Celiac Disease

Key Points

• Celiac disease is caused by a sensitivity to gluten.

• It is more common in people with Down syndrome.

• It can be diagnosed through an assessment including a history, physical, blood work, and a small bowel biopsy done during an endoscopy.

• It is treated by following a gluten-free diet.

Sections

Overview of Celiac Disease

Signs and Symptoms

Diagnosis

Genetic Testing

Screening     

Treatment

Additional Resources

 

What is celiac disease?

Celiac disease is a sensitivity to gluten, a protein in wheat, barley, and rye. When the individual with celiac disease is exposed to gluten (most commonly by ingesting it by mouth), it causes an inflammation in the intestine. The inflammation causes the villi (microscopic fingers in the small intestine) to slough off. This reduces the surface area of the small intestine, decreasing its ability to absorb vitamins, minerals, and calories. Over time, celiac disease results in malabsorption of nutrients in food (decreased absorption of calories, vitamins, and/or minerals). 

 

Why do some people get celiac disease but not others?

People who have celiac disease have a genetic predisposition to the disease. That is, it tends to run in families. There are also groups of people (such as those of Northern European ancestry) who are thought to be more likely to develop the disorder. When individuals who have the genetic predisposition are exposed to some environmental stimuli (thought to probably be an unknown virus), an immune reaction is set off and celiac disease becomes active. 

 

Why is it important in Down syndrome?

Down syndrome (DS) increases a person's susceptibility to celiac disease. Celiac disease is an autoimmune disorder, which are conditions in which the person's own immune system attacks certain organ systems in the body. Autoimmune disorders are more common in people with DS. Having three of the 21st chromosome, as people with DS have, impacts the immune system in a variety of ways, including increasing the frequency of autoimmune conditions.  Other examples of autoimmune disorders that are more common in people with DS include hypothyroidism (underactive thyroid), type 1 diabetes, and alopecia (a type of hair loss).

Estimates for the frequency of celiac disease in people with and without DS vary. While there is consensus that people with DS have a higher frequency of celiac disease, there is no consensus on how much higher the frequency is.

 

What are the signs and symptoms of celiac disease?

Gastrointestinal (GI)

• Diarrhea

• Weight loss

• Increased gas

• Constipation

• Changes in appetite

• Abdominal discomfort

• Bloating

Other

• Muscle cramps

• Dizziness

• Nervousness

• Weakness

• Fatigue, lack of energy

• Seizures

• Psychological or behavior changes

• Complications from poor absorption of vitamins and/or minerals

• Dermatitis herpetiformis is an extremely itchy rash with associated blisters that are seen on the elbows, knees, scalp, back, and buttocks. The presence of this rash indicates that a patient has celiac disease. 

• There are many other possible symptoms. 

Longstanding, untreated celiac disease is associated with intestinal lymphoma (a type of cancer) and other gastrointestinal malignancies; however, this is thought to be uncommon in people with DS. This article by Swigonski et al.  provides additional information. 

 

How is celiac disease diagnosed?

A good history and physical exam are the first steps. It is important to assess for the above symptoms and signs. In addition to assessing for findings that are consistent with celiac disease, it is important to assess for other symptoms and signs that might indicate a different condition. 

Blood testing

When celiac disease is suspected, the next step is typically blood testing. The American Gastroenterological Association  and the Celiac Disease Foundation  both recommend using a blood test called Tissue Transglutaminase IgA antibody (tTG-IgA) to test for celiac disease.

In addition, it is recommended to get a total IgA antibody to ensure that the patient generates enough of this antibody to render the celiac disease test accurate. If someone cannot make enough of IgA, then the tTG-IgA is likely to be low and an inaccurate measure of celiac disease.

Small bowel biopsy

If the blood test comes back positive, then the definitive test for celiac disease is a small bowel biopsy. This test is usually performed by a gastroenterologist (a medical doctor who specializes in disorders of intestines and liver. The gastroenterologist does the test by passing an endoscope, a flexible tube equipped with video capabilities, through the mouth and down to the small bowel. A small sample of intestinal tissue is taken (biopsied). This procedure is called an esophagogastroduodenoscopy (EGD). It usually requires sedation and may require general anesthesia for some people with DS.

Some individuals with DS and their families opt not to undergo an endoscope procedure. They choose to proceed with the gluten-free diet based on the symptoms and the results of blood tests. In a small study we did at the Adult Down Syndrome Center, using the standard normal values for tTG-IgA, only about 50% of those with an abnormal blood test had biopsy proven celiac disease when they underwent an EGD and biopsy. It has been suggested that a higher value should be considered normal for people with DS, but that value has not been determined. A higher normal value would likely result in fewer EGDs but may also miss more celiac disease. In addition, anesthesia required for medical procedures does have higher risk in people with DS. Limiting the number of EGDs to only people at higher risk for celiac disease can reduce anesthesia complications. 

Are there times when a biopsy is recommended despite a normal tTG-IgA?

If someone has a normal tTG-IgA but has a low total IgA, the reason for the normal tTG-IgA may be that the individual cannot make adequate IgA at all and, therefore, will not have an elevated tTG-IgA. In this situation, a biopsy may be considered.

Additionally, in some individuals, if there is a strong suspicion of celiac disease, even with a normal tTG-IgA and a normal total IgA, a biopsy may be indicated. Even using standard values for tTG-IgA, the tTG-IgA will be falsely negative in some individuals with DS. In other words, they have celiac disease but for reasons not always known, their tTG-IgA is not high. This does not appear to be common but does occur.

Other testing

Additional blood testing is also recommended to look for complications of celiac disease including anemia, vitamin and mineral deficiencies, and other health conditions. Sometimes, it is also recommended to assess for other autoimmune diseases since a person may have more than one autoimmune condition. 

It is important to discuss all the options with your physician or health care provider to determine what the best diagnostic and management strategy is on a patient-to-patient basis. 

 

What is genetic testing for celiac disease?

Many individuals with celiac disease have one or both genes DQ2 or DQ8. Some researchers are now finding that there may be additional genes involved in making a person susceptible to developing celiac disease. These other genes seem to play a greater role in celiac disease in people with DS than in people without DS. This research suggests people with DS may have celiac disease based on genes other than or in addition to DQ2 or DQ8. 

When it was thought that all people with celiac disease had one or both of DQ2 or DQ8, some advocated doing genetic testing for these two genes to determine whether the individual has the genetic predisposition to develop celiac disease. However, if positive, it does not indicate whether the person has developed celiac disease or just has the predisposition. Assessing the history, physical exam, blood work, and EGD with biopsy are still required to assess for the actual presence of the disease. 

Celiac disease genetic testing considerations for people with DS

The use of genetic testing has not been a widely accepted way to assess for celiac disease. Often, it is not covered by insurance, and it can be costly. However, when it was thought you could not have celiac disease if you did not have DQ2 or DQ8, it was sometimes helpful to do genetic testing. If negative for those two genes, then no additional testing was indicated because the understanding was that the person could not have celiac disease.

However, as additional genes now appear to predispose people with DS to celiac disease, the benefit of genetic testing is even less clear. Even if negative for DQ2 and DQ8, the person may have other genes that predispose to celiac disease. If one could test for all the genes associated with celiac disease, it would give more value in the diagnosis. Currently, it is not known what all those genes are. Research continues to evaluate for all the genes that may predispose people to celiac disease. It is possible (or even likely) that the list of genes associated with celiac disease in people with DS may not be the same as people without DS. 

 

Should people with DS be screened for celiac disease?

The GLOBAL Medical Care Guidelines for Adults with Down Syndrome state, "Adults with Down syndrome should receive an annual assessment for gastrointestinal and non-gastrointestinal signs and symptoms of celiac disease using targeted history, physical examination, and clinical judgment of good practice." There is no evidence to support doing a periodic blood test for everyone with DS.

Similarly, the American Academy of Pediatrics Health Supervision for Children and Adolescents with Down Syndrome (pediatric guidelines) recommend screening for symptoms of celiac disease at each health supervision appointment with a history and physical (but not blood testing). 

In both guidelines, if symptoms are present, additional testing is indicated. Since celiac disease can cause a wide variety of symptoms, many symptoms may prompt the health care provider to do celiac blood testing. 

 

Treating celiac disease

Currently, the only treatment for celiac disease is diet. It requires strict adherence to eliminating gluten in the diet.

How do I get started?

The recommended first step is a consultation with a dietitian/nutritionist who is knowledgeable about celiac disease and a gluten-free diet. Reviewing printed literature, internet material, and other sources of information is also very helpful. We have found interacting with other people with celiac disease to be extremely beneficial. Whether it be a support group or more informally, talking to and getting day-to-day advice from people who are living the gluten-free life is very helpful. Membership in a local celiac society is one way to meet this need.

What foods should be avoided?

As mentioned above, the main categories of food that need to be avoided to be gluten-free are wheat, barley, and rye. Common foods that contain these ingredients are: 

Wheat

• Breads

• Baked goods

• Pasta

• Salad dressings

Barley

• Malt

• Soup

Rye

• Cereals

It is also important to read labels on food because gluten can be hidden in unexpected places. Look for "gluten-free" labels. "Wheat-free" foods may still contain gluten. Also, pay attention to the allergens and ingredients for any food. 

What foods can be eaten?

• Meats, seafood

• Fruits, vegetables

• Nuts

• Dairy

• Some grains

  • Rice

  • Corn

  • Soy

  • Potato

  • Quinoa

  • Oats

Recipes

You can still eat the foods you love by substituting out flour. A few ideas are listed below, but there are many great recipes  and a list of gluten-free foods  on the Celiac Disease Foundation's website. 

• Pizza (cauliflower rice as crust)

• Chicken tenders (coat in quinoa)

• Carrot cake (coconut flour)

• Cheesecake (ground pecans)

• Muffins (almond flour)

Is the diet easy to follow?

Gluten is in a lot of foods and is also used in processing many foods. Reviewing lists of gluten-free  and gluten-containing  foods can be helpful. Although following the diet can be challenging, there are more gluten-free foods available, more restaurants with gluten-free choices, and more information being shared about ways to make following the diet a natural part of daily life than ever before.

How can I assist a person with DS to follow the diet?

Helping with food choices is an important first step (and to do that you must learn about appropriate food choices first). It is also important to teach the person with DS as much as he/she is capable of. Several of our patients have a solid understanding of gluten-free foods. Others have benefited from using celiac disease visuals such as a small picture book with pictures of acceptable and unacceptable foods. The unacceptable foods have a line or some other designation through them. Storing pictures in smart phones might be a way for some to have access to many pictures. There are also apps designed to help with making gluten-free choices. We list some of them in our Nutrition and Hydration Apps resource. Ongoing education and reminders are important. Encouraging participation in food preparation may also increase understanding. 

Are there other treatments?

Currently, there are no other treatments for celiac disease but there are issues to address in addition to diet. Blood work testing for vitamin and mineral deficiency should be considered. Supplements with some vitamins and minerals might be indicated.

Poor calcium absorption can lead to osteoporosis. Therefore, a bone density test is usually considered. If indicated by the results, treatment for osteoporosis is recommended. However, for several reasons, the benefit of testing and treating osteoporosis in people with DS is unclear. The GLOBAL Medical Care Guidelines for Adults with Down Syndrome state: 

"For primary prevention of osteoporotic fractures in adults with Down syndrome, there is insufficient evidence to recommend for or against applying established osteoporosis screening guidelines, including fracture risk estimation; thus, good clinical practice would support a shared decision-making approach." 

We recommend discussing this with your health care provider. Adequate calcium intake and regular weight bearing exercise are important to reduce the risk of osteoporosis and fractures related to osteoporosis.

 

Additional resources

Celiac Disease - Diagnosis and Treatment  (Mayo Clinic)

Celiac Disease  (Cleveland Clinic)

What is Celiac Disease?  (Celiac Disease Foundation)

Celiac Disease  (NIH National Institute of Diabetes and Digestive and Kidney Diseases)

Celiac Disease Resources  (National Celiac Association)

Gluten-Free Safe Spots  (Gluten-Free Food Service)

 

Original article was written by Robert Campbell, DO in September 2017. Article was updated by Brian Chicoine, MD in August 2023.