CONTRIBUTION OF PLASMA-CORTISOL TO CORTICOSTEROID-SUPPRESSED PERIPHERAL-BLOOD NATURAL-KILLER-CELL ACTIVITY IN CROHNS-DISEASE

We recently showed that patients with active ileocecal Crohn's disease (CD) have a temporarily suppressed peripheral blood natural killer (N K) cell activity during treatment with oral budesonide or prednisolone . This suppression was caused by a decrease in the number of CD16(+) N K cells in the circulation. In the present study we evaluated the cont ribution of cortisol in plasma to this suppressed NK cell activity. Th e CD patients took part in a controlled study where they received eith er oral budesonide or prednisolone for 10 weeks. Before treatment, and at 4 and 10 weeks of treatment, peripheral blood NK cell activity, nu mbers of circulating CD16(+) NK cells, and plasma cortisol levels were analysed. These parameters were determined both before and 30 min aft er administration of adrenocorticotropic hormone (ACTH). The ACTH-indu ced plasma cortisol increase was accompanied by a stimulated NK cell a ctivity, when both are suppressed by corticosteroid treatment, without changing the number of CD16(+) NK cells. Therefore, a low plasma cort isol level contributes to the corticosteroid mediated NK cell suppress ion in active ileocecal CD.