Coeliac disease on the rise: the COVID-19 vaccination hypothesis

Abstract

Introduction
Coeliac disease (CD) is a common lifelong autoimmune condition, more frequently diagnosed in women, with a global prevalence of 1–2%. Its broad clinical spectrum necessitates careful suspicion for timely diagnosis. Over the past 2 years, we have observed a sharp rise in cases, coinciding with the post-pandemic era, prompting this study. Some research suggests that viral infections may trigger autoimmune diseases, such as CD. This study explores the potential link between the surge in cases and factors such as infections and vaccinations.

Method
In this retrospective analysis, the medical records of a cohort of 454 patients were categorised according to date, age, gender, clinical manifestations, CD serology and histopathological findings. Data on vaccine type and dosage were analysed to explore a potential association.
Results were classified as follows:
Positive CD diagnosis: confirmed by serology and/or histopathology;
Negative CD diagnosis: both serology and histopathology results were negative;
Borderline CD: serology results fell within the grey zone, and histopathology was insufficient for a definitive diagnosis according to the Marsh-Oberhuber classification (stages 0 & 1).
Subdivisions: each diagnostic category was further subdivided based on vaccination status (vaccinated, unvaccinated, or unknown).
Gender analysis: results were also evaluated by patient sex.

Results
The results showed that 47.4% of the cohort tested positive or borderline for CD, including 32.8% of vaccinated patients who experienced symptoms during and after the coronavirus 2019 (COVID-19) pandemic. Notably, positivity increased among men, deviating from typical patterns. Many files lacked infection status, and genetic studies were not conducted because of cost, highlighting the need for further research.

Figure 1 visually represents CD diagnoses based on vaccination status using serology/histopathology results. It categorises patients into vaccinated (orange), unvaccinated (blue) and unknown status (green). Among vaccinated patients, 204 tested negative, while 149 were positive/borderline for CD. In the unvaccinated group, 33 were negative, and 37 were positive/borderline for CD. In the unknown group, 20 tested negative, and 11 tested positive/borderline for CD.

This breakdown suggests a notable CD prevalence, raising clinical suspicion about a link to COVID-19 vaccination/infection. The Chi-square value (6.18) supports this, but the p value (0.186) exceeds the statistical significance threshold (<0.05). While not statistically significant, the post-pandemic case surge may hold clinical significance.

Conclusion
To conclude, the data point toward an increasing trend in CD diagnosis, putting us at the forefront of managing a serious autoimmune systemic illness that carries a significant burden on healthcare. There are a few potential factors contributing to this trend, including:

• Enhanced awareness and increased availability of diagnostic tools;
• Suboptimal processing techniques of gluten-containing foods may increase immunogenicity;
• The possibility of an immunomodulating effect of the COVID-19 virus and its vaccine on the immune system.

Case reports suggest COVID may contribute to autoimmune diseases, such as rheumatoid arthritis. Despite lacking statistical significance, the data do not justify accepting the null hypothesis. The potential link between CD and COVID-19 vaccination/infection requires further study through larger prospective and retrospective studies.