What is chronic granulomatous disease (CGD)?
Chronic granulomatous disease (CGD) is an inherited disorder that affects the immune system.
In people with this condition, phagocytes – which are types of white blood cells of the cellular immune system such as neutrophils and macrophages – are unable to attack and destroy certain microbes. Infections associated with these microbes can be life-threatening.
In people with CGD, infections often occur more commonly in the skin, lung, lymph nodes and liver. CGD can increase your risk of developing abscesses (pus-filled pockets) in the internal organs. Some people with CGD develop inflammation (swelling) at various sites in the body.
How common is CGD?
CGD is not common. Doctors diagnose it in about 1 out of every 200,000 to 250,000 people worldwide. CGD occurs more often in males than in females.
Who is at risk of developing CGD?
People who have a family member with CGD are at a higher risk of having the disease. In most cases, it is inherited. Less commonly a spontaneous genetic mutation causes it.
Symptoms and Causes
What are the symptoms of chronic granulomatous disease (CGD)?
Signs and symptoms of CGD usually appear early in childhood and very uncommonly are diagnosed in adults. They can include:
- Recurrent infections caused by bacteria and fungi
- Abscesses in the liver, lungs, skin or spleen
- Granulomas (masses of cells that develop at sites of inflammation or infection)
- Chronic abdominal pain with diarrhea, nausea and vomiting, intestinal obstruction
- Liver function test abnormalities
- Swelling in the lymph nodes (sometimes called lymph glands)
What causes CGD?
CGD is a type of genetic disorder called a primary immunodeficiency disease (PIDD). The immune system does not work properly in people with these diseases.
White blood cells are an essential part of your immune system’s defenses. People with CGD have a faulty gene that makes white blood cells called neutrophils less able to produce reactive oxygen species, in what is known as a “respiratory burst.” Without a fully functional respiratory burst, these phagocytes cannot kill certain bacteria and fungi.
The genetic mutations associated with CGD are hereditary (passed from a parent to a child). Doctors classify CGD into two types based on the gene involved:
- X-linked CGD: This most common type of the disease involves a mutation of the CYBB gene. It almost always affects males.
- Autosomal recessive CGD: Mutations in the CYBA, NCF1, NCF2, CYBC1, or NCF4 genes cause this type of CGD.
Diagnosis and Tests
How is chronic granulomatous disease (CGD) diagnosed?
Your doctor will ask about your family medical history and order several tests to diagnose CGD. These tests include:
- Physical exam: During a physical exam, doctors can look for inflammation and granulomas.
- Blood tests: Doctors use blood tests, including specialized tests called DHR or nitroblue tetrazolium, that add chemicals to a sample of blood to measure white blood cells’ ability to make reactive oxygen species
- Genetic testing: A doctor studies a sample of blood or tissue to identify a faulty gene that causes CGD.
Management and Treatment
What are the treatments for chronic granulomatous disease (CGD)?
Doctors use several different drugs to manage the symptoms of CGD:
- Antibiotics: Antibacterial drugs are used both for prophylaxis (prevention) and for treatment of acute infections
- Antifungals: Antifungal drugs such as itraconazole may be used both for prophylaxis and for treatment of acute infections
- Corticosteroids: These may be used to treat inflammatory manifestations, but are used carefully, as broad immunosuppressants may also lead to infections.
- Interferon-gamma injections: A synthetic (human-made) version of a substance produced by the body’s immune system may decrease the severity and frequency of infections. (This treatment may be used less often due to its expense, side effects and effectiveness as compared to prophylaxis itraconazole.)
For some people, doctors may use a stem cell transplant to treat or, in some cases, cure CGD. During a stem cell transplant, healthy stem cells from a donor replace the faulty neutrophils in the white blood cells so they can fight infections. Because this procedure is complicated and has risks, doctors look at a person’s age, health and other factors when considering it.
What are the complications associated with CGD?
CGD can lead to complications including:
- Autoimmune disorders (when the body attacks its own cells) – though this happens in less than 5 percent of all cases
- Difficulty digesting food due to abscesses and inflammation in the intestines
- Growth retardation
- Inflammatory bowel disease (disorder that involves bloody stool, diarrhea, stomach pain and vomiting)
How can you prevent chronic granulomatous disease (CGD)?
You cannot prevent CGD. People with a family history of the disease who want to have children should seek genetic counseling to learn about the risk of having a child with the disorder.
Outlook / Prognosis
What is the prognosis (outlook) for people with chronic granulomatous disease (CGD)?
Doctors can successfully manage many cases of CGD. Treatments may continue indefinitely to keep infections and inflammation from becoming severe.
With ongoing treatment and support, many people with CGD live active and fulfilling lives. Prompt treatment is needed so that a doctor can treat infections before they become severe or life-threatening.
When should I see a healthcare provider about chronic granulomatous disease (CGD)?
Contact your healthcare provider if you or your child experiences symptoms of CGD.
What questions should I ask my doctor?
If you or your child has CGD, you may want to ask your doctor:
- What caused CGD to develop?
- What do I need to know about managing CGD?
- Should my family or I consider genetic testing?