The absolute neutrophil count (ANC) is a laboratory test that measures the number of neutrophils, a type of white blood cell, in a sample of blood. Neutrophils are an important component of the body’s immune system and are involved in fighting infections caused by bacteria and fungi.
The ANC is typically reported as the number of neutrophils per microliter (µL) of blood. Normal ANC values range from 1,500 to 8,000 cells/µL. The ANC is used to assess the risk of infection in individuals who are undergoing chemotherapy or radiation therapy for cancer, as these treatments can suppress the bone marrow’s ability to produce neutrophils and increase the risk of developing infections.
An ANC below 500 cells/µL is considered severe neutropenia and places the individual at high risk for bacterial and fungal infections. Treatment for neutropenia may include growth factor therapy to stimulate the production of neutrophils or prophylactic antibiotics to prevent infections. In some cases, hospitalization may be necessary.
The ANC can also be used to monitor individuals with certain types of infections, such as bacterial meningitis or sepsis, as the ANC can provide an indication of the body’s response to the infection. In these cases, a high ANC may indicate an active infection, while a low ANC may indicate a compromised immune system.
In addition to chemotherapy and radiation therapy, other factors that can affect the ANC include certain medications, viral infections, autoimmune disorders, and congenital disorders such as severe congenital neutropenia. An ANC that is persistently low or high may warrant further evaluation to determine the underlying cause and appropriate treatment.