Raising the Cut-Off Level of Anti-Tissue Transglutaminase Antibodies to Detect Celiac Disease Reduces the Number of Small Bowel Biopsies in Children with Type 1 Diabetes: A Retrospective Study

Do Serological Tests Eliminate the Need for Endoscopic Biopsy for the Diagnosis of Symptomatic Patients with Celiac Disease? A Retrospective Study with Review of Literature

Background: Celiac disease is one of the most common genetic allergies worldwide. The prevalence of celiac disease in Iran is similar to or even higher than the global prevalence. Celiac disease is a chronic inflammatory disease that affects the small intestine. Affected patients are allergic to gluten protein that exists in some grains, such as wheat and barley. Methods: Serological endomysial IgA antibody (EMA-AB) and tissue transglutaminase IgA antibody (TTG-IgA) tests were performed on 114 patients aged the ages of 0-18 years with histopathological findings of celiac disease. The results of these tests were compared to the results of the histopathological study of the duodenal biopsy. Results: Based on the receiver operating characteristic (ROC) curve and a calculation of the TTG-IgA test's sensitivity and specificity, the best diagnostic limit for the TTG-IgA test is 144, which has the best sensitivity and specificity. At this value (cut-off), the test's sensitivity was 62%, and the specificity was 93.7%. For the endomysial test, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 80%, 93%, 90%, and 75%, respectively. Conclusion: The diagnostic accuracy of the endomysial test is better than that of the TTG-IgA test in general for diagnosing patients with celiac disease. In the TTG-IgA test, false-positive cases are high due to a cut-off of 20, reducing the test's specificity. In these false-positive cases, the endomysial test helps in better diagnosis.

Review article: Becoming and being coeliac-special considerations for childhood, adolescence and beyond

Classically considered a disease of early childhood characterised by malabsorption and failure to thrive, coeliac disease is now recognised to arise in genetically susceptible individuals at any age. Although permissive HLA genotypes are the strongest predictor of coeliac disease, they are not sufficient. Several prospective cohort studies enrolling genetically at-risk infants have investigated the role of potential triggers of coeliac disease autoimmunity, such as timing of gluten introduction, viral infections and dietary patterns. Much less is known about triggers of coeliac disease in adulthood. Better understanding of factors leading to coeliac disease may be helpful in the management of those with potential coeliac disease (elevated serum celiac antibodies without villous atrophy in the small intestine), many of whom initiate a gluten-free diet without demonstration of villous atrophy. There are a range of clinical presentations of celiac disease in childhood and patterns of coeliac serology, including fluctuation and spontaneous reversion on a gluten-containing diet, vary. There is a current debate over best strategies to manage adults and children with potential coeliac disease to avoid over-treatment and under-treatment. Childhood and adolescence carry unique issues pertaining to the diagnosis and management of coeliac disease, and include nutrition and growth, rescreening, repeat biopsy, dietary adherence concerns and transition to adult care. In conclusion, while coeliac disease has similar pathogenesis and general clinical manifestations in paediatric and adult populations, diagnostic and management approaches need to adapt to the developmental stages.

Islet autoantibody types mark differential clinical characteristics at diagnosis of pediatric type 1 diabetes

BACKGROUND

We aimed to study whether islet autoantibody type marks differential characteristics at the time of type 1 diabetes (T1D) diagnosis.

METHODS

We studied 711 children with newly diagnosed autoimmune T1D. We compared demographic (sex, age, race/ethnicity), clinical (pubertal development, BMI percentile, diabetic ketoacidosis [DKA]) and laboratory (glucose, hemoglobin A1c [HbA1c], C-peptide, tissue transglutaminase antibodies [tTGA], thyroglobulin antibodies, and thyroid peroxidase antibodies [TPOA]) characteristics by presence/absence of autoantibodies to insulin (IAA), GAD65 (GADA), or IA-2/ICA512 (IA-2A). Islet autoantibody titers were evaluated among the children positive for the relevant autoantibody type. We used multivariable analysis to adjust for potential confounders.

RESULTS

IAA+ was statistically associated with younger age (p < 0.0001) and lower HbA1c (p = 0.049) while Tanner stage, GADA status and number of positive islet autoantibodies were not significant in the multivariable model. GADA+ was associated with female sex (OR = 4.0, p = 0.002) and negatively with elevated tTGA titers (>50 U/mL) (OR = 0.21, p = 0.026) but not with age, IAA status, IA-2A status, islet autoantibody number, or thyroid autoimmunity. None of the associations with IA-2A positivity was statistically significant in the multivariable analysis. In multivariable models, IAA titer was significantly associated with younger age (p = 0.006), DKA (p = 0.017) and higher tTGA levels (p = 0.002); GADA titer with female sex (p = 0.028), racial minority (p = 0.046) and TPOA positivity (p = 0.021); and IA-2A titer with older age (p = 0.001) and not being African American (p = 0.024).

CONCLUSIONS

Islet autoantibody type is associated with differential characteristics at diagnosis of pediatric T1D. Longitudinal and mechanistic studies are needed to evaluate T1D endotypes by autoantibody type.

Accuracy of Screening Tests for Celiac Disease in Asymptomatic Patients With Type 1 Diabetes

INTRODUCTION

To evaluate the diagnostic performance of celiac serologic tests in asymptomatic patients with type 1 diabetes (T1D).

METHODS

Patients with T1D asymptomatic for celiac disease were prospectively screened with immunoglobulin A anti-tissue transglutaminase. Test characteristics were calculated and optimal cutoffs for a positive screen determined.

RESULTS

Two thousand three hundred fifty-three patients were screened and 101 proceeded to biopsy. The positive predictive value of immunoglobulin A anti-tissue transglutaminase at the assay referenced upper limit of normal (30CU) was 85.9%, and the sensitivity and specificity were 100% and 38%, respectively.

DISCUSSION

Thresholds extrapolated from the general population for the diagnostic evaluation of celiac disease are not suitable for use in asymptomatic T1D patients. Population-specific screening cutoffs are required.

Celiac disease can be predicted by high levels of tissue transglutaminase antibodies in children and adolescents with type 1 diabetes

OBJECTIVES

Children with type 1 diabetes (T1D) are not included in guidelines regarding diagnosis criteria for celiac disease (CD) without a diagnostic biopsy, due to lack of data. We explored whether tissue transglutaminase antibodies (anti-tTG) that were ≥ 10 times the upper limit of normal (10× ULN) predicted CD in T1D.

METHODS

Data from the Swedish prospective Better Diabetes Diagnosis study was used, and 2035 children and adolescents with T1D diagnosed between 2005-2010 were included. Of these, 32 had been diagnosed with CD before T1D. The children without CD were repeatedly screened for CD using anti-tTG antibodies of immunoglobulin type A. In addition, their human leukocyte antigen (HLA) were genotyped. All children with positive anti-tTG were advised to undergo biopsy. Biopsies were performed on 119 children and graded using the Marsh-Oberhüber classification.

RESULTS

All of the 60 children with anti-tTG ≥10x ULN had CD verified by biopsies. The degree of mucosal damage correlated with anti-tTG levels. Among 2003 screened children, 6.9% had positive anti-tTG and 5.6% were confirmed CD. The overall CD prevalence, when including the 32 children with CD before T1D, was 7.0% (145/2035). All but one of the children diagnosed with CD had HLA-DQ2 and/or DQ8.

CONCLUSIONS

As all screened children and adolescents with T1D with tissue transglutaminase antibodies above 10 times the positive value 10x ULN had CD, we propose that the guidelines for diagnosing CD in screened children, when biopsies can be omitted, should also apply to children and adolescents with T1D as a noninvasive method.

ESPGHAN 'biopsy-sparing' guidelines for celiac disease in children with low antitransglutaminase during COVID-19

OBJECTIVES

Recent guidelines for celiac disease have allowed a biopsy-free approach in endomysial antibodies (EMAs) positive children with high antitransglutaminase (TGA-IgA) titer [>10 time upper limit of normal (ULN)]. Esophagogastroduodenoscopy is still necessary for diagnosis in children with lower title. Because elective pediatric endoscopy has been substantially shouted down during coronavirus disease (COVID-19) pandemic, many children remained undiagnosed - and therefore untreated - for a long time. We aimed to analyze the feasibility and accuracy of a biopsy-free approach in suspected celiac disease children with TGA-IgA values <10 ULN to facilitate the diagnostic process by avoiding endoscopy.

METHODS

In this study cohort, we retrospectively analyzed all biopsy-confirmed diagnosis of celiac disease in our center (between 2014 and 2019). The positive predictive value (PPV) of TGA-IgA titers between 5 and 10 ULN and positive EMA in diagnosing celiac disease were determined. Mucosal atrophy and resolution of symptoms after gluten-free diet (GFD) were considered to confirm initial diagnosis.

RESULTS

Of 430 celiac disease patients (F: 274; mean age 7.54 years) diagnosed by endoscopy, 84 (F: 46; mean age 8 years) with TGA-IgA between 5 and 10 ULN and positive EMA were identified. The PPV of TGA-IgA between 5 and 10 ULN and positive EMA was 0.93 (95% confidence interval 0.90-0.96). All these children had a symptom resolution and antibodies normalization after GFD.

CONCLUSION

During the COVID-19 outbreak, a temporarily reduction of the TGA-IgA threshold for biopsy-sparing approach seems feasible in EMA positive children with TGA-IgA between 5 and 10 ULN.