Development of a Risk Score for Extraintestinal Manifestations of Coeliac Disease

Celiac disease and bone health: is there a gap in the management of postmenopausal osteoporosis?

Malabsorption due to celiac disease (CD) may contribute to postmenopausal osteoporosis. This study aimed to survey participants with CD regarding their bone density, fractures, and bone-preserving medications; to compare tolerance of bone-preserving medications in participants with and without CD; and to review the evidence for CD screening and osteoporosis therapies in the setting of CD. We recruited 131 participants with CD and 102 participants without CD. Of those with CD, 87% were diagnosed in adulthood and 40% had no recognized gastrointestinal symptoms. In 21% CD was diagnosed after the diagnosis of osteoporosis and in 9% after a fracture. No difference was found in the tolerability of bone medications between participants with CD and those without. Review of the literature found that, although monitoring of bone health is recommended for patients with CD, screening for CD is not generally accepted for patients with osteoporosis, although studies of the prevalence of CD in osteoporosis had incomplete ascertainment methods. There is a lack of well-conducted studies and therefore insufficient data for the efficacy and tolerability of bone medication in CD. In conclusion, both CD and menopause lead to bone loss. Identifying CD in postmenopausal women should lead to modification of osteoporosis management.

Comparison of DNA methylation profiles from saliva in Coeliac disease and non-coeliac disease individuals

BACKGROUND

Coeliac disease (CD) is a autoimmune disease characterised by mucosal inflammation in the small intestine in response to dietary gluten. Genetic factors play a key role with CD individuals carrying either the HLA-DQ2 or HLA-DQ8 haplotype, however these haplotypes are present in half the general population making them necessary but insufficient to cause CD. Epigenetic modifications, including DNA methylation that can change in response to environmental exposure could help to explain how interactions between genes and environmental factors combine to trigger disease development. Identifying changes in DNA methylation profiles in individuals with CD could help discover novel genomic regions involved in the onset and development of CD.

METHODS

The Illumina InfiniumMethylation450 Beadchip array (HM450) was used to compare DNA methylation profiles in saliva, in CD and non-CD affected individuals. CD individuals who had been diagnosed at least 2 years previously; were on a GFD; and who were currently asymptomatic; were compared to age and sex-matched non-CD affected healthy controls. Bisulphite pyrosequencing was used to validate regions found to be differentially methylated. These regions were also validated in a second larger cohort of CD and non-CD affected individuals.

RESULTS

Methylation differences within the HLA region at HLA-DQB1 were identified on HM450 but could not be confirmed with pyrosequencing. Significant methylation differences near the SLC17A3 gene were confirmed on pyrosequencing in the initial pilot cohort. Interestingly pyrosequencing sequencing of these same sites within a second cohort of CD and non-CD affected controls produced significant methylation differences in the opposite direction.

CONCLUSION

Altered DNA methylation profiles appear to be present in saliva in CD individuals. Further work to confirm whether these differences are truly associated with CD is needed.

Comparing DNA methylation profiles in saliva and intestinal mucosa

BACKGROUND

Altered epigenetic profiles are a feature of intestinal diseases, including ulcerative colitis and Crohn's disease. DNA methylation studies in these diseases have utilised intestinal mucosal tissue or blood which can be difficult to collect, particularly for large-scale research studies. Saliva is an attractive alternative for epigenetic studies as it is easy to collect and provides high quality methylation profiles. The aim of the study was to determine the utility of saliva as an alternative for DNA methylation studies of intestinal disorders.

RESULTS

DNA methylation in saliva and intestinal mucosa samples were compared in individuals (n = 10) undergoing endoscopies using the Illumina Infinium Methylation 450 K Beadchip array. We found that DNA methylation was correlated between tissue types within an individual (Pearson correlation co-efficient r = 0.92 to 0.95, p < 0.001). Of the 48,541 probes (approximately 11% of CpG sites) that were differentially methylated between saliva and intestinal mucosa (adjusted p < 0.001, |Δβ| ≥ 20%), these mapped to genes involved in tissue-specific pathways, including the apelin signalling and oxytocin pathways which are important in gastrointestinal cytoprotection and motility.

CONCLUSIONS

This study suggests that saliva has the potential to be used as an alternate DNA source to invasive intestinal mucosa for DNA methylation research into intestinal conditions.