June 22, 2021

I, Science

The science magazine of Imperial College

Sophia Ho reveals the real impacts of gluten intolerance
Coeliac_pathology wikipedia
Biopsy of small bowel showing coeliac disease manifested by blunting of villi, crypt hyperplasia, and lymphocyte infiltration of crypts (from Wikipedia)

It was in 2007 when Karen started to see the signs. Working in the police force for over 20 years, she was an exceptionally healthy and athletic individual.

Seven years ago, however, some changes became apparent. Karen began to frequently feel tired, lethargic, out of breath with her pulse racing. She also felt bloated after virtually every meal, lost weight and even noticed some thinning of her hair and eyebrows.

As Karen had family members that suffered from hypothyroidism, an underactive thyroid, she asked her doctors to test her for the same condition. It turned out that Karen suffered instead from hyperthyroidism, an overactive thyroid, for which she was given medication.

However, after taking the medication, which restored her normal thyroid activity, Karen still experienced the same symptoms as before. In addition, she continued to gain weight and no amount of exercise allowed her to lose it. Most surprisingly, she started to develop vitiligo (partial skin depigmentation).

The issue finally resolved when Karen decided to seek a private consultant and endocrinologist, who at long last was able to diagnose her as a sufferer of Coeliac disease, confirmed via a gut biopsy. Previous blood tests had not been able to establish this, which is not uncommon for Coeliac patients.

Coeliac disease (CD) is an autoimmune disease that affects the large intestine in response to a protein found in wheat, barley and rye, known as gluten. Gluten gives dough elasticity and allows it to rise, and can be found in various food products such as bread, pasta, chocolate and soy sauce. CD has been documented throughout history, from as early as the first century AD, as a condition that manifests as malabsorption, diarrhoea or constipation, weight loss, bloatedness, fatigue and stomach pains.

Closed_and_open_conformations_of_tissue transglutaminase wikipedia
Compact (inactive) and extended (active) conformations of tissue transglutaminase

Upon exposure to gluten, an intestinal enzyme known as tissue transglutaminase modifies its soluble component, gliadin, forming a new complex. In Coeliac patients, this new complex triggers an inflammatory response, which destroys epithelial cells in the small projections lining the intestine, known as villi. This leads to the impaired absorption of nutrients in the intestine, and to the symptoms listed above and those Karen experienced. Indeed, the biopsy taken from her revealed that her villi had largely deteriorated.

The only known and successful way to deal with CD is to exclude gluten in your diet for life Current research has focused on generating genetically modified wheat designed to reduce stimulation of the immune response. Alternative solutions have looked at ways to produce ingestible enzymes that remove the stimulatory gliadin protein and prevent it from triggering inflammation.

CD is fairly common and can even be hereditary – it is believed to affect up to 1% of the world’s population. Many remain undiagnosed, as symptoms may not always be presented, or, as in Karen’s case, don’t manifest until adult age.

After seeing the consultant and following his recommended diet, Karen’s condition dramatically improved: her hair started to regrow, and her energy levels and weight returned to normal. Further tests on her hyperthyroidism also proved that it was caused and influenced by her issues with CD, and most likely won’t affect her again provided she continues to avoid gluten-containing foods. On the other hand, her vitiligo, also caused by CD, may stay with her for life. However, a biopsy taken a year ago revealed that the villi lining of Karen’s intestine was restored to normal.

Only one small concern remains. We mentioned that CD is known to be a genetic predisposition. Karen’s consultant has stated that as many as 85% of her family may also be ‘Coeliacs’. It may now be time to reveal that Karen is in fact my maternal aunt!

Karen’s condition now hardly affects her; her life has returned to normal and we always ensure that her needs are met at every family food gathering. In the meantime, we shall all be on the lookout for any symptoms of our own!

Sophia Ho is studying for an MSc in Molecular Medicine

Images from Wikipedia: damaged villi; tissue transglutaminase structure