What is Celiac disease?
Celiac disease is a serious autoimmune disease that occurs in genetically predisposed people where the ingestion of gluten leads to damage in the small intestine. It is estimated to affect 1 in 100 people worldwide, but only about 30% are properly diagnosed. When people with celiac disease eat gluten (a protein found in wheat, rye, and barley), their body mounts an immune response that attacks the small intestine. These attacks lead to damage on the villi, small fingerlike projections that line the small intestine, that promote nutrient absorption. When the villi get damaged, nutrients cannot be absorbed properly into the body. Celiac disease is hereditary, meaning that it runs in families. People with a first-degree relative with celiac disease (parent, child, sibling) have a 1 in 10 risk of developing celiac disease. Celiac disease can develop at any age after people start consuming gluten. Left untreated, celiac disease can lead to additional serious health problems.
Symptoms of Celiac Disease
Celiac disease can be difficult to diagnose because it affects people differently. There are more than 200 known celiac disease symptoms which may occur in the digestive system or other parts of the body. Some people develop celiac disease as a child, others as an adult. The reason for this is still unknown. Some people with celiac disease have no symptoms at all, but still test positive on the celiac disease blood test. Others may have a negative blood test, but have a positive intestinal biopsy. However, all people with celiac disease are at risk for long-term complications, whether or not they display any symptoms.
Celiac symptoms
- The most common symptoms in adults include:
- Abdominal pain
- Bloating and gas
- Cognitive impairment
- Constipation
- Diarrhea
- Depression and anxiety
- Fatigue
- Headaches or migraines
- Iron-deficiency anemia
- Itchy, blistery skin rash (dermatitis herpetiformis)
- Joint pain
- Missed periods
- Mouth ulcers and canker sores
- Nausea and vomiting
- Osteoporosis and osteomalacia
- Peripheral neuropathy
- Reduced functioning of the spleen (hyposplenism)
- Weight loss
Classical, Non-classical, and Silent Celiac Disease
According to the World Gastroenterology Organization, celiac disease may be divided into two types: classical and non-classical. In classical celiac disease, patients have signs and symptoms of malabsorption, including diarrhea, steatorrhea (pale, foul-smelling, fatty stools), and weight loss or growth failure in children. In non-classical celiac disease, patients may have mild gastrointestinal symptoms without clear signs of malabsorption or may have seemingly unrelated symptoms. They may suffer from abdominal distention and pain, and/or other symptoms such as: iron-deficiency anemia, chronic fatigue, chronic migraine, peripheral neuropathy (tingling, numbness, or pain in hands or feet), unexplained chronic hypertransaminasemia (elevated liver enzymes), reduced bone mass and bone fractures, and vitamin deficiency (folic acid and B12), difficulty losing weight, late menarche/early menopause and unexplained infertility, dental enamel defects, depression and anxiety, dermatitis herpetiformis (itchy skin rash), etc.
Silent celiac disease
First-degree relatives should always be screened, since there is a 1 in 10 risk of developing celiac disease. Silent celiac disease is also known as asymptomatic celiac disease. Patients do not complain of any symptoms, but still experience villous atrophy damage to their small intestine. Studies show that even though patients thought they had no symptoms, after going on a strict gluten-free diet, they report better health and a reduction in acid reflux, abdominal bloating, and distention and flatulence. First-degree relatives, whether or not experiencing symptoms, should always be screened, since there is a 1 in 10 risk of developing celiac disease. Second-degree relatives also have an increased risk of developing the disease. 1 The number of ways celiac disease can affect patients, combined with a lack of training in medical schools and primary care residency programs, contributes to the poor diagnosis rate in the United States. Currently, it is estimated that 80% of the celiac disease population remains undiagnosed.
Testing & Diagnosis
A simple blood test is available to test for celiac disease. People with celiac disease who eat gluten have higher than normal levels of certain antibodies in their blood. These antibodies are produced by the immune system because it views gluten (the proteins found in wheat, rye, and barley) as a threat. You must be on a gluten-containing diet for antibody (blood) testing to be accurate. The First Step: tTG-IgA Test For most children and adults, the best way to test for celiac disease is with the Tissue Transglutaminase IgA antibody (tTG-IgA), plus an IgA antibody in order to ensure that the patient generates enough of this antibody to render the celiac disease test accurate. IgA Endomysial antibody (EMA): The EMA test has a specificity of almost 100%, making it the most specific test for celiac disease, although it is not as sensitive as the tTG-IgA test. About 5-10% of people with celiac disease do not have a positive EMA test. It is also very expensive in comparison to the tTG-IgA and requires the use of primate esophagus or human umbilical cord. It is usually reserved for difficult to diagnose patients.
Testing & Diagnosis
Total serum IgA: This test is used to check for IgA deficiency, a condition associated with celiac disease that can cause a false negative tTG-IgA or EMA result. If you are IgA deficient, your doctor can order a DGP or tTG-IgG test. Deamidated gliadin peptide (DGP IgA and IgG): This test can be used to further screen for celiac disease in individuals with IgA deficiency, which affects 2-3% of patients with celiac disease, or people who test negative for tTg or EMA antibodies. IgA deficiency in a patient may be indicative of other diseases that may cause villus atrophy, such as giardiasis, small-bowel bacterial overgrowth (SIBO) or common variable immunodeficiency (CVID). While it is very rare, it is possible for someone with celiac disease to have negative antibody test results. If your tests were negative, but you continue to experience symptoms, consult your physician and undergo further medical evaluation. Video capsule endoscopy (VCE): VCE has a sensitivity of 89% and specificity of 95% for celiac diagnosis. This method of testing is more sensitive at detecting macroscopic atrophies in comparison with regular upper endoscopy (92% vs. 55%). VCE is also useful in detecting complications linked with celiac disease. Intestinal fatty acid binding protein (I-FABP): When cellular damage occurs, this cytosolic protein is released into the systemic circulation of blood and could indicate unintentional gluten intake. Radiology: Some radiological findings may indicate the presence of celiac disease, e.g., small-bowel dilation, wall thickening, vascular changes, and others.
Treatment & Follow-Up
Lifelong Adherence to the Gluten-Free Diet The only treatment for celiac disease is to follow a strict gluten-free diet for life. This means avoiding foods and beverages that gluten, a protein found in wheat, rye, barley, and triticale ( a hybrid of wheat and rye.) Vitamins and Dietary Supplements Commonly, people with celiac disease are deficient in fiber, iron, calcium, magnesium, zinc, folate, niacin, riboflavin, vitamin B12, and vitamin D, as well as in calories and protein. Deficiencies in copper and vitamin B6 are also possible, but less common. Supplementation of B12 and folate may help individuals with celiac disease recover from anxiety and depression caused by vitamin deficiencies.
Source
What is Celiac Disease? | Celiac Disease Foundation- www.celiac.org