Introduction
Celiac disease may be defined as a disease of the proximal small intestine characterised by an abnormal small intestinal mucosa and associated with permanent intolerance to gluten. Removal of gluten from the diet leads to full clinical remission and restoration of the small intestinal mucosa to normal. Not all patients respond to the withdrawal of gluten from the diet.
Etiology
The disease is caused by the toxic action of ingested gluten on the mucosa of the small intestine. This action may occur because the intestine lacks the enzymes to detoxicate injurious peptides produced during the digestion of gluten or because local immunological reactions are induced in the intestinal mucosa. The toxic fraction of the wheat protein is known as gluten. Gliadin is the alcohol-soluble portion of the gluten and is toxic, whereas glutenin, the alcohol-insoluble portion, is non-toxic. In addition to wheat, barley and rey are toxic. Oats, maize and rice are harmless. Many enzymes, including peptidases, are deficient in the intestinal mucosa of untreated celiac patients, but activity increases when there is mucosal recovery during treatment with a gluten free diet.
Incidence in India
There has been very few studies from India on celiac disease. Cases are reported from N Delhi, PGI chandigarh, Lucknow (representing wheat eating population in India). Some of the studies report 26% cases of malabsorption and 4-5 % cases of chronic diarrhea have celiac disease. PGI chandigarh report 20-40 new cases every year. One of the gastro department report 7% of there indoor patients and 5% of there Clinic patients are of celiac disease.
Immunological reactions in celiac
There is an increased number of IgA, IgM and IgG plasma cells in the jejunal mucosa, and increased amount of IgA, IgM and IgG in jejunal secretions. Serum IgA concentrations are often high and IgM concentrations low, both abnormalities returning to normal on withdrawal of gluten. There is a raised number of intraepithelial lymphocytes, probably T cells, in celiac disease. Differential cell counts on the lamina propria show that there is an increase in the absolute number of plasma cells and a decrease in the number of lymphocytes. Splenic atrophy is common in adult celiac disease. Individuals with HLA-B8, HLA-DW3 are more likely to have celiac disease than those without antigen.
Childhood Celiac Disease
Diarrhea, vomiting, and failure to thrive occur most frequently. In infants younger than 9 months vomiting is frequent and diarrhea may be severe, especially with intercurrent infections. Children aged 9 to 18 months who develop celiac disease fail to thrive gradually 3 to 6 months after the introduction of cereals, a condition attended by anorexia and frequent soft, pale, bulky stools. The fulminant clinical condition, known as celiac crisis accompanied by skin bleeding, hypocalcemic tetany, hpoalbunemia and edema is now rare with early diagnosis. But not, so rare in underprivileged societies. One may still see a child with celiac disease with distended abdomen, wasted buttocks, and depleted shoulder girdles, anemia, rickets, personality problems and short stature. These children are generally labeled as typical nutritional PEM cases.
Laboratory Findings
Jejunal Biopsy It is a gold standard for the diagnosis. Histologic alterations are graded as follows (i) Grade 0: normal (ii) Grade 1: slight villous atrophy, (iii) Grade 2: subtotal villous atrophy, (iv) Grade 3: total villous atrophy. Other indirect tests are fat determination in feces, serum folate determination, intestinal sugar absorption (i) lactose absorption test, (ii) D-xylose absorption test, (iii) lactulose-mannitol test, determination in serum of antigliadin, antireticulin, or antiendomysium antibodies. Number of patients show an increase in the number and thickness of the ileal folds (jejunalization) by barium meal examination. The characteristic blood picture of the celiac disease is a mild, hypochromic, macrocytic anemia.
Treatment
A lifelong, strict exclusion of gluten, as found in wheat, rye and barley, is the universal approach to the management of celiac disease. Apart from gluten free diet patients may temporarily need a diet poor in lactose. Corticosteroids produce histological and clinical improvement, but it is not known whether they act by suppressing immunological mechanisms or by other means. They are used in the severely ill patient, and some physicians use them in patients who fail to respond to a gluten free diet. Usually withdrawal of corticosteroids leads to clinical and histological relapse. Supportive therapy of calcium, iron, multivitamins are needed as per patient requirements.
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