Cyclic and chronic neutropenia: an update on diagnosis and treatment.

摘要

DD Cyclic neutropenia is a rare disease in which neutro-phils and other white blood cell counts fluctuate, usually on a 21 -day cycle. When the neutrophil count is low-and it can go down to 0 cells/muL-patients are very susceptible to infections. It is a terrible disease because patients are at risk of contracting a severe or even life-threatening infection every 3 weeks throughout their lives. Cyclic neutropenia is an autosomal-dominant disease. Multiple family members in each generation can have the disease; sometimes half the members of a family are affected. Neutropenia and its associated infections and risk of death lead to substantial medical care and hospitalization.The cause of cyclic neutropenia is almost always a mutation in ELANE, the gene that encodes neutrophil elastase. This gene is for an enzyme that is produced and packaged in the primary granules of neutrophils. The mutation causes the production of, an abnormal protein that damages the cells as they develop, leading to a failure of cell production. Among the many different mutations that can occur, some are associated with cycling of blood counts. This manifestation is probably a milder abnormality than that associated with severe congenital neutropenia, in which mutations are so severe that patients have very low blood counts all the time.