Corticosteroid Administration and Localized Leukocyte Mobilization in Man

Mobilization of leukocytes into a serum-filled chamber was quantitatively measured in duplicate in normal subjects during two control periods and while they were receiving prednisone or dexamethasone. The normal mobilization of leukocytes from blood to chamber serum (71.6 X 10⁶ per square centimeter of abrasion surface per 24 hours) was slightly decreased by prednisone (62.8 X 10⁶ per square centimeter per 24 hours) but significantly increased by dexamethasone (132.3 X 10⁶ per square centimeter per 24 hours). By calculation the clearance of granulocytes from blood to serum was significantly decreased by prednisone. This difference in the effect of the two steroids may be of relevance when extravascular granulocytes are of importance in defense against bacterial invasion during corticosteroid treatment. ALTERATION by corticosteroids of leukocyte response to local inflammatory stimuli has been studied quantitatively and qualitatively in the mouse,¹ rat,^{2, 3} rabbit^{4, 5} and man,^{6, 7} with inconsistent results. Fruhman² found it necessary to employ massive doses of subcutaneous cortisol to reduce neutrophil mobilization into the peritoneal cavity of rats. Boggs et al.,⁷ in a semiquantitative study in man, employing the skin-window cover-slip technic of Rebuck,⁸ observed fourfold depression of the local inflammatory reaction with moderate doses of cortisol and prednisone. Rebuck and Mellinger⁶ earlier found depression and delay, especially of the mononuclear phase of cell exudation, with the same technical approach. A.