Young Age at Diagnosis of Type 1 Diabetes Is Associated with the Development of Celiac Disease-Associated Antibodies in Children Living in Newfoundland and Labrador, Canada

Meta-Analysis: Global Prevalence of Coeliac Disease in Type 1 Diabetes

BACKGROUND

Coeliac disease (CD) is common in patients with type 1 diabetes (T1D), but prevalence varies globally due to differing screening protocols. There have been substantial changes in screening guidelines over the past two decades.

AIM

To evaluate CD prevalence in patients with T1D, focusing on screening studies using antitissue transglutaminase (anti-tTG) antibody.

METHODS

We searched PubMed, Web of Science, Embase and Scopus for studies published up to 11 December 2023 using keywords related to CD and diabetes. We used random-effects models for overall prevalence and all subgroups, with heterogeneity assessed using Cochran's Q test and the I2 statistic performed in STATA 18.

RESULTS

We included 106 articles involving 65,102 T1D patients across 40 countries. The pooled CD seroprevalence and confirmed CD prevalence were 9% (95% confidence interval, CI, 8%-10%) and 6% (95% CI 5%-7%), respectively. The prevalence was higher in females and children. Denmark, Saudi Arabia and Libya exhibited the highest prevalence (11%), followed by India and Egypt (10%). Belgium, France, Germany, South Africa and the United States had the lowest prevalence (2%). High-income countries showed significantly a lower CD prevalence than middle-income countries (p = 0.03). Meta-regression based on the Human Development Index (HDI) indicated that countries with higher HDI have lower seroprevalence and confirmed CD prevalence.

CONCLUSION

Approximately 1 in 16 patients globally and 1 in 12 patients in Asia and the Middle East with T1D has CD. We suggest that all patients with T1D should be screened for CD.

Influence of Age and Type 1 Diabetes Mellitus on Serological Test for Celiac Disease in Children

PURPOSE

Serological tests of tissue transglutaminase (TTG) and deamidated gliadin (DGP) antibodies for celiac disease diagnosis show conflicting correlation with histology in young children and in type 1 diabetes mellitus (T1DM). Tests' ability to predict histology and cutoff values based on age and T1DM was evaluated.

METHODS

A retrospective study of children who had celiac serological tests between 6/1/2002 and 12/31/2014 at a pediatric hospital.

RESULTS

TTG IgA displayed similar results in predicting histology between <4.0 and ≥4.0 years age groups with sensitivity 98% and 93%, and specificity 88% and 86%, respectively. In children <4.0 years old, sensitivity for DGP antibodies was 100% and specificity 94%; in ≥4.0 years age groups, sensitivity was 60%, 88% for DGP IgA and IgG and specificity 95%, 96%, respectively. TTG IgA had low specificity in patients with T1DM compared with non-T1DM, 42% vs. 91%. Positive TTG IgA with normal histology was associated with higher T1DM prevalence at 36% compared with negative tests at 4%. Finally, the TTG IgA cutoff value was higher in T1DM at 36 vs. 16.3 units in non-T1DM. DGP IgG cutoff showed similar values between age groups; TTG IgA and DGP IgA cutoffs were lower in <4.0 years at 8.3 and 11.9 units than ≥4.0 years at 23.4 and 19.9, respectively.

CONCLUSION

TTG IgA is sufficient for the <4.0 years age group and DGP antibodies had no advantage over TTG IgA in older children. The cutoff value to determine a positive TTG IgA should be higher for children with T1DM.

Celiac Disease and Celiac Antibodies in DM1 Patients: When Are Screening and Biopsy Recommended?

INTRODUCTION

The prevalence of celiac disease (CD) is increased in diabetes mellitus type 1 (DM1) patients. In most cases, CD is diagnosed in asymptomatic patients and hence periodic screening tests are recommended, but the timing, frequency of tests and indication for duodenal biopsy is unclear. The purpose of this study was to investigate the dynamics of CD serology in DM1 and identify risk factors for CD.

METHODS

Celiac serology and duodenal biopsy results from 1990 until 2015 were collected from patients with DM1. The outcome of positive celiac serology, the incidence and risk factors for CD in DM1 patients were investigated.

RESULTS

A total of 314 DM1 patients who had celiac serology were identified, with follow-up period up to 23 years. Of 31 patients (9.9%) with positive celiac serology, 11(35.4%) had spontaneous normalization after various time periods. Eighteen patients were diagnosed with CD (58.1% of positive celiac serology, 5.73% of the study cohort). Age under 4.5 years was a risk factor for CD, but not family background of autoimmune diseases or gender. All patients with CD diagnosis were diagnosed during the first 6 years following DM1 diagnosis.

CONCLUSION

Screening asymptomatic DM1 patients for CD beyond 6 years after diagnosis is not recommended. Spontaneous normalization of CD serology occurs, and hence, serologic follow-up may be performed. In children with DM1 diagnosis under the age of 4.5 years or with positive CD serology at DM1 diagnosis, there is an increased risk for CD and therefore positive serology should lead to biopsy.