Mast cells and eosinophils are involved in activation of ulcerative colitis

The intestinal mucosal immune cells such as the mast cells and eosinophils play an important role in the pathogenesis of ulcerative colitis (UC). The aim of present study was to compare the number of mast cells and eosinophils in patients with active and non-active ulcerative colitis. Another purpose was to found whether the number of eosinophils could correlate with number of mast cells in both tested groups.

The twenty-five of formalin-fixed, paraffin-embedded tissue specimens of active ulcerative colitis, the twenty of non-active ulcerative colitis and the ten of controls were retrieved from archival material. Tryptase and chymase immunopositive cells were detected using immunohistochemical method. Additionally, the number of mast cells and eosinophils were detected using the most common histochemical methods.

The number of eosinophils and toluidine blue stained and tryptase immunopositive mast cells was significantly increased in active UC compared to non-active UC. In active stage of UC positive correlation between the number of mast cells stained with toluidine blue and the number of chymase and tryptase immunopositive mast cells were observed. Moreover, the number of eosinophils was significantly correlated with number of mast cells stained with toluidine blue and number of tryptase- and chymase immunopositive mast cells. In non-active stage of UC positive correlation was observed only between the number of mast cells stained with toluidine blue and chymase immunopositive cells and eosinophils.

In conclusion, our findings confirmed that mast cells and eosinophils are functionally involved in the course of UC.