Serum Granulocyte Colony-Stimulating Factor Levels in Chronic Neutropenia of Infancy

Abstract
Eight infants with chronic neutropenia ranging in age from 1 to 13 months were studied for serum granulocyte colony-stimulating factor (G-CSF) levels. Serum G-CSF levels were elevated, especially when peripheral blood absolute neutrophil counts (ANC) were under 500/.mu.l in seven patients with autoimmune neutropenia. On the other hand, in a patient with congential agranulocytosis (Kostmann (type), G-CSF levels were below the sensitivity of the assay (< 50 pg/ml) despite severe neutropenia (< 100/.mu.l).