Gluten Ataxia Diagnosis

Researchers believe there are three autoimmune conditions triggered by an immune system reaction to gluten consumption: celiac disease, the skin rash dermatitis herpetiformis, and gluten ataxia, which involves damage to your brain that causes problems with balance, gait and vision.

Of the three conditions, gluten ataxia is the only one without a straightforward path to diagnosis. In fact, although awareness of gluten ataxia is growing, it hasn't been accepted by all mainstream physicians.

It's possible to use certain blood tests to screen for gluten ataxia, but the accuracy of these hasn't been validated, and it's possible they may miss people with the condition or possibly over-diagnose it. In many cases, the only real test of whether a person has gluten ataxia or not is to place that person on a gluten-free diet and see if gluten ataxia symptoms improve.

Gluten Ataxia Diagnosis Usually Involves Blood Antibody Testing

Diagnosing gluten ataxia usually involves using the celiac disease blood tests to look for abnormal levels of different types of gluten antibodies. However, the antibodies that may indicate gluten ataxia is present aren't necessarily the same ones that indicate celiac disease may be present.

The typical "celiac disease blood test panel" can consist of up to four or five individual tests. Of these, the AGA-IgA and the AGA-IgG tests are less specific to celiac disease (i.e., they're frequently thought to show false positives for the condition).

But these are the tests that may help to diagnose gluten ataxia.

A recent consensus report from top researchers on celiac disease and gluten sensitivity recommended using the AGA-IgA and AGA-IgG to screen for gluten ataxia in patients with otherwise unexplained ataxia symptoms.

Physicians also should screen for celiac disease using the tTG-IgA antibody test, which is more specific (i.e., shows fewer false positives) for celiac, according to the consensus document, which includes the input of Dr. Marios Hadjivassiliou, a neurologist in the U.K.

and the author of several papers on gluten ataxia.

If levels of tTG-IgA are elevated (research shows about 38% will have these elevated antibodies, although the antibodies won't be as high as they are in patients with intestinal symptoms), then the expert consensus statement recommends proceeding with an intestinal biopsy to test for celiac disease. One-third of gluten ataxia patients will show intestinal damage in the form of villous atrophy in an endoscopy, the researchers say.

If villous atrophy is present, then the person would be diagnosed with celiac disease, which requires a gluten-free diet.

However, if any antibodies to gluten are present in lab tests, then the recommendation is for all ataxia patients "with no alternative cause for their ataxia" to try a strict gluten-free diet for six to 12 months to see if it helps with their ataxia symptoms. Regular follow-up should include retesting to see if and when the antibodies from gluten fall to normal levels.

"Stabilization or even improvement of the ataxia after one year would be a strong indicator that the patient suffers from gluten ataxia," the consensus statement concluded.

Research on Gluten Ataxia Ongoing

It's possible that genetic testing might eventually be useful in diagnosing gluten ataxia — about 80% of gluten ataxia sufferers have one or both of the main celiac disease genes, HLA-DQ2 or HLA-DQ8, according to research by Dr. Hajivassiliou. Another 20% carry the HLA-DQ1 gene, which according to Dr. Hajivassiliou has been associated with neurological reactions to gluten.

Still, the current recommendation for diagnosing gluten ataxia involves using AGA-IgG and AGA-IgG blood tests, plus tests looking for high levels of more specific types of anti-gluten antibodies known as IgG and IgA anti-tTG6 antibodies.

Timing of a gluten ataxia diagnosis is critical, Dr. Hajivassiliou warns, because irreversible damage can set in if the disease process continues unabated. Therefore, he urges all ataxia patients to be tested for anti-gluten antibodies when they're first diagnosed, and says that physicians should prescribe a gluten-free diet for those who test positive on any of the blood antibody tests even if they don't have celiac disease.

Sources:

Bushara K. Neurologic presentation of celiac disease. Gastroenterology. 2005 Apr;128(4 Suppl 1):S92-7.

Fasano A. et al. Spectrum of gluten-related disorders: consensus on new nomenclature and classification. BMC Medicine. BMC Medicine 2012, 10:13 doi:10.1186/1741-7015-10-13. Published: 7 February 2012

Hadjivassiliou M. et al. Gluten sensitivity as a neurological illness. Journal of Neurology, Neurosurgery and Psychiatry. 2002;72:560-563 doi:10.1136/jnnp.72.5.560.

Hadjivassiliou M. et al. Gluten Ataxia. The Cerebellum. 2008;7(3):494-8.

Rashtak S. et al. Serology of celiac disease in gluten-sensitive ataxia or neuropathy: role of deamidated gliadin antibody. Journal of Neuroimmunology. 2011 Jan;230(1-2):130-4. Epub 2010 Nov 6.

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