World Library  
Flag as Inappropriate
Email this Article


Article Id: WHEBN0000185373
Reproduction Date:

Title: Agranulocytosis  
Author: World Heritage Encyclopedia
Language: English
Subject: Clozapine, Atypical antipsychotic, Metiamide, Levamisole, Antipsychotic
Collection: Monocyte and Granulocyte Disorders
Publisher: World Heritage Encyclopedia


Classification and external resources
Specialty Hematology
ICD-10 D70
ICD-9-CM 288.0
DiseasesDB 8994
MedlinePlus 001295
MeSH D000380

Agranulocytosis, also known as agranulosis or granulopenia, is an acute condition involving a severe and dangerous leukopenia (lowered white blood cell count), most commonly of neutrophils causing a neutropenia in the circulating blood.[1][2] It is a severe lack of one major class of infection-fighting white blood cells. People with this condition are at very high risk of serious infections due to their suppressed immune system.

In agranulocytosis, the concentration of granulocytes (a major class of white blood cells that includes neutrophils, basophils, and eosinophils) drops below 500 cells/mm³ of blood.


  • Classification 1
  • Signs and symptoms 2
  • Causes 3
  • Diagnosis 4
  • Treatment 5
  • See also 6
  • References 7


The term "agranulocytosis" derives from the Greek: a, meaning without; granulocyte, a particular kind of white blood cell (containing granules in its cytoplasm); and osis, meaning condition [esp. disorder]. Consequently, agranulocytosis is sometimes described as "no granulocytes", but a total absence is not required for diagnosis. However, "-osis" is commonly used in blood disorders to imply cell proliferation (such as in "leukocytosis"), while "-penia" to imply reduced cell numbers (as in "leukopenia"); for these reasons, granulopenia is a more etymologically consistent term, and as such, is sometimes preferred to "agranulocytosis" (which can be misinterpreted as "agranulocyt-osis", meaning proliferation of agranulocytes (i.e. lymphocytes and monocytes). Despite this, "agranulocytosis" remains the most widely used term for the condition.

The terms agranulocytosis, granulocytopenia and neutropenia are sometimes used interchangeably. Agranulocytosis implies a more severe deficiency than granulocytopenia. Neutropenia indicates a deficiency of neutrophils (the most common granulocyte cell) only.

To be precise, neutropenia is the term normally used to describe absolute neutrophil counts (ANCs) of less than 500 cells per microlitre, whereas agranulocytosis is reserved for cases with ANCs of less than 100 cells per microlitre.

The following terms can be used to specify the type of granulocyte referenced:

Signs and symptoms

Agranulocytosis may be pneumonia, urinary tract infection). Septicemia may also progress rapidly.


A large number of drugs[3] have been associated with agranulocytosis, including Aubagio immunomodulatory agent with anti-inflammatory properties, antiepileptics, antithyroid drugs (carbimazole, methimazole, and propylthiouracil), antibiotics (penicillin, chloramphenicol and co-trimoxazole), cytotoxic drugs, gold, NSAIDs (indomethacin, naproxen, phenylbutazone, metamizole), mebendazole, allopurinol[4] the antidepressant mirtazapine, and some antipsychotics (the atypical antipsychotic clozapine[5]). Clozapine users in the United States, Canada, and the UK must be nationally registered for monitoring of low WBC and absolute neutrophil counts (ANC).

Although the reaction is generally idiosyncratic rather than proportional, experts recommend that patients using these drugs be told about the symptoms of agranulocytosis-related infection, such as a sore throat and a fever.

The Centers for Disease Control traced outbreaks of agranulocytosis among cocaine users, in the US and Canada between March 2008 and November 2009, to the presence of levamisole in the drug supply. The Drug Enforcement Administration reported that, as of February 2010, 71% of seized cocaine lots coming into the US contained levamisole as a cutting agent.[6] Levamisole is an antihelminthic (i.e. deworming) drug used in animals. The reason for adding levamisole to cocaine is unknown,[7] although it can be due to their similar melting points and solubilities.


The diagnosis is made after a complete blood count, a routine blood test. The absolute neutrophil count in this test will be below 500, and can reach 0 cells/mm³. Other kinds of blood cells are typically present in normal numbers.

To formally diagnose agranulocytosis, other pathologies with a similar presentation must be excluded, such as aplastic anemia, paroxysmal nocturnal hemoglobinuria, myelodysplasia and leukemias. This requires a bone marrow examination that shows normocellular (normal amounts and types of cells) blood marrow with underdeveloped promyelocytes. These underdeveloped promyelocytes, if fully matured, would have been the missing granulocytes.


In patients that have no symptoms of infection, management consists of close monitoring with serial blood counts, withdrawal of the offending agent (e.g., medication), and general advice on the significance of fever.

Transfusion of granulocytes would have been a solution to the problem. However, granulocytes live only ~10 hours in the circulation (for days in spleen or other tissue), which gives a very short-lasting effect. In addition, there are many complications of such a procedure.

See also


  1. ^ eMedicine/Stedman Medical Dictionary
  2. ^ Neutropenia at eMedicine
  3. ^ Andersohn F, Konzen C, Garbe E (May 2007). "Systematic review: agranulocytosis induced by nonchemotherapy drugs". Ann. Intern. Med. 146 (9): 657–65.  
  4. ^ Elisa Mari,Franco Ricci,Davide Imberti,Massimo Gallerani (June 2011). "Agranulocytosis: an adverse effect of allopurinol treatment". Italian Journal of Medicine 5 (2): 120–3.  
  5. ^ Diaz, Jaime (1996). How Drugs Influence Behavior. Englewood Cliffs: Prentice Hall.  
  6. ^ U.S. Department of Justice; National Drug Intelligence Center (February 2010). "Colombian Cocaine Producers Increase Use of a Harmful Cutting Agent". National Drug Threat Assessment 2010. 
  7. ^ "Agranulocytosis associated with cocaine use — four States, March 2008–November 2009". MMWR Morb. Mortal. Wkly. Rep. 58 (49): 1381–5. December 2009.  
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.