Italy Leads The World In Screening For Celiac Disease

Celiac disease is common but often undetected. Researchers are looking at ways to make the disease both easier to diagnose and easier to treat.

By Jason Tye-Din, WEHI

MELBOURNE, Sept 10 — The land of pizza and pasta — Italy — has become the first country in the world to pass a law requiring all children under the age of 18 to be screened for celiac disease and type 1 diabetes.

Celiac disease is an autoimmune illness which causes a range of health problems and is triggered by dietary gluten — a protein found in wheat, rye, and barley — that is ubiquitous in Western and increasingly Eastern diets.

For people with celiac disease, this means foods such as pasta, pizza, bread, pastries, and dumplings are forever off the menu unless they can find a gluten-free alternative. Even a bite can trigger symptoms akin to a case of bad food poisoning.

Italy introduced its population screening programme in recognition that celiac disease is common but often undiagnosed.

The programme begins this year, prompting other countries to consider whether they should follow suit.

At the same time, researchers are looking at ways the disease may be more easily detected and treated.

Celiac disease results from an abnormal immune response to dietary gluten in genetically susceptible individuals.

Nearly half of the Western population carries the genes that increase susceptibility to celiac disease.

Diagnosis involves a blood test to detect certain celiac disease antibodies and identifying characteristic damage to the small intestine through a gastroscope, which collects tiny samples or biopsies of the intestinal lining.

In the past 50 years, the prevalence of celiac disease has risen four-fold, independent of increased awareness and testing, for reasons largely unknown.

Screening studies using antibody tests indicate that celiac disease affects approximately one to two per cent of people globally.

There is considerable variation within and between countries, reflecting differences in genetic risk and environmental exposure, with gluten consumption being a significant factor.

For example, celiac disease is common in northern India, where wheat is a dietary staple, but less common in southern India, where rice predominates.

Although there are limited population studies in Asia, celiac disease appears to be common in Malaysia and has been reported in China. Despite sparse data from Indonesia and Japan, cases of celiac disease have been documented in these countries too.

Given that wheat consumption in the Asia-Pacific region has increased by approximately 30 per cent over the past decade, a rise in celiac disease is likely.

Improved medical and community awareness in the Indo-Pacific will be crucial for ensuring timely diagnosis, as alarmingly, in most countries more than 50 percent of individuals with celiac disease are unaware of their condition.

The delay in diagnosis is partly due to the wide variability and subtlety of symptoms, which can include abdominal pain, altered bowel habits, weight loss, lethargy, headaches and brain fog.

Additional issues may involve nutrient deficiencies such as iron deficiency anaemia, reduced bone density, increased infection rates, liver function abnormalities, infertility and certain cancers such as lymphoma.

Some people show no obvious symptoms, making it easy for doctors to overlook the diagnosis.

Italy’s population screening programme aims to overcome the limitations of case-finding by screening all people regardless of symptoms. The effectiveness of this approach will be evaluated in the coming years.

Another factor hindering diagnosis is that testing methods to detect antibodies and intestinal biopsies are only informative when the patient is consuming gluten.

Since 10 to 20 percent of people living in Western countries are reducing or eliminating gluten for various reasons, testing for celiac disease in this group is problematic.

Research is underway to develop better diagnostic methods beyond these traditional approaches.

Gluten-specific T cells — a type of white blood cell crucial for the development of celiac disease — are rare in the blood and hence difficult to detect.

Australian research shows that these cells can be identified using an ultrasensitive blood test that detects a biomarker called interleukin-2, secreted by T cells after gluten exposure in a test tube.

A community study is validating this promising approach. If accurate, this simple blood test may avoid the need for patients to have intestinal biopsies or consume gluten in order to make a diagnosis.

A strict and lifelong gluten-free diet is currently the only treatment for celiac disease, but it is complex and burdensome.

Gluten-free foods are expensive, often less palatable and even tiny amounts of gluten can trigger adverse symptoms akin to acute food poisoning.

These treatment limitations mean that a third of patients  continue to experience symptoms or intestinal damage, increasing the risk of long-term health complications.

Clearly, new treatment approaches are needed.

Pharmaceutical companies are exploring two main strategies: reducing the amount of gluten exposed to the immune system and restoring immune tolerance to gluten.

The first approach involves using enzymes to degrade gluten or drugs to minimise its “toxicity”, aiming to assist but not replace the gluten-free diet.

The second approach targets and modifies gluten-specific immune pathways, potentially allowing a return to a normal gluten-containing diet. Restoring normal immune function would effectively be a cure for celiac disease.

Multiple early-stage clinical trials testing these approaches are underway, with researchers in Australia and New Zealand taking a leading role.

A successful pharmaceutical drug for celiac disease would help patients and also change how the condition is viewed, moving it from a dietary issue to a medical one.

Looking ahead, novel tools targeting the immune response to gluten may improve the diagnosis of celiac disease.

If Italy’s screening programme proves successful, similar early detection strategies might become widespread.

Collectively, these approaches may help reduce the burden of undiagnosed disease in the community.

Understanding why celiac disease develops is of substantial interest, as this knowledge could inform preventative strategies.

A large Australian study is examining environmental factors contributing to celiac disease and type 1 diabetes, which share the same genetic risk markers.

Environmental factors that disrupt the gut microbiome, such as infections, may play a key role in someone going on to develop celiac disease.

Findings from this study could lead to ways to prevent celiac disease in children who are genetically at-risk.

While these developments are promising, they will take time.

Until then, it’s encouraging to know that potential treatments are on the horizon, offering hope that one day people with celiac disease may safely enjoy pizza, pasta and bread once again.

Jason Tye-Din is the head of the Coeliac Research Lab at WEHI, a gastroenterology consultant at The Royal Melbourne Hospital and a principal research fellow at University of Melbourne.

Article courtesy of 360info. 

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