BUDESONIDE AND PREDNISOLONE SUPPRESS PERIPHERAL-BLOOD NATURAL-KILLER-CELLS IN CROHNS-DISEASE

Aim: To study the effect of oral budesonide and prednisolone on peripheral blood natural killer (NK) cell activity in patients with active ileocaecal Crohn's disease (Crohn's disease activity index, CDAI greater than or equal to 200). Methods: One group of patients was treated for 10 weeks with oral budesonide (n = 9; 9 mg/day), and another group of patients for the same period with prednisolone (n = 9; 40 mg/day). Budesonide was tapered to 6 mg/day after 8 weeks and prednisolone after 2 weeks to 5 mg/day in the last week. Before treatment, and at 2, 4 and 10 weeks of treatment, natural killer cell activity was determined with a Cr-51 release assay, and the number of CD16(+) NK cells by Fluoresence activated cell sorter (FACS) analysis. Results: Budesonide, as well as prednisolone treatment, significantly decreased natural killer cell activity at weeks 2 and 4. This decrease was found to be accompanied by a similar decrease in the number of CD16(+) NK cells. At 10 weeks, natural killer cell activity had almost returned to pre-treatment levels in the budesonide group and was significantly higher than pre-treatment levels in the prednisolone group. Disease activity was significantly decreased in all patients at week 2 until the end of the trial period. Conclusion: Both budesonide and prednisolone treatment suppress peripheral blood natural killer cell activity of patients with active ileocaecal Crohn's disease by decreasing the numbers of CD16(+) NK cells in the circulation.