Saturday, December 23, 2006

Celiac disease with negative endomysial antibody not only exists but may be longstanding, more severe and associated with higher risk of lymphoma

A new report Finland not only confirms others studies showing celiac disease can be present in absence of a positive anti-endomysial antibody (EMA) but also this may be associated with longstanding, undiagnosed, more severe and complicated disease with a higher risk of lymphoma and death.

Celiac disease occurs with negative endomysial antibody:
Twenty two people without IgA deficiency, a cause of false negative EMA, were confirmed to have celiac disease by small intestinal biopsy that not only had classical changes but deposits of tissue transglutaminase IgA (tTG) in the intestinal tissue not found in people without celiac disease.

Endomysial antibody negative celiac patients are older and more often men:
The EMA negative patients were not only on average older (median age 55 versus 40 for EMA+) but more commonly men (59%) compared with the usual women predominance seen in celiac disease.

Endomysial antibody negative celiac patients have higher death rate:
During follow up 27% or six of twenty-two patients with negative EMA blood test diagnosed with celiac disease died during the follow up. Because these patients were on average older at time of their diagnosis it is presumed they had been undiagnosed and untreated for longer time than those who had a positive blood test.

Endomysial antibody negative celiac patients get lymphoma:
Three of the twenty-two with negative EMA had enteropathy-associated T cell lymphoma (EATL), a known complication of untreated, undiagnosed longstanding celiac disease. Two had an earlier small bowel biopsy that was consistent with celiac disease but was the diagnosis was overlooked because their EMA was negative.

Endomysial antibody negative celiac patients have severe intestinal damage:
The biopsies of EMA positive and EMA negative patients were not significantly different. Patients with negative EMA had advanced intestinal damage (Marsh III, partial to total villous atrophy) just as often as the blood test positive patients.

Duodenal biopsies testing for TG2 deposits may be done in future:
This study demonstrates that transglutaminase (TG2) is present in intestinal tissue in celiac disease but not in patients without celiac disease. Because these deposits can be detected when celiac blood test are negative or biopsy is equivocal, this testing may be useful in seronegative celiac disease instead of subjecting the patient to potentially dangerous gluten challenge or delay in diagnosis and instituting timely treatment with gluten-free diet. Without testing for TG2 in intestinal biopsy diagnosis of celiac disease may not be correctly made and gluten-free diet started early enough to prevent an increased risk of lymphoma and early death.

Duodenal biopsy indicated for symptoms or family history:
This study would support an approach that any patient with symptoms or signs of celiac disease should undergo an upper endoscopy with small biopsy regardless of EMA blood test results especially if they are a relative of celiac patient and/or DQ2 or DQ8 positive.

Endomysial antibody negative blood tests do not rule out celiac disease:
A negative EMA blood test does not rule out celiac disease but instead may result in delay in diagnosis and treatment. This delay in diagnosis and treatment may increase risk of more complications including lymphoma and death.

Celiac disease misperceptions may be a threat to your life:
This study further illustrates the expanding knowledge as well as misperceptions about celiac disease. Doctors who have told patients that they either don't have celiac disease or don't need a small bowel biopsy because of a negative endomysial antibody test should shudder. If you have been told you do not have celiac because you have a negative EMA despite having suggestive symptoms or a family history of celiac I recommend you have a small bowel biopsy. If you already have but were told that biopsy was not diagnostic or because your EMA was negative you don't have celiac disesase, I suggest you ask your doctor to reconsider the possibility. This is especially true if you are HLA DQ2 and/or DQ8 positive. Your life may be at risk.

Stay tuned as the Food Doc reviews another important article in the same December 2006 issue of Gut as this article also concluding that positive blood tests are not required for diagnosis of celiac disease and adding that mild biopsy findings of intraepithelial lymphocytosis without villous atrophy can result in malabsorption severe enough to result in anemia and osteoporosis.

Salmy TT. Endomysial antibody negative coeliac disease: clinical characteristics and intestinal autoantibody deposits. Gut 2006;55:1746-1753.

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