What is agranulocytosis?

Agranulocytosis is a rare condition in which your bone marrow doesn’t make enough of a certain type of white cell, most often neutrophils. Neutrophils are a type of white blood cell that your body needs to fight off infections. They make up the largest percentage of white blood cells in your body.

Neutrophils are a critical part of your body’s immune system. They’re often the first immune cells to arrive at the site of infection. They consume and destroy harmful invaders like bacteria.

In agranulocytosis, the low level of neutrophils means that even minor infections can progress into serious ones. Weak microbes or germs that usually cause no harm suddenly can evade the body’s defenses to attack your body.

Agranulocytosis can sometimes be asymptomatic in the absence of an infection. The early symptoms of agranulocytosis may include:

  • sudden fever
  • chills
  • sore throat
  • weakness in your limbs
  • sore mouth and gums
  • mouth ulcers
  • bleeding gums

Other signs and symptoms of agranulocytosis can include:

  • fast heart rate
  • rapid breathing
  • low blood pressure
  • skin abscesses

There are two types of agranulocytosis. The first type is congenital, meaning you’re born with the condition. The second type is acquired. You can acquire agranulocytosis from certain drugs or medical procedures.

In both forms of agranulocytosis, you have a dangerously low neutrophil count. Healthy levels in adults usually fall in the range of 1,500 to 8,000 neutrophils per microliter (mcL) of blood. In agranulocytosis, you have less than 500 per mcL.

In acquired agranulocytosis, something causes your bone marrow to either fail to produce neutrophils or produce neutrophils that don’t grow into fully mature, functioning cells. It’s also possible for something to cause the neutrophils to die too quickly. In congenital agranulocytosis, you inherit a genetic abnormality that causes this.

Acquired granulocytosis can be caused by:

  • certain medications
  • exposure to chemicals, such as the insecticide DDT
  • diseases that affect bone marrow, such as cancer
  • serious infections
  • exposure to radiation
  • autoimmune diseases, such as systemic lupus erythematosus
  • nutritional deficiencies, including low levels of vitamin B-12 and folate
  • chemotherapy

A study from 1996 found that about 70 percent of cases of acquired agranulocytosis are linked to medications. Drugs that can cause agranulocytosis include:

  • antithyroid medications, such as carbimazole and methimazole (Tapazole)
  • anti-inflammatory medications, such as sulfasalazine (Azulfidine), dipyrone (Metamizole), and nonsteroidal anti-inflammatory drugs (NSAIDs)
  • antipsychotics, such as clozapine (Clozaril)
  • antimalarials, such as quinine

Women are more likely to develop agranulocytosis than men are. It can occur at any age. However, inherited forms of the condition are more often found in children, who usually pass away from this condition well before reaching adulthood. Acquired agranulocytosis occurs most frequently in older adults.

Your doctor will likely take a detailed medical history. This includes questions about recent drug treatments or illnesses. Blood and urine samples are needed to check for infection and to do a test known as a white blood cell count. Your doctor may take a marrow sample if they suspect a problem with your bone marrow.

Genetic testing is necessary to check for a hereditary form of agranulocytosis. You may need to get tested for possible autoimmune disorders.

If agranulocytosis is due to an underlying illness, that condition will be treated first.

If a drug needed for another condition causes agranulocytosis, your doctor may prescribe a substitute treatment. If you’re taking several different drugs, you may need to stop taking them. This could be the only way to find what medication is causing the problem. Your doctor will likely prescribe antibiotics or antifungal drugs to treat any infection.

A treatment called a colony-stimulating factor can be used for some people, such as those who have acquired agranulocytosis from chemotherapy. This treatment encourages the bone marrow to produce more neutrophils. It can be used along with your chemotherapy cycles.

Although not widely used, a transfusion of neutrophils may be the best temporary treatment for some people.

Because agranulocytosis makes you vulnerable to infection, it can be very dangerous if it’s left untreated. One complication of agranulocytosis is sepsis. Sepsis is an infection of the blood. Without treatment, sepsis can be fatal.

With timely treatment, the outlook for agranulocytosis is better. In many cases, the condition can be managed. People who develop agranulocytosis after a viral infection may even find that the condition resolves itself.

The only way to prevent agranulocytosis is to avoid the drugs that may cause it. If you need to take a drug known to trigger the condition, you’ll need to get regular blood tests to check your neutrophil levels. Your doctor may advise you to stop taking the drug if you have lowered neutrophil counts.