Antibody Concentrations Decrease 14-Fold in Children With Celiac Disease on a Gluten-Free Diet but Remain High at 3 Months

Tolerance-inducing therapies in coeliac disease - mechanisms, progress and future directions

Coeliac disease is an autoinflammatory condition caused by immune reactions to cereal gluten proteins. Currently, the only available treatment for the condition is a lifelong avoidance of gluten proteins in the diet. There is an unmet need for alternative therapies. Coeliac disease has a strong association with certain HLA-DQ allotypes (DQ2.5, DQ2.2 and DQ8), and these disease-associated HLA-DQ molecules present deamidated gluten peptides to gluten-specific CD4+ T cells. The gluten-specific CD4+ T cells are the drivers of the immune reactions leading to coeliac disease. Once established, the clonotypes of gluten-specific CD4+ T cells persist for decades, explaining why patients must adhere to a gluten-free diet for life. Given the key pathogenic role of gluten-specific CD4+ T cells, tolerance-inducing therapies that target these T cells are attractive for treatment of the disorder. Lessons learned from coeliac disease might provide clues for treatment of other HLA-associated diseases for which the disease-driving antigens are unknown. Thus, intensive efforts have been and are currently implemented to bring an effective tolerance-inducing therapy for coeliac disease. This Review discusses mechanisms of the various approaches taken, summarizing the progress made, and highlights future directions in this field.

Gluten-Free Diet Induces Rapid Changes in Phenotype and Survival Properties of Gluten-Specific T Cells in Celiac Disease

BACKGROUND & AIMS

The treatment of celiac disease (CeD) with gluten-free diet (GFD) normalizes gut inflammation and disease-specific antibodies. CeD patients have HLA-restricted, gluten-specific T cells persisting in the blood and gut even after decades of GFD, which are reactivated and disease driving upon gluten exposure. Our aim was to examine the transition of activated gluten-specific T cells into a pool of persisting memory T cells concurrent with normalization of clinically relevant biomarkers during the first year of treatment.

METHODS

We followed 17 CeD patients during their initial GFD year, leading to disease remission. We assessed activation and frequency of gluten-specific CD4+ blood and gut T cells with HLA-DQ2.5:gluten tetramers and flow cytometry, disease-specific serology, histology, and symptom scores. We assessed gluten-specific blood T cells within the first 3 weeks of GFD in 6 patients and serology in an additional 9 patients.

RESULTS

Gluten-specific CD4+ T cells peaked in blood at day 14 while up-regulating Bcl-2 and down-regulating Ki-67 and then decreased in frequency within 10 weeks of GFD. CD38, ICOS, HLA-DR, and Ki-67 decreased in gluten-specific cells within 3 days. PD-1, CD39, and OX40 expression persisted even after 12 months. IgA-transglutaminase 2 decreased significantly within 4 weeks.

CONCLUSIONS

GFD induces rapid changes in the phenotype and number of gluten-specific CD4+ blood T cells, including a peak of nonproliferating, nonapoptotic cells at day 14. Subsequent alterations in T-cell phenotype associate with the quiescent but chronic nature of treated CeD. The rapid changes affecting gluten-specific T cells and disease-specific antibodies offer opportunities for clinical trials aiming at developing nondietary treatments for patients with newly diagnosed CeD.

The use of urine peptidomics to define dietary gluten peptides from patients with celiac disease and the clinical relevance

INTRODUCTION

Determination of urinary gluten immunogenic peptides (GIP) has emerged as one of the most attractive test to monitor the adherence to the gluten-free diet (GFD) of patients with celiac disease (CD), being a simple, noninvasive and direct method to detect gluten contamination of the GFD.

AREAS COVERED

We conducted a scoping review in Medline (PubMed) of articles published up to April 2023 that analyzed any aspect of the clinical relevance of the use of urinary GIP measurement in patients with CD. A total of 17 articles reporting the clinical use of urinary peptidomics for the follow-up of CD patients were finally included.

EXPERT OPINION

Available data suggest that a negative urinary GIP result is a reliable noninvasive predictor of intestinal mucosa healing in CD patients treated with the GFD, especially if testing three urine samples on different days including the weekend. Due to conflicting results about the sensitivity and the specificity of the urinary GIP determination, additional in-depth information is needed, particularly related to (1) the relationship between the amount of ingested gluten and the quantity of urinary GIP excreted in treated CD patients, (2) the GIP kinetics and best timing for sample collection.

ESPGHAN Position Paper on Management and Follow-up of Children and Adolescents With Celiac Disease

OBJECTIVES

To gather the current evidence and to offer recommendations for follow-up and management.

METHODS

The Special Interest Group on Celiac Diseases of the European Society of Paediatric Gastroenterology Hepatology and Nutrition formulated ten questions considered to be essential for follow-up care. A literature search (January 2010-March 2020) was performed in PubMed or Medline. Relevant publications were identified and potentially eligible studies were assessed. Statements and recommendations were developed and discussed by all coauthors. Recommendations were voted upon: joint agreement was set as at least 85%.

RESULTS

Publications (n = 2775) were identified and 164 were included. Using evidence or expert opinion, 37 recommendations were formulated on: The need to perform follow-up, its frequency and what should be assessed, how to assess adherence to the gluten-free diet, when to expect catch-up growth, how to treat anemia, how to approach persistent high serum levels of antibodies against tissue-transglutaminase, the indication to perform biopsies, assessment of quality of life, management of children with unclear diagnosis for which a gluten-challenge is indicated, children with associated type 1 diabetes or IgA deficiency, cases of potential celiac disease, which professionals should perform follow-up, how to improve the communication to patients and their parents/caregivers and transition from pediatric to adult health care.

CONCLUSIONS

We offer recommendations to improve follow-up of children and adolescents with celiac disease and highlight gaps that should be investigated to further improve management.

Time to normalisation of tissue transglutaminase in paediatric coeliac disease is dependent on initial titre and half of patients will normalise within 12 months

BACKGROUND

Coeliac disease (CD) is common. Response to a gluten-free diet is assessed through serial measurement of tissue transglutaminase (TTG) antibody titre. However, the relationship of TTG titres to symptoms and the speed of normalisation is poorly understood.

METHODS

Patients seen in 2020, and under follow-up in the Southampton CD clinic, had blood results, growth measures and symptom data collated. Time to normalisation, predictors of normalisation and relationship of TTG to growth/symptoms were assessed.

RESULTS

57 patients were included. All had TTG results from the time of diagnosis and follow-up. All families reported dietary compliance.Median TTG at diagnosis was 100 μ/L (range 0.3-4360), 94.7% of the patients had symptoms compatible with CD. At 6-12 months after diagnosis, the median TTG was 3.8 μ/mL (range 0.3-133). In terms of response, 29 of the 57 patients (50.9%) had a TTG below 4 μ/mL (upper normal limit). A further 25 patients (43.9%) had a TTG<10 times the upper limit of normal. Ten patients (17.5%) had a persistently high TTG (median=8.55 μ/mL, range 4.1-303) after >12 months.TTG at diagnosis was correlated with TTG at 6-12 months, β=0.542, p=0.000016. Patients with TTG<10 times the upper limit of normal at diagnosis group were more likely to have normalised at 6-12 months compared with >10 times normal (85% vs 32.4%, p=0.0015). TTG titres did not correlate with growth measures (Z-scores) at diagnosis or at follow-up.

CONCLUSIONS

Normalisation of TTG levels occurs within 6-12 months for around half of patients. Higher TTG levels at diagnosis take longer to normalise. The role of compliance is unclear.

Precision of autoantibody assays in clinical diagnostic laboratories: What is the reality?

BACKGROUND

ISO 15189 accreditation remains a challenge for specialized laboratories. In the field of autoimmunity, beside the crucial problem of absence of standardization, laboratories have to manage the analytical performances of the large panel of assays in terms of sensitivity and specificity, but also on their measurement precision for which no reference values are available on biorepositories.

METHODS

As an initiative of the French EASI (European Autoimmunity Standardization Initiative) group, French clinical diagnostic laboratories were requested to participate in a survey aiming to analyze the coefficients of variation (CVs) of intra-run and inter-run variability obtained with assays quantifying 14 different autoantibodies. Two performance goals corresponding to the 90th percentile and the 50th percentile (lowest CV values reached by 90% and 50% of laboratories respectively) defined for three levels of concentration were calculated. The impact on the assay performances of the number of measurements, of the nature of the internal quality control (IQC) and the type of immunoassay, was also analyzed.

RESULTS

414 and 616 values of intra-run and inter-run CVs were collected, respectively. The 50th percentile performance goals were comprised between 1.0% and 8.9% for the intra-run CVs, and between 1.8% and 14.6% for the inter-run CVs. At 90th percentile, the performance goals were comprised between 3.2% and 13.5% for the intra-run CVs, and between 7.3% and 30.8% for the inter-run CVs. CVs calculated from 10 values were similar to those obtained from more values. Higher imprecision was observed when the antibody levels of the IQC was lower than 2 fold the positive threshold. Commercial IQCs gave lower CVs than IQCs derived from patient samples.

CONCLUSION

Our results allow proposing some acceptability limits for the precision performances of the autoantibody assays, compatible with the reality of life in diagnostic laboratories and clinical care.

Nutrition Assessment, Interventions, and Monitoring for Patients with Celiac Disease: An Evidence Analysis Center Scoping Review

The objectives of this scoping review were to identify and characterize studies examining nutrition assessment, interventions, and measures to monitor gluten-free diet (GFD) adherence/compliance in patients with celiac disease (CD). An electronic literature search of four databases (Cochrane Database for systematic reviews, CINAHL, Embase, and Ovid MEDLINE) was conducted to identify articles examining nutrition care in CD individuals. Except for narrative review, grey literature, and case study/report, all types of peer-reviewed articles published between January 2007 and August 2018 were eligible. There were a total of 10,823 records; 10,368 were excluded during the first round of screening due to irrelevancy and/or duplication. Of the 455 full-text articles that were assessed, 292 met the criteria and were included. Most of the studies were observational studies (n=212), followed by experimental trials (n=50), evidence-based practice guideline (EBPG)/report/statement (n=16), and systematic review (SR) (n=14). Nine original studies examined assessment, focusing mainly on different tools/ways to assess GFD adherence. The majority of the included original articles (n=235) were in the nutrition intervention category with GFD, oats, and prebiotics/probiotics as the top-three most studied interventions. There were eight SRs on GFD and five on oats. One SR and 21 original studies investigated the effectiveness of different measures to monitor GFD adherence/compliance. Although recent CD EBPGs were identified, different methods with varying levels of rigor, in terms of literature search and assessment of evidence strength, were used. Based on this scoping review, interventions focused on gluten-free diet and oats have been significantly covered by either SRs or EBPGs. Studies related to prebiotics/probiotics and education program/counseling focused interventions, as well as assessment, in CD patients have increased in recent years. Thus, it might be beneficial to conduct SRs/EBPGs focused on these topics to guide practitioners.