What is agranulocytosis?

Granulocytes, also known as neutrophils, are white blood cells that make up part of a person’s immune system. These cells contain enzymes that can kill bacteria and other organisms and break down substances that may harm the body. Without granulocytes, a person has a higher risk of developing frequent or chronic (long-term) infections.

Agranulocytosis (lack of granulocytes) is a condition in which the absolute neutrophil count (ANC) is less than 100 neutrophils per microliter of blood. Normally, there are at least 1500 neutrophils per microliter of blood.

For granulocyte (neutrophil) counts between 100 and 1500 per microliter of blood, the term “granulocytopenia” or “neutropenia” is used. This means that too few neutrophils are present. The lower the neutrophil count and the longer it remains low, the greater the risk of developing a dangerous infection.

Agranulocytosis is very serious and can be life-threatening. If it is not treated, it can lead to death, most commonly through septicemia (bacterial infection of the blood).

How common is agranulocytosis?

Agranulocytosis occurs among all age groups and in all racial groups. The acquired form is more common among older people, while the inherited form is more often seen in children. The exact frequency of the condition is not known, but the number of cases is estimated at 1 million to 3.4 million people per year.

What causes agranulocytosis?

Agranulocytosis may be acquired or inherited. In the acquired form, either the bone marrow cannot produce enough stem cells that mature into granulocytes, or granulocytes are destroyed more quickly than they can be replaced. Usually, other cell types, such as red cells or platelets, are affected, also.

There are many different causes of acquired agranulocytosis. These include:

  • Chemotherapy to treat cancer.
  • The use of some prescription drugs, particularly certain antibiotics, and anti-thyroid and anti-psychotic medications.
  • Exposure to toxic substances, such as arsenic or mercury.
  • Bone marrow failure disorders such as aplastic anemia.
  • Other medical conditions, such as tumors or some autoimmune diseases.

The congenital (present at birth) form of agranulocytosis is caused by a genetic (inherited) abnormality. Infantile genetic agranulocytosis (Kostmann disease) is a rare form of the inherited disease that is present in newborns.

What are the symptoms of agranulocytosis?

Symptoms of agranulocytosis may include:

  • Sores in the mouth, throat, or gastrointestinal tract.
  • Chronic infections of the gums, throat, or skin.
  • Fever.
  • Chills.
  • A life-threatening drop in blood pressure, which may cause weakness or lightheadedness.

Last reviewed by a Cleveland Clinic medical professional on 02/02/2017.


  • National Organization for Rare Disorders. Agranulocytosis, Acquired Accessed 2/3/2017.
  • Access Medicine Quick Medical Dx & Rx. Neutropenia Accessed 2/3/2017.
  • Ibáñez L, Vidal X, Ballarín E, et al. Population-Based Drug-Induced Agranulocytosis. Arch Intern Med. 2005;165(8):869-874. doi:10.1001/archinte.165.8.869

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy