Question: what blood tests confirm celiac disease

Reference:
 Celiac disease Overview Celiac disease (gluten-sensitive enteropathy), sometimes called sprue or coeliac, is an immune reaction to eating gluten, a protein found in wheat, barley and rye. If you have celiac disease, eating gluten triggers an immune response in your small intestine. Over time, this reaction damages your small intestine's lining and prevents absorption of some nutrients (malabsorption). The intestinal damage often causes diarrhea, fatigue, weight loss, bloating and anemia, and can lead to serious complications. In children, malabsorption can affect growth and development, in addition to the symptoms seen in adults. There's no cure for celiac disease - but for most people, following a strict gluten-free diet can help manage symptoms and promote intestinal healing. Symptoms The signs and symptoms of celiac disease can vary greatly and are different in children and adults. The most common signs for adults are diarrhea, fatigue and weight loss. Adults may also experience bloating and gas, abdominal pain, nausea, constipation, and vomiting. However, more than half of adults with celiac disease have signs and symptoms that are not related to the digestive system, including: - Anemia, usually resulting from iron deficiency - Loss of bone density (osteoporosis) or softening of bone (osteomalacia) - Itchy, blistery skin rash (dermatitis herpetiformis) - Damage to dental enamel - Mouth ulcers - Headaches and fatigue - Nervous system injury, including numbness and tingling in the feet and hands, possible problems with balance, and cognitive impairment - Joint pain - Reduced functioning of the spleen (hyposplenism) - Acid reflux and heartburn In children under 2 years old, typical signs and symptoms of celiac disease include: - Vomiting - Chronic diarrhea - Swollen belly - Failure to thrive - Poor appetite - Muscle wasting Older children may experience: - Diarrhea - Constipation - Weight loss - Irritability - Short stature - Delayed puberty - Neurological symptoms, including attention-deficit/hyperactivity disorder (ADHD), learning disabilities, headaches, lack of muscle coordination and seizures Dermatitis herpetiformis is an itchy, blistering skin disease that stems from intestinal gluten intolerance. The rash usually occurs on the elbows, knees, torso, scalp and buttocks. Dermatitis herpetiformis is often associated with changes to the lining of the small intestine identical to those of celiac disease, but the disease may not produce noticeable digestive symptoms. Doctors treat dermatitis herpetiformis with a gluten-free diet or medication, or both, to control the rash. Consult your doctor if you have diarrhea or digestive discomfort that lasts for more than two weeks. Consult your child's doctor if your child is pale, irritable or failing to grow or has a potbelly and foul-smelling, bulky stools. Be sure to consult your doctor before trying a gluten-free diet. If you stop or even reduce the amount of gluten you eat before you're tested for celiac disease, you may change the test results. Celiac disease tends to run in families. If someone in your family has the condition, ask your doctor if you should be tested. Also ask your doctor about testing if you or someone in your family has a risk factor for celiac disease, such as type 1 diabetes. Causes Celiac disease occurs from an interaction between genes, eating foods with gluten and other environmental factors, but the precise cause isn't known. Infant feeding practices, gastrointestinal infections and gut bacteria might contribute to developing celiac disease. Sometimes celiac disease is triggered - or becomes active for the first time - after surgery, pregnancy, childbirth, viral infection or severe emotional stress. When the body's immune system overreacts to gluten in food, the reaction damages the tiny, hair-like projections (villi) that line the small intestine. Villi absorb vitamins, minerals and other nutrients from the food you eat. If your villi are damaged, you can't get enough nutrients, no matter how much you eat. Some gene variations appear to increase the risk of developing the disease. But having those gene variants doesn't mean you'll get celiac disease, which suggests that additional factors must be involved. The rate of celiac disease in Western countries is estimated at about 1 percent of the population. Celiac disease is most common in Caucasians; however, it is now being diagnosed among many ethnic groups and is being found globally. Risk factors Celiac disease can affect anyone. However, it tends to be more common in people who have: - A family member with celiac disease or dermatitis herpetiformis - Type 1 diabetes - Down syndrome or Turner syndrome - Autoimmune thyroid disease - Microscopic colitis (lymphocytic or collagenous colitis) - Addison's disease - Rheumatoid arthritis Diagnosis Researchers estimate that only 20 percent of people with celiac disease may receive a diagnosis. Doctors may order two blood tests to help diagnose celiac disease. - Serology testing looks for antibodies in your blood. Elevated levels of certain antibody proteins indicate an immune reaction to gluten. - Genetic testing for human leukocyte antigens (HLA-DQ2 and HLA-DQ8) can be used to rule out celiac disease. If the results of these tests indicate celiac disease, your doctor may order an endoscopy to view your small intestine and to take a small tissue sample (biopsy) to analyze for damage to the villi. It's important to be tested for celiac disease before trying a gluten-free diet. Eliminating gluten from your diet may change the results of blood tests so that they appear to be normal. Treatment A strict, lifelong gluten-free diet is the only way to manage celiac disease. In addition to wheat, foods that contain gluten include: - Barley - Bulgur - Durum - Farina - Graham flour - Malt - Rye - Semolina - Spelt (a form of wheat) - Triticale Your doctor may refer you to a dietitian, who can help you plan a healthy gluten-free diet. Once you remove gluten from your diet, inflammation in your small intestine generally begins to lessen - usually within several weeks, though you may start to feel better in just a few days. Complete healing and regrowth of the villi may take several months to several years. Healing in the small intestine tends to occur more quickly in children than adults. If you accidentally eat a product that contains gluten, you may experience abdominal pain and diarrhea. Some people experience no signs or symptoms after eating gluten, but this doesn't mean it's not harmful to them. Even trace amounts of gluten in your diet can be damaging, whether or not they cause signs or symptoms. Hidden gluten can be present in foods, medications and nonfood products, including: - Modified food starch, preservatives and food stabilizers - Prescription and over-the-counter medications - Vitamin and mineral supplements - Herbal and nutritional supplements - Lipstick products - Toothpaste and mouthwash - Envelope and stamp glue - Play-Doh Vitamin and mineral supplements If your nutritional deficiencies are severe, your doctor or dietitian may recommend taking vitamin and mineral supplements. You may need to supplement your levels of: - Calcium - Folate - Iron - Vitamin B-12 - Vitamin D - Vitamin K - Zinc Vitamins and supplements are usually taken in pill form. If your digestive tract has trouble absorbing vitamins, your doctor may give them by injection. You need to be sure that the vitamins and supplements are gluten-free. Follow-up care If you have celiac disease, you will need medical follow-up to make sure your symptoms have responded to a gluten-free diet. Doctors will also want to be sure you are getting the support you need to maintain the diet for life. They will use blood tests to monitor your response. The results of these tests, which are primarily designed as a way to detect celiac disease, usually become negative once you have been gluten-free for six to 12 months. If test results remain positive, then your doctor may try to find the reason, the most common being unintentional exposure to gluten in your diet. However, these tests are not perfect, and even if the results become negative, it is possible that you could still be exposed to a significant amount of gluten and continue to have symptoms and damage to your intestines. If you continue to have symptoms, or your symptoms recur, you may need a follow-up endoscopy with biopsies to ensure that healing has occurred. Adults typically have a greater need for follow-up testing, although children may require it, too. Some doctors recommend a routine re-biopsy if you are diagnosed in adulthood, as healing is often quite slow and uncertain. It also can be helpful to follow up with an expert dietitian for assistance in adapting to, and maintaining, a healthy, nutritious, gluten-free diet. Medications to control intestinal inflammation If your small intestine is severely damaged, your doctor may recommend steroids to control inflammation. Steroids can ease severe signs and symptoms of celiac disease while the intestine heals. Dermatitis herpetiformis If you have this itchy, blistering skin rash that sometimes accompanies celiac disease, your doctor may recommend a skin medication (dapsone) along with the gluten-free diet. Refractory celiac disease If you have refractory celiac disease, you may continue to have severe symptoms, or your symptoms may lessen but then relapse. In either case, your small intestine does not heal. When this happens, you likely will require evaluation in a specialized center. Refractory celiac disease can be quite serious and there is currently no proven treatment. People with refractory celiac disease should be treated by experts. There may be several causes for this condition. Doctors will often use steroid therapy - either a topical budesonide or systemic steroids such as prednisone. Sometimes, they will use the same medications used to treat other conditions. Potential future treatments While the only proven therapy for celiac disease is a gluten-free diet, it is not perfect. People with celiac disease may often be accidentally exposed to gluten, possibly causing severe symptoms. Several treatments are in development for celiac disease. Some try to neutralize or bind to gluten. Others address the barrier of the intestine, blocking the leakiness that gluten can trigger. Still others target the body's immune system. Researchers have also been trying to genetically modify wheat, but have not yet been successful. None of these treatments is likely to be approved within the next two to three years. However, given the number of different approaches, there is a good chance that there will be additional treatments available for celiac disease in the future. Lifestyle and home remedies If you've been diagnosed with celiac disease, you'll need to avoid all foods that contain gluten. Ask your doctor for a referral to a dietitian, who can help you plan a healthy gluten-free diet. It's important to get enough vitamins, nutrients, fiber and calcium in your diet. Here's an overview of foods that contain gluten and gluten-free foods that are safe to eat. Avoid food and drinks containing: - Barley - Bulgur - Durum - Farina - Graham flour - Malt - Rye - Semolina - Spelt (a form of wheat) - Triticale - Wheat Packaged foods should be avoided unless they're labeled as gluten-free or have no gluten-containing ingredients. In addition to cereals, pastas and baked goods - such as breads, cakes, pies and cookies - other packaged foods that may contain gluten include: - Beer - Candies - Gravies - Imitation meats or seafood - Processed luncheon meats - Salad dressings and sauces, including soy sauce - Self-basting poultry - Soups Certain grains, such as oats, can be contaminated with wheat during growing and processing. Pure oats are not harmful for most people with celiac disease. In the United States, doctors generally recommend avoiding oats unless they have been specifically labeled gluten-free. Outside of the United States, different labeling laws for oats apply. Occasionally, even pure oats can be a problem for people with celiac disease. Many basic foods are allowed in a gluten-free diet, including: - Fresh meats, fish and poultry that aren't breaded, batter-coated or marinated - Fruits - Most dairy products - Potatoes - Vegetables - Wine and distilled liquors, ciders and spirits Grains and starches allowed in a gluten-free diet include: - Amaranth - Arrowroot - Buckwheat - Corn - Cornmeal - Gluten-free flours (rice, soy, corn, potato, bean) - Pure corn tortillas - Quinoa - Rice - Tapioca Carob is a potential substitute for gluten, but more research is needed about its effect on people with celiac disease. Fortunately for bread and pasta lovers with celiac disease, an increasing number of gluten-free products are available. If you can't find any at your local bakery or grocery store, check online. There are gluten-free substitutes for many gluten-containing foods. However, be aware that processed gluten-free foods may contain excessive fat and calories. Alternative medicine There are no proven treatments that assist with celiac disease. Enzyme therapies that claim to digest gluten may be available in health food stores or other outlets, but there is no scientific evidence that they are effective in treating celiac disease. 

Answer: There are two blood tests your doctor may order to help diagnose celiac disease. Serology testing looks for antibodies in your blood, which can indicate an immune reaction to gluten. Genetic testing for human leukocyte antigens (HLA-DQ2 and HLA-DQ8) can be used to rule out celiac disease. If the results of these tests indicate celiac disease, your doctor may order an endoscopy to view your small intestine and to take a small tissue sample (biopsy) to analyze for damage to the villi.