Serum prolidase activity in ankylosing spondylitis and rheumatoid arthritis.

The aim of the present study was to emphasize the collagen turnover in 2 of the most common chronic inflammatory rheumatic diseases by evaluating serum prolidase activity (SPA) in ankylosing spondylitis (AS) and rheumatoid arthritis (RA). 30 patients who met the modified New York Criteria for the classification of AS, 29 patients who met the 2010 Rheumatoid Arthritis Classification Criteria for the classification of RA, and 31 healthy controls were enrolled in the study. Serum samples of the patients and the controls were collected and SPA was measured by a spectrophotometric method. The comparison of the SPA in these 3 groups was statistically examined. In both patient groups, the SPA was lower than in the control group. SPA in patients with AS was statistically significantly lower than in the control and RA groups (P < 0.001/P = 0.002). No statistically significant difference was found between the RA and the control groups (P = 0.891). In conclusion, lower SPA is presumably associated with decreased collagen turnover and fibrosis, leading to decreased physical functions in both chronic inflammatory musculoskeletal diseases.