<<Disclaimer: Verify this information before applying it to your situation.>> Q. One case I know of had elevated gliadins (both types) but normal EMA and ARA, plus an inconclusive biopsy. Do you see this often? K. If the tests are performed using well standardized tests with known positive and negative predictive values then you can make the statement that if the serological tests are negative CD can virtually be ruled out. The problem is that some of these assays, especially the gliadin, can give you false positive results. In our laboratory we rarely see positive AGA results in the absence of EMA and ARA antibodies. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Q. Are there any unique factors to be considered for children? I've heard that the serology has a lower predictive value for children under age two, since IgA may be depressed, or with anyone who has a condition which depresses IgA. K. Not really. It is not true that the serological methods have lower predictive value in children less than two years of age. In all the studies that we did, there was 100% correlation of the EMA to the disease activity irrespective of the age. H. There are age dependent changes in several blood parameters during childhood. It is well known that immunoglobulin levels depend on the age of children. E.g. the IgA class immunoglobulins reach the adult level only by 16 years of age, and the blood level of IgA immunoglobulins is only 1/5th of adult value below two years of age. A large study from Europe (Brgin-Wollf et al. Arch Dis Child 1991;66:941-947) showed that the endomysium antibody test is less specific and sensitive in children below two years of age. They found that the sensitivity of the EmA test decreased from 98% to 88% in children younger than 2 years of age. It means that 12% of their patients with celiac disease, who were younger than two years of age, did not have an increase in their endomysium antibody levels. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Q. How important is it for a confirmed celiac to have repeat biopsies or serology when on a gluten free diet? K. It is important for the serum tests to be negative in patients with CD. These tests provide strong indicators that the gluten free diet followed is effective and is free of gluten. Sometimes drugs or other intakes may be contaminated with gluten that may continue sensitization and the disease process which may be subclinically. We and others believe once the diagnosis of CD is confirmed and the patient is on a gluten free diet, repeat tests once in 3-6 months may be sufficient. H. If a patient has histologically (endoscopy) and serologically (antibody tests) proved celiac disease, and his/her symptoms disappeared on a gluten-free diet, a repeat biopsy is not necessary. The serological tests are useful tools for estimating the effectiveness of the diet after 3-6 months on a gluten-free diet. The disappearance of antibodies from the blood takes months, if there was not any accidental gluten challenge (dietary mistake). ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Q. There are different practices amongst g/i's on repeat biopsies vs. serology, and on gluten challenges. My son's g/i, for example, took the position that since my son's symptoms stopped on a GF diet, and his previously sky-high EMA and ARA went back to normal, that it was unnecessary to do either a repeat biopsy or a gluten challenge. From the celiac list correspondence, I now see that my g/i is rather liberal. K. I think your son's GI is doing the right thing. That is, if the EMA, ARA are normal (<1:2.5) and he is on a gluten free diet then there is no need to perform biopsy studies. The previous studies relating the EMA to biopsy studies tend to confirm this impression. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Q. Should my child have general anesthesia or conscious sedation prior to the biopsy? H. The biopsy is a small piece of tissue, such as from the inside lining of the intestine, that has been removed to look for diseases. The biopsy itself is not painful, because there are no pain-sensitive nerves inside the small intestine. An intestinal biopsy can be done in either of two ways depending on the age of the children and the tradition of the institution. Sometimes a blind biopsy procedure is performed by a biopsy capsule. This is thin flexible tube with a capsule at the tip, which has a hole and a tiny knife inside the capsule. This capsule is introduced into the intestine under fluoroscopy (X-ray) control. Alternatively, with an endoscopy the doctor can see inside the digestive tract without using an x-ray to obtain biopsies. The biopsy specimens are processed and viewed under the microscope to identify or exclude celiac disease. An important basic rule is that the biopsy should be performed safely. For a safe procedure children (and adults) should be sedated. There are two methods of sedation: unconscious (general anesthesia) and conscious sedation. During both kinds of sedation the vital parameters (heart rate, blood pressure, oxygen saturation) of patients are continuously monitored. The method of choice depends on the child. Conscious sedation is performed with two different intravenous medications. One of them is a sedative medication (e.g. Versed), which causes amnesia in 80-90% of children, and even older children do not recall the procedure. The second medication is a pain-killer type medication (e.g. Fentanyl), which further reduces the discomfort associated with the procedure. In addition, the throat is sprayed with a local anesthetic in older children, which makes the throat numb and prevents retching at the introduction of the endoscope. During general anesthesia the anesthesiologist uses sleep-gases (e.g. halothan) and intravenous medications and then places a tube into the trachea. Children are completely unconscious. This is a safer way to perform endoscopy, because the patients are fully relaxed and their airway is protected. However, the anesthesia itself has certain complications. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~