No association between serum adenosine deaminase activity and disease activity in Crohn's disease.

BACKGROUND: Adenosine deaminase activity is proposed as a marker of inflammation in some inflammatory conditions. AIMS: To investigate the association of serum adenosine deaminase activity and disease activity in Crohn's disease patients.
METHODS: In a cross-sectional study, 30 consecutive known cases of Crohn's disease (15 with active disease and 15 in remission) referring to a university hospital in Tehran (Iran) and 15 age- and gender-matched healthy controls were studied. Disease activity was assessed using the Crohn's disease activity index (cutoff >150). Total serum adenosine deaminase activity, C-reactive protein, erythrocyte sedimentation rate, and fecal calprotectin were evaluated in patients. Serum adenosine deaminase activity was measured in controls.
RESULTS: Mean age of the patients was 36.8 ± 12.6 years, and 56.7 % were male. Serum adenosine deaminase activity in patients with active disease, patients in remission, and controls was 12.3 ± 5.9, 14.6 ± 6.2, and 11.9 ± 6.4 U/L, respectively (P = 0.458). Compared with patients in remission, those with active disease had higher erythrocyte sedimentation rate (40.4 ± 30.6 vs. 16.9 ± 16.0 mm/h, P = 0.014) and higher frequency of positive C-reactive protein (66.6 vs. 13.3 %, P = 0.004) and positive fecal calprotectin tests (86.6 vs. 33.3 %, P = 0.004). Serum adenosine deaminase activity was not correlated with erythrocyte sedimentation rate (r = 0.05, P = 0.761) and was not different between patients with positive and negative C-reactive protein (12.2 ± 5.4 vs. 14.2 ± 6.5 U/L, P = 0.393) and fecal calprotectin tests (11.7 ± 5.3 vs. 16.0 ± 6.5 U/L, P = 0.063).
CONCLUSIONS: In patients with Crohn's disease, serum adenosine deaminase activity is not associated with clinical disease activity or with other inflammation markers and cannot be suggested as an inflammation marker.