Leukocytosis

Leukocytosis
SpecialtyInfectious disease, pathology

Leukocytosis is a condition in which the white cell (leukocyte) count is above the normal range in the blood.[1][2] It is frequently a sign of an inflammatory response,[3] most commonly the result of infection, but may also occur following certain parasitic infections or bone tumors as well as leukemia. It may also occur after strenuous exercise, convulsions such as epilepsy, emotional stress, pregnancy and labor, anesthesia, as a side effect of medication (e.g., lithium), and epinephrine administration.[1] There are five principal types of leukocytosis:[4]

  1. Neutrophilia (the most common form)[5]
  2. Lymphocytosis
  3. Monocytosis
  4. Eosinophilia
  5. Basophilia

This increase in leukocyte (primarily neutrophils) is usually accompanied by a "left upper shift" in the ratio of immature to mature neutrophils and macrophages. The proportion of immature leukocytes increases due to proliferation and inhibition of granulocyte and monocyte precursors in the bone marrow which is stimulated by several products of inflammation including C3a and G-CSF. Although it may indicate illness, leukocytosis is considered a laboratory finding instead of a separate disease. This classification is similar to that of fever, which is also a test result instead of a disease.[citation needed] "Right shift" in the ratio of immature to mature neutrophils is considered with reduced count or lack of "young neutrophils" (metamyelocytes, and band neutrophils) in blood smear, associated with the presence of "giant neutrophils". This fact shows suppression of bone marrow activity, as a hematological sign specific for pernicious anemia and radiation sickness.[6]

A leukocyte count above 25 to 30 × 109/L is termed a leukemoid reaction, which is the reaction of a healthy bone marrow to extreme stress, trauma, or infection. It is different from leukemia and from leukoerythroblastosis, in which either immature white blood cells (acute leukemia) or mature, yet non-functional, white blood cells (chronic leukemia) are present in peripheral blood. [citation needed]

  1. ^ a b Rogers, Kara, ed. (2011), "Leukocytosis definition", Blood: Physiology and Circulation, Chicago: Britannica Educational Publishing, p. 198, ISBN 978-1-61530-250-5, retrieved 12 November 2011
  2. ^ TheFreeDictionary > Leukocytosis Citing: Gale Encyclopedia of Medicine, 2008 and The American Heritage Medical Dictionary, 2007
  3. ^ Porth, Carol Mattson (2011), "White blood cell response", Essentials of Pathophysiology: Concepts of Altered Health States (3rd ed.), Philadelphia: Wolters Klower Health/Lippincott Williams & Wilkins, pp. 64–65, ISBN 978-1-58255-724-3, retrieved 13 November 2011
  4. ^ Zorc, Joseph J, ed. (2009), "Leukocytosis", Schwartz's Clinical Handbook of Pediatrics (4th ed.), Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins, p. 559, ISBN 978-0-7817-7013-2, retrieved 12 November 2011
  5. ^ Schwartz, M. William, ed. (2003), "Leukocytosis", The 5-Minute Pediatric Consult (3rd ed.), Philadelphia: Lippincott Williams & Wilkins, p. 54, ISBN 0-7817-3539-4, retrieved 12 November 2011
  6. ^ Lutan, Vasile. Fiziopatologie medicală. Vol. 2, 31.3.2.1. Leucocitozele; "Cartea electronică: Lutan, Vasile. Fiziopatologie medicală. Vol. 2". Archived from the original on 2012-03-27. Retrieved 2011-09-25.