Background:
The aim of this study was to assess the activity of eosinophils, neutrophils, and CD4þ as well as CD8þ T-cells in 11 patients with active collagenous colitis (CC) before and after 8 weeks of budesonide treatment (9 mg once daily) compared to 10 healthy individuals.
Methods: Clinical symptoms were recorded and intestinal biopsy samples were taken and analyzed by flow cytometry. Eosinophils with a high surface expression of CD44 and low CD9 expression were classified as activated. Neutrophil activity was assessed by their expression of CD66b, and CD69 was used as an activation marker for T-cells.
Results: All patients responded to the treatment. The eosinophils in active CC showed increased activity compared to controls. The activity was back to control levels after treatment. Neutrophils were not activated in CC patients before or after treatment. CD8þ T-cells from untreated CC patients had a lower activity than controls, and a tendency of lower activity was observed on CD4þ T-cells. After treatment, the activity was increased on both types of T-cells and was not different from controls.
Conclusions:
In the present study we demonstrated that the inflammation in CC is characterized by activated eosinophils but there is no neutrophil activity. CD4þ and CD8þ T-cells are increased in numbers in active CC but, surprisingly, they had a lower grade of activity than in control subjects. The major finding of this study is that budesonide treatment restores the normal activation of eosinophils and T-cells, accompanied by clinical remission.