Pediatric Celiac Disease in Central and East Asia: Current Knowledge and Prevalence

The current state of pediatric gastroenterology in under-resourced nations

Background

Pediatric gastroenterology (GI) care in low- and middle-income countries (LMICs) faces substantial challenges due to limited healthcare infrastructure, inadequate resources, and a shortage of specialized healthcare professionals. These challenges lead to delayed diagnoses and treatment, exacerbating the morbidity and mortality associated with pediatric GI diseases, which include both infectious conditions like diarrhea and chronic conditions such as inflammatory bowel disease (IBD) and liver diseases.

Aim

The aim of this review is to examine the current state of pediatric GI care in LMICs, identify the key challenges these regions face, and propose strategies to improve healthcare outcomes for children affected by GI disorders.

Methods

This review synthesizes existing literature from a range of LMICs, analyzing factors such as the economic burden of healthcare, barriers to access, the availability of diagnostic and therapeutic services, and the state of pediatric hepatology and endoscopy. Studies included in the review were sourced from countries in sub-Saharan Africa, South Asia, and other LMIC regions, focusing on pediatric GI disorders and healthcare delivery.

Results

Economic burden: Families in LMICs face significant economic barriers in accessing pediatric GI care, with treatment costs often exceeding household income, especially in private healthcare settings. Healthcare access: Limited access to healthcare facilities, especially in rural areas, coupled with the shortage of trained pediatric gastroenterologists and necessary medical equipment, leads to delayed diagnoses and inadequate care for conditions like Helicobacter pylori infections and chronic liver diseases. Sanitation and infectious diseases: Poor sanitation and lack of access to clean water contribute to the high prevalence of diarrheal diseases, which can be reduced through better hygiene practices and improved infrastructure. Training gaps: The shortage of trained healthcare workers, particularly pediatric specialists, hinders effective care delivery, with healthcare workers often overburdened due to workforce migration and low salaries. Hepatology and endoscopy: Pediatric hepatology, especially in the context of viral hepatitis, and the availability of pediatric GI endoscopy are severely limited in LMICs, further complicating the management of liver diseases and GI conditions in children.

Conclusion

Improving pediatric GI care in LMICs requires addressing systemic challenges such as inadequate healthcare infrastructure, limited financial resources, and a shortage of trained professionals. Prevention strategies like vaccination, sanitation improvements, and public health education campaigns are crucial for reducing the prevalence of pediatric GI diseases. In addition, enhancing access to specialized training, healthcare services, and diagnostic tools will improve outcomes for children in resource-limited settings. Continued international collaboration and investment in local healthcare systems are essential for creating sustainable solutions and bridging the gap in pediatric GI care.

Celiac Disease and Gut Microbiota: Herbal Treatment and Gluten-Free Diet

Celiac disease (CD) manifests as a targeted autoimmune response that adversely affects the small intestine, primarily affecting individuals with a particular genetic predisposition. Diagnosis centers on identifying this gluten-sensitive enteropathy, which can be ameliorated through the implementation of a gluten-free diet (GFD), correlating with mucosal healing and symptom alleviation. The human microbiota, a vast symbiotic community within the gastrointestinal tract, profoundly impacts human health. Advances in genome sequencing have elucidated the intricate relationship between gut microbiota and autoimmune diseases, including CD, emphasizing the significant role of dietary patterns in shaping the gut microbiota. The influence of GFD on microbiota composition, the only clinically validated treatment for CD, leads to a nutritional shift and potential macronutrient imbalance. Emerging research also highlights the therapeutic potential of various herbs with antioxidant, anti-inflammatory, antimicrobial, gastroprotective, and immunomodulatory properties as complementary approaches to manage CD. This chapter synthesizes the complex interactions between genetics, diet, gut microbiota, and potential herbal interventions in CD, paving the way for more comprehensive understanding and management strategies.

Celiac Disease in Moroccan Children: Diagnostic Characteristics and Determinants of Diagnosis Delay

Advances in the field of celiac disease have led to a better understanding of the disease, but it remains underdiagnosed and poses a daily challenge to clinicians to make a timely diagnosis. This study aims to analyze and describe diagnosis characteristics, diagnosis delay, and the factors influencing this delay in Moroccan children. Our study included 324 children diagnosed during the study period from January 01, 2010, to December 30, 2019, at the Department of Pediatrics, Hassan II University Hospital in Fez, Morocco. Data were collected using a collection grid and then analyzed using SPSS 26 software (IBM Corp., Armonk, NY). The results showed a female predominance (n=197, 60.8%), with a diagnosis age of 73.8±46.8 months. The mean age onset of symptoms was 51.3±41.2 months, and the diagnosis delay was 22.2±22.6 months, with only 32.7% (n=106) diagnosed less than 12 months after symptom onset. The most common consultation reason was diarrhea (n=149, 46%) and growth delay (n=105, 32.4%) and 50.5% (n=98) of parents consulted a pediatrician first. The three clinical, serologic, and histologic criteria made it possible to agree on the diagnosis, with the clinical profile dominated by the digestive form at 84.9% (n=279), serologic with the presence of IgA transglutaminase antibodies (95.7%; n=310), and histologic with villous atrophy at 91.7% (n=297). Unfortunately, 14.8% (n=48) of the children were diagnosed with a celiac crisis. The multivariate logistic regression analysis showed that as symptoms onset age increased, so did the risk of late diagnosis (OR=0.96, 95% CI: 0.94 to 0.97, p<0.001). Age of diagnosis was also associated with delayed diagnosis (OR=19.68, 95% CI: 8.77 to 44.15, p<0.001). The combination of these variables and the diagnosis delay argues in favor of adopting a diagnosis strategy that includes raising awareness among healthcare professionals of the need to identify typical and atypical cases early in order to reduce the adverse effects of late diagnosis and the complications that can result. This methodology for improving diagnoses may also unearth previously unknown aspects of celiac disease in Moroccan children.

Celiac Disease in Uzbek Children: Insights into Disease Prevalence and Clinical Characteristics in Symptomatic Pediatric Patients

BACKGROUND

A few studies on pediatric Celiac Disease (CD) are available from Central Asia. Recent immunogenetic research has highlighted that the HLA-DQ2/8 genetic predisposition to CD as well as the dietary intake of gluten in this geographical area, are comparable to other regions of the world where CD prevalence is known to be 1% or higher.

METHODS

This is a prospective and cross-sectional study investigating the prevalence and clinical characteristics of CD in symptomatic children referred to the pediatric gastroenterology department of a tertiary hospital in Uzbekistan from 1 September 2021, until 31 July 2022. In addition to collecting the relevant information related to clinical manifestations and laboratory analyses from the clinical files, a specific survey was also administered to patients' guardians. Serological, histopathological, and immunogenetic parameters specific to CD, fecal zonulin, and pancreatic elastases were assessed in CD patients.

RESULTS

The study population consisted of 206 children. Overall, almost all of them (n = 192; 93.2%) were referred because of gastrointestinal manifestations, which were associated with extra-gastrointestinal manifestations in most cases (n = 153; 74.3%); a minority (n = 14; 6.8%) was mainly referred due short stature and/or growth failure only. Among all of these study participants, CD was diagnosed in 11 children (5.3%). Notably, although diarrhea was similarly reported in CD and non-CD patients, watery diarrhea (type 7 according to the Bristol stool scale) was much more frequently and significantly observed in the former group. All of these CD patients showed anti-tTG IgA 10 times higher than the upper normal limit, except one child with lower serum levels of total IgA; however, all of them received a diagnostic confirmation by histopathological analysis due to the lack of EMA testing in the country. Notably, most CD children (82%) showed a Marsh III histological grading. Around half patients (54.5%) showed zonulin values above the reference range, whereas none showed insufficient levels of pancreatic elastase. However, no correlation or association between zonulin and clinical, laboratory, histopathological, and immunogenetic parameters was found.

CONCLUSIONS

This study may further suggest a relevant prevalence of CD in Uzbek children, based on this partial picture emerging from symptomatic patients only. Additionally, we highlighted the prevalence of typical CD forms with watery diarrhea, which should strongly support a full diagnostic work-up for CD in the local clinical setting. The high levels of anti-tTG IgA and high Marsh grade might also lead us to speculate a significant diagnostic delay despite the classical clinical expression of CD.

Population-Based Screening for Coeliac Disease in Lithuanian Children from 2009 to 2014

Background and Objectives. Coeliac disease is an autoimmune disorder provoked by a dietary group of proteins called gluten in genetically predisposed individuals. Over the past several decades, the prevalence of coeliac disease has been steadily growing and it is now recognized to be occurring worldwide. The prevalence varies greatly between ethnic, racial groups and regionally. Such variability makes local epidemiological studies important for spreading awareness and setting a threshold for suspicion of coeliac disease. We explored the potential application of a quick point-of-care test for the purpose of detecting a presence of IgA class TG2 antibodies for coeliac disease and screening in a Lithuanian pediatric population. Previously, there were no data regarding coeliac disease prevalence in Lithuania. Materials and Methods. Overall, we included 1458 children 11-13 years of age from several Lithuanian schools selected randomly in this study. Utilizing one point-of-care test using a single blood sample taken from a fingertip, we identified the existence of IgA class TG2 antibodies. Only children whose parents gave consent were enrolled in the study. Those with positive IgA class TG2-ab were directed to a tertiary hospital for additional clinical assessment and confirmation of suspected coeliac disease. Results. A total of two (0.14%) of the 1458 enrolled children were detected with the presence of TG2 antibodies and the coeliac disease diagnosis was further confirmed with histological examination of duodenal biopsy samples. Additionally, we checked that patients had not previously reported any clinical symptoms and signs that could suggest coeliac disease or any other disease of the gastrointestinal tract. Conclusions. The detected prevalence of coeliac disease in the Lithuanian pediatric population is 1:729. The rapid finger prick test for the presence of IgA class TG2 antibodies is a reasonable and accurate method to screen for celiac disease in children.

Visual Analysis of Psychological Resilience Research Based on Web of Science Database

Background

The importance of psychological resilience that people show in coping with stress and adversity is prominent, but few studies have used rigorous bibliometric tools to analyze the knowledge structure and distribution of psychological resilience research.

Objective

The purpose of this study was to sort out and summarize the previous studies on psychological resilience by using bibliometrics. Specifically, the time distribution of psychological resilience research was determined by publication trend, the power distribution was determined by the distribution of countries, authors, institutions and journals, the hot research spots were analyzed according to the results of keyword cluster analysis, and the research frontier was explored according to the results of burst keywords.

Methods

CiteSpace5.8.R3 was used to analyze the literatures on psychological resilience collected in Web of Science core Collection database from January 1, 2010, to June 16, 2022.

Results

A total of 8462 literatures were included after screening. Research on psychological resilience has been on the rise in recent years. The United States had made a high contribution in this field. Robert H Pietrzak, George A Bonanno, Connor KM and others were highly influential. J Pers Soc Psychol has the highest citation frequency and centrality. The research hot spots focus on five aspects: study on psychological resilience related to COVID-19 pandemic, influencing factors of psychological resilience, psychological resilience related to PTSD, study on psychological resilience of special population, and the molecular biology and genetic basis of psychological resilience. Psychological resilience related to COVID-19 pandemic was the most cutting-edge research aspect.

Conclusion

The current situation and trend of psychological resilience research were found in this study, which may be used to identify more hot issues and explore new research directions in this field.

Meta-Analysis and Systematic Review of HLA DQ2/DQ8 in Adults with Celiac Disease

Although people with human leukocyte antigens (HLA) DQ2 and/or DQ8 are more likely to develop celiac disease (CD), the condition cannot be fully explained by this genetic predisposition alone. Multiple, as yet unidentified, factors contribute to the genesis of CD, including genetics, the environment, and the immune system. In order to provide insight into a prospective possibility and an expanded screening technique, we aim to undertake a comprehensive and meta-analytical study of the assessment and distribution of HLA class II (HLA-DQ2/DQ8) in adult CD patients. A systematic review was conducted using an electronic search of databases (PubMed, Google Scholar, Embase, and Direct Science) from January 2004 to February 2022. DQ2/DQ2 homozygotes have the highest risk of developing CD. DQ2/DQ8 typing is an effective test to exclude CD from the differential diagnosis of a patient with CD symptoms. Although other non-HLA genes have been associated with CD, they are rarely considered at diagnosis because they account for only a small proportion of the heritability of CD. This finding, together with the information gathered previously, may be useful in considering widely available and economically feasible screening options for celiac disease in young people.

Questionnaire-based survey to determine an at-risk group for coeliac disease among school children in Moscow, Russia

AIM

Coeliac disease (CD) is a chronic digestive disorder which presents in diverse ways and is under-diagnosed. The purpose of this study was to provide insights into suspected CD among Russian schoolchildren, through defining the percentage of participants in an 'at-risk' group for CD in a paediatric cohort, by means of a questionnaire as a primary screening tool.

METHODS

Russian school children of both sexes age 7-18 years were enrolled in a population-based study to identify individuals affected by CD. Each participant was presented with a structured questionnaire based on criteria that can be used to reveal symptomatic signs of CD. Following on, we developed a case-finding strategy for the 'at-risk' group, based on serological and genetic testing and, where possible, endoscopic examination of participants.

RESULTS

10.2% of questionnaire respondents (312/3070) were classified as an at-risk group. Pathobiological CD analysis of this group returned positive test results for 13.5% of participants (42/312), and 0.6% of them (2/312) had CD confirmed by biopsy sample analysis.

CONCLUSIONS

Our findings suggest that at-risk groups among children with symptomatic or some oligosymptomatic CD presentations can be identified through adopting a questionnaire as part of a population-based screening survey, if generally accepted screening programs are inaccessible.

Gluten contamination in labelled gluten-free, naturally gluten-free and meals in food services in low-, middle- and high-income countries: a systematic review and meta-analysis

The gluten-free diet is based on the consumption of foods without gluten, which aims to manage celiac disease. The concern of celiac patients is that these foods should be safe. However, gluten contamination can affect these foods. The objectives of this review and meta-analysis were first, to identify articles that detected gluten contamination in gluten-free foods using validated methods. Second, to quantify the overall prevalence of gluten contamination of naturally gluten-free foods, labelled gluten-free products, and meals prepared in food services. Third, to highlight the influence of the country's income and the period of study on this prevalence. The studies were identified in Scopus, Science Direct, Web of Science, PubMed, and Google Scholar. Forty articles were included according to PRISMA guidelines. The statistical meta-analysis was performed using MedCalc 19 software. The results show that in the gluten-free foods analysed, the overall prevalence of gluten contamination was estimated at 15.12% (95% CI: 9.56%-21.70%), with more than 20 mg/kg of gluten. Naturally gluten-free foods were significantly more contaminated than labelled gluten-free products and than meals in food services (28.32%; 9.52%; 4.66% respectively; p < 0.001). Moreover, it was noticed that oats were the most contaminated food. In addition, the prevalence of gluten contamination has significantly decreased over time. The majority of the studies were carried out in upper-middle-income and high-income countries, while only one study was conducted in lower-middle income countries. Therefore, it is necessary to implement preventive actions to reduce gluten contamination, ensuring safe gluten-free foods for celiac patients, including low-income countries.

The global burden of coeliac disease: opportunities and challenges

Coeliac disease is a systemic disorder characterized by immune-mediated enteropathy, which is caused by gluten ingestion in genetically susceptible individuals. The clinical presentation of coeliac disease is highly variable and ranges from malabsorption through solely extra-intestinal manifestations to asymptomatic. As a result, the majority of patients with coeliac disease remain undiagnosed, misdiagnosed or experience a substantial delay in diagnosis. Coeliac disease is diagnosed by a combination of serological findings of disease-related antibodies and histological evidence of villous abnormalities in duodenal biopsy samples. However, variability in histological grading and in the diagnostic performance of some commercially available serological tests remains unacceptably high and confirmatory assays are not readily available in many parts of the world. Currently, the only effective treatment for coeliac disease is a lifelong, strict, gluten-free diet. However, many barriers impede patients' adherence to this diet, including lack of widespread availability, high cost, cross-contamination and its overall restrictive nature. Routine follow-up is necessary to ensure adherence to a gluten-free diet but considerable variation is evident in follow-up protocols and the optimal disease management strategy is not clear. However, these challenges in the diagnosis and management of coeliac disease suggest opportunities for future research.

Development of Gluten-Free Rice Flour Noodles That Suit the Tastes of Japanese People

Gluten-free rice flour noodles with a flavor and texture profile preferred by the Japanese people were developed. The rice noodles contained potato starch (PS) as a binder. “Koshihikari” was selected from several candidate varieties based on its pasting properties. Since the Japanese people prefer the chewy texture of wheat flour “Udon” noodles, first, the stress−strain characteristics of “Udon” noodles in Japan were quantified, using a mechanical test. Next, different formulations of rice noodles were prepared by changing the amount of PS blended into the noodles. The mechanical tests on wheat and rice noodles show that rice noodles made from 85% rice flour and 15% PS have a texture similar to that of “Udon” noodles. Brown rice noodles containing roasted brown rice flour were also developed. Since brown rice flour hinders the binding of the dough, it was necessary to increase the amount of PS to increase the binding of roasted brown rice flour. Finally, noodles with 70% white rice flour, 10% brown rice flour, and 20% PS were produced. The gas chromatography−mass spectrometry analysis of the volatile compounds contained in white rice noodles and brown rice noodles identified the volatile compounds characteristic each of type.

Epidemiological, clinical, and histological presentation of celiac disease in Northwest China

BACKGROUND

Research on celiac disease (CD) in northwest China is still in its infancy. At present, large-sample data on the epidemiological, clinical, and pathological characteristics of CD are limited.

AIM

To investigate the epidemiological, clinical, and pathological characteristics of CD in northwest China.

METHODS

The clinical data of 2884 patients with gastrointestinal (GI) symptoms were retrospectively analyzed. Total immunoglobulin A (IgA) and anti-tissue transglutaminase (tTG) IgA levels were examined in all patients. Gastroscopy and colonoscopy were performed in patients with positive anti-tTG IgA and deficient total IgA levels. Atrophy of the duodenal and ileal villi was examined and histopathological examinations were performed. The modified Marsh–Oberhuber classification system was used to grade villous atrophy in the duodenum or distal ileum. The patients’ Helicobacter pylori (H. pylori) infection status was compared in terms of clinical presentation and Marsh grade. Statistical analyses were performed using the t-test or chi-square test.

RESULTS

Among the 2884 patients, 73 were positive for serum anti-tTG IgA, and 50 were diagnosed with CD. The CD detection rate was significantly higher in Kazakhs (4.39%) than in Uyghurs (2.19%), Huis (0.71%), and Hans (0.55%). The main symptoms of CD were chronic diarrhea, anorexia, anemia, fatigue, weight loss, sleep disorders, osteopenia, and osteoporosis. The body mass index of patients with CD was significantly lower than that of patients without CD. A total of 69 patients with positive serum anti-tTG IgA and two patients with deficient total IgA levels underwent GI endoscopy. Endoscopy revealed crypt hyperplasia and/or duodenal villous atrophy, mainly manifested as nodular mucosal atrophy, grooves, and fissures. The difference in H. pylori infection rates was not statistically significant between CD and non-CD patients but was significantly different among CD patients with different Marsh grades.

CONCLUSION

Among the patients with GI symptoms in northwestern China, the prevalence of CD was more in the Uyghur and Kazakh populations. H. pylori infection may be associated with CD severity.

Investigation of the Factors Affecting Bone Mineral Density in Children with Celiac Disease

PURPOSE

Children with celiac disease (CD) are at an increased risk of low bone mineral density (BMD) owing to malabsorption of fat-soluble vitamins, inflammation, and malnutrition. This study aimed to determine the prevalence and risk factors for low BMD in Iranian children with CD.

METHODS

This prospective cohort study examined 149 Iranian children with CD between 2011 and 2018 at Zabol University of Medical Sciences. BMD was measured using dual-energy X-ray absorptiometry. Demographic, clinical, and laboratory data were collected from patients' medical records. Logistic regression analysis was performed to identify the factors associated with low areal BMD (BMD-Z <-2) in the lumbar spine and femoral neck. Descriptive data were analyzed using the mean, standard deviation, and relative frequency. Data were analyzed using the chi-square test, t-test, and analysis of variance.

RESULTS

Of the 149 children with CD, 27.5% had osteoporosis. The mean body mass index (BMI) Z score was -1.28±1.2. Lower BMI was associated with a higher likelihood of BMD-Z (odds ratio 2.17; p≤0.05).

CONCLUSION

Overall, the findings of this study showed that there was no correlation among Marsh classification, presence of specific human leukocyte antigens, and low BMD in Iranian children with CD. BMI can be a predictor of bone density in children with CD and may be applied clinically in early screenings to evaluate the bone health status in these children.

Celiac Disease Revisited

Celiac disease (CD) is a systemic disease triggered by gluten ingestion in genetically predisposed individuals. It manifests primarily as an autoimmune enteropathy associated with specific circulating autoantibodies and a human leukocyte antigen haplotype (HLA-DQ2 or HLA-DQ8). It afflicts roughly 1% of the population, though the majority of patients remain undiagnosed. Diarrhea and malabsorption are classic manifestations of CD; however, both children and adults can be paucisymptomatic and present extraintestinal manifestations such as anemia, osteoporosis, and abnormal liver tests. CD screening is not recommended for the general population, and it should be focused on high-risk groups. CD diagnosis is challenging and relies on serological tests, duodenal histology, and genetic testing. Particularly difficult presentations to manage are seronegative patients, seropositive patients without villus atrophy, and patients who have started a gluten-free diet before the diagnostic workup. The only proven treatment is a lifelong gluten-free diet. We present an in-depth review on the physiopathology and management of CD, with a particular emphasis on diagnostic challenges.

Reliability of the Multiplex CytoBead CeliAK Immunoassay to Assess Anti-tTG IgA for Celiac Disease Screening

Background and Objective: The diagnosis of Celiac Disease (CD) is first based on the positivity for specific serological markers. The CytoBead CeliAK immunoassay simultaneously measures antibodies (IgA) directed to tissue transglutaminase (tTG), endomysium (EMA), and deamidated gliadin (DG), in addition to providing a control for total IgA levels. The aim of this study is to assess the reliability of this multiplex assay to detect anti-tTG IgA positive patients, compared with a conventional single-parameter enzyme-linked immunosorbent assay (ELISA). Methods: Serum samples from 149 pediatric patients were assessed by both CytoBead CeliAK immunoassay and ELISA, in order to evaluate their concordance for the measurement of anti-tTG IgA. Results: The measurement of anti-tTG IgA by CytoBead CeliAK immunoassay basically showed a complete concordance rate with the conventional and single-parameter ELISA, according to the respective cutoff values (3 U/ml and 10 U/ml). Conclusions: Our comparative analysis demonstrates a substantial equivalency between multiplex CytoBead CeliAK assay and the single-parameter conventional ELISA to assess anti-tTG IgA antibody in the context of the screening for CD in children. Importantly, CytoBead CeliAK assay could present some preanalytic, analytic, and economic advantages.

TagSNP approach for HLA risk allele genotyping of Saudi celiac disease patients: effectiveness and pitfalls

BACKGROUND

Celiac disease (CD) is a genetically complex autoimmune disease which is triggered by dietary gluten. Human leukocyte antigen (HLA) class II genes are known to act as high-risk markers for CD, where >95% of CD patients carry (HLA), DQ2 and/or DQ8 alleles. Therefore, the present study was conducted to investigate the distribution of HLA haplotypes among Saudi CD patients and healthy controls by using the tag single nucleotide polymorphisms (SNP).

METHODS

HLA-tag SNPs showing strong linkage value (r2>0.99) were used to predict the HLA DQ2 and DQ8 genotypes in 101 Saudi CD patients and in 103 healthy controls by using real-time polymerase chain reaction technique. Genotype calls were further validated by Sanger sequencing method.

RESULTS

A total of 63.7% of CD cases and of 60.2% of controls were predicted to carry HLA-DQ2 and DQ8 heterodimers, either in the homozygous or heterozygous states. The prevalence of DQ8 in our CD patients was predicted to be higher than the patients from other ethnic populations (35.6%). More than 32% of the CD patients were found to be non-carriers of HLA risk haplotypes as predicted by the tag SNPs.

CONCLUSION

The present study highlights that the Caucasian specific HLA-tag SNPs would be of limited value to accurately predict CD specific HLA haplotypes in Saudi population, when compared with the Caucasian groups. Prediction of risk haplotypes by tag SNPs in ethnic groups is a good alternate approach as long as the tag SNPs were identified from the local population genetic variant databases.

Celiac Disease in Asia beyond the Middle East and Indian subcontinent: Epidemiological burden and diagnostic barriers

Celiac Disease (CD) had been considered uncommon in Asia for a long time. However, several studies suggested that, in the Indian subcontinent and Middle East countries, CD is present and as prevalent as in Western countries. Outside these Asian regions, the information about the epidemiology of CD is still lacking or largely incomplete for different and variable reasons. Here, we discuss the epidemiological aspects and the diagnostic barriers in several Asian regions including China, Japan, Southeast Asia and Russia/Central Asia. In some of those regions, especially Russia and Central Asia, the prevalence of CD is very likely to be underestimated. Several factors may, to a different extent, contribute to CD underdiagnosis (and, thus, underestimation of its epidemiological burden), including the poor disease awareness among physicians and/or patients, limited access to diagnostic resources, inappropriate use or interpretation of the serological tests, absence of standardized diagnostic and endoscopic protocols, and insufficient expertise in histopathological interpretation.

Fecal and Duodenal Microbiota in Pediatric Celiac Disease

Background and Objective: The gut microbiota plays a role in regulating the host immunity. Therefore, alterations in gut microbiota (or dysbiosis) have been investigated in several gastrointestinal diseases, including Celiac Disease (CD). The aim of this study is to summarize the main characteristics of the gut microbiota in pediatric CD. Methods: We performed a systematic review to retrieve the available studies investigating the gut microbiota in pediatric CD patients and controls. In detail, after the screening of >2,200 titles from the medical literature, 397 articles were assessed for eligibility based on the abstracts: of those, 114 full-text original articles were considered as eligible according to the aim of this systematic review. Results: The final search output consisted of 18 articles describing the gut microbiota of CD children and including one or more control groups. Eleven pediatric studies provided information on the duodenal microbiota and as many investigated the fecal microbiota; three articles analyzed the microbiota on both fecal and duodenal samples from the same cohorts of patients. Conclusion: Due to the heterogeneity of the experimental procedures and study design, it is not possible to evidence any specific celiac signature in the fecal and/or duodenal microbiota of CD children. However, some specific components of the fecal microbiota and, in detail, Bifidobacterium spp. (e.g., Bifidobacterium longum) may deserve additional research efforts, in order to understand their potential value as both probiotic therapy and diagnostic/prognostic biomarker.

Navigating celiac disease and the gluten-free diet in China

BACKGROUND

Little is known about celiac disease (CeD) diagnosis and management in China.

AIM

This pilot aimed to be the first study to describe, quantitatively and qualitatively, how individuals living in China navigate CeD and the gluten-free diet (GFD).

METHODS

Participants were 13 adults and four parents of children with reported CeD, recruited from 11 mainland China cities via an online GFD support group. CeD-specific quality of life (CD-QOL and CD-PQOL) and diet adherence (CDAT) were assessed. In-depth interviews addressed experiences with CeD and the GFD.

RESULTS

Six of 17 participants reported biopsy- or serology-confirmed CeD. The mean (SD) adult CDAT score was 15.2 (3.6), > 13 indicating inadequate GFD adherence. The mean adult CD-QOL score was 62.1 (24.1) out of 100, in the "medium" to "good" range. Results were similar in children. Major interview themes included: (1) a challenging journey to obtain diagnosis; (2) social and structural barriers to maintaining the GFD; and (3) reliance on self in management of CeD.

CONCLUSION

Obtaining a diagnosis, maintaining a GFD, and living with CeD can be extremely challenging in mainland China. Results suggest an urgent need for CeD-specific education and Asian-adapted GFD guidance for both healthcare practitioners and patients.

Pediatric Ulcerative Colitis in Kazakhstan: First Case Series from Central Asia and Current Clinical Management

The diagnoses of ulcerative colitis have increased in pediatric patients in the last two decades. Whereas there are several reports from most areas of the world, no clinical studies describing the clinical management of pediatric ulcerative colitis are currently available from Central Asia. In this article, we first describe a case series of pediatric patients affected with ulcerative colitis in Kazakhstan. This is a retrospective study including 25 consecutive pediatric patients diagnosed with ulcerative colitis in a tertiary pediatric hospital. The available demographic, clinical, hematological and inflammatory parameters at diagnosis and at the first one-year follow-up have been provided and analyzed. Most pediatric patients diagnosed with ulcerative colitis were older than 12 years, with prevalence of male gender. The analysis of clinical, laboratory, endoscopic parameters at the diagnosis suggested a significant diagnostic delay compared to developed countries; however, most of them showed clinical, laboratory and endoscopic improvements at the one-year follow-up. Even though the therapeutic approach and outcomes resulted to be consistent with other clinical studies from developed countries, several aspects of the medical follow-up should be improved, especially in pediatric patients with extensive disease.

Prevalence of coeliac disease in Northwest China: heterogeneity across Northern Silk road ethnic populations

BACKGROUND

Epidemiological data of coeliac disease are lacking from the central Asian region.

AIMS

To verify the occurrence of coeliac disease amongst four major ethnic groups of Xinjiang Uyghur Autonomus Region, China.

METHODS

2277 in-patients with gastrointestinal symptoms (1391 Han, 608 Uyghur, 146 Kazakh and 132 Hui; mean age: 54 ± 12.8 years) were included. Total IgA, anti-deamidated gliadin peptide (DGP)-IgG, and anti-tissue transglutaminase (anti-tTG)-IgA were analysed. All antibody-positive subjects were further tested for endomysial (EMA) antibodies and were HLA genotyped. All subjects with antibody positivity were asked to undergo intestinal biopsy. In addition, a subset of antibody-negative subjects were tested for HLA-DQA1and DQB1.

RESULTS

Among the 2277 subjects, 29 subjects were defined as coeliac disease autoimmune (positive results for anti-tTG IgA and EMA-IgA) (1.27%; 95% confidence interval, 0.81%-1.73%), eight of them underwent biopsy and all showed coeliac disease histology (0.35%; 95% Cl, 0.11%-0.59%). The frequency of coeliac disease autoimmunity was lowest among the Han (0.79%), followed by the Uyghur (1.81%), the Kazakh (2.05%) and the Hui (3.03%). The frequency of the HLA-DQ2 and/or DQ8 haplotype was highest in the Uyghur (52.1%), followed by the Hui (44.4%), the Kazakh (40.0%) and the Han (39.4%). Besides, a three times higher frequency of coeliac disease autoimmunity was found among rural living subjects with significantly higher wheat consumption compared to urban living subjects (3.16% vs 0.97%, P < 0.01).

CONCLUSIONS

In Xinjiang, coeliac disease does occur, especially in the rural area. The HLA haplotype and environment play key roles in the development of coeliac disease.

Serological screening for celiac disease in adults in Japan: Shimane CoHRE study

Background and Aim

Celiac disease (CD) is a chronic autoimmune enteropathy triggered by ingested gluten in genetically predisposed individuals. Although common in Europe and the United States, cases of CD are rarely encountered in East Asia, including Japan, and its prevalence remains to be fully evaluated in a large‐scale study. We previously investigated the presence of CD in adults in Japan, which revealed a low prevalence of 1 (0.05%) of 2008 nonclinical subjects, while 1 (2.1%) of 47 symptomatic patients was diagnosed based on serology and duodenal histopathology results. To confirm those results, we conducted an additional retrospective serological screening study of adults in Japan.

Methods

Serum samples were collected from 2055 adults who underwent a health examination in four local areas of Shimane prefecture in Japan from July 2008 to August 2013. As a screening test for CD, the antitissue transglutaminase IgA antibody (TTG) titer was determined in all subjects, and a value greater than 10 U/mL was considered to be evidence of CD.

Results

Of the 2055 subjects, 4 (0.19%) showed a high concentration of TTG. Although two of the four who were seropositive had died at the time of this retrospective study, none reported prominent digestive symptoms such as diarrhea or weight loss in a follow‐up survey.

Conclusions

Among a general population in Japan, a positive rate of serological tests for CD was noted in 0.19%, indicating quite a low presence, consistent with our previous results.

Carrier frequency of HLA-DQB1*02 allele in patients affected with celiac disease: A systematic review assessing the potential rationale of a targeted allelic genotyping as a first-line screening

BACKGROUND

Celiac Disease (CD) is an immune-mediated disorder, in which the HLA immunogenetic background (DQ2 and DQ8 heterodimers) and environmental trigger (gluten) are well established. Indeed, both factors are necessary - but not sufficient - to develop CD. However, it is very likely that CD is underdiagnosed in both developing and developed countries, due to several aspects, including the fact that a lot of patients present mild and/or atypical symptoms, without the presence of any recognized risk factors. Therefore, the possibility and feasibility of widened screening strategies to identify CD patients are debated.

AIM

To provide further evidence of the main epidemiological importance of HLA-DQB1*02 allele in the population of CD patients.

METHODS

We performed a systematic search in PubMed, EMBASE, Cochrane, Web of Science and Scopus databases, in order to produce a systematic review assessing the carrier frequency of HLA-DQB1*02 allele in the celiac population. Following the PRISMA guidelines, we retrieved all the original articles describing CD patients' HLA-DQB1 genotype in such a way that could allow to assess the HLA-DQB1*02 carrier frequency among CD patients, along with the evidence of the appropriate diagnostic work-up to achieve a correct and final diagnosis of CD.

RESULTS

The final output of this systematic search in the medical literature consisted of 38 studies providing the appropriate HLA-DQB1 genotype information of the respective CD population. According to this systematic review, including a pool of 4945 HLA-DQ genotyped CD patients, the HLA-DQB1*02 carrier frequency was 94.94%, meaning that only 5.06% of CD patients were completely lacking this allelic variant. Interestingly, if we consider only the studies whereby the prevalence of CD patients affected with type 1 diabetes mellitus was supposed or clearly established to be very low, the frequency of non-HLA-DQB1*02 carriers among CD patients dropped to 3.65%.

CONCLUSION

Such a high carrier frequency of the HLA-DQB1*02 allelic variant (which is > 95%-96% in CD patients without risk factors, like type 1 diabetes mellitus comorbidity) might be exploited to consider a cost-effective and widened screening approach. If a sustainable strategy could be implemented through a low-cost targeted genetic test to detect the individual presence of HLA-DQB1*02 allele, an appropriate algorithm for serological screening in individuals resulting to be genetically predisposed to CD, might be considered.

Genetic predisposition to celiac disease in Kazakhstan: Potential impact on the clinical practice in Central Asia

BACKGROUND

Celiac disease (CD) is a systemic immune-mediated disorder developing in HLA genetically predisposed individuals carrying HLA-DQ2 and/or HLA-DQ8 molecules. Recent evidences supported a predominant importance of HLA-DQB1 locus and, in particular, HLA-DQB1*02 alleles. This diagnosis is poorly considered in Kazakhstan, because of the assumption that CD is not prevalent in this population.

OBJECTIVE

To demonstrate that the genetic predisposition to CD in Kazakhstan is not negligible and is actually comparable to Western populations.

METHODS

Through the analysis of HLA-DQ genotypes of healthy bone marrow donors from Kazakhstan's national registry, we estimated the HLA-related genetic predisposition to CD in the country.

RESULTS

We demonstrated that the frequency of CD-related HLA-DQB1 alleles and, as a consequence, of predisposed individuals to CD in Kazakhstan is significant and comparable to countries with the highest disease prevalence.

CONCLUSION

Considering the dietary style in Kazakhstan, including wheat as a staple food, these results provided a preliminary background of knowledge to expect a significant CD prevalence in Kazakhstan and Central Asia by implementing appropriate and cost-effective diagnostic strategies.

HLA-DQB1*02 allele in children with celiac disease: Potential usefulness for screening strategies

Through a retrospective analysis of a real-life cohort of children with celiac disease (CD), who underwent HLA-DQ genotyping, we supported our previous findings indicating the presence of HLA-DQB1*02 allele in at least 90%-95% of pediatric patients. In the present study, reporting the HLA-DQ analysis from 184 children (age range: 1-16 years) diagnosed with CD in a single centre, we found that 97.29% of all these CD children (n = 179 out of 184 genotyped patients) resulted to be carriers of at least one copy of HLA-DQB1*02 allele. If a widened screening for CD should result to be appropriate in the pediatric population after further clinical research, this observation might be potentially exploited to consider a two-step screening strategy, starting with the HLA-DQB1*02 targeted analysis followed by the specific serology for CD in these predisposed patients only. However, additional and larger studies are needed to support our findings.

Relevance of HLA-DQB1*02 Allele in the Genetic Predisposition of Children with Celiac Disease: Additional Cues from a Meta-Analysis

Background and Objectives: Celiac disease (CD) is a multifactorial immune-mediated disorder, triggered by the ingestion of gluten in genetically-predisposed subjects carrying MHC-DQ2 and -DQ8 heterodimers, which are encoded by four HLA-DQ allelic variants, overall. This meta-analysis aims at providing further epidemiological support to the predominant relevance of one specific allele, namely HLA-DQB1*02, in the predisposition and genetic risk of CD. Materials and Methods: We performed a search of MEDLINE/PubMed, Embase, Web of Science, and Scopus, retrieving all publications (case-control study, cross-sectional, and retrospective cohort study) on the association between HLA class II polymorphisms and first-degree relatives (FDRs) of children with CD. After a critical reading of the articles, two investigators independently performed data extraction according to the following inclusion criteria: HLA class II genes, any DQ and DR molecules, and CD diagnosed following the current clinical guidelines. A third participant was consulted for discussion to reach an agreement concerning discrepancies. Results: Our search strategy selected 14 studies as being eligible for inclusion, and those were submitted for data extraction and analysis. These studies were published between 1999 and 2016 and, collectively, enrolled 3063 FDRs. Positive and negative likelihood ratios (LR+ and LR-, respectively) for CD diagnosis, according to the presence of the HLA-DQ genotype coding a complete MHC-DQ2 and/or MHC-DQ8 molecules, were 1.449 (CI 1.279-1.642) and 0.187 (CI 0.096-0.362), respectively. If only the isolated presence of HLA-DQB1*02 allele is considered, the pooled estimation of LR+ was 1.659 (CI 1.302-2.155) and, importantly, the LR- still showed a very good discriminatory power of 0.195 (CI 0.068-0.558). Conclusions: Through our differential meta-analysis, comparing the presence of the genotype coding the full MHC-DQ2 and/or DQ8 molecules with the isolated presence of HLA-DQB1*02 allelic variant, we found that the LR- of the latter analysis maintained the same value. This observation, along with previous evidences, might be useful to consider potential cost-effective widened screening strategies for CD in children.