What Is Chronic Granulomatous Disease?
Chronic granulomatous disease (CGD) is a rare, inherited disease that typically presents in childhood with recurrent, serious, and possibly fatal bacterial and fungal infections. The disease is a disorder of a specific enzyme in the immune system, resulting in the inability of immune cells to destroy bacteria and fungus that cause infection . It is caused by several different genetic mutations and inherited in families.
The most common symptoms are recurrent respiratory and skin infections, although infection anywhere in the body is possible. CGD is diagnosed by a blood test and requires genetic testing to confirm the diagnosis.
Treatment is focused on the prevention of serious bacterial and fungal infections using prophylactic medication and frequent screening. The prognosis for CGD is vastly improved over the past 20 years, but average life expectancy is still only 40 years. Hematopoietic cell transplant (also known as HCT or bone marrow transplant) is a cure for CGD but it is not without risk, and this decision depends on the severity, availability of donors, and patient and family preferences.
You should visit your primary care physician. If he/she has ruled out other reasons for you getting sick, your doctor will refer you to a specialist, who will do special tests of your immune cells. Treatment is vigilance in looking out for infections.
How common is Chronic Granulomatous Disease?
Chronic Granulomatous Disease is also known as
- Phagocytic disorder
- Primary immunodeficiency disorder
Chronic Granulomatous Disease Symptoms
The symptoms of chronic granulomatous disease are extensive as infection or inflammation can occur in many different systems in the body. The following is a list of the most common symptoms but is not comprehensive.
The main symptoms experienced in chronic granulomatous disease include the following.
- Growth retardation
- Failure to thrive
- Frequent recurrent bacterial or fungal infection
The following infections commonly occur and reoccur with chronic granulomatous disease.
- Staph aureus (bacteria)
- Aspergillus (fungus)
- Serratia (bacteria)
- Klebsiella (bacteria)
- Burkholderia (bacteria)
- Nocardia (bacteria)
Respiratory symptoms commonly experienced with chronic granulomatous disease include the following.
- Difficulty breathing
- Chest pain
The following abdominal symptoms may occur with chronic granulomatous disease.
- Enlarged liver
- Enlarged spleen
- Abdominal pain
The following skin symptoms may be experienced with chronic granulomatous disease.
- Enlarged, swollen, or painful lymph nodes
- Cellulitis (bacterial infection of the skin)
- Severe acne
- Painful inflammation of the nostrils
Chronic Granulomatous Disease Causes
Immune system deficiency
The immune system is comprised of multiple types of cells that fight many different types of infections. A specific cell, the phagocyte, is responsible for killing bacteria and fungus that invade the body. These phagocytes engulf or “eat” the offending bacteria or fungus. Once engulfed, they release an enzyme called nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) that helps to kill the bacteria or fungus, thus fighting the infection. In CGD, there is a mutation in the gene that makes the enzyme NOX. This results in the inability of the phagocytic cells to kill the bacteria or fungus. As a result, the immune system is unable to effectively fight infections caused by bacteria or fungus, resulting in repeated, severe bacterial and fungal infections . People with CGD are particularly susceptible to a specific set of bacterial and fungal infections including Aspergillus Staph, Burkholderia, Serratia, Nocardia, and Klebsiella . It is unclear exactly why patients with CGD are more affected by these specific infections.
The NOX enzyme is made up of five different proteins, and if there mutations in any of these five proteins, this can result in a defective NOX protein leading to CGD. Most of these mutations are autosomal recessive mutations, meaning they are passed in families but only cause disease in a child if both parents have the genetic mutation. One mutation is an x-linked mutation, which means it is carried on the X chromosome and can only be passed from a mother to her son. Different genetic mutations result in different levels of dysfunction by the NOX enzyme. Some genetic mutations result in more severe forms of CGD and others result in less severe forms.
The following diagnostic methods are considered for chronic granulomatous disease.
- Neonatal screening: It is possible to use genetic screening during pregnancy to test for CGD if there is a family history of CGD. This requires obtaining a fetal blood sample or amniotic fluid sample. If you have CGD or a family history of CGD and are considering pregnancy, consult with a genetic specialist.
- Blood test: In order to diagnose CGD, the function of the NOX enzymes needs to be tested, which is also referred to as neutrophil function testing. This is tested using a blood sample. The most common test of the enzymes is known as the dihydrorhodamine 123 test. An older but also commonly used test is known as the nitroblue tetrazolium (NBT) test.
- Genetic testing: If you have a positive blood test, you should have a genetic test to confirm the diagnosis. Genetic testing takes a blood sample and looks at your genetic make-up to find the specific mutation causing the disease. The genetic mutation is also important in predicting the severity of the disease (see prognosis below).
When CGD was initially discovered, patients rarely survived into adulthood. Now, however, the survival of the disease has dramatically improved and the average survival for patients with CGD is 40 years . This is largely due to earlier diagnosis and the use of prophylactic antibiotics to prevent infection (see treatment below). The leading cause of death in people with CGD is respiratory fungal infections. The survival is linked to the level of dysfunction in the NOX enzyme, which correlates with how well the immune system is able to function.
- X-linked CGD: Some of the x-linked genetic mutations are associated with worse immune function and are at higher risk for severe and life-threatening infections.
- Autosomal Recessive CGD: These mutations are usually associated with some preserved immune function, less severe disease, and better life expectancy.
Treatment Options and Prevention
The management of CGD is focused on preventing bacterial and fungal infections with prophylactic medications and the following measures .
- Bacterial prophylaxis: People with CGD should be on lifelong prophylactic antibiotics to prevent bacterial infection. Typically, trimethoprim-sulfamethoxazole (TMP-SMX, Bactrim) is used. This greatly reduces the chance of severe bacterial infection.
- Fungal prophylaxis: People with CGD should be on lifelong prophylactic antifungal to prevent fungal infection. Typically, itraconazole is used. This greatly reduces the chance of severe fungal infection.
- Vaccination: Live bacterial vaccines are not recommended for patients with CGD as they may cause severe reactions. Otherwise, patients with CGD should receive all viral vaccines and inactivated or subunit bacterial vaccines on a normal childhood schedule.
- Screening for infection: People with CGD may have serious infections but be asymptomatic or minimally symptomatic at first. Therefore, it is recommended that they have blood tests intermittently to look for inflammatory markers that may indicate an infection is present. These specific blood tests are the ESR and CRP. If either is elevated it should prompt further imaging (either CT or MRI) to find the infection in order to appropriately treat it.
Other treatments that will likely be necessary throughout the course of chronic granulomatous disease, and include the following. Stem cell transplant is a definitive cure for CGD, however, it has risks and this decision depends on prognosis, donor availability, and your preference .
- Treatment of infection: If an infection is found, it needs to be treated promptly and aggressively. This may involve antibiotics or antifungal medication. For severe infections, patients may need to be admitted to the hospital to receive intravenous antibiotics or antifungals. In some cases, surgery is warranted if an infection is in the abdomen and needs to be drained or washed out for definitive treatment.
- Anti-inflammatory therapy: Inflammation in the gastrointestinal system or urinary tract can cause pain, diarrhea, difficulty urinating, among other symptoms. These symptoms are typically treated with oral steroids. Some other anti-inflammatory drugs including azathioprine or sulfasalazine are used as well.
- Hematopoietic cell transplant (HCT, bone marrow transplant): In HCT, you receive blood-forming cells (cells from which all immune cells develop) from a healthy donor with similar but not identical genetics. Donors are often siblings or parents. Outcomes of HCT are generally better in young patients, but can also be effective for older patients with severe recurrent infections. However, HCT is risky and can result in worsening of disease or death. The risk and benefits of HCT should be discussed extensively with a specialist.
When to Seek Further Consultation
Anyone with a family history of CGD warrants evaluation by a specialist. If you have a family history of CGD and are considering becoming pregnant, consult a genetic specialist. Anyone with a diagnosis of CGD should be treated and followed by a specialist. Typically, a Hematology-Oncology expert cares for patients with CGD.
Questions Your Doctor May Ask to Diagnose
To diagnose this condition, your doctor would likely ask about the following symptoms and risk factors.
- Has any part of your body become paler than normal?
- Have you been feeling more tired than usual, lethargic or fatigued despite sleeping a normal amount?
- Are you experiencing unusually quick or severe fatigue when doing physical activity or exercising?
- Do you have dry skin?
- Are you short for your age?
The above questions are also covered by our A.I. Health Assistant.
- Chronic Granulomatous Disease (CGD). American Academy of Asthma Allergy & Immunology. AAAAI Link
- Cooper MA, Pommering TL, Koranyi K. Primary Immunodeficiencies. Am Fam Physician. 2003 Nov 15;68(10):2001-2009. AAFP Link
- Marciano BE, Spalding C, Fitzgerald A, et al. Common severe infections in chronic granulomatous disease. Clin Infect Dis. 2014;60(8):1176-83. NCBI Link
- Arnold DE, Heimall JR. A Review of Chronic Granulomatous Disease. Adv Ther. 2017;34(12):2543-2557. NCBI Link
- CGD Society - Management of CGD. CGD Society. CGD Society Link