Cyclic neutropenia

Cyclic neutropenia is a rare blood disorder and a form of congenital neutropenia. The bone marrow changes its rate of neutrophil production, so the neutrophil count falls to a low point roughly every three weeks and stays low for a few days at a time. Neutrophils make up most of the circulating white blood cells, so each low phase puts the body at serious risk of inflammation and infection. In contrast to severe congenital neutropenia, the condition responds well to treatment with granulocyte colony-stimulating factor, also called filgrastim, which raises the neutrophil count, shortens the length of each cycle and lowers both the severity and the frequency of infections.