From Wikipedia, the free encyclopedia

Agranulocytosis
Classification & external resources

ICD-10	D70.
ICD-9	288.0

Agranulocytosis (literally meaning an decrease of agranulocytes or more commonly, a lack of granulocytes) is an acute condition involving a severe and dangerous leukopenia (reduction in the number of white blood cells) in the body. Concentrations of granulocytes (a class which includes neutrophils, basophils and eosinophils) can often drop to below 500 cells/mm³ of blood), less than a sixth of the reference value of 3-10 x 10³ cells/mm³.

Contents 1 Signs and symptoms 2 Diagnosis 3 Classification 4 Treatment 5 See also

Agranulocytosis may be asymptomatic, but may clinically present with sudden fever, rigors and sore throat. Infection of any organ may be rapidly progressive (e.g. pneumonia, urinary tract infection). Septicaemia may develop.

A large number of drugs have been associated with agranulocytosis, including antiepileptics, antithyroid drugs (carbimazole and methimazole), antibiotics (penicillin, chloramphenicol and co-trimoxazole), cytotoxic drugs, gold, NSAIDs (indomethacin, naproxen, phenylbutazone) some antipsychotics (the atypical antipsychotic clozapine), whose users must be nationally registered for monitoring of low WBC and ANC, and the antidepressant mirtazapine (Remeron). Although the reaction is generally idiosyncratic rather than proportional, experts recommend that patients be told about the symptoms of agranulocytosis (generally starting with a sore throat and a fever).^{[citation needed]}

Neutropenia and agranulocytosis is associated 100% with gum disease.

The diagnosis is made on a full blood count, a routine blood test performed frequently in general practice and especially in hospital setting.

The neutrophil count is below 500 and can reach 0 cells/mm3. Other series are generaly spared. The myelogram (bone marrow sample) shows normocellular blood marrow with promyelocyte's maturation arrest. To formally diagnose agranulocytosis, other pathologies with a similar presentation must be excluded, such as aplastic anemia, paroxysmal nocturnal hemoglobinuria, myelodysplasia and acute leukemia; this generally requires a bone marrow examination.

The terms "agranulocytosis", granulocytopenia, and neutropenia are often used interchangeably, although "agranulocytosis" implies a more severe deficiency than "granulocytopenia", and "neutropenia" implies a deficiency of neutrophils only. The following terms can be used to specify the type of granulocyte referenced:

• neutrophil -- neutropenia
• eosinophil -- eosinopenia - not commonly used
• basophil -- basopenia - very rarely used

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

Infection in patients with low white blood cell counts is generally treated urgently, and usually includes a broad-spectrum penicillin or cephalosporin (piperacillin-tazobactam, ceftazidime or ticarcillin clavulanate) or meropenem in combination with gentamycin or amikacin.^{[citation needed]}

If the patient remains febrile after 4-5 days and no causative organism for the infection has been identified, antibiotics are generally changed to a glycopeptide (e.g. vancomycin), and subsequently an antifungal agent (e.g. amphothericin B) is added to the regimen.^{[citation needed]} In agranulocytosis, the use of recombinant G-CSF (filgrastim) often results in hematologic recovery.^{[citation needed]}

• Complete blood count
• Granulocytosis