Alterations of Leukocyte and Lymphoid Function PDF

CHAPTER 30 Alterations of Leukocyte and...

CHAPTER 30 Alterations of Leukocyte and Lymphoid Function Kathryn L. McCance, Neal S. Rote http://evolve.elsevier.com/McCance/ Content Updates Chapter Summary Review Review Questions Case Studies Animations CHAPTER OUTLINE Alterations of Leukocyte Function, 963 Lymphadenopathy, 976 Quantitative Alterations of Leukocytes, 963 Malignant Lymphomas, 976 Infectious Mononucleosis, 966 Plasma Cell Malignancies, 983 Lymphoid Neoplasm: Leukemias, 968 Alterations of Splenic Function, 988 Alterations of Lymphoid Function, 976 Disorders involving leukocytes range from deficiencies in the quality Chapter 9.) Other leukocyte alterations include infectious mononucleosis and quantity of leukocytes (leukopenia) to increased numbers of and cancers of the blood—leukemia and multiple myeloma. leukocytes (leukocytosis) in response to infections or proliferative disorders, such as leukemia. Many hematologic disorders are malignancies, Quantitative Alterations of Leukocytes and many nonhematologic malignancies act like malignancies and can Leukocytosis is a leukocyte count that is higher than normal; conversely, metastasize to bone marrow, affecting leukocyte production. Because leukopenia is a count that is lower than normal. Leukocytosis or of the complexity of hematologic disorders a large portion of this chapter leukopenia may affect all cell types or only a specific type of leukocyte is devoted to malignant disease. and may result from a variety of physiologic conditions and alterations. Leukocytosis occurs as a normal protective response to physiologic stressors, such as infection, strenuous exercise, emotional changes, ALTERATIONS OF LEUKOCYTE FUNCTION temperature changes, anesthesia, surgery, pregnancy, and some drugs, Leukocyte function is affected if too many or too few white cells are hormones, and toxins. It is also caused by pathologic conditions, such present in the blood or if the cells that are present are structurally or as malignancies and hematologic disorders. Leukopenia is never normal functionally defective. Quantitative leukocyte disorders, such as infec- and is defined as an absolute blood cell count less than 4000 cells/μL. tions and leukemias, result from decreased production in the bone Leukopenia is associated with a decrease in the number of neutrophils, marrow or accelerated destruction of cells in the circulation. Other which increases the risk for infection. The absolute neutrophil count quantitative alterations, however, occur in response to infections. (ANC) is calculated by multiplying the white blood cell count by the Qualitative leukocyte disorders consist of disruptions of leukocyte percent of band and segmented neutrophils. The ANC is classiied as function. Phagocytic cells (granulocytes, monocytes, macrophages) may mild (1000 to 1500 cells/μL), moderate (500 to 1000 cells/μL), or severe lose their phagocytic capacity to function. Lymphocytes may lose their (