Celiac Disease | Celiac Testing | Allergy

Celiac Disease and Testing

by Allergy Guy


Celiac disease is a serious condition affecting the intestine. It is a genetic condition triggered by eating gluten. Further resources appear at the bottom of this article.

Recent data has shown that the incidence of celiac in the general population is as high as 1% in North America and Europe.(1) Celiac is therefore as high as 1 in 100. To put this in perspective, other diseases that are presently screened in newborns are much lower; for example, the incidence of hypothyroid in newborns is 1 in 4,000, and phenylketonuria is 1 in 13,500 to 19,000. To screen for celiac in newborns is more difficult, as celiac does not generally show up until age 2. If you have Irish or Scottish blood, the incidence of celiac may be as high as 1 in 15.

Celiac disease is a proximal small intestinal inflammatory disease that may involve a variable length of the intestine. The proximal intestine is the site of absorption of iron, calcium, fat-soluble vitamins, and folic acid, as well as the products of the digestion of fats, carbohydrates, and proteins. Diarrhea is thought to be a hallmark, but may not occur because the distal small intestine can compensate and absorb the products of the digestion of fats and carbohydrates. Diarrhea is determined more by the length of intestine involved rather than the severity of a segment found on biopsy. Other factors involved in diarrhea include pancreatic insufficiency, lactose intolerance (about 40% of the population) and bacterial overgrowth. (Green, Peter H.R., The Many Faces of Celiac Disease: Clinical Presentation of Celiac Disease in the Adult Population. NIH Consensus Conf. June 28-30, 2004).

The number of people currently found to be celiac is only .02 to .27 percent of the population, which means that for every patient found to have a diagnosis of celiac, there are 3 to 10 others who have not yet been diagnosed. The disease satisfies the criteria for mass screening.

One of the tests being used is a blood test for IgA tissue transglutaminase antibody. Sometimes, however, unless the disease is severe, this does not show up in the blood so an even more specific test may be done for this antibody in the stool (done by www.enterolab.com). This latter test can be ordered directly by a patient.
One of the risks of undetected celiac is that of small intestinal lymphoma. Dietary elimination of gluten has been found to prevent this malignant condition.(2) Overall, there is an increased risk of developing Non Hodgkin’s Lymphoma, especially of the T-cell type and primarily localized in the gut. Strict adherence to a gluten-free diet appears to affect the occurrence of these cancers.

Screening had been advocated to prevent malabsorption. Subclinical osteoporosis has been found in undetected celiac patients, some of which appear to be asymptomatic. It has been hypothesized that early gluten-free dietary treatment might prevent the development also of autoimmune conditions such as thyroid disease, Sjogren’s syndrome, Type 1 diabetes and Addison’s disease.

Screening is definitely indicated when there is evidence of malabsorption, iron, B12 or folate deficiency. Infertility, osteoporosis, loss of balance and polyneuropathy, arthritis of unknown etiology, chronic liver disease of unknown etiology, suspicion of dermatitis herpetiformis, and irritable bowel syndrome, are also seen in celiac patients. They may also present with nausea.

After one year on a gluten-free diet, a significant increase in bone mineral density was noted .(3)

Mortality rate was increased in celiac patients who went undiagnosed or did not stay on a gluten-free diet, if they had a more severe form of the disease.(4)

Delayed puberty occurs in some celiac patients, thought to be due to malabsorption of B vitamins, iron and folic acid.(5) Jameson reports a correlation between zinc deficiencies and the severity of villous atrophy in adults. He also reports that the more pronounced the lesions in the bowel, the lower the levels seen for iron, copper, folate, and B12.(6 )Recovery from iron deficiency anaemia is possible on a gluten-free diet alone.(7)

Body composition and parameters such as weight, body mass index and fat mass improve after starting a GFD in symptomatic patients with celiac. (Anne Cranney, M.D., M.Sc.) Although it is thought that most patients lose weight, some actually present as overweight. (Murray JA, et al. Clin Gastroenterol Hepatol. 2003;1:19-27.)

Celiac has been associated with a wide spectrum of neurological and psychiatric disorders including cerebellar ataxia (dizziness), peripheral neuropathy (numbness in the limbs), myositis (pain in the muscles), epilepsy (seizures), dementia (loss of memory), psychosis and depression.(8) Recent studies had shown extra-intestinal manifestations of celiac in patients even without intestinal pathology. These include migraine, encephalopathy, chorea, brain stem dysfunction, myelopathy, mononeueritis, Guillian Barre-like syndrome, and neuropathy with positive antiganglioside antibodies.(9)

Prevalence appears to be female to male 3 to 1. The majority of people are diagnosed in their fourth to sixth decades. The delay in diagnosis is not unique to North America, but rather is considered to be physician-based rather than due to delay in patients seeking medical help.(10) Initially, patients often receive the diagnosis of irritable bowel syndrome, or some alternative.(11)

Major modes of presentation are screening of first-degree relatives of affected patients. Sometimes patients with not typically associated celiac symptoms, such as esophageal reflux,(12) or heartburn(13) are found to have celiac at routine endoscopy exam.

Patients with celiac disease have a ten-fold prevalence of autoimmune disease compared with the general population, suggesting an increased burden of illness. Frequently the autoimmune disease is diagnosed first.
Not all patients have positive serologies. Those with sero-negative celiac have identical clinical presentations, associated disorders, and respond to a gluten-free diet as well. Negative serologic tests are seen more often in patients with lesser degrees of villous atrophy.

The spectrum of celiac disease is great. The vast majority of patients have silent disease, but the associated diseases may have severe manifestations. Many have associated autoimmune disease. Some have mild levels of fatigue, irritability, bloating off and on, and think this is normal. They will often avoid participation in high cardiac output sports.(14)

In the lab it would be common to find a low RBC folate, RBC zinc, low serum B12, low cholesterol, and low triglycerides (less that .75), a low vitamin D (1,25 OH vit D), low vitamin A and K, and a low ionized calcium, or 24-hour urine calcium, as well as low plasma or urinary proteins. Depending on where the atrophy has occurred in the small bowel, there may be variations in levels of the above-mentioned nutrients. Men generally have a more severe osteoporosis when it is present.

If a patient has vague symptoms of fatigue, headache, bloating, irritability, and that is all, without the more severe osteoporosis and malignancy, I would recommend that they consider sending away to the Enterolab in Dallas Texas to do, at least, a stool analysis for transglutaminase antibodies. That test is $99 USD, and if it is positive, it may be worth doing more that they offer, such as malabsorption and genetic testing. It would also be wise to bring your results to your doctor and ask for a consult to a gastroenterologist for further work up.

Dr. Jennifer Armstrong


Notes

1 Maki M, Mustalahti K, Kokkonen J, et al. Prevalence of celiac disease among children in Finland. N Engl J Med. 2003;348:2517-2524.
2 Holmes GKT, Prior P, Lane MR, Pope D, Allan RN. Malignancy in Celiac disease, effect of a gluten-free diet. Gut. 1989;30;333-338.
3 Moreno ML, Vazquez H, Mazure R, Smecuol E, Niveloni S, Pedreira S, et al. Stratification of bone fracture risk in patients with celiac disease. Clinical Gastroenterol Hepatol. 2004;2:127-134.
4 Corrarao g, Corrazza GR, Bagnardi V, Brusco G, Ciacci C, Cottone M, et al. Mortality in patients with celiac disease and their relatives: a cohort study. Lancet. 2001;358:356-61.
5 Bona G, Marinello d, Oderda g. Mechanisms of abnormal puberty in celiac disease. Horm res. 2002;57(suppl 2):63-65.
6 Jameson S. Celiac disease, insulin-like growth factor, bone mineral density, and zinc. Scand J Gastroenterol. 2000;35:894-896.
7 Annibale B, Severi C, Chostolini A, et al. Efficacy of gluten-free diet alone on recovery from iron-deficiency anemia in adult celiac patients. Am J Gasytroenterol. 2001 Jan;96(1):132-137.
8 Cooke W, Smith W. Neurological disorders associated with adult celiac disease. Brain. 1966: 89(4):683-722.
9 Wills AJ, Turner B, Lock RJ, Johnston SL, Unsworth DJ, Fry L. Dermatitis herpetiformis and neurological dysfunction. J Neurol Neurosurg Psychiatry. 2002;72(2):259-261.
10 Lankisch PG, Martinez Schramm A, Peterson F, Droge M, Lehnick d, Lembcke B. Diagnostic intervals for recognizing celiac disease. Z gastroenterol. 1996;34:473-477
11 Sanders DS, Carter MJ, Hurlstone DP, et al. Association of adult celiac disease with irritable bowel syndrome: a case-control study in patients fulfilling ROME II criteria referred to secondary care. Lancet. 2001;358:1504-1508.
12 Green PH, Shane E, Rotterdam H, Forde KA, Grossbard L. significance of unsuspected celiac disease detected at endoscopy. Gastrointest Endosc. 2000;52:60-65.
13 Bardella MT, Minoli G, Ravizza D, et al. Increased prevalence of celiac disease in patients with dyspepsia. Arch Intern Med.
2000;160:1489-1491.
14 West J, Logan Rf, Hill PG, et al. Seroprevalence, correlateds, and characteristics of undetected celiac disease in England. Gut.


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