The degree of mucosal damage varies from one celiac patient to another. Also, the amount of the small intestine that is affected also varies, with the damage usually progressing from the beginning of the small intestine and then moving downward toward the end of the small intestine. This may explain the variable symptoms in different patients. For example, when a significant portion of the small intestine is involved, diarrhea, malabsorption, and weight loss result. When damage is isolated to only the top portion of the small intestine, the only affect may be iron deficiency. (Incidentally, when iron deficiency is not corrected by iron supplements, it is highly likely that celiac disease is the cause of the deficiency.)
Gluten in a celiacs diet causes the immune system to produce gliadin antibodies in the intestine. Some of these leak into the bloodstream where they can be detected in blood tests. These blood tests are useful for screening for celiac disease, though a small intestinal biopsy remains the gold standard for diagnosing celiac disease (celiac disease).
There are few diseases for which diet and nutritional issues are more important than for celiac disease. At this time, the only known treatment of celiac disease is the removal of wheat, barley, rye, and oats from the celiacs diet. On the surface this sounds simple, but complete removal of dietary gluten can be very difficult. Gluten-containing grains are ubiquitous in the Western diet. Also, grain-derived food additives such as partially hydrolyzed vegetable protein [and modified food starch] are widely used in processed foods and oral medications. Content labels are often vague or incomplete regarding these additives.
What further complicates matters is a lack of significant experience on the part of physicians and dietitians in the dietary treatment of celiac disease. This is mainly because there are so few celiac patients for anyone practitioner. Therefore the best sources of dietary information for a new patient are other knowledgeable, more experienced celiacs.
It is very important that the diet be followed with full and strict compliance. Celiacs, especially if theyve had active celiac disease for a longtime, are at higher than normal risk for GI malignancies.(Fortunately, compliance to a good gluten-free diet returns the risk of malignancy and life expectancy to that of the general population.)Another complication of long-term untreated celiac disease is bone loss, which maybe irreversible in older patients.
When a large portion of the small intestine is affected by active celiac disease, the result can be a generalized malabsorption problem, resulting in deficiencies of water- and fat-soluble vitamins and minerals. Folic acid deficiency is particularly common in celiac disease because, like iron, it is absorbed in the upper small intestine [where the highest concentration of celiac-related damage generally occurs]. Folic acid is necessary for DNA replication, which occurs in cell turnover. So a deficiency of folic acid can impair the regenerative ability of the small intestine. Vitamin B12, also essential to DNA synthesis, is not malabsorbed as commonly as folic acid.
Magnesium and calcium deficiency are also common in active celiac disease, because of decreased intestinal absorption AND because these minerals tend to bind with malabsorbed fat which passes through the system. It is particularly important for doctors to assess the magnesium status of celiacs, because without correction of a magnesium deficiency, low levels of calcium and potassium in the blood cannot usually be corrected with supplements. In severe cases, magnesium supplementation should be done intravenously because of the tendency of oral magnesium to cause diarrhea.
Supplemental calcium generally should be provided to celiacs, possibly with vitamin D, to help restore tissue and bone calcium levels to normal. The exact dose of calcium is not known. Dr. Fine usually recommends 1500-2000 mg of elemental calcium per day, divided into two doses, for several years and sometimes indefinitely. , , 
Zinc is another mineral that often becomes depleted in patients with chronic malabsorption. Zinc supplementation (usually the RDA via multi-vitamin and mineral supplements) helps avoid skin rashes and restores normal taste.
Up to 20% of celiacs will continue to experience loose or watery stools even after going on a gluten-free diet. Sometimes this is due to inadvertent gluten in the diet, but a recent study at Dr. Fines medical center showed that in these cases other diseases epidemiologically associated with celiac disease are present. These include microscopic colitis, exocrine pancreatic insufficiency, lactose intolerance, selective IgA deficiency, hypo- or hyperthyroidism, and Type I diabetes mellitus. When diarrhea continues after beginning a gluten-free diet, a search for these associated diseases or others should be undertaken and treated if found.
The use of cortico steroids has been advocated in celiacs when the response to the gluten-free diet is sluggish or absent. This is necessary more often in older than in younger patients. However, pancreatic enzyme supplements (prescribed by a doctor) may be needed to help digestion and resolve ongoing malabsorption in some patients.
The endomysial antibody blood test is highly accurate and specific for detecting celiac disease. However, the current method of detecting these antibodies involves an operator looking through a microscope and observing the antibody binding on monkey esophagus or human umbilical cord tissue substrates. The correct interpretation of results is highly dependent on the skill and experience of the technician interpreting the fluorescence pattern through the microscope. Moreover, determination of the amount of antibody present relies upon repeat examinations following dilutions of the blood serum, with the last positive test being reported as a titer.
A new discovery was reported by a research group in Germany. The antigen substrate of the endomysial antibodies has been identified. This allows the development of a new test that can detect and measure serum endomysial antibodies in one, chemically-based test run [thus greatly reducing the potential for human error and significantly reducing the time needed for each test--ed.] These new tests should be available for clinical use shortly.
In a recent study, Dr. Fine found that the frequency of positive stool blood tests was greater in patients with total villous atrophy relative to partial villous atrophy, and all tests were negative in treated patients without villous atrophy. This suggests that fecal occult blood may be a non-invasive and inexpensive method of following the response of the damaged intestine to treatment. Also, it should be noted that the high frequency of positive tests due to villous atrophy will decrease the accuracy of the tests when used for cancer screening in this same patient population (which is how these tests are normally used by health care providers).
There have been two recent reports touting the lack of deleterious effects when 50 grams of oats per day are added to the diet of celiac patients. Although this finding is exciting for celiacs, both studies possess certain limitations. In the first study, published by a Finnish group, the exclusion criteria for symptoms and histopathology were somewhat strict, so that patients with more mild forms of celiac disease seemingly were selected for study. And though no damage to duodenal histology occurred after one year of oats consumption, no physiologic or immunologic parameters of disease activity were measured. Furthermore, several patients in the treatment group dropped out of the study for reasons not mentioned in the article. The second and more recent study involved only 10 patients, studied for twelve weeks. The favorable results of this study must be interpreted with caution because of the small sample size and short study period. Even the one-year treatment period in the Finnish study may be too short to observe a harmful effect, as it is known that small intestinal damage sometimes will not occur for several years following there introduction of gluten to a treated celiac. At the worst, an increase in the incidence of malignancy may result from chronic ingestion of oats, an effect that could take decades to manifest. Therefore, this issue will require further study before oats can be recommended for the celiac diet.