Correction of human cyclic neutropenia with prednisolone.

A 70-year-old woman with cyclic neutropenia was treated with 16 mg of etiocholanolone and 25 mg of prednisolone intramuscularly every other day. During 14 weeks' treatment amplitude of cyclic fluctuations in neutrophil counts gradually decreased, but pretreatment cycles returned promptly after treatment was stopped. Prednisolone alone every other day (25 mg) reproduced this result, and by 23 weeks, neutrophil counts became stable at about 1500 per cubic millimeter. tcycling of monocytes, platelets and reticulocytes was also eliminated, as were symptoms that had accompanied neutropenic periods. In addition, bone-marrow neutrophil precursors and neutrophil marrow reserves were stabilized. The patient was subsequently maintained satisfactorily with oral prednisolone, 20 mg every other day. These studies demonstrate that the discontinuous myeloid maturation that occurs in cyclic neutropenia can be corrected with prednisolone every other day.