P238. Diagnostic value of serum adenosine deaminase levels in patients with inflammatory bowel diseases
C. Gonen1, Y. Gokden1, A. Salturk1, K. Kochan1, S. Ozkara2, 1Haydarpasa Numune Training and Research Hospital, Department of Gastroenterology, Istanbul, Turkey, 2Haydarpasa Numune Training and Research Hospital, Department of Pathology, Istanbul, Turkey
Adenosine deaminase (ADA) is a purine catabolic enzyme, and has been considered as a marker of T-cell activation. Serum ADA activity has been shown to increase in inflammatory conditions. The aim of this study was to investigate the diagnostic value of serum ADA levels in patients with inflammatory bowel diseases (IBD).
A total of 92 patients with IBD (43 Crohn's disease [CD] and 49 ulcerative colitis [UC]), and 31 healthy controls (HC) were included in this study. Haematological and biochemical parameters were determined for both patients and controls. Serum ADA levels were studied by spectrophotometric analysis. UC patients were classified as inactive, if endoscopic Mayo scores less than 3 and Rachmilewitz Clinical Activity Index less than 5. CD patients with Crohn's Disease Activity Index <150 and endoscopic SES-CD <3 were classified as inactive.
Serum ADA levels were elevated significantly in IBD patients (median 24.77 U/L, range 9.6–74.9 U/L) compared to the HC group (median 20.8 U/L, 13.8–38.9 U/L) (p:0.0013). Although there were no difference between UC (median 23.8, 9.6–43) and CD patients (median 26.5, 13.8–74.9), serum ADA levels were significantly higher in both groups compared to controls (p: 0.02). Serum ADA levels were increased significantly in active UC patients (median 25.65, 9.6–43) when compared to inactive UC patients (median 20.9, 11–28.7), and controls (p < 0.005). When a cut off level of 21.64 U/L was used with a confidence interval of 77%, to distinguish active UC from inactive patients, a sensitivity of 89% and a specifity of 60% have been reached. There were no significant correlation between serum ADA levels and disease extent or localization.
Serum ADA levels were found to be elevated in IBD patients when compared to healthy controls suggesting a partial role of activated T-cell activity in the disease pathogenesis. Serum ADA activity can be used as an alternative marker to identify IBD patients, and to discriminate active and inactive UC patients. Further studies are needed to investigate the role of ADA activity measurement for disease diagnosis, and activity assesment.