[Colony-stimulating activity in urine and serum in a child with cyclic neutropenia]

Colony stimulating activity (CSA) was estimated in daily urine samples and weekly plasma specimens of a 4-year-old girl with familial cyclic neutropenia. Nadirs of neutrophils and peaks of monocytes were found in regular cycles of 28 days. A close correlation was observed between nadirs of neutrophils and peaks of blood monocytes and colony stimulating activity in the urine. The role of colony stimulating factor as regulatory factor in granulopoiesis in cyclic neutropenia is discussed.