A low neutrophil count, or neutropenia, is clinically significant because neutrophils are a type of white blood cell that help fight off infection. Patients become more vulnerable to infectious diseases, especially bacterial and fungal infections, the lower their neutrophil count is, according to the Mayo Clinic.
Neutrophils are created in bone marrow and then travel throughout the body via the bloodstream to sources of infection, states WebMD. At the site of an infection, neutrophils mount an immune response by releasing chemicals that destroy the foreign bacteria and other microorganisms. Neutropenia is caused primarily by any condition that damages the structure or function of bone marrow, the source of neutrophils, such as leukemia or during chemotherapy treatment. Other causes of neutropenia include infections such as tuberculosis or hepatitis, certain prescription medications such as antibiotics or diuretics, nutritional deficiencies, and the destruction of neutrophils outside of the bone marrow such as in lupus or rheumatoid arthritis.
Low neutrophil counts generally do not cause any symptoms, unless the condition is causing a concurrent infection. Neutropenia is usually detected on a complete blood count, the Mayo Clinic reports. Mild cases of neutropenia may not require treatment. Significantly low neutrophil counts are treated by managing the underlying cause or infection, taking immunosuppressive drugs, and stimulating the bone marrow to produce more white blood cells.