoid arthritis. The absence of correl ations between serum substance P and clinical or laboratory indices of inflammation may reflect complex interactions between neurogenic infl ammation and other pathogenic mechanisms, which may influence clinical features and laboratory tests in rheumatoid arthritis patients.