Positive Correlation of Fecal Calprotectin With Serum Antioxidant Enzymes in Patients With Inflammatory Bowel Disease: Accidental Numerical Correlation or a New Finding?

Background: Oxidative stress occuring in patients diagnosed with inflammatory bowel disease (IBD), but the relationship between oxidative stress, disease activity and inflammatory markers has not been well established.

Materials And Methods: A total of 30 patients diagnosed with IBD and 30 volunteers who had normal colonoscopies, selected as controls, were used for this study. The serum levels of antioxidant enzymes (catalase and glutathione peroxidase) and oxidative markers (malondialdehyde [MDA] and total antioxidant capacity) were compared between the 2 groups. Furthermore, their correlations with disease activity scores and inflammatory markers, especially the fecal calprotectin, were examined.

Results: Catalase and glutathione peroxidase concentrations were significantly correlated with the level of fecal calprotectin in patients with IBD. Nevertheless, there were no significant correlations between the concentrations of the above-mentioned enzymes and C-reactive protein, erythrocyte sedimentation rate or the activity scores of IBD patients. It should be noted that MDA and total antioxidant capacity levels did not correlate with the inflammatory markers or the disease activity scores.

Conclusions: There was a positive correlation between fecal calprotectin and serum antioxidant enzymes in patients with IBD, but, there was no correlation between antioxidant and oxidative markers in terms of disease activity scores. Hence, the observed significant correlation between the antioxidant enzymes and the fecal calprotectin may be due to either the pro-oxidant potential of calprotectin or its antioxidant role.