Neutropenia is a deficiency in the number of neutrophils, also known as polymorphonuclear leukocytes, or PMNs. Neutropenia is generally defined as an absolute neutrophil count <1,500/mL. Counts of <500/mL represent severe, life-threatening deficiency. Neutropenia often accompanies other disorders, but here we describe neutropenia when it occurs in isolation or as the predominant characteristic of disease. Most cases are acquired due to increased destruction of neutrophils (eg, from infections, drugs, immune defects) or decreased production of neutrophils (eg, from nutritional defects, malignancies). Chemotherapeutic treatment is a common cause of neutropenia. Some congenital disorders are also associated with neutropenia and vary in severity, from mild conditions such as benign familial or constitutional neutropenia, which may not lead to infections, to severe congenital disorders that result in serious chronic infections (Gibson, 2014). Infection-related neutropenia in children may be caused by a virus (Gibson, 2014). Laboratory testing for neutropenia includes CBC, immunoglobulin evaluation, flow cytometry, and genetic testing.
Last Update: March 2019