Chronic granulomatous disease (CGD) is an inherited disorder in which white blood cells lose their ability to destroy certain bacteria and fungi. It is described as a primary immunodeficiency disorder. “Primary” means it is not caused by some other disease or disorder.
CGD is a genetic disease in which the body’s cells that eat certain invaders, also called phagocytes, do not make hydrogen peroxide and other chemicals needed to kill certain bacteria and molds. As a result of this defect, patients with CGD get more infections, and they also get too many immune cells forming “knots” called granulomas, hence the name of the disease. Another problem in CGD is that patients can get excessive inflammation even when there is not an infection, and that inflammation can cause diarrhea, and bladder and kidney problems.
People with CGD are unable to fight off common germs and get very sick from infections that would be mild in healthy people. This is because the presence of CGD makes it difficult for cells called neutrophils to produce hydrogen peroxide. The immune system requires hydrogen peroxide to fight specific kinds of bacteria and fungi. These severe infections can include skin or bone infections and abscesses in internal organs (such as the lungs, liver or brain). Aside from the defective neutrophil function in CGD, the rest of the immune system is normal. People with CGD can be generally healthy until they become infected with one of these germs. The severity of this infection can lead to prolonged hospitalizations for treatment.
Inflammation can occur in many different areas of the body in people with chronic granulomatous disease. Most commonly, granulomas occur in the gastrointestinal tract and the genitourinary tract. In many cases the intestinal wall is inflamed, causing a form of inflammatory bowel disease that can lead to stomach pain, diarrhea, nausea, and vomiting. Other common areas of inflammation in people with chronic granulomatous disease include the stomach, colon, and rectum, as well as the mouth and throat. Additionally, granulomas within the gastrointestinal tract can lead to tissue breakdown and pus production (abscesses). Inflammation in the stomach can prevent food from passing through to the intestines (gastric outlet obstruction), leading to an inability to digest food. These digestive problems cause vomiting after eating and weight loss. In the genitourinary tract, inflammation can occur in the kidneys, bladder, and genitalia. Inflammation of the lymph nodes (lymphadenitis) and bone marrow (osteomyelitis), which both produce immune cells, can lead to further impairment of the immune system.
The exact incidence of chronic granulomatous disease (CGD) is unknown. CGD affects approximately 1 infant per 200,000-250,000 live births.
Causes
In chronic granulomatous disease (CGD), immune system cells called phagocytes are unable to kill some types of bacteria and fungi. This disorder leads to long-term (chronic) and repeated (recurrent) infections. The condition is often discovered very early in childhood. Milder forms may be diagnosed during the teenage years or even in adulthood.
About half of CGD cases are passed down through families as a recessive, sex-linked trait. This means that boys are more likely to get the disorder than girls. The defective gene is carried on the X chromosome. Boys have 1 X and 1 Y chromosome. If a boy has an X chromosome with the defective gene, he may inherit this condition. Girls have 2 X chromosomes. If a girl has 1 X chromosome with the defective gene, the other X chromosome may have a working gene to make up for it. A girl has to inherit the defective gene from both parents in order to have the disease.
Babies and CGD – Female carriers of an X-linked disorder have a 25% chance with each pregnancy to have a carrier daughter like themselves, a 25% chance to have a non-carrier daughter, a 25% chance to have a son affected with the disease and a 25% chance to have an unaffected son. If a male with an X-linked disorder is able to reproduce, he will pass the defective gene to all of his daughters who will be carriers. A male cannot pass an X-linked gene to his sons because males always pass their Y chromosome instead of their X chromosome to male offspring.
Who is at Risk?
- Race – Chronic granulomatous disease affects persons of all races.
- Sex – Approximately 80% of patients with CGD are male, because the main cause of the disease is a mutation in an X-chromosome–linked gene. However, defects in autosomal genes may also underlie the disease and cause CGD in both males and females.
- Age – Symptom onset typically occurs at a young age, although the diagnosis has been at an older age in some patients. Typically, patients with CGD have recurrent pyogenic infections that start in the first year of life. Occasionally, the onset may be delayed until the patient is aged 10-20 years.
Symptoms
- Bone infections
- Frequent and difficult-to-clear skin infections
- Abscesses
- Chronic infection inside the nose
- Furuncles
- Impetiginized eczema (eczema complicated by an infection)
- Impetigo
- Perianal abscesses (abscesses around the anus)
- Joint infections
- Persistent diarrhea
- Pneumonia
- Occurs frequently
- Difficult to cure
- Swollen lymph nodes in the neck; those develop early in life, and stay swollen or occur frequently. The lymph nodes may form abscesses that require surgical drainage.
Complications
- Bone damage and infections
- Chronic infections in the nose
- Pneumonia that keeps coming back and is hard to cure
- Lung damage
- Skin damage
- Swollen lymph nodes that stay swollen, occur often, or form abscesses that need surgery to drain them
Treatment
Medications – Antibiotics are used to treat the disease and may also be used to prevent infections. A medicine called interferon-gamma may also help reduce the number of severe infections. Surgery may be needed to treat some abscesses.
- Sulfasalazine and azathioprine are useful steroid-sparing agents. Tumor necrosis factor alpha inhibitors such as infliximab are effective anti-inflammatory agents but might significantly increase the risk of severe and even fatal infections.
- Methotrexate and hydroxychloroquine (Plaquenil) can be effective in those with arthritides or lupuslike problems.
Surgery – Bone marrow transplant is another treatment option for some people with severe symptoms of CGD.
Alternative Treatment