The Determination Of The Prevalence Of Undiagnosed Celiac Sprue In A Population Of Non Hodgkin's Lymphoma Patients

Celiac sprue is a disorder characterized by the symptoms of malabsorption and an abnormal small bowel histology, which is due to the patient's intolerance to gluten. Gluten is a protein found in wheat and wheat products. The typical symptoms of malabsorption include weight loss, abdominal distention, bloating, diarrhea and steatorrhea. However, the severity of the disease varies greatly among the celiac sprue patients. For example, a patient may have the typical small bowel histological changes, consistent with celiac sprue, but may be asymptomatic, may have iron deficiency anemia without a source of bleeding or have a metabolic bone disease without the symptoms of malabsorption. The histological changes seen in celiac sprue are the blunting and flattening of the small bowel villi along with crypt hyperplasia. These changes are nonspecific and can be seen in tropical sprue, viral gastroenteritis and severe intestinal bacterial overgrowth. However, the diagnosis of celiac sprue is established when there is clinical, biochemical and histological improvement after the commencement of a gluten free diet. Celiac sprue has been considered a disease that largely occurs in Caucasian populations. Furthermore, celiac sprue is a fairly common disease in Northern Europe, Italy and among Ashkenazi Jews, where serological screening tests have reported the prevalence to be 1 in 250 to 3)00 of the general population. (1,2) One study in Northern Ireland reported an even greater prevalence of 1 in 122(3). In contrast, celiac sprue in the U. S. is considered to be a rare occurrence, an orphan disease. However, a recent study in Baltimore evaluating the blood donor pool reported a similar prevalence of celiac sprue in the U.S. in agreement with the European studies.(4) Possibly, the lack of recognition of celiac sprue in the U.S. is due to many celiac sprue patients being asymptomatic, having latent or silent disease. The screening tests for celiac sprue are serological assays for antighadin antibody and antiendomysial antibody. The antighadin antibody is the antibody to gliadin peptides. Gliadin is the alcohol soluble fraction of gluten. In celiac sprue patients, gliadin peptides are toxic and induce the characteristic small bowel lesions. Both antighadin IgG and IgA antibodies are present in the serum of celiac sprue patients unless the patient is IgA deficient. The IgA antibody is a dimer and is secreted into the lumen of the small bowel. Thus, the presence of the antighadin IgA antibody in untreated celiac sprue patients is more specific but less sensitive than the IgG antibody. The sensitivity of the antighadin IgA antibody ranges from 55-85% as compared to 65-95% for the antighadin IgG antibody. In contrast, the specificity for the antighadin IgA antibody is 80100% as compared to 60-100% for the antighadin IgG antibody(5). The antiendomysial antibody is directed against the smooth muscle cells of the primate GI tract. Why this antibody is present in celiac sprue patients is unclear, however most likely its due to an epiphenomena. Surprisingly, there is nearly 100% specificity with the antiendomysial IgA antibody and a sensitivity of 89100%(5). The only antiendomysial antibody tested for is IgA, whose positivity and titer level correlates with the severity of the small bowel lesion. These serological tests besides being used to screen populations to determine the prevalence of celiac sprue, can be used to monitor compliance with a gluten free diet. If there is strict adherence to the diet, the antibody titers will normalize. Also, these screening tests can determine candidacy for a jejunal biopsy. This is important, since it is still necessary to identify the histological changes consistent with celiac sprue, before committing a patient to a lifetime on a gluten free diet. There have been many studies revealing a higher than expected incidence of malignancy in celiac sprue patients.(6-10) However, only certain types of malignancy have been shown to have an increased