The Usefulness of Genotyping of Celiac Disease-Specific HLA among Children with Type 1 Diabetes in Various Clinical Situations

Metabolic control, adherence to the gluten-free diet and quality of life among patients with type 1 diabetes and celiac disease

AIMS

In this cross-sectional study, we aimed to evaluate metabolic control, adherence to a gluten-free diet (GFD), and quality of life (QoL) in individuals with type 1 diabetes (T1D) and celiac disease (CD).

METHODS

We targeted individuals with T1D and CD at a major tertiary hospital in Saudi Arabia. We gathered retrospective data from medical records and prospectively assessed glycemic control using HbA1c and ambulatory glucose metrics, adherence to a GFD using the Celiac Dietary Adherence Test (CDAT), and QoL using the Celiac Disease Quality of Life survey (CD-QoL).

RESULTS

Forty-eight out of 1095 patients screened (4.38%) were included. Mean age and HbA1c were 21.3 (± 6.6) and 8.3% (± 0.8%). The average time in range% and above range% were 38.5 (range 24-68) and 29.6 (± 7.4). The median hypoglycemic events/month was 8, with a median duration of 80 min. The median overall CDAT and CD-QoL scores were 20.5 and 54. No significant correlations were observed between glucose management indicator (GMI), % in target, and CDAT/CD-QoL scores (all p > 0.05).

CONCLUSIONS

No significant effect of GFD on QoL or glycemic control was observed. Further prospective studies are warranted to establish solid evidence of the impact of GFD on individuals with T1D and CD.

Combination of HLA-DQ2/-DQ8 Haplotypes and a Single MSH5 Gene Variant in a Polish Population of Patients with Type 1 Diabetes as a First Line Screening for Celiac Disease?

Patients with type 1 diabetes (T1D) are at increased risk for developing celiac disease (CD). The aim of the study was to assess the usefulness of celiac-specific human leukocyte antigen (HLA) haplotype and the rs3130484 variant of MSH5 gene, a previously described non-HLA variant associated with CD in the Polish population as a first-line screening for CD in T1D pediatric patients. Serological CD screening performed in the T1D group (n = 248) and healthy controls (n = 551) allowed for CD recognition in 20 patients (8.1%) with T1D (T1D + CD group). HLA-DQ2, HLA-DQ8 and the rs3130484 variant were genotyped with TaqMan SNP Genotyping Assays. The T1D + CD group presented a higher, but not statistically significant, frequency of HLA-DQ2 in comparison with T1D subjects. Combining the rs3130484 with HLA-DQ2/HLA-DQ8 typing significantly increased the sensitivity of HLA testing from 32.7% to 68.7%, and the accuracy of estimating CD prediction from 51.7% to 86.4% but decreased the specificity from 100% to 78.2%. The receiver operating characteristic curve analysis confirmed the best discrimination for the combination of both genetic tests with an area under curve reaching 0.735 (95% CI: 0.700–0.7690) in comparison with 0.664 (95% CI: 0.632–0.696) for HLA typing alone. Results show the low utility of HLA-DQ2/HLA-DQ8 typing for CD screening in T1D pediatric patients. Combination of the rs3130484 variant of the MSH5 gene and HLA testing increases both the sensitivity and the predictive value of the test accuracy, but still, the obtained values are not satisfactory for recommending such testing as the first-line screening for CD in T1D patients.

New Evidence in the Pathogenesis of Celiac Disease and Type 1 Diabetes Mellitus: A Systematic Review

Celiac disease (CD) and type 1 diabetes mellitus (T1DM) are autoimmune diseases that coexist frequently. These illnesses share a common genetic background. This study aims to review the different pathophysiologic mechanisms that have been studied about the coexistence of CD and T1DM, to contrast them, and to summarize their specific role in these autoimmune diseases. We conducted a systematic review following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) checklist and used the Medical Subject Headings (MeSH) search strategy to obtain relevant articles. We found 585 papers which were reduced to 355 after removing duplicates. Later, the filters and inclusion/exclusion criteria were applied which ended the search with 78 articles. Finally, we reviewed the articles that contained information about the pathogenesis of CD and T1DM, their coexistence, and how the pathogenesis impacts clinical outcomes. The reviewed studies strongly conclude that the presence of human leukocyte antigen (HLA) genes DQ2 and DQ8 are high-risk for developing the coexistence of CD and T1DM. We found that killer immunoglobulin-like receptor (KIR) genes, enterovirus infection in gut cells, and gut microbiota dysbiosis with the predominance of Bacteroides spp. also play a role in the pathogenesis and development of symptoms of CD in patients with the previous diagnosis of T1DM. CD4+ and CD8+ cell levels vary among patients and studies, consequently, more study on this topic is needed.