RT Book, Section A1 Lichtman, Marshall A. A1 Kaushansky, Kenneth A1 Kipps, Thomas J. A1 Prchal, Josef T. A1 Levi, Marcel M. SR Print(0) ID 1126652061 T1 Neutropenia and Neutrophilia T2 Williams Manual of Hematology, 8e YR 2011 FD 2011 PB McGraw-Hill Education PP New York, NY SN 9780071622424 LK hemonc.mhmedical.com/content.aspx?aid=1126652061 RD 2024/03/19 AB Leukopenia refers to a reduced total leukocyte count.Granulocytopenia refers to a reduced granulocyte (neutrophils, eosinophils, and basophils) count.Neutropenia refers to a reduced neutrophil count: less than 1.5 × 109/L in patients from age 1 month to 10 years, and less than 1.8 × 109/L in patients older than age 10 years. Table 31–1 outlines the classification of neutrophil disorders.Agranulocytosis literally means a complete absence of blood granulocytes but is used to indicate very severe neutropenia, usually a neutrophil count < 0.5 × 109/L.Americans of African descent (as do some other ethnic groups) have lower mean neutrophil counts than do Americans of European descent.The risk of infections is inversely related to the severity of the neutropenia: patients with qualitatively normal neutrophils and neutrophil counts of 1.0 to 1.8 × 109/L are at little risk; patients with counts of 0.5 to 1.0 × 109/L are at low or slight risk; and patients with counts less than 0.5 × 109/L are at higher risk.Patients with severe, prolonged neutropenia are at particular risk for bacterial and fungal infections.The risk is calculated not only by the neutrophil count but by complicating factors as follows:— The longer the duration of severe neutropenia, the greater the risk of infection.— The risk of infection is greater when the count is falling rapidly or when there is associated monocytopenia, lymphocytopenia, or hypogammaglobulinemia.— Neutropenia caused by disorders of hematopoietic progenitor cells (e.g., chemotherapy-induced marrow suppression, severe inherited neutropenia) generally results in a greater susceptibility to infections compared with neutropenia resulting from accelerated turnover (e.g., immune neutropenia).— Integrity of the skin and mucous membranes, blood supply to tissues, presence of an indwelling catheter, and nutritional status are also important in considering infection risk.Neutropenia can be classified as: (1) disorders of production; (2) disorders of distribution and turnover; (3) drug-induced neutropenia; and (4) neutropenia with infectious diseases.