RELATIONSHIP BETWEEN GLUCOCORTICOID RECEPTOR AND RESPONSE TO GLUCOCORTICOID THERAPY IN ULCERATIVE-COLITIS

PURPOSE: To clarify the relationship between the glucocorticoid recept or and the effectiveness of glucocorticoid therapy in patients with ul cerative colitis, we investigated the number and apparent dissociation constant of glucocorticoid receptor in peripheral blood mononuclear l eukocytes of patients with ulcerative colitis. MATERIALS AND METHODS: Eleven patients with ulcerative colitis (5 who responded to intravenou s glucocorticoids and 6 who did not) and ten control subjects were stu died. The number and apparent dissociation constant of glucocorticoid receptor were measured using a whole-cell binding assay. Results were expressed as a median (interquartile range). RESULTS: The number of gl ucocorticoid receptors from the six nonresponders, five responders, an d ten healthy controls were 4922 (range, 4484-5643), 3413 (range, 3183 -4450), and 3610 (range, 2594-3979) binding sites/cell, respectively. The apparent dissociation constant of the glucocorticoid receptors fro m the nonresponders, responders, and healthy controls were 7.03 (range , 5.66-10), 4.27 (range, 4-5.13), and 6.18 (range, 5.86-6.74) nM, resp ectively. Nonresponders had a significant increase both in the number of binding sites and in the apparent dissociation constant compared wi th responders (P = 0.045; P = 0.029). CONCLUSIONS: The increased numbe r and apparent dissociation constant of glucocorticoid receptor are cl osely associated with the effectiveness of glucocorticoid therapy. The measurement of the number and apparent dissociation constant of gluco corticoid receptor may be useful in predicting response to glucocortic oids.