Wednesday, Apr 16, 2014 | 02:41 AM

Madisons Foundation - Moms And Dads In Search Of Needed Support

Chronic Granulomatous Disease (CGD)
Tuesday, 17 June 2003
Thursday, 28 July 2005

What

Chronic Granulomatous Disease (CGD) is a genetic disorder in which the immune system is not effective against a bacterium called Staphylococcus aureus (Staph) as well as some less common bacteria and fungi, such as Aspergillus, Pseudomonas, Serratia, and Burkholderia cepacia. Aspergillus and Burkholderia cepacia are now the most common organisms that cause problems for children with CGD. Normally the immune system can fight and kill these bacteria and fungi; however, because the immune system is not functioning correctly, children with this disorder have an increased susceptibility to infection caused by these organisms. Variations in the frequency of infections are very common in children with CGD.

Who

CGD occurs in 1 out of every 200,000 people. Males are four times more likely than females to have CGD. The majority of children with CGD are diagnosed before the age of five years. This disease is genetic which means it can be inherited or passed on in families. For CGD, there are two possible patterns of transmission: X-linked inheritance (more common) and autosomal recessive inheritance. Females inherit two X chromosomes, one from each parent. Males inherit one X chromosome from the mother and one Y chromosome from the father. Females, having two X chromosomes, are less affected by the X-linked form because they have one X chromosome with the normal gene which overrides the deleterious effects of the other X chromosome with the abnormal gene. Males, on the other hand, are affected more often and more seriously because they only have one X chromosome, and if it contains the abnormal gene, there is no other X chromosome with the normal gene to counterbalance the effects of the abnormal gene. Mothers who carry the abnormal gene often do not know they have it until they have a son with the disease. A child may also inherit CGD through an autosomal recessive inheritance pattern in which two defective copies (one from each parent) of the gene on another set of non-sex chromosomes is passed on to the child. This type of inheritance affects males and females equally.

Signs and Symptoms

Children with CGD are usually healthy when they are first born. Within a few months to the first 3 to 5 years, the child begins to develop infections that do not respond to typical treatment or go away for a little while and then come back (recurrent infections). Both normal and abnormal bacteria and fungi may cause these infections which are deeper, more persistent, and more invasive than usual so physicians begin to question if the child has an immune deficiency. Children who have CGD can have infections that affect any organ or body region. Pneumonia is the most common infection, and abscesses of the skin and organs are the second most common infections. Other potential sites of infection include the lymph nodes, the bone marrow and adjacent bone, and the blood. Repeated infections can cause masses, called granulomas, that block the gastrointestinal and urinary tracts and cause abdominal pain. Other symptoms include fevers, skin rashes, cough, enlarged spleen and liver, boils, swollen gland or lymph nodes, severe resistant facial acne, and painful inflammation of the nostrils. Children with the X-linked form have an increased risk for chorioretinitis (inflammation within the eye).

Possible Causes

For CGD, there are many different possible genes that could be abnormal and cause this disorder. They all affect the formation of an enzyme called NADPH oxidase which helps the immune system cells called phagocytes kill off bacteria and fungi. Having only one of these abnormal genes would change the DNA encoding for the enzyme, which would lead to ineffective killing of the organism and increased susceptibility to serious infections seen in CGD. Normally, organisms such as bacteria and fungi are killed by cells in the body called phagocytes (a type of white blood cell) that can ingest organisms. Enzymes (special proteins that carry out certain functions) like NADPH oxidase are found in these phagocytes and make specific oxygen-carrying compounds that are needed to kill the bacteria and fungi. A child who has the abnormal genes that causes CGD will still have phagocytes that can move and ingest organisms. However, the abnormal gene causes the enzyme within the phagocyte to be defective so it does not make the oxygen-containing compounds and cannot kill the organisms. This causes the child to be more susceptible to infection caused by these bacteria and fungi.

Diagnosis

Phagocytes are obtained from the blood and tests are run to determine whether the phagocytes are able to create the products that they use to kill organisms. Tests that can determine if phagocytes are functioning correctly include the Nitroblue Tetrazolium test (NBT) and Dihydrorhodamine Test (DHR). An infected child will also likely have an elevated ESR (erythrocyte sedimentation rate, a sign of inflammation and infection), as well as increased levels of immunoglobulins in the blood (also related to frequent infections). An imaging study such as a CT scan or an MRI may be done to identify specific lesions caused by fungi and bacteria within the child’s body. Genetic tests could also be done to determine if the child has one of the abnormal genes needed for CGD. Most children are diagnosed before 5 years of age, with the average age being 3 years for the X-linked form and 7.8 years for the autosomal-linked form.

Treatment

Early diagnosis is crucial. The main goal is to prevent infection and the related consequences afterward. Some antibiotics may be given continuously to prevent infection (prophylaxis). Trimethoprim-sulfamethoxazole (Bactrim) is the standard for prevention of Staphylococcal infections, but other antibiotics may be given if the child is allergic to this medicine. Antifungals like Itraconazole are given continuously as well. Gamma interferon, made normally by the body to fight infection, may be given to help boost the child’s immune system. Aggressive use of antibiotics is used to treat infections. If the infection becomes serious, intravenous (IV) antibiotics may become necessary. The child may need a white blood cell transfusion if the infection is not responding to normal treatments, and a blood transfusion may be given if the child has anemia. Cortisosteroids may be given to shrink granulomas in the intestinal tract that are causing obstruction. Many precautions should be taken with children who have CGD. Placing a child in a large day care institution should be carefully considered, since there is an increased risk of infections. Using filtration systems for drinking water or drinking bottled water should be considered to avoid possible infection from the water. The child should only go swimming in pools that are well chlorinated, never in lakes or rivers. A specific fungus, Aspergillus, is present in marijuana and can cause respiratory problems, thus smoking marijuana should be avoided. Hot and moldy/dusty environments should be avoided. Currently, only a bone marrow transplant can be done to definitively cure CGD, and there are a few successful cases. Research is being done to make this procedure safer in order to help cure more children. Research is also being done on gene therapy in an attempt to replace the faulty genes involved in CGD.

Prognosis

Over the past few years, the quality of life and life expectancy for people with CGD has improved remarkably. Hospitalizations for intravenous antibiotics may be needed to treat persistent infections. One of the most serious concerns is the lung disease and scarring due to the recurrent lung infections; therefore, it is important to diagnose and treat all infections, especially pneumonia, immediately and appropriately. With appropriate diagnosis, treatment, and precautions taken, children with CGD can have a better prognosis for leading relatively normal lives. Many people with CGD are now living into their 30’s.

Connect with other parents

In the spirit of community and support, Madisons Foundation offers the unique service of connecting parents of children with rare diseases. If you would like to be connected to other parents of children with this disease, please fill out this brief form.

Weblinks

The Chronic Granulomatous Disease Association
This is a great website with many resources and information available to families and patients dealing with CGD. It has links to several newsletters, personalized stories of families and patients, chat forums, and search options.

The Children’s Hospital at Westmead
This website is clear and easy to understand with basic information about CGD and links to other resources.

CGD- A Guide for CGD Patients and their Families
This website provides a detailed summary of the disease and links to larger organizations.

Google Search for Chronic Granulomatous Disease (CGD)

References and Sources

Chronic Granulomatous Disease www.utdol.com/application/topic.asp?file=immunnon/2165&type=P&selectedTitle=1~20 Medical Therapy of Immune Deficiency www.utdol.com/application/topic.asp?file=immunnon/5128 www.niaid.nih.gov www.primaryimmune.org