The risk for celiac disease after Covid-19 infection.

BACKGROUND: Celiac disease (CD) is an autoimmune disease leading to gastrointestinal symptoms and mineral deficiencies. The pathogenetic mechanisms, besides the clear HLA association, are elusive. Among environmental factors infections have been proposed. Covid-19 infection results in a systemic inflammatory response that often also involves the gastrointestinal tract. The aim of the present study was to investigate whether Covid-19 infection could increase the risk for CD. PATIENTS AND METHODS: All patients, both children and adults, in the county Skåne (1.4 million citizens) in southern Sweden with newly diagnosed biopsy- or serology-verified CD or a positive tissue transglutaminase antibody test (tTG-ab) during 2016-2021 were identified from registries at the Departments of Pathology and Immunology, respectively. Patients with a positive Covid-19 PCR or antigen test in 2020 and 2021 were identified from the Public Health Agency of Sweden. RESULTS: During the Covid-19 pandemic (March 2020 - December 2021), there were 201 050 cases of Covid-19 and 568 patients with biopsy- or serology-verified CD or a first-time positive tTG-ab tests, of which 35 patients had been infected with Covid-19 before CD. The incidence of verified CD and tTG-ab positivity was lower in comparison to before the pandemic (May 2018 - February 2020; 22.5 vs. 25.5 cases per 100 000 person-years, respectively, incidence rate difference (IRD) -3.0, 95% CI -5.7 - -0.3, p = 0.028). The incidence of verified CD and tTG-ab positivity in patients with and without prior Covid-19 infection was 21.1 and 22.4 cases per 100 000 person-years, respectively (IRD - 1.3, 95% CI -8.5-5.9, p = 0.75). CONCLUSIONS: Our results indicate that Covid-19 is not a risk factor for CD development. While gastrointestinal infections seem to be an important part of the CD pathogenesis, respiratory infections probably are of less relevance.

Celiac disease and COVID-19 in adults: A systematic review.

BACKGROUND: Celiac disease (CD) is an autoimmune disease affecting around 1.4% of the total human population. Local and systemic manifestations are described in CD. Viral infections seem to trigger CD or even have a worse outcome in CD patients. The evidence on the relationship between CD and coronavirus disease (COVID-19) is limited. To evaluate existing evidence on the association between CD and COVID-19, we conducted the current systematic review. METHODS: We systematically searched Pubmed, Scopus, and Embase databases to find articles that reported risks or outcomes of COVID-19 in CD patients. Papers in any language published up to November 17, 2022, were evaluated for possible inclusion. The results were analyzed qualitatively. This study is registered with PROSPERO(CRD42022327380). RESULTS: We identified 509 studies by searching databases; 14 reported data on the risk or outcome of COVID-19 in CD patients and were eligible for qualitative synthesis. We found that the relative risk of acquiring COVID-19 in CD patients may be lower than in the general population. Approximately 90% of infected patients were treated as an outpatient, and 10% were hospitalized. GFD adherence and Health-related quality of life (HR-QOL) were more or less the same before and during the pandemic. The gluten-free products (GFP) supply seems to be plunged during the pandemic. The data on the psychological effects of the pandemic were conflicting. CONCLUSION: The risk of acquiring COVID-19 in CD patients is lower than in the general population. Females were more likely to be infected by COVID-19, and the most common comorbidity in infected patients was a chronic lower respiratory disease; around 10% of infected patients needed hospitalization, GFD adherence, and HR-QOL was more or less the same before and during the pandemic, depression, anxiety, and stress levels of patients varied among studies. Patients had more difficulties accessing GFPs based on limited data.

Celiac Disease and the Gluten Free Diet during the COVID-19 Pandemic: Experiences of Children and Parents.

The COVID-19 pandemic perturbed the everyday life of children and those with chronic illnesses, along with the lives of their families. Patients with celiac disease (CD) follow a strict gluten-free diet (GFD), and gluten ingestion is associated with negative health outcomes. The aim of this study was to investigate the experiences of children with CD and their families concerning their GFD, symptoms and CD management during the first period of the COVID-19 pandemic. A cross-sectional questionnaire-based study was performed including 37 Dutch pediatric patients with CD, along with their parents. The majority reported good compliance to the GFD and stated that the diet was easier to follow during the pandemic, mainly due to eating more meals in the home. Some discovered a greater variety of GF products by utilizing online shopping, potentially increasing the financial burden of the GFD. Concerning general dietary habits, 21.6% reported a healthier eating pattern, in contrast to 37.8% and 10.8% who consumed more unhealthy snacks and fewer fruits and vegetables, respectively, than normal during the pandemic. The natural experiment of the COVID-19 pandemic provides valuable information regarding the management of pediatric CD. Education on healthy dietary patterns is important, especially for children with restrictive diets, and the findings of this study show that there is room for improvement in this respect, regardless of the current pandemic.

Prevalence and clinical outcomes of COVID-19 in patients with pre-existing celiac disease: A systematic review and meta-analysis.

There is a scarcity of scientific evidence addressing the outcomes of COVID-19 in celiac disease (CD) patients. This systematic review and meta-analysis aimed to evaluate the correlation between pre-existing CD and COVID-19. A rigorous literature search was conducted using multiple databases. All eligible observational studies were included from around the globe. The random effect model calculated the pooled prevalence and associated 95% confidence intervals (CI). Mantel-Haenszel odds ratios were produced to report the overall effect size using random effect models for severity and mortality outcomes. Funnel plots, Egger regression tests, and Begg-Mazumdar's rank correlation test were used to appraise publication bias. Data from 11 articles consisting of 44,378 CD patients were obtained. Overall pooled random-effects estimate of SARS-CoV-2 infection in CD patients was 4.25% (95% CI, I2  = 98%). Our findings also indicated that pre-existing CD was not associated with an increased risk of hospitalisation with COVID-19 illness (OR = 1.04, 95% CI 0.87-1.24, I2  = 0%) and mortality due to illness (OR = 0.92, 95% CI 0.56-1.5, I2  = 45%) compared with patients without pre-existing CD. No significant publication bias was evident in the meta-analysis. The preliminary data from our analysis suggest that SARS-CoV-2 infection in patients with pre-existing CD is not associated with an increased risk of hospitalisation or mortality. Additional studies are required to overcome the restrictions of the limited data available at present.

Increased Risk of Hospitalization in Celiac Disease With COVID-19 Infection Is Mitigated by Vaccination.

BACKGROUND: We sought to describe clinical characteristics of celiac disease (CD) patients infected with coronavirus disease 2019 (COVID-19) and estimate hospitalization risk, intensive care unit (ICU) requirement, mortality, and thrombosis, and the impact of vaccination on these outcomes. METHODS: We performed a single-center, retrospective cohort study comparing biopsy-proven CD patients with a matched sample of non-CD (referent) patients diagnosed with COVID-19 between March 2020 and January 2022. Matching ensured 2 referent patients for every 1 CD patient by age, sex, ethnicity, and COVID-19 diagnosis date. We also adjusted for general and celiac-specific comorbidity. The primary outcome was hospitalization. Secondary outcomes included ICU requirement, mortality, and thrombosis. We also compared these outcomes between vaccinated and unvaccinated individuals. RESULTS: We included 330 patients: 110 with CD (mean age 47 years, 83% female) and 220 matched referents. Hospitalization occurred in 27 CD patients (24%) and 25 referent patients (11%) (hazard ratio, 2.10; 95% confidence interval, 1.21-3.65; P = .009). Vaccination was associated with significantly decreased risk of hospitalization (hazard ratio, 0.53; 95% confidence interval, 0.31-0.93; P = .026). Four unvaccinated CD patients and 2 unvaccinated referent patients required ICU. No mortality occurred among CD patients, and 2 referent patients died. No thrombosis occurred in either group. CONCLUSIONS: CD patients with COVID-19 have a higher risk of hospitalization compared with non-CD referents. This risk is mitigated by vaccination in CD patients as it is in non-CD referents. ICU requirement occurred only in unvaccinated CD patients, and no CD patient died. Vaccination against COVID-19 should be strongly recommended in patients with CD as it is for non-CD patients in the general population.

Humoral immunogenicity of COVID-19 vaccines in patients with coeliac disease and other noncoeliac enteropathies compared to healthy controls.

OBJECTIVES: Data are lacking on the immunogenicity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in patients affected by coeliac disease, Whipple's disease and other noncoeliac enteropathies (NCE), characterised by primary or drug-related immunosuppression. We aimed to assess humoral response to SARS-CoV-2 vaccination in these patients compared to controls. METHODS: Between December 2021 and January 2022, IgG anti-SARS-CoV-2 spike protein antibodies were measured in serum samples of coeliac disease, Whipple's disease and NCE patients attending our gastroenterology outpatient clinic for follow-up, who had received their first SARS-CoV-2 vaccination dose 3-6-9 (±1) months prior. Humoral response was compared with healthy controls (vaccinated healthcare workers undergoing serological screening), matched for gender, age, and time from first vaccine dose at sample collection. RESULTS: A total of 120 patients [107 coeliac disease; 10 Whipple's disease; 2 common-variable immunodeficiency (CVID); 1 idiopathic villous atrophy; 77 F, 42 ± 16 years] and 240 matched controls (154 F, 43 ± 14 years) were enrolled. At 3, 6 and 9 months, humoral response in coeliac patients was not impaired compared to controls. Inadequate humoral response to vaccination was significantly more common among Whipple's disease patients than controls ( P < 0.001). Patients on immunosuppressive therapy had markedly lower IgG anti-SARS-CoV-2 antibody titres (median 14 vs. 520 BAU/mL, P < 0.001). As expected, patients with CVID showed no humoral response to vaccination. CONCLUSIONS: Humoral immunogenicity of SARS-CoV-2 vaccines was not reduced in coeliac disease patients compared to controls, although it was in Whipple's disease and CVID patients. Post-vaccination humoral response should be monitored in patients with Whipple's disease and chronic enteropathies on immunosuppressive therapy in order to schedule vaccine booster doses.

The Influence of SARS-CoV-2 Pandemic on the Diagnosis of Celiac Disease and Clinical Practice in Pediatric Gastroenterology.

Celiac disease (CD) has a high prevalence but remains largely underdiagnosed. Although extensive studies have confirmed that children with CD do not have an increased risk of severe COVID-19, public health regulations associated with the SARS-CoV-2 pandemic may have exacerbated this problem. The aim of this study was to assess the effect of SARS-CoV-2 on the number of new-onset CD cases. Additionally, the role of SARS-CoV-2 in autoimmune diseases and its influence on clinical practice in pediatric gastroenterology were briefly reviewed. We described the data from the hospital electronic registry of new-onset CD, during the COVID-19 pandemic and 2 years before. A total of 423 children were diagnosed with CD between March 2018 and February 2022: 228 in the 2-year pre-COVID-19 period and 195 during the pandemic. The number of patients during the COVID-19 pandemic was 14.5% lower than in the previous years. The quarterly comparison of CD diagnoses showed a reduction in all quarters. A reduction in diagnoses during the lockdown and in the following months was evident and not compensated thereafter. This is the first study to evaluate the impact of SARS-CoV-2 on the diagnosis of CD in children. Further studies are necessary to improve the system of biopsy-sparing diagnosis and to evaluate the effect of the diagnostic delay. Special attention should be given to the implementation of telemedicine services.

Australasian paediatric gastroenterologist practices of coeliac disease diagnosis before and during the COVID-19 pandemic.

AIM: To explore the perceptions and practices of Australasian paediatric gastroenterologists in diagnosing coeliac disease (CD) before and during the COVID-19 pandemic. METHODS: Paediatric gastroenterologists in Australasia were invited via email to complete an anonymous online questionnaire over a 2-week period in 2021. RESULTS: The questionnaire was completed by 39 respondents: 33 from Australia and six from New Zealand (NZ) equating to a 66% response rate. Thirty-four (87%) of the 39 respondents reported they currently practised non-biopsy diagnosis of CD in eligible children, while the rest diagnosed CD using biopsy confirmation only. All NZ respondents practised non-biopsy CD diagnosis. A majority of responders (76%) who practised non-biopsy CD diagnosis followed the 2020 European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) guidelines. Twenty-two (56%) respondents reported that they started using a non-biopsy CD diagnosis protocol before the pandemic and did not change their practice during the pandemic, 10 (26%) started diagnosing non-biopsy CD during the pandemic, 5 (13%) stated their practices of CD were not impacted by the pandemic and 2 (5%) did not respond on whether the pandemic changed their practice. CONCLUSION: The majority of Australasian gastroenterologist respondents reported they routinely utilised the 2020 ESPGHAN diagnostic criteria in eligible children; half of them started prior to the pandemic and another quarter started this approach due to the pandemic. A minority of practitioners routinely rely only on biopsy confirmation to diagnose CD.

Features of ZED1227: The First-In-Class Tissue Transglutaminase Inhibitor Undergoing Clinical Evaluation for the Treatment of Celiac Disease.

ZED1227 is a small molecule tissue transglutaminase (TG2) inhibitor. The compound selectively binds to the active state of TG2, forming a stable covalent bond with the cysteine in its catalytic center. The molecule was designed for the treatment of celiac disease. Celiac disease is an autoimmune-mediated chronic inflammatory condition of the small intestine affecting about 1-2% of people in Caucasian populations. The autoimmune disease is triggered by dietary gluten. Consumption of staple foods containing wheat, barley, or rye leads to destruction of the small intestinal mucosa in genetically susceptible individuals, and this is accompanied by the generation of characteristic TG2 autoantibodies. TG2 plays a causative role in the pathogenesis of celiac disease. Upon activation by Ca2+, it catalyzes the deamidation of gliadin peptides as well as the crosslinking of gliadin peptides to TG2 itself. These modified biological structures trigger breaking of oral tolerance to gluten, self-tolerance to TG2, and the activation of cytotoxic immune cells in the gut mucosa. Recently, in an exploratory proof-of-concept study, ZED1227 administration clinically validated TG2 as a "druggable" target in celiac disease. Here, we describe the specific features and profiling data of the drug candidate ZED1227. Further, we give an outlook on TG2 inhibition as a therapeutic approach in indications beyond celiac disease.

A High-throughput Multiplexed Screening for Type 1 Diabetes, Celiac Diseases, and COVID-19.

An ongoing clinical trial, Autoimmunity Screening for Kids (ASK), is the first screening study in the general population for type 1 diabetes (T1D) and celiac disease in the United States. With the coronavirus disease 2019 (COVID-19) pandemic, the epidemiology of COVID-19 in the general population and knowledge about the association between COVID-19 infection and T1D development are urgently needed. The currently standard screening method of the radio-binding assay (RBA) has met two great challenges: low efficiency with a single assay format and low disease specificity with a large proportion of low-affinity antibodies generated in screening. With the platform of the multiplex electrochemiluminescence (ECL) assay we established previously, a novel 6-Plex ECL assay was developed that combines, in a single well, all four islet autoantibodies (IAbs) to insulin, glutamic acid decarboxylase (GAD65), insulinoma antigen 2 (IA-2), and Zinc transporter 8 (ZnT8) for T1D, transglutaminase autoantibodies (TGA) for celiac disease, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor-binding domain (RBD) antibodies for COVID-19. The assay was validated in blind using 880 samples from the ASK study, including 325 positive samples and 555 all antibody-negative samples, and compared with the standard RBAs and a single ECL assay. With the advantages of high efficiency, low cost, and low serum volume, this assay has been accepted as the primary screening tool for the ASK study.

Evidence supporting safe diagnosis of coeliac disease in children with antitissue transglutaminase titre ≥5 times upper limit of normal.

OBJECTIVE: European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) guidelines on coeliac disease (CD) recommend that children who have IgA-based antitissue transglutaminase (TGA-IgA) titre ≥10× upper limit of normal (ULN) and positive antiendomysial antibody, can be reliably diagnosed with CD via the no-biopsy pathway. The aim of this study was to examine the relationship between TGA-IgA ≥5×ULN and histologically confirmed diagnosis of CD. METHODS: Data including TGA-IgA levels at upper gastrointestinal endoscopy and histological findings from children diagnosed with CD following endoscopy from 2006 to 2021 were analysed. CD was confirmed by Marsh-Oberhuber histological grading 2 to 3 c. Statistical analysis was performed using χ² analysis (p<0.05= significant). RESULTS: 722 of 758 children had histological confirmation of CD. 457 children had TGA-IgA ≥5×ULN and 455 (99.5%) of these had histological confirmation for CD; the two that did not had eventual diagnosis of CD based on clinicopathological features. 114 of 457 had between TGA-IgA ≥5×ULN and <10×ULN, all had confirmed CD. The likelihood of a positive biopsy with TGA-IgA ≥5×ULN (455/457) compared with TGA-IgA <5×ULN (267/301) has strong statistical significance (p<0.00001). The optimal TGA-IgA cut-off from receiver operating characteristic curve analysis was determined to be below 5×ULN for the two assays used. CONCLUSION: 99.5% of children with TGA-IgA ≥5×ULN had histological confirmation of CD, suggesting that CD diagnosis can be made securely in children with TGA-IgA ≥5×ULN. If other studies confirm this finding, there is a case to be made to modify the ESPGHAN guidelines to a lower threshold of TGA-IgA for serological diagnosis of CD.

Celiac Disease and Targeting the Molecular Mechanisms of Autoimmunity in COVID Pandemic.

Celiac disease (CD) comprises over 1% of the world's population and is a chronic multisystem immune-mediated condition manifested by digestive and/or extradigestive symptoms caused by food intake of gluten. This review looked at the risk of children diagnosed with CD developing SARS-CoV-2 infection and possible severe forms of COVID-19. A better understanding of the interaction and effects of SARS-CoV-2 infection in CD is very important, as is the role of environmental and genetic factors, but especially the molecular mechanisms involved in modulating intestinal permeability with impact on autoimmunity. CD inspired the testing of a zonulin antagonist for the fulminant form of multisystem inflammatory syndrome in children (MIS-C) and paved the way for the discovery of new molecules to regulate the small intestine barrier function and immune responses. Original published works on COVID-19 and CD, new data and points of view have been analyzed because this dangerous virus SARS-CoV-2 is still here and yet influencing our lives. Medical science continues to focus on all uncertainties triggered by SARS-CoV-2 infection and its consequences, including in CD. Although the COVID-19 pandemic seems to be gradually extinguishing, there is a wealth of information and knowledge gained over the last two years and important life lessons to analyze, as well as relevant conclusions to be drawn to deal with future pandemics. Zonulin is being studied extensively in immunoengineering as an adjuvant to improving the absorption of new drugs and oral vaccines.

Late Onset of ANCA Vasculitis as a Side Effect of Levamisole Treatment in Nephrotic Syndrome.

Levamisole is effectively used in steroid-dependent nephrotic syndrome and the more frequent side effects reported are cytopenia and liver enzymes alterations. Several studies have demonstrated that this drug can induce high titers of circulating perinuclear antineutrophil cytoplasmic autoantibodies (ANCA) and vasculitis, most of them occurring in the case of prolonged use. A four-year-old boy that was affected with steroid-dependent nephrotic syndrome was treated with Levamisole as a steroid-sparing agent at a dose of 2 mg/kg/48 h. After initiation of the treatment, the number of relapses drastically decreased, enabling a significant reduction in the cumulative steroid dose. Levamisole was well tolerated, and was therefore administered for several years. At the age of 15, he was also diagnosed with celiac disease. After nine years of continuous Levamisole treatment, he presented with a high fever, hand and foot joint arthritis, and increased levels of total and direct bilirubin. Since the symptoms started two days after the injection of the second dose of the COVID-19 vaccine, it was initially concluded that these manifestations were rare vaccination side effects. Therefore, he did not receive any specific treatments, and Levamisole was continued at the same dose. After an initial improvement, two months later, the patient presented with the same symptoms. Suspecting Levamisole-induced vasculitis, an ANCA titer was measured and this returned positive. Clinical manifestations and double positivity for both myeloperoxidase (MPO) and anti-proteinase 3 (PR3) antibodies argued against the fact that that these findings were secondary to vaccination, cocaine abuse, or celiac disease. Assuming that we were facing a rare drug reaction, Levamisole was promptly interrupted. This resulted in a rapid remission of fever and arthritis improvement, and a decrease in ANCA titers. By reporting this case, we want to raise awareness among clinicians regarding a rare complication of treatment with Levamisole that is often misdiagnosed due to the fact that the current literature lacks univocal guidelines regarding the precise timing of ANCA titrations and the duration of the treatment.

High-Throughput Multiplex Electrochemiluminescence Assay Applicable to General Population Screening for Type 1 Diabetes and Celiac Disease.

Objective: Large-scale screening of the general population for islet autoantibodies (IAbs) to detect type 1 diabetes (T1D) has started worldwide. The standard screening method of separate radio-binding assay (RBA) for each IAb is an inefficient bottleneck. Furthermore, most positive results by RBA in screening of general population individuals without a clinical diagnosis of T1D are low-affinity and not predictive of future diabetes. Research Design and Methods: We have developed and validated a novel 6-Plex assay based on electrochemiluminescence (ECL) technology that combines in a single well high-affinity IAbs (to insulin, GAD, IA-2, and ZnT8), transglutaminase autoantibodies for celiac disease, and severe acute respiratory syndrome coronavirus 2 antibodies. The Autoimmunity Screening for Kids (ASK) provided 880 serum samples, from 828 children aged 1-17 years without diabetes who were previously tested for IAbs using single ECL assays and RBA assays. Results: Levels of all six antibodies in the 6-Plex ECL assay correlated well with respective single ECL assay levels. Similar to single ECL assays, the 6-Plex ECL assay positivity was congruent with the RBA in 95% (35/37) of children who later developed T1D and in 88% (105/119) high-risk children with multiple IAbs. In contrast, only 56% (86/154, P < 0.0001) of children with persistent single IAb by RBA were found to be positive by 6-Plex ECL assay. Of 555 samples negative for all IAbs by RBA, few (0.2%-0.5%) were positive at low levels in the 6-Plex ECL assay. Conclusions: The study demonstrated that the 6-Plex ECL assay compares favorably to the standard RBAs in terms of disease specificity for general population screening in children. The 6-Plex ECL assay was therefore adopted as the primary screening tool in the general population screening ASK program with advantages of high efficiency, low cost, and low serum volume.