The growing concern of delayed diagnosis in Coeliac Disease

Coeliac Disease slipping through the system

Coeliac disease, often perceived as a condition that manifests in early childhood, has a cloak of invisibility when it comes to its late onset in adults. This systemic inflammatory disorder, which shows no mercy to the villi of the small intestine when gluten is consumed, remains largely underdiagnosed. The recent Australian study by the Wesley Research Institute in Brisbane sheds light on a critical area: the silent sufferers who are the adult first-degree relatives of diagnosed coeliac patients.

The unfortunate reality is that many struggle with symptoms for years, being told it’s likely other conditions such as irritable bowel syndrome, or caused by stress, or simply bad luck. For some Australians, this is the reality of undiagnosed coeliac disease. A recent study from Wesley Research Institute has helped to lift misconceptions on Coeliac disease and late diagnoses. 

The Brisbane study underlines a startling contrast: while the prevalence among child relatives was around 11%, for adults, it dropped to a mere 1.4%. Does this mean fewer adults possess the genetic predisposition? Quite the contrary. A staggering 86% of the participants carried the coeliac susceptibility haplotypes, with a significant number having high-risk genotypes.

International delays

A 2018 study by Finnish Celiac Society (which approximately 70-80% of diagnosed coeliacs join within 1 year of diagnosis) found that on average, individuals experienced symptoms of coeliac disease for three years before receiving a diagnosis, with over half (54%) of the patients facing a diagnostic delay of at least three years. The age when coeliac disease was diagnosed did not differ significantly between those with a delayed diagnosis (median age 50, ranging from 16 to 75 years) and those without (median age 48, ranging from 17 to 82 years). 

Among the studied demographic factors, being a student or a homemaker was linked to a shorter time to diagnosis when compared to those who were employed. Other demographic characteristics, such as gender, marital status, type of occupation, leadership role at work, place of residence, and the location where celiac disease was first suspected or ultimately diagnosed, did not seem to influence the length of time taken to diagnose the condition. Findings indicate that even a brief postponement in diagnosing celiac disease can lead to a greater health impact, affecting both individuals and the wider community.

Genetic lottery

The problem, it appears, is not in the genetic lottery but in the vigilance of diagnostic practices. General Practitioners (GPs) and health professionals must sharpen their focus on this elusive chameleon of gastrointestinal disorders. What markers should they be alert to? The study points to two: HLA-DQ genotyping and serum anti-tissue transglutaminase (tTG) IgA and anti-deamidated gliadin peptide (DGP) IgG levels.

Currently, the strongest beacon leading to a coeliac diagnosis is a family history of the disease. Given this, shouldn’t we cast a more discerning eye towards first-degree relatives, especially adults, who present with compatible symptoms, no matter how subtle or intermittent? The Australian study emphasises that a proactive approach can uncover hidden cases of coeliac disease, allowing for timely intervention.

Yet, herein lies the rub: not all participants with positive serology proceeded to a definitive diagnostic small bowel biopsy, and this was a limitation of the study. One cannot help but wonder how many adults walk away from the doctor’s office with unresolved symptoms because the threshold for further investigation was not met or because the symptoms were atypical or misattributed to other conditions.

Adult onset coeliac disease can be a masquerader — its presentations are myriad, and its symptoms often overlap with those of other disorders. Fatigue, anaemia, unexplained gastrointestinal symptoms, and a plethora of non-gastrointestinal signs should wave the red flag, especially when occurring in individuals with a family history of coeliac disease.

Malignancy risk increased in delayed diagnosis

Research provides a concerning insight into the long-term consequences of delayed diagnosis in celiac disease, particularly the risk of malignancy. It suggests that individuals diagnosed at an older age have a notably higher likelihood of developing cancer compared to those diagnosed earlier. The link between diagnostic delay and increased cancer risk is thought to be due to the extended period during which the body is exposed to gluten, which may be especially hazardous in terms of gastrointestinal cancers like small bowel carcinoma and non-Hodgkin’s lymphoma.

Interestingly, a study by the Italian registry of coeliac complications points out that certain cancers expected to be more common in the celiac population, and conditions such as oropharyngeal and esophageal squamous carcinoma were not observed. This discrepancy might be explained by differing severity levels in the study populations or potential protective dietary and environmental factors specific to the Italian population from where the study sample was drawn.

It’s important to note that while small bowel carcinoma is generally rare and typically male-dominated, the majority of cases in this study occurred in females, aligning with the higher prevalence of coeliac disease in women. This finding emphasises the suspected association between coeliac disease and small bowel neoplasms.

From a public health standpoint, the evidence of an elevated cancer risk in patients with coeliac disease and the unclear benefits of a gluten-free diet in cancer prevention does not support widespread serological screening for coeliac disease in the general population solely as a preventative measure for cancer, but does raise awareness for the potential implications of delayed diagnoses.

Awareness brings about vigilance

The Brisbane study is a call to action. It reveals a need for greater awareness and a lower threshold for coeliac screening in symptomatic adults, particularly those with a family history. Health professionals should be reminded that serological markers can be the harbingers of latent coeliac disease and that genetic predisposition might necessitate a more nuanced approach to diagnosis.

In conclusion, the Australian research offers invaluable insight — but it also poses questions. How many adults with latent coeliac disease are we missing? Are we doing enough to look beyond the tip of the iceberg?  It is time to fine-tune our antennae towards the subtleties of late onset coeliac disease. Enhancing physician knowledge about the varied presentations of the disease and implementing screenings for those at higher risk could significantly curtail these diagnostic delays on a broader scale. After all, no individual should have to endure a diminished quality of life due to a disease that, once unmasked, can be managed with a simple, albeit strict, dietary change.

Fuchs, Valma et al. “Delayed celiac disease diagnosis predisposes to reduced quality of life and incremental use of health care services and medicines: A prospective nationwide study.” United European gastroenterology journal vol. 6,4 (2018): 567-575. doi:10.1177/2050640617751253 

Muir, R. et al. (2023) Undiagnosed coeliac disease identified by active case finding in first degree relatives of people with coeliac disease in Australia: A prospective observational study, The Medical Journal of Australia. Available at: https://www.mja.com.au/journal/2023/219/8/undiagnosed-coeliac-disease-identified-active-case-finding-first-degree (Accessed: 02 November 2023). 

Silano, Marco et al. “Delayed diagnosis of coeliac disease increases cancer risk.” BMC gastroenterology vol. 7 8. 9 Mar. 2007, doi:10.1186/1471-230X-7-8