Celiac disease in children with diarrhea in 4 cities in China

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.

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.

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.

Celiac disease may be rare among children in South China

Objective

The prevalence of celiac disease (CD) varies geographically and ethnically; however, the prevalence among children in South China remains unknown. We therefore determined the occurrence of CD among Chinese children in South China.

Methods

Serum samples were collected from children and assessed for anti-tissue transglutaminase IgA antibodies (anti-tTG-IgA) and total IgA. Anti-tTG-IgA+ participants underwent human leukocyte antigen (HLA) DQ2/DQ8 determination. Samples with serum total IgA <0.05 g/L were also analyzed for anti-tTG-IgG, and for HLA-DQ2/DQ8 if the values were above borderline. Participants who were anti-tTG-IgA/IgG+ and HLA-DQ2+ and/or HLA-DQ8+ underwent small bowel biopsy.

Results

A total of 8794 children were enrolled, of whom 479 had chronic unexplained abdominal symptoms. Three (0.034%) children were anti-tTG-IgA+ and ten (0.114%) had serum total IgA <0.05 g/L, all of whom were anti-tTG-IgG−. The three positive children were all HLA-DQ2+ and/or HLA-DQ8+. Two underwent gastroscopy, and histopathology of small intestinal biopsy showed duodenal villous blunting in one and increased intraepithelial lymphocytes in the other, neither consistent with a diagnosis of CD.

Conclusion

Our study showed a prevalence of CD autoimmunity of 0.034% and failed to identify any cases of CD, suggesting a low prevalence of CD among children in South China.

Prevalence of celiac disease in China: Meta-analysis and serological survey in high-risk populations

OBJECTIVE

To summarize data from a serological survey of high-risk populations in Guangdong Province, China, and to perform a meta-analysis to investigate the prevalence and seroprevalence of celiac disease (CD) in the Chinese general and high-risk populations.

METHODS

We collected data from the serological survey of high-risk population of CD in Guangdong Province, China (N = 1390) by testing their serum tissue transglutaminase immunoglobulin A (tTG-IgA), deamidated gliadin peptides immunoglobulin A (DGP-IgA) and deamidated gliadin peptides immunoglobulin G (DGP-IgG). Additionally, a literature search was performed on PubMed, EMBASE, Cochrane Library and three Chinese databases for articles published up to 20 December 2020 to estimate the pooled prevalence and seroprevalence of CD in China.

RESULTS

In the serological survey, 0.94% (13/1390) of individuals were positive for CD antibodies. In a meta-analysis of 18 studies, the seroprevalence of CD in the general Chinese population was 0.27% (95% confidence interval [CI] 0.02%-0.71%). While that in the high-risk population was 8.34% (95% CI 4.90%-12.54%) (odds ratio 7.27, 95% CI 4.06-13.04). The prevalence of biopsy-confirmed CD in high-risk Chinese populations was 4.44% (95% CI 1.53%-8.58%). The seroprevalence of CD varied with patients' geographical origin, being higher in northern China than in southern China.

CONCLUSIONS

Early diagnosis of CD by serological screening in high-risk population and generous serological testing in those with vague symptoms, especially in northern China, are recommended.

Emergence of Celiac disease and Gluten-related disorders in Asia

Celiac disease (CeD) is a systemic, immune-mediated enteropathy, which is triggered by gluten protein in genetically susceptible individuals. CeD, once thought to be an uncommon disease, is now recognized to affect approximately 40-60 million people globally. While CeD is now well reported from a few Asian countries such as India, China, Pakistan, and Middle Eastern countries; it is still believed to be uncommon in the rest of Asia. Gluten-related diseases other than CeD, like non-celiac gluten sensitivity (NCGS) are also emerging globally. CeD and NCGS may present with either intestinal or extra-intestinal symptoms, and a proportion of them have overlapping symptoms with irritable bowel syndrome. Hence, many of them are misdiagnosed as having irritable bowel syndrome in clinical practice. In this review, we discuss the emergence of CeD and other gluten-related disorders, both globally and in Asia, the overlapping manifestations between gluten-related disorders and irritable bowel syndrome, and the challenges associated with diagnosis and management of CeD in Asia.

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.

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.

Prevalence of celiac disease in low and high risk population in Asia-Pacific region: a systematic review and meta-analysis

This systematic review and meta-analysis study was conducted to estimate the pooled prevalence of CD in low and high risk groups in this region. Following keywords were searched in the Medline, PubMed, Scopus, Web of Science and Cochrane database according to the MeSH terms; celiac disease, prevalence, high risk population and Asian-Pacific region. Prevalence studies published from January 1991 to March 2018 were selected. Prevalence of CD with 95% confidence interval (CI) was calculated using STATA software, version 14. The pooled sero-prevalence of CD among low risk group in Asia-Pacific region was 1.2% (95% CI 0.8-1.7%) in 96,099 individuals based on positive anti-tissue transglutaminase (anti-t-TG Ab) and/or anti-endomysial antibodies (EMA). The pooled prevalence of biopsy proven CD in Asia-Pacific among high and low risk groups was 4.3% (95% CI 3.3-5.5%) and 0.61% (95% CI 0.4-0.8%) in 10,719 and 70,344 subjects, respectively. In addition, the pooled sero-prevalence and prevalence of CD in general population was significantly higher in children compared with adults and it was significantly greater in female vs. male (P < 0.05). Our results suggest high risk individuals of CD are key group that should be specifically targeted for prevention and control measures, and screening may prove to have an optimal cost-benefit ratio.

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.

Screening for coeliac disease in children and adults living in a slum of Dhaka, Bangladesh

Background and objective

Serological screening with a confirmation through biopsy has improved the understanding of coeliac disease (CD) epidemiology worldwide. Prevalence of CD in Bangladesh is not yet explored and therefore, we aimed to assess the seroprevalence of CD in slum-dwelling malnourished children and adults in Dhaka.

Methods

Serum samples were collected from three different cohorts: stunted (length-for-age Z-scores (LAZ) <−2) and at risk of stunting children (LAZ <−1 to −2) and malnourished adults (body mass index <18.5 kg/m²). Samples from all the participants were assessed for anti-tissue transglutaminase antibody (tTG-IgA) and total serum IgA by ELISA. Positive tTG-IgA and randomly selected low IgA values were reconfirmed using anti-tTG-IgG and gliadin IgG ELISA. CD was diagnosed when second screening tests were found positive and the participants were further investigated by small bowel biopsy.

Results

A total of 818 participants (240 stunted, 272 at risk of stunting children and 306 malnourished adults) were enrolled in the study. Overall, anti-tTG-IgA was positive in 5/818 (0.6%; 95% CI 0.25% to 1.46%). Of the five positive cases, anti-tTG-IgG and gliadin IgG were found positive in only one participant. Duodenal biopsy of positive participant revealed characteristic lesions of CD. Randomly selected low IgA values were found negative in tTG-IgG and gliadin IgG for all the participants. No participant was found total IgA deficient.

Conclusion

The incidence of coeliac autoimmunity is low in malnourished slum dwellers regardless of age in Bangladesh. It is important to investigate the nationwide prevalence to reveal the definite picture.

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

The current prevalence of pediatric Celiac Disease (CD) is estimated to be around 1% in the general population, worldwide. However, according to the geographic area, a great variability of CD prevalence has been described. Whereas a number of studies are available from Europe, North and South America, Australia, South-West Asia, and North Africa, the knowledge and awareness of CD in large parts of the remaining world areas is definitively poor. In several countries of Central and East Asia, the consumption of wheat is consistent and/or has significantly increased in recent decades, and CD is supposed to be underdiagnosed in children. In this mini-review, we aimed to summarize the current knowledge about the prevalence of pediatric CD in Central and East Asia, paying attention to the HLA-DQ immunogenetic background as well. Indeed, CD is likely not to be as uncommon as previously or currently thought in countries like Russia, Kazakhstan, and China, in addition to India, where pediatric CD has been clearly showed to be quite prevalent. Therefore, there is an urgent need for population-based studies on the prevalence of CD in those countries, especially in children, in order to increase the awareness of this disease and to improve the diagnostic strategy in these areas.

Autoantibodies in the Extraintestinal Manifestations of Celiac Disease

Increased antibody reactivity towards self-antigens is often indicative of a disruption of homeostatic immune pathways in the body. In celiac disease, an autoimmune enteropathy triggered by the ingestion of gluten from wheat and related cereals in genetically predisposed individuals, autoantibody reactivity to transglutaminase 2 is reflective of the pathogenic role of the enzyme in driving the associated inflammatory immune response. Autoantibody reactivity to transglutaminase 2 closely corresponds with the gluten intake and clinical presentation in affected patients, serving as a highly useful biomarker in the diagnosis of celiac disease. In addition to gastrointestinal symptoms, celiac disease is associated with a number of extraintestinal manifestations, including those affecting skin, bones, and the nervous system. Investigations of these manifestations in celiac disease have identified a number of associated immune abnormalities, including B cell reactivity towards various autoantigens, such as transglutaminase 3, transglutaminase 6, synapsin I, gangliosides, and collagen. Clinical relevance, pathogenic potential, mechanism of development, and diagnostic and prognostic value of the various identified autoantibody reactivities continue to be subjects of investigation and will be reviewed here.

Gluten-free living in China: The characteristics, food choices and difficulties in following a gluten-free diet - An online survey

BACKGROUND

Individuals adhering to a gluten-free diet (GFD) have been scarcely researched within a Chinese population. This present study was conducted to assess the characteristics, food choices, shopping preferences, and emotions and attitudes of individuals following a GFD.

METHODS

Individuals following a GFD were invited to complete an online questionnaire about their demography and geography characteristics, gluten-free food choices, shopping preferences, GFD management and subjective difficulty towards the diet. Distribution of the characteristics was described, and univariate and multivariate logistic regressions performed to explore the relationship between the above-mentioned variables and subjective difficulty in following a GFD.

RESULT

209 individuals following a GFD completed the questionnaire, most of whom were young, single and well-educated females from developed provinces or municipalities in China. Multiple regression showed that age, education level, advice on starting a GFD, duration before discovering a gluten intolerance, food choices and ways of GFD management were significantly associated with the subjective difficulty in following a GFD.

CONCLUSION

Our findings offer a basic characteristics pattern of the population on a GFD in mainland China. Nearly one-third of GFD followers found the diet challenging to be followed. We suggest that sufficient celiac disease and gluten-induced disorder education be conducted among healthcare practitioners. Early diagnosis of gluten-induced disorders and defining an Asian-adapted GFD, as well as an increase in public awareness, may help adherence to a strict GFD in China.

Prevalence of Celiac Disease Autoimmunity Among Adolescents and Young Adults in China

BACKGROUND & AIMS

In China, epidemiologic information on celiac disease autoimmunity is scarce and fragmented. We investigated the prevalence of celiac disease autoimmunity in the general Chinese population.

METHODS

In a cross-sectional prospective study, 19,778 undiagnosed Chinese adolescents and young adults (age, 16-25 y) were recruited from consecutive new students who underwent routine physical examinations at 2 universities in Jiangxi, China, from September 2010 through October 2013; the students were from 27 geographic regions in China. All subjects were tested for serum IgG, IgG against deamidated gliadin peptides (IgG anti-DGP), and IgA anti-tissue transglutaminase antibodies (IgA anti-tTG). We also analyzed HLA genotypes in subgroups of participants with different results from tests for serum markers of celiac disease.

RESULTS

A total of 434 students (2.19%) tested positive for serum markers for celiac disease (95% confidence interval [CI], 1.99%-2.41%), 0.36% of the students tested positive for anti-tTG IgA (95% CI, 0.28%-0.46%), and 1.88% tested positive for anti-DGP IgG (95% CI, 1.70%-2.09%). The prevalence of celiac disease autoimmunity (positive results in assays for anti-tTG IgA and anti-DGP-IgG) was 0.06% (95% CI, 0.03%-0.10%). Celiac disease autoimmunity was associated with the consumption of wheat and female sex. The prevalence in the Shandong province in north China, where wheat is a staple in the diet, was 0.76% (95% CI, 0.21%-1.95%). The frequencies of the HLA-DQ2/-DQ8 genotypes associated with celiac disease were higher in subjects with celiac disease autoimmunity, based on detection of both serum markers, than in subjects with positive results from a single test (P < .01). All subjects with positive results from both assays carried the HLA-DQ2 genotype.

CONCLUSIONS

Approximately 2% of adolescents or young adults in China had positive results from assays for serum markers for celiac disease. The prevalence of celiac disease autoimmunity in the Shandong province in north China, where wheat is a staple in the diet, was 0.76%.

Cross-sectional study of coeliac autoimmunity in a population of Vietnamese children

OBJECTIVE

The prevalence of coeliac disease (CD) in Vietnam is unknown. To fill this void, we assessed the prevalence of serological markers of CD autoimmunity in a population of children in Hanoi.

SETTING

The outpatient blood drawing laboratory of the largest paediatric hospital in North Vietnam was used for the study, which was part of an international project of collaboration between Italy and Vietnam.

PARTICIPANTS

Children having blood drawn for any reason were included. Exclusion criteria were age younger than 2 years, acquired or congenital immune deficiency and inadequate sample. A total of 1961 children (96%) were enrolled (838 females, 1123 males, median age 5.3 years).

OUTCOMES

Primary outcome was the prevalence of positive autoimmunity to both IgA antitransglutaminase antibodies (anti-tTG) assessed with an ELISA test and antiendomysial antibodies (EMA). Secondary outcome was the prevalence of CD predisposing human leucocyte antigens (HLA) (HLA DQ2/8) in the positive children and in a random group of samples negative for IgA anti-tTG.

RESULTS

The IgA anti-tTG test was positive in 21/1961 (1%; 95% CI 0.61% to 1.53%); however, EMA antibodies were negative in all. HLA DQ2/8 was present in 7/21 (33%; 95% CI 14.5% to 56.9%) of the anti-tTG-positive children and in 72/275 (26%; 95% CI 21% to 32%) of those who were negative.

CONCLUSIONS

Coeliac autoimmunity is rare in Vietnam, although prevalence of HLA DQ2/8 is similar to that of other countries. We hypothesise that the scarce exposure to gluten could be responsible for these findings.

Practical insights into gluten-free diets

Coeliac disease is a global disease, and the only currently available treatment is a gluten-free diet (GFD). Although conceptually simple, the diet changes are substantial and have a profound effect on a patient's life. Untreated coeliac disease is associated with complications, including excess mortality, most of which can be avoided with a strict GFD. However, there are many barriers, including availability, cost and safety of gluten-free foods, and gluten cross-contamination. The GFD can be restrictive in social situations, leading to poor quality of life and, ultimately, nonadherence. As the number of patients with coeliac disease increases worldwide, clinicians need to be aware of the challenges patients face. Heightened awareness by physicians, dietitians and other providers can help maximize successful treatment, improve outcomes, and reduce health-care costs and disease burden. Routine follow-up is necessary to reinforce the need for a GFD, provide social and emotional support, and achieve mucosal healing, leading to reduced risk of complications. Unfortunately, there is wide variation in follow-up practices. The objective of this Review is to increase awareness of the challenges, management and follow-up of patients with coeliac disease to help them achieve GFD adherence and prevent complications whilst preserving their quality of life.

Adherence to gluten-free diet and barriers to adherence in patients with celiac disease

BACKGROUND

While adherence to gluten-free diet (GFD) is essential for effective control of celiac disease, the level of adherence to GFD may vary. We assessed the level of adherence to GFD and identified barriers to adherence in patients with celiac disease.

METHODS

Both treatment-naive and follow up patients with celiac disease were recruited from a celiac disease clinic. All the patients were assessed for symptom improvement using celiac symptom index (CSI), weight, and hemoglobin; adherence to GFD using detailed dietary history and food-labeled quiz questionnaire; identification of barriers to GFD using a self-administered 36-point questionnaire; and quality of life using a standard 36-item short form (SF36) questionnaire.

RESULTS

Among the patients who were already on GFD, only 53.3% maintained an excellent or good level of adherence, which increased to 92.4% at 6 months with repeated counseling. Among the treatment-naive patients, 64.8% maintained either excellent or good compliance at 1 month after first counseling, which increased to 96.3% at 6 months with repeated counseling. The most common barrier to adherence was non-availability of GFD. Certain barriers could be modified with repeated counseling and education. Response to GFD, as measured by CSI, gain in weight, and improvement in hemoglobin, was better in those having either excellent or good compliance to GFD compared to those who remained poorly adherent.

CONCLUSIONS

Repeated counseling increased the level of adherence to GFD.

DQ2, DQ7 and DQ8 Distribution and Clinical Manifestations in Celiac Cases and Their First-Degree Relatives

HLA-linked genes are relevant to celiac disease (CD); the potential genetic differences present worldwide are not fully understood. Previous results suggest that the distribution of HLA-DQ2/DQ7/DQ8 in Chile may differ from that in Europe and North America. In celiac patients and their first-degree relatives (FDRS), we assessed their clinical, serological and histological characteristics, determined HLA-DQ2, HLA-DQ7 and HLA-DQ8 alleles and genotypes, and evaluated the relations between them. A total of 222 individuals were assessed (56 cases, 166 FDRs). 16.9% of FDRs were tTG positive; 53.6% of them showed overweight/obesity and 3% undernourishment; they spontaneously declared being asymptomatic, but detailed questioning revealed that 60.7% experienced symptoms, which had not been investigated. DQ2 was present in 53.9% and 43.9.0% of cases and FDRs (p < 0.05). The most frequent genotype distribution was DQ2/DQ7 (fr 0.392 (cases) and 0.248 (FDRs), respectively, p < 0.02). The next most common genotypes were HLA-DQ2/DQ8 (fr 0.236 in FDRs and 0.176 in cases, p < 0.05). 3.92% cases were not HLA-DQ2/DQ8 carriers. Among tTG positive FDRs, 57.4%, 22.3% and 20.2% carried DQ2, DQ7 and DQ8, respectively. In cases, 72.7% of the biopsies classified Marsh ≥ 3 carried at least one DQ2; 91.7% of DQ2/DQ2 and 88.3% of DQ2/DQ7 were Marsh ≥ 3. Thus, DQ2 frequency is lower than reported; the higher frequency found for DQ8 and DQ7 concur with recent publications from Argentine and Brazil. These results suggest that although CD may manifest clinically in ways similar to those described in other populations, some genetic peculiarities in this region deserve further study.

World perspective and celiac disease epidemiology

In Europe and the USA, the mean frequency of celiac disease (CD) in the general population is approximately 1%, with some regional differences, the reasons for which remain elusive. A similar disease prevalence has been found in other countries mostly populated by individuals of European origin, e.g. Australia and Argentina. In Western countries, a true rise in overall CD prevalence of CD has been documented. CD is a common disorder in North Africa, the Middle East and India; however, the diagnostic rate is low in these countries due to low availability of diagnostic facilities and poor disease awareness. The highest CD prevalence in the world (5.6%) has been described in an African population originally living in Western Sahara, the Saharawi, of Arab-Berber origin. The reasons for this high CD frequency are unclear but could be primarily related to recent dietary changes and genetic factors, given the high level of consanguinity of this population. Further studies are needed to quantify the incidence of the celiac condition in apparently 'celiac-free' areas such as Sub-Saharan Africa and the Far East. In many developing countries, the frequency of CD is likely to increase in the near future given the diffuse tendency to adopt Western, gluten-rich dietary patterns. As most cases currently escape diagnosis all over the world, an effort should be made to increase the awareness of CD polymorphism. A cost-effective case-finding policy and new strategies of mass CD screening could significantly reduce the morbidity and mortality associated with untreated disease. The current high prevalence of CD is just the last link in a chain of events started about 10,000 years ago after wheat domestication and diffusion from the Middle East. We hypothesize different mechanisms to explain the so-called evolutionary celiac paradox of co-localization of gluten consumption and HLA CD-predisposing genotypes.

Prevalence of serum celiac antibodies in a multiracial Asian population--a first study in the young Asian adult population of Malaysia

Background

Celiac disease (CD) is an immune-mediated disorder induced by the ingestion of gluten in genetically susceptible persons. The prevalence of CD in Malaysia is unknown. We aim to determine the seroprevalence of CD antibodies and also investigate the correlation between H. pylori infection and CD in the young and healthy multiracial Malaysian population.

Methods

Healthy young adult volunteers between the ages of 18–30 years were consecutively recruited from June 2012 to May 2014 at the University of Malaya Medical Centre (UMMC), Kuala Lumpur. Serum samples from all the participants were tested for anti-gliadin antibody immunoglobulin A/immunoglobulin G (IgA/IgG) and anti-tissue transglutaminase antibody (tTG) IgA/IgG. Samples positive for both anti-gliadin and anti-tTG were further validated for anti-human endomysial IgA antibodies (EmA). Serological diagnosis of CD was made when anti-gliadin, anti-tTG and anti-EmA were positive.

Results

562 qualified participants with mean age 24 ± 2.4 years old were recruited into our study. CD was found in 7 participants where most of them were asymptomatic and unaware of their CD status. The median of anti-gliadin and anti-tTG IgA/IgG value was 38.2 U/ml (interquartile range, 28.3–60.4 U/ml) and 49.2 U/ml (interquartile range, 41.1–65.9 U/ml), respectively. Seroprevalence of CD antibodies was 1.9% (6 out of 324) in female while only 0.4% (1 out of 238) in male. Seroprevalence among Malay was 0.8% (2 of 236), Chinese was 1.7% (3 of 177) and Indian was 1.3% (2 of 149). Overall, seroprevalence of CD antibodies in healthy asymptomatic adults in the Malaysian population was 1.25% (95% CI, 0.78%-1.72%). No significant relationship was discovered between CD and H. pylori infection.

Conclusions

The seroprevalence of CD antibodies in healthy young adults in the Malaysian population was 1.25% (1 in 100). CD is underdiagnosed and it could be a much greater problem in Malaysia than previously thought.

Issues associated with the emergence of coeliac disease in the Asia–Pacific region: a working party report of the World Gastroenterology Organization and the Asian Pacific Association of Gastroenterology

BACKGROUND AND AIM

Once thought to be uncommon in Asia, coeliac disease (CD) is now being increasingly recognized in Asia–Pacific region. In many Asian nations, CD is still considered to be either nonexistent or very rare. In recognition of such heterogeneity of knowledge and awareness, the World Gastroenterology Organization and the Asian Pacific Association of Gastroenterology commissioned a working party to address the key issues in emergence of CD in Asia.

METHODS

A working group consisting of members from Asia–Pacific region, Europe, North America, and South America reviewed relevant existing literature with focus on those issues specific to Asia–Pacific region both in terms of what exists and what needs to be done.

RESULTS

The working group identified the gaps in epidemiology, diagnosis, and management of CD in Asian–Pacific region and recommended the following: to establish prevalence of CD across region, increase in awareness about CD among physicians and patients, and recognition of atypical manifestations of CD. The challenges such as variability in performance of serological tests, lack of population-specific cut-offs values for a positive test, need for expert dietitians for proper counseling and supervision of patients, need for gluten-free infrastructure in food supply and creation of patient advocacy organizations were also emphasized.

CONCLUSIONS

Although absolute number of patients with CD at present is not very large, this number is expected to increase over the next few years or decades. It is thus appropriate that medical community across the Asia–Pacific region define extent of problem and get prepared to handle impending epidemic of CD.

Advances in coeliac disease

PURPOSE OF REVIEW

To summarize the recent advances in coeliac disease.

RECENT FINDINGS

Details of the polygenic nature of coeliac disease with the human leukocyte antigen (HLA) locus as the dominating genetic element have been uncovered. The existence of a large number of non-HLA coeliac disease genes, only partly shared by each individual patient, suggests the genetic heterogeneity of the disease. The critical role for HLA-DQ-restricted CD4 T cells recognizing antigenic gluten peptides is further substantiated. Involvement of CD8 T cells has received new attention. Other components of wheat than gluten, in particular the amylase trypsin inhibitors, may also play a role. The disease is becoming more prevalent. New guidelines state that coeliac disease diagnosis in children can be made on the basis of clinical signs, serology and genetics without the need of biopsy. The clinical entity 'noncoeliac gluten sensitivity' has received much attention, but diagnostic and pathophysiological definitions are still elusive. The risk for mortality and morbidity in coeliac disease is less than previously thought.

SUMMARY

Our understanding of the basic and clinical aspects of coeliac disease increases. Coeliac disease stands out as a major health problem of almost global occurrence. Case finding, distinguishing coeliac disease from other gluten-sensitive conditions, better care and balanced use of resources are the current challenges.

The tip of the "celiac iceberg" in China: a systematic review and meta-analysis

Objective

Until recently, celiac disease was considered to be rare in China. We aimed to estimate its true status.

Methods

By searching the MEDLINE database and four Chinese full-text databases (CNKI, CBM, VIP and WANFANG) (up to August 2012), as well as two HLA allele frequency net databases and the Chinese Statistics Yearbook databases, we systematically reviewed the literature on definite and suspected cases of celiac disease, the predisposing HLA allele frequencies, and on gluten exposure in China. Meta-analysis was performed by analyzing DQ2, DQ8 and DQB1*0201 gene frequencies and heterogeneity in populations from different geographic regions and ethnicities in China.

Results

At present, the number of reported celiac disease cases is extremely low in China. The frequencies of the HLA-DQ2.5 and HLA-DQ8 haplotypes were 3.4% (95% confidence interval 1.3–5.5%) and 2.1% (0.1–4.1%), respectively. HLA-DQ2 and HLA-DQ8 antigen frequencies were 18.4% (15.0–21.7%) and 8.0% (4.5–11.4%), respectively. The frequency of the DQB1*0201 allele was 10.5% (9.3–11.6%) and it was more common in the northern Chinese than in the southern Chinese populations. The chance of being exposed to gluten is rapidly increasing all over China nowadays.

Conclusion

The data on HLA haplotyping, in conjunction with increasing wheat consumption, strongly suggests that the occurrence of celiac disease is more common in China than currently reported. Coordinated measures by the Chinese government, medical and agricultural research institutions, and food industries, would be justified to create more awareness about celiac disease and to prevent it becoming a medical and societal burden.

Problems and challenges to adaptation of gluten free diet by Indian patients with celiac disease

Celiac disease is emerging in India and has become a public health problem. Almost 6-8 million Indians are estimated to have celiac disease. While there is a large pool of patients with celiac disease in India, until now, only a fraction of them have been diagnosed. With increasing awareness about celiac disease amongst health care providers and the general population, a massive increase in the number of patients with celiac disease is expected now and in the subsequent decade in India. While the number of patients with celiac disease is increasing, the country's preparedness towards the emerging epidemic of this disease is minimal. There are a number of issues, which requires urgent attention. Some of the key issues include increased awareness amongst health care professionals and the general public about the disease and its management, team-based management of patients with celiac disease, proper counseling and supervision of patients, training of dietitians in the management of patients with celiac disease, industrial production of reliable and affordable gluten-free food, and food labeling for gluten contents.

Celiac disease: a disease with varied manifestations in adults and adolescents

OBJECTIVE

We aimed to determine the characteristics of patients with celiac disease and differences between those who presented during adolescence or adulthood.

METHODS

We retrospectively reviewed the case records of 233 consecutive patients with celiac disease who were diagnosed at 12-18 years or >18 years of age. The diagnosis of celiac disease was made on the basis of the modified European Society of Pediatric Gastroenterology, Hepatology and Nutrition criteria.

RESULTS

The diagnosis of celiac disease was made after 18 years of age in 153 (65.7%) patients. Median duration of symptoms at the diagnosis was 54 months (range 1 month to 29 years). In all, 103 (44.2%) patients with atypical manifestations were referred by other departments for evaluation. Chronic diarrhea (48.5%), short stature (27.0%) and chronic anemia (9.0%) were the common modes of presentation. Elevated level of aminotransaminase were present in 50 (24.3%) patients. Chronic diarrhea, hypocalcemia and hypoalbuminemia were present in significantly higher number of adult than adolescent patients. In all, 227 (97.4%) patients responded to a 6-month gluten-free diet and six non-responders were non-compliant.

CONCLUSIONS

More than 40% of the patients with celiac disease present to clinicians other than gastroenterologists or internists with atypical manifestations. A high index of suspicion is required for diagnosing its variant forms.

Systematic review: worldwide variation in the frequency of coeliac disease and changes over time

BACKGROUND

Coeliac disease (CD), originally thought to be largely confined to Northern Europe and Australasia and uncommon in North America and the Middle East, is now recognised to be equally common in all these countries. It is still thought to be rare in the Orient and Sub-Saharan Africa.

AIM

To assess geographical differences and time trends in the frequency of CD.

METHODS

Medline and Embase searches were conducted on 10 November 2012, from 1946 and 1980 respectively, using the key words: coeliac disease or celiac disease + prevalence or incidence or frequency.

RESULTS

There were significant intra- and inter-country differences in the prevalence and incidence of CD. Only 24 ethnic Chinese and Japanese patients have been reported in the English literature. Of CD-associated HLA DQ antigens, DQ2 occurs in 5-10% of Chinese and sub-Saharan Africans, compared to 5-20% in Western Europe. DQ8 occurs in 5-10% of English, Tunisians and Iranians, but in <5% of Eastern Europeans, Americans and Asians. The prevalence and incidence of both clinically and serologically diagnosed CD increased in recent years. These geographical and temporal differences seem genuine, although variable indices of suspicion and availability of diagnostic facilities are confounding factors.

CONCLUSIONS

Coeliac disease is increasing in frequency, with significant geographical differences. Although few cases have been described to date in the Orient and Sub-Saharan Africa, there is a significant prevalence of HLA DQ2 and wheat consumption is of the same order as that in Western Europe. CD may therefore become more common in the future in these countries.

Celiac disease in the developing world

The prevalence of celiac disease (CD) in many developing countries is similar to that of developed areas, in both low- and high-risk groups. The disorder is underestimated because of lack of disease awareness. CD is strongly associated with HLA-DQ2 in developing countries. Clinical presentation may be characterized by chronic diarrhea, anemia, stunting and increased mortality. Few studies have addressed atypical or silent CD. Diagnosis is initially made by serologic tests and is confirmed by small intestinal biopsies. In developing countries the adherence to the treatment is still difficult because of poor availability of dedicated gluten-free food.