Neutropenia: Is a decrease in circulating neutrophils

Neutropenia is a decrease in circulating neutrophils in the nonmarginal pool, which constitutes 4-5% of total body neutrophil stores. Most of the neutrophils are contained in the bone marrow, either as mitotically active (one third) or postmitotic mature cells (two thirds). Neutropenia is an abnormally low number of neutrophils (a type of white blood cell) in the blood. Neutropenia, if severe, significantly increases the risk of life-threatening infection. Neutropenia is often a side effect of the treatment of cancer with chemotherapy or radiation therapy. Neutropenia, or a state of low neutrophils, in itself has a wide differential that includes a primary disorder of production in the bone marrow, genetic deficiency, and cyclical deficiency. Additional causes of primary neutropenia include malignant disorders of marrow failure, such as leukopenia, or infiltrative hematologic neoplasms, such as high-grade lymphoma. Neutropenia can also be secondary to marrow extrinsic causes, including autoimmune diseases, cytotoxic chemotherapy, or ... Neutrophils make up the majority of WBCs and are formed in the bone marrow. They are the “first responders” and quickly appear at the site of infection, ingesting and destroying foreign particles. They can be found in the pus of a wound and play a role in acute inflammation (redness, warmth, swelling, and pain). A normal neutrophil count (also called absolute neutrophil count or ANC) is between 2500 and 5000. A low neutrophil count is known as neutropenia. Neutropenia can be caused by a ...