Monocyte cellular function in asthmatic patients on alternate-day steroid therapy.

Monocyte cellular function in 15 asthmatics on alternate-day steroid therapy (mean dose of prednisone, 45.4 +/- 17.45 mg qod) was studied at 8 A.M. and noon after receiving an 8 A.M. steroid dose and at 8 A.M. the following day, and was contrasted to function in 16 healthy controls. Monocyte chemotaxis, bacterial killing and phagocytosis, and oil phagocytosis were not significantly altered by the steroid dose. On the other hand, all the patients experienced monocytopenia, lymphopenia, and neutrophilia 4 hr following the administration of steroid. The lack of functional impairment on this clinically relevant steroid regimen is consistent with the lack of serious infections seen in patients on such regimens. This study re-enforces the need to differentiate the effect of even small doses of steroid on circulating cell populations from direct effects on cell function which occur only with very high or frequent steroid dose regimens.