Prevalence of celiac disease: before and after a national change in feeding recommendations

Relationship between gluten availability and celiac disease prevalence: A geo-epidemiologic systematic review

Celiac disease is a global disease requiring genetic susceptibility and gluten exposure to trigger immune-mediated enteropathy. The effect of the degree of gluten-containing grain availability on celiac disease prevalence is unknown. Our objective was to compare country-based gluten availability to celiac prevalence using a systematic literature review. We searched MEDLINE, Embase, Cochrane, and Scopus until May 2021. We included population-based serum screening with confirmatory testing (second serological study or small intestine biopsy) and excluded specific, high-risk, or referral populations. We determined country-specific gluten availability using the United Nations food balance for wheat, barley, and rye. Human leukocyte antigen (HLA) frequencies were obtained from allelefrequencies.net. The primary outcome was association between gluten-containing grain availability and celiac disease prevalence. Generalized linear mixed models method with Poisson's link was used for analysis. We identified 5641 articles and included 120 studies on 427 146 subjects from 41 countries. Celiac disease prevalence was 0-3.1%, median 0.75% (interquartile range 0.35, 1.22). Median wheat supply was 246 g/capita/day (interquartile range 214.8, 360.7). The risk ratio (RR) for wheat availability on celiac disease was 1.002 (95% confidence interval [CI]: 1.0001, 1.004, P = 0.036). A protective association was seen with barley, RR 0.973 (95% CI: 0.956, 0.99, P = 0.003), and rye, RR 0.989 (95% CI: 0.982, 0.997, P = 0.006). The RR for gross domestic product on celiac disease prevalence was 1.009 (95% CI: 1.005, 1.014, P < 0.001). The RR for HLA-DQ2 was 0.982 (95% CI: 0.979, 0.986, P < 0.001), and that for HLA-DQ8 was 0.957 (95% CI: 0.950, 0.964, P < 0.001). In this geo-epidemiologic study, gluten-containing grain availability showed mixed associations with celiac disease prevalence.

The prevalence of having coeliac disease in children with type 1 diabetes was not significantly higher during the Swedish coeliac epidemic

AIM

From 1986 to 1996, there was a four-fold increase in coeliac disease among young Swedish children, known as the Swedish coeliac epidemic. Children with type 1 diabetes have an increased risk of developing coeliac disease. We studied whether the prevalence of coeliac disease differed in children with type 1 diabetes born during and after this epidemic.

METHODS

We compared national birth cohorts of 240 844 children born in 1992-1993 during the coeliac disease epidemic and 179 530 children born in 1997-1998 after the epidemic. Children diagnosed with both type 1 diabetes and coeliac disease were identified by merging information from five national registers.

RESULTS

There was no statistically significant difference in the prevalence of coeliac disease among children with type 1 diabetes between the two cohorts: 176/1642 (10.7%, 95% confidence interval 9.2%-12.2%) in the cohort born during the coeliac disease epidemic versus 161/1380 (11.7%, 95% confidence interval 10.0%-13.5%) in the post-epidemic cohort.

CONCLUSION

The prevalence of having both coeliac disease and type 1 diabetes was not significantly higher in children born during, than after, the Swedish coeliac epidemic. This may support a stronger genetic disposition in children who develop both conditions.

Changing Pattern of Childhood Celiac Disease Epidemiology: Contributing Factors

Up until the 1960s and 1970s, diarrhea, malabsorption syndrome, and failure to thrive were the presenting symptoms and signs of celiac disease (CD) in young infants; however this disease was also at the same time reported to be disappearing. Indeed, clinical childhood CD was seen to transform into a milder form, resulting in an upward shift in age at diagnosis during the 1970s (and years later for many countries). This changing pattern of CD presentation then altered the epidemiology of the disease, with major differences between and within countries observed. An awareness of the changing clinical nature of CD and use of case-finding tools to detect even clinically silent CD became an important factor in this changing epidemiology. Countries report both low and high prevalence but it seems to be on the increase resulting in a population-based level of 1-2%. This paper discusses the potential causes and environmental factors behind these observed clinical changes, identifying new clues from different studies published at the time this transformation took place. For instance, it was found that breastfeeding postponed the diagnosis of the disease but did not altogether prevent it. Moreover, gluten introduction at a young age, specifically at the mean age of 2 months, seemed to also have a clear impact in inducing malabsorption syndrome and failure to thrive in young infants in addition to other factors such as gluten intake volume and type of cereal present in the weaning food. Further, the impact of cow's milk and its high osmolarity might have played an important role; humanized milk formulas were not yet invented. Future epidemiological studies on the contributing environmental factors to the shift in CD presentation are thus recommended for countries in which these changing clinical features are still being observed.

Tissue transglutaminase autoantibodies in children with newly diagnosed type 1 diabetes are related to human leukocyte antigen but not to islet autoantibodies: A Swedish nationwide prospective population-based cohort study

OBJECTIVES

This study explored the association between tissue transglutaminase autoantibody (tTGA), high-risk human leucocyte antigen (HLA) genotypes and islet autoantibodies in children with newly diagnosed type 1 diabetes (T1D).

PATIENTS AND METHODS

Dried blood spots and serum samples were taken at diagnosis from children <18 years of age participating in Better Diabetes Diagnosis (BDD), a Swedish nationwide prospective cohort study of children newly diagnosed with T1D. We analyzed tTGA, high-risk HLA DQ2 and DQ8 (DQX is neither DQ2 nor DQ8) and islet auto-antibodies (GADA, IA-2A, IAA, and three variants of Zinc transporter; ZnT8W, ZnT8R, and ZnT8QA).

RESULTS

Out of 2705 children diagnosed with T1D, 85 (3.1%) had positive tTGA and 63 (2.3%) had borderline values. The prevalence of tTGA was higher in children with the HLA genotypes DQ2/2, DQ2/X or DQ2/8 compared to those with DQ8/8 or DQ8/X (p = .00001) and those with DQX/X (p ≤ .00001). No significant differences were found in relation to islet autoantibodies or age at diagnosis, but the presence of tTGA was more common in girls than in boys (p = .018).

CONCLUSION

tTGA at T1D diagnosis (both positive and borderline values 5.4%) was higher in girls and in children homozygous for DQ2/2, followed by children heterozygous for DQ2. Only children with DQ2 and/or DQ8 had tTGA. HLA typing at the diagnosis of T1D can help to identify those without risk for CD.

Global Prevalence of Celiac Disease: Systematic Review and Meta-analysis

BACKGROUND & AIMS

Celiac disease is a major public health problem worldwide. Although initially it was reported from countries with predominant Caucasian populations, it now has been reported from other parts of the world. The exact global prevalence of celiac disease is not known. We conducted a systematic review and meta-analysis to estimate the global prevalence of celiac disease.

METHODS

We searched Medline, PubMed, and EMBASE for the keywords celiac disease, celiac, celiac disease, tissue transglutaminase antibody, anti-endomysium antibody, endomysial antibody, and prevalence for studies published from January 1991 through March 2016. Each article was cross-referenced with the words Asia, Europe, Africa, South America, North America, and Australia. The diagnosis of celiac disease was based on European Society of Pediatric Gastroenterology, Hepatology, and Nutrition guidelines. Of 3843 articles, 96 articles were included in the final analysis.

RESULTS

The pooled global prevalence of celiac disease was 1.4% (95% confidence interval, 1.1%-1.7%) in 275,818 individuals, based on positive results from tests for anti-tissue transglutaminase and/or anti-endomysial antibodies (called seroprevalence). The pooled global prevalence of biopsy-confirmed celiac disease was 0.7% (95% confidence interval, 0.5%-0.9%) in 138,792 individuals. The prevalence values for celiac disease were 0.4% in South America, 0.5% in Africa and North America, 0.6% in Asia, and 0.8% in Europe and Oceania; the prevalence was higher in female vs male individuals (0.6% vs 0.4%; P < .001). The prevalence of celiac disease was significantly greater in children than adults (0.9% vs 0.5%; P < .001).

CONCLUSIONS

In a systematic review and meta-analysis, we found celiac disease to be reported worldwide. The prevalence of celiac disease based on serologic test results is 1.4% and based on biopsy results is 0.7%. The prevalence of celiac disease varies with sex, age, and location. There is a need for population-based prevalence studies in many countries.

Dermatitis Herpetiformis: A Common Extraintestinal Manifestation of Coeliac Disease

Dermatitis herpetiformis (DH) is a common extraintestinal manifestation of coeliac disease presenting with itchy papules and vesicles on the elbows, knees, and buttocks. Overt gastrointestinal symptoms are rare. Diagnosis of DH is easily confirmed by immunofluorescence biopsy showing pathognomonic granular immunoglobulin A (IgA) deposits in the papillary dermis. A valid hypothesis for the immunopathogenesis of DH is that it starts from latent or manifest coeliac disease in the gut and evolves into an immune complex deposition of high avidity IgA epidermal transglutaminase (TG3) antibodies, together with the TG3 enzyme, in the papillary dermis. The mean age at DH diagnosis has increased significantly in recent decades and presently is 40⁻50 years. The DH to coeliac disease prevalence ratio is 1:8 in Finland and the United Kingdom (U.K.). The annual DH incidence rate, currently 2.7 per 100,000 in Finland and 0.8 per 100,000 in the U.K., is decreasing, whereas the reverse is true for coeliac disease. The long-term prognosis of DH patients on a gluten-free diet is excellent, with the mortality rate being even lower than for the general population.

Gluten Introduction to Infant Feeding and Risk of Celiac Disease: Systematic Review and Meta-Analysis

OBJECTIVE

To assess the evidence regarding the effect of time of gluten introduction and breastfeeding on the risk of developing celiac disease (CD).

STUDY DESIGN

We included randomized controlled trials and observational studies evaluating the proper timing for introducing gluten to the infant diet, the appropriate quantity of gluten consumption at weaning, and the effect of breastfeeding on CD risk. Studies were located through the electronic databases Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), EMBASE (Ovid), and System for Information on Grey Literature in Europe (SIGLE). Two independent authors collected the data.

RESULTS

A total of 1982 studies were identified, 15 of which were eligible for data extraction. A meta-analysis was performed on 2 randomized controlled trials, 10 cohort studies, and 1 case-control study. There was a 25% increase in CD risk with late (>6 months) vs recommended (4-6 months) gluten introduction (risk ratio [RR], 1.25; 95% CI, 1.08-1.45). There was no significant effect of breastfeeding vs no breastfeeding on CD risk (OR, 0.55; 95% CI, 0.28-1.10), with substantial heterogeneity (I(2) = 92%) among studies.

CONCLUSION

There is currently no evidence to support that early introduction of gluten to the infant diet increases the risk of CD; however, late introduction of gluten may be associated with increased risk of CD. More studies are needed that control for potential confounders and that evaluate environmental factors in low-risk families.

Prevalence of celiac disease autoimmunity in children with type 1 diabetes: regional variations across the Øresund strait between Denmark and southernmost Sweden

OBJECTIVES

The aim was to determine the prevalence of celiac disease autoimmunity in children with type 1 diabetes (T1D) diagnosed in Denmark and Sweden.

METHODS

A total of 662 Swedish children with T1D were matched with 1080 Danish children with T1D and 309 healthy children from Sweden and 283 from Denmark served as controls. Sera were analyzed for the presence of IgA and IgG (IgAG) autoantibodies against deamidated gliadin peptide (DGP) and tissue transglutaminase (tTG) with enzyme-linked immunosorbent assay (ELISA) and IgG-tTG separately in a radioligand binding assay (RBA). Human leukocyte antigen (HLA)-DQB1 and DQA1 genotyping were determined in the T1D cohorts.

RESULTS

In the Swedish T1D cohort, 17.2% (114/662) were IgAG-DGP/tTG positive compared with 11.7% (126/1080) in the Danish T1D cohort (p = 0.001) and with 9.4% (29/309) Swedish (p = 0.001) and 5.7% (16/283) Danish (p = 0.003) controls. In the Swedish T1D cohort, both levels of IgAG-DGP/tTG and IgG-tTG were higher compared with the levels in the Danish T1D (p < 0.001). In the control group, 2.8% of the Danish children were positive for both IgAG-DGP/tTG and IgG-tTG, compared to 0.3% of the Swedish. Presence of HLA-DQ2 was equally distributed among 89 children with T1D positive for both IgAG-DGP/tTG and IgG-tTG.

CONCLUSION

The discrepancy in levels of IgAG-DGP/tTG and IgG-tTG between Swedish and Danish T1D cohorts was independent of HLA and suggests that regional variations in comorbidity of celiac disease in T1D is caused by difference in exposure to environmental factors.

Celiac disease in children

Celiac disease is an autoimmune enteropathy, triggered by ingestion of gluten in genetically predisposed individuals. Since the use of anti-transglutaminase and anti-endomysium antibodies in the early 1990s, two main groups of clinical presentation can be identified: patients with a symptomatic form of the disease, and patients with a pauci (a)-symptomatic form detected during the work-up of another autoimmune disease or due to a family history of celiac disease. The prevalence of both forms of the disease is currently estimated between 1/100 and 1/400. Classical form of the disease is characterized by occurrence of diarrhoea, failure to thrive, and abdominal bloating in young infants in the months following gluten introduction. Serological tests show high level of anti-transglutaminase and anti-endomysium antibodies. Until recently, the diagnosis required duodenal biopsies that show villous atrophy. HLA genotype can help for diagnosis: the absence of the HLA-DQ2 or DQ8 alleles has a high negative predictive value. European guidelines recently proposed to reconsider the need for systematic endoscopy in typical symptomatic forms with high level of anti-transglutaminase and positive anti-endomysium. These recommendations are being assessed now. Currently, the gluten-free diet remains the only effective treatment for celiac disease. Children with celiac disease have to exclude from their diet all products containing wheat, barley and rye. Gluten-free diet causes clinical remission within a few weeks, but normalization of the small bowel mucosa and negativity of anti-transglutaminase antibodies are obtained in several months or even years. Gluten-free diet is useful to obtain clinical assessment, but also to prevent long-term complications of celiac disease, mainly osteoporosis, other autoimmune diseases, decreased fertility and cancers.

Survey on computer aided decision support for diagnosis of celiac disease

Celiac disease (CD) is a complex autoimmune disorder in genetically predisposed individuals of all age groups triggered by the ingestion of food containing gluten. A reliable diagnosis is of high interest in view of embarking on a strict gluten-free diet, which is the CD treatment modality of first choice. The gold standard for diagnosis of CD is currently based on a histological confirmation of serology, using biopsies performed during upper endoscopy. Computer aided decision support is an emerging option in medicine and endoscopy in particular. Such systems could potentially save costs and manpower while simultaneously increasing the safety of the procedure. Research focused on computer-assisted systems in the context of automated diagnosis of CD has started in 2008. Since then, over 40 publications on the topic have appeared. In this context, data from classical flexible endoscopy as well as wireless capsule endoscopy (WCE) and confocal laser endomicrosopy (CLE) has been used. In this survey paper, we try to give a comprehensive overview of the research focused on computer-assisted diagnosis of CD.

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The state-of-the-art research in automated diagnosis of celiac disease is presented.

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A systematic review of methods and techniques used in this field is given.

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Specific issues and challenges in the field are identified and discussed.

Infant feeding and anti-tissue transglutaminase antibody concentrations in the Generation R Study

BACKGROUND

Celiac disease (CD) has emerged as a common, but largely undiagnosed health problem. Numerous studies examined the influence of infant nutrition on the development of diagnosed CD. However, results are still inconsistent. In addition, the effect of infant feeding practices on the development of potential forms of CD might be different.

OBJECTIVE

The objective was to examine whether the timing of gluten introduction and breastfeeding duration are associated with CD autoimmunity (CDA) in children at the age of 6 y.

DESIGN

This study was embedded in the Generation R Study, a population-based prospective cohort study. Participants included 1679 Dutch children who were positive for human leukocyte antigen (HLA) DQ2/DQ8. Data on the timing of gluten introduction (<6 mo compared with ≥6 mo) and duration of breastfeeding (<6 mo compared with ≥6 mo) were obtained by questionnaire. Serum samples were analyzed for anti-tissue transglutaminase (anti-tTG) concentrations at age 6 y. Anti-tTG concentrations were categorized into negative (<7 U/mL) and positive (≥7 U/mL) values. Positive anti-tTG concentrations were further categorized based on ≥10 times the upper limit of normal (ULN) values of the test kit (≥7-70 and ≥70 U/mL). Multivariable logistic regression analyses were performed.

RESULTS

Positive anti-tTG concentrations were found in 43 children, 26 of whom had concentrations ≥10 times the ULN (≥70 IU/mL). The introduction of gluten from the age of 6 mo onward and breastfeeding for ≥6 mo were not significantly associated with positive anti-tTG concentrations. In addition, the timing of gluten introduction and duration of breastfeeding were not significantly associated with positive anti-tTG concentrations below or above 10 times the ULN.

CONCLUSIONS

Delayed introduction of gluten beyond the age of 6 mo does not increase the risk of CDA. In addition, breastfeeding for ≥6 mo does not decrease the risk of CDA in children at 6 y of age.

Prevalence of thyroid autoimmunity in children with celiac disease compared to healthy 12-year olds

Objectives. Studies have suggested a correlation between untreated celiac disease and risk for other autoimmune diseases. We investigated the prevalence of thyroid autoimmunity in 12-year-old children (i) with symptomatic celiac disease diagnosed and treated with a gluten-free diet, (ii) with screening-detected untreated celiac disease, and (iii) without celiac disease. Methods. Blood samples from 12632 children were collected. All celiac disease cases, previously diagnosed and newly screening-detected, were identified. Per case, 4 referents were matched. Blood samples were analyzed for autoantibodies against thyroid peroxidase (TPOAb). The cut-off value for TPO positivity was set to 100 U/mL. Results. Altogether, 335 celiac disease cases were found. In the entire celiac disease group, 7.2% (24/335) had elevated titers of TPOAb compared to 2.8% (48/1695) of the referents. Among the previously diagnosed celiac disease cases, 7.5% (7/93, OR 2.8, 95% CI 1.2-6.4) was TPOAb positive and among screening-detected cases, 7.0% (17/242, OR 2.6, 95% CI 1.5-4.6) was TPOAb positive. Conclusion. Children with celiac disease showed a higher prevalence of thyroid autoimmunity. We could not confirm the hypothesis that untreated celiac disease is associated with increased risk of developing thyroid autoimmunity. Early initiation of celiac disease treatment might not lower the risk for other autoimmune diseases.

High prevalence of celiac disease in Swedish children and adolescents with type 1 diabetes and the relation to the Swedish epidemic of celiac disease: a cohort study

AIM

The aim was to determine the prevalence and clinical and temporal relationship of celiac disease (CD) in a population of Swedish children with type 1 diabetes mellitus (T1DM) before, during, and after the Swedish epidemic of CD (birth cohorts 1984-1996).

METHODS

Retrospective chart review between 1995 and 2005 was conducted of 1151 children (0-18 years old, born 1981-2004) with T1DM.

RESULTS

A prevalence of 9.1% (95% CI: 7.2-11.2) of CD in T1DM children was found. No significant difference in prevalence of CD was observed in different birth years, in contrast to the Swedish epidemic of CD. Sixty-two percent of children diagnosed with CD after T1DM onset had pathological levels of antibodies within the first 24 months. The presence or absence of gastrointestinal symptoms had no predictable value for biopsy-confirmed CD or not.

CONCLUSION

The onset of CD in the T1DM population does not follow the pattern of the general population during the Swedish epidemic of CD. The shared genetic component in the human leukocyte antigen region in cases with comorbidity of CD and T1DM may overrule other CD-causing factors in the general population. Children with T1DM should be screened for CD at diagnosis and repeatedly at least during the first 2 years, even if asymptomatic.

Early feeding and risk of celiac disease in a prospective birth cohort

OBJECTIVES

Timing of gluten introduction has been associated with the risk of celiac disease (CD) in children, but the optimal time window is unknown. We aimed to study the effect of age of gluten introduction on the risk of CD, adjusting for continued breastfeeding.

METHODS

In The Norwegian Mother and Child Cohort Study, a prospective birth cohort including 107,000 children, CD was identified by questionnaires and by linkage to the Norwegian Patient Register. Gluten introduction was reported monthly from 0 to 6 months of age, and breastfeeding from 0 to 18 months.

RESULTS

After exclusion of cases with insufficient information, 324 children with CD in a cohort of 82,167 were used in the analyses. Gluten was introduced before or at 4 months in 8.0%, 5 to 6 months in 45.3%, and after 6 months in 46.6%, whereas continued breastfeeding was stable at ≈ 78% at 6 months age. CD was diagnosed in 3.68/1000 of the infants with gluten introduction at 5 to 6 months compared with 4.15/1000 with late and 4.24/1000 with early gluten introduction. After adjustment for the child's age and gender, breastfeeding, and maternal CD, delayed gluten introduction was associated with an increased risk of CD (adjusted odds ratio, 1.27 [95% confidence interval, 1.01-1.65], P = .045). Breastfeeding >12 months was also associated with increased risk (adjusted odds ratio, 1.49 [95% confidence interval, 1.01-2.21], P = .046).

CONCLUSIONS

We found an increased risk of CD in children introduced to gluten after 6 months and a higher risk in children breastfed after 12 months age.

Epidemiology of coeliac disease and comorbidity in Norwegian children

OBJECTIVES

The aim of this study was to describe the occurrence of clinically diagnosed coeliac disease in children ages 0 to 12 years in Norway, including regional variation and coexisting type 1 diabetes mellitus, thyroid disease, and Down syndrome.

METHODS

The Norwegian Patient Register (NPR) contains individual-level hospital data from 2008 onward. Small-bowel biopsies for establishing the coeliac disease diagnosis are only performed at public hospitals reporting to the NPR. Data on all hospital contacts during 2008-2011 when a diagnosis of coeliac disease was registered were retrieved from the NPR for patients born between 1999 and 2011, allowing estimation of the proportion registered with coeliac disease at ages 0 to 12 years in a cohort study.

RESULTS

A total of 3006 individuals (58.2% girls) were recorded as having coeliac disease among 797,360 children, corresponding to a proportion of 3.8/1000 (95% confidence interval [CI] 3.7-3.9/1000) children, 4.5 (CI 4.3-4.7) among girls and 3.1 (CI 2.9-3.3/1000) among boys (P < 0.001). The proportion increased with age up to approximately 6 years and was 5.0/1000 (CI 4.5-5.6) at the age of 12 years, and was slightly higher in the south/west (3.9/1000) as compared to the middle/north (3.5/1000) regions of Norway (P = 0.013). A total of 214 of 3006 (7.1%) patients with coeliac disease were registered with coexisting conditions: type 1 diabetes mellitus (n = 142, 4.7%), Down syndrome (n = 47, 1.6%), or thyroid disease (n = 41, 1.4%).

CONCLUSIONS

In this first nationwide study of clinically diagnosed coeliac disease in Norwegian children, we found a high occurrence, comparable with that in Sweden. Comorbidity was common, but routine screening of high-risk groups contributed to a limited number of cases.

Timing of introduction of solid food and risk of allergic disease development: understanding the evidence

Strategies to prevent or reduce the risk of allergic diseases are needed. The time of exclusive breastfeeding and introduction of solid foods is a key factor that may influence the development of allergy. For this reason, the aim of this review was to examine the association between exposure to solid foods in the infant's diet and the development of allergic diseases in children. Classical prophylactic feeding guidelines recommended a delayed introduction of solids for the prevention of atopic diseases. Is it really true that a delayed introduction of solids (after the 4th or 6th month) is protective against the development of eczema, asthma, allergic rhinitis and food or inhalant sensitisation? In recent years, many authors have found that there is no statistically significant association between delayed introduction of solids and protection for the development of allergic diseases. Furthermore, late introduction of solid foods could be associated with increased risk of allergic sensitisation to foods, inhalant allergens and celiac disease in children. Tolerance may be driven by the contact of the mucosal immune system with the allergen at the right time of life; the protective effects seem to be enhanced by the practice of the breastfeeding at the same time when weaning is started. Therefore, recent guidelines propose a "window" approach for weaning practice starting at the 17th week and introducing almost all foods within the 27th week of life to reduce the risk of chronic diseases such as allergic ones and the celiac disease. Guidelines emphasize the role of breastfeeding during the weaning practice.

Prevalence of childhood celiac disease and changes in infant feeding

OBJECTIVES

Between 1984 and 1996, Sweden experienced an "epidemic" of clinical celiac disease in children <2 years of age, attributed partly to changes in infant feeding. Whether infant feeding affects disease occurrence and/or the clinical presentation remains unknown. We investigated and compared the total prevalence of celiac disease in 2 birth cohorts of 12-year-olds and related the findings to each cohort's ascertained infant feeding.

METHODS

A 2-phase cross-sectional screening study was performed in which 13 279 children from 2 birth cohorts participated: children born during the epidemic (1993) and children born after the epidemic (1997). Previously diagnosed cases were reported and confirmed. Blood samples were analyzed for serological markers and children with positive values were referred for small intestinal biopsy. Infant feeding practices in the cohorts were ascertained via questionnaires. Prevalence comparisons were expressed as prevalence ratios.

RESULTS

The total prevalence of celiac disease was 29 in 1000 and 22 in 1000 for the 1993 and 1997 cohorts, respectively. Children born in 1997 had a significantly lower risk of having celiac disease compared with those born in 1993 (prevalence ratio: 0.75; 95% confidence interval: 0.60-0.93; P = .01). The cohorts differed in infant feeding (specifically, in the proportion of infants introduced to dietary gluten in small amounts during ongoing breastfeeding).

CONCLUSIONS

A significantly reduced prevalence of celiac disease in 12-year-olds indicates an option for disease prevention. Our findings suggest that the present infant feeding recommendation to gradually introduce gluten-containing foods from 4 months of age, preferably during ongoing breastfeeding, is favorable.

Coeliac disease in children: a social epidemiological study in Sweden

AIM

Little is known on the possible existence of socioeconomic and geographical differences in early coeliac disease (CD) risk. Therefore, we investigated these aspects in children before age two.

METHODS

Linking the Swedish Medical Birth Registry to several other national registries, we identified all singletons born in Sweden from 1987 to 1993 (n = 792,401) and followed them until 2 years of age to identify cases of CD. Applying multilevel logistic regression analysis, we investigated the association between socioeconomic position (SEP) and CD in children and also whether a possible geographical variation in CD risk was explained by individual characteristics.

RESULTS

Low SEP was associated with CD in boys OR 1.37 (95% CI 1.03-1.82), but not in girls OR 0.87 (95% CI 0.68-1.12). We found a considerable geographical variation in disease risk (i.e. intra-municipality correlation ≈ 10%) that was not explained by individual characteristics.

CONCLUSIONS

Low SEP is associated with CD in boys but not in girls. Also, CD appears to be conditioned by geographical area of residence. While our study represents an innovative contribution to the epidemiology of CD in children, the reasons for the observed geographical and socioeconomic differences could be speculated but are still unknown.

ESPGHAN's 2008 recommendation for early introduction of complementary foods: how good is the evidence?

Since 2002, the World Health Organization and many governments and professional associations have recommended exclusive breastfeeding for 6 months followed by complementary feeding (giving solid foods alongside breast milk) as optimal infant feeding practice. Several articles have been published challenging this recommendation. Arguably, the most influential has been the 2008 commentary of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) Committee on Nutrition, which recommended that complementary foods should be introduced to all infants between 17 and 26 weeks. We challenge the validity of ESPGHAN's position, questioning the adequacy of the literature search, the interpretation and evidence used to reach their conclusions and the balance of an approach that focuses on disease prevention, with scant consideration of growth and neuromotor development. We contend that ESPGHAN's position should be understood as an expert opinion that may be influenced by conflicts of interest. In our view, the ESPGHAN position paper is not evidence based and does not justify a change of the current public health recommendation for 6 months of exclusive breastfeeding. At an individual level, health professionals should understand that developmental readiness for starting solid foods has an age range like other developmental milestones; that fewer infants will probably be ready to start complementary feeding before, rather than after, 6 months; and that their role is to equip parents with the confidence and skills to recognise the signs of developmental readiness. This empowerment process for infants and parents should be preferred over the prescriptive ESPGHAN approach.

The prevalence of coeliac disease is significantly higher in children compared with adults

BACKGROUND

Some limited studies of coeliac disease have shown higher frequency of coeliac disease in infancy and adolescence than in adulthood. This finding has remained unnoticed and not adequately demonstrated.

AIM

To assess whether there are age and gender differences in coeliac disease prevalence.

METHODS

A total of 4230 subjects were included consecutively (1 to ≥80 years old) reproducing the reference population by age and gender. Sample size was calculated assuming a population-based coeliac disease prevalence of 1:250. After an interim analysis, the paediatric sample was expanded (2010 children) due to high prevalence in this group. Anti-transglutaminase and antiendomysial antibodies were determined and duodenal biopsy was performed if positive. Log-linear models were fitted to coeliac disease prevalence by age allowing calculation of percentage change of prevalence. Differences between groups were compared using Chi-squared test.

RESULTS

Twenty-one subjects had coeliac disease (male/female 1:2.5). Coeliac disease prevalence in the total population was 1:204. Coeliac disease prevalence was higher in children (1:71) than in adults (1:357) (P = 0.00005). A significant decrease of prevalence in older generations was observed [change of prevalence by age of -5% (95% CI: -7.58 to -2.42%)]. In the paediatric expanded group (1-14 years), a decrease of coeliac disease prevalence was also observed [prevalence change: -17% (95% CI: -25.02 to -6.10)].

CONCLUSIONS

The prevalence of coeliac disease in childhood was five times higher than in adults. Whether this difference is due to environmental factors influencing infancy, or latency of coeliac disease in adulthood, remains to be demonstrated in prospective longitudinal studies.

The PreventCD Study design: towards new strategies for the prevention of coeliac disease

BACKGROUND

PreventCD (www.preventcd.com) is a European multicentre study, which studies the influence of infant nutrition, and that of genetic, immunologic and environmental factors, on the risk of developing coeliac disease (CD). The hypothesis is that it is possible to induce tolerance to gluten by introducing small quantities of gluten to infants, preferably while they are still being breast-fed, and that this might also reduce the risk for related autoimmune disorders.

AIM

To describe the design of this ongoing European CD research project.

METHODS

PreventCD encompasses two study designs and two study populations: (i) a European multicentre study: a prospective, double-blind, randomized dietary-intervention study among infants from families with high risk of CD, and (ii) a Swedish population-based CD screening study among 12-year-olds from the general population, divided into two birth cohorts that differ with respect to infant feeding practices.

DISCUSSION

PreventCD is expected to elucidate some of the genetic and immunological mechanisms involved in the process of immune intolerance.

The prevalence of celiac disease in Europe: results of a centralized, international mass screening project

INTRODUCTION

Although the prevalence of celiac disease (CD) has been extensively investigated in recent years, an accurate estimate of CD frequency in the European population is still lacking. The aims of this study were: 1) to establish accurately the prevalence of CD in a large sample of the European population (Finland, Germany, Italy, and UK), including both children and adults; and 2) to investigate whether the prevalence of CD significantly varies between different areas of the European continent.

MATERIALS AND METHODS

Samples were drawn from the four populations. All 29,212 participants were tested for CD by tissue transglutaminase (tTG) antibody test. Positive and border-line findings were further tested for serum endomysial antibodies (EMA). All serological determinations were centrally performed. Small-bowel biopsies were recommended to autoantibody-positive individuals. Previously diagnosed cases were identified.

RESULTS

The overall CD prevalence (previously diagnosed plus anti-tTG and EMA positives) was 1.0% (95% CI 0.9-1.1). In subjects aged 30-64 years CD prevalence was 2.4% in Finland (2.0-2.8), 0.3% in Germany (0.1-0.4), and 0.7% in Italy (0.4-1.0). Sixty-eight percent of antibody-positive individuals showed small-bowel mucosal changes typical for CD (Marsh II/III lesion).

CONCLUSIONS

CD is common in Europe. CD prevalence shows large unexplained differences in adult age across different European countries.

Prevention measures and exploratory pharmacological treatments of celiac disease

Increasing prevalence, protean clinical manifestations, and lack of pharmacological therapy make celiac disease (CD) a complex and highly relevant illness in gastroenterology. This chronic inflammatory disorder of the small intestine is caused by the ingestion of gluten containing cereals in genetically susceptible individuals, leading to a variety of gastrointestinal (GI) and non-GI manifestations. Awareness among physicians is growing due to accessible and highly accurate diagnostic and screening methods. Recent evidence suggests a possible rising incidence of CD. Environmental factors such as early life gluten exposure, intestinal infections, short duration of breast-feeding, and changes in intestinal microbiota have been proposed to have a role in CD pathogenesis. Thus, prevention approaches to diminish the rising prevalence of CD are currently being evaluated. Still, the cornerstone treatment of CD remains a strict gluten-free diet. This nutritional regime is demanding, and non-adherence is common because of social isolation, financial issues, or restriction of food diversity. Allowing patients to occasionally consume small amounts of gluten would greatly improve their quality of life. Owing to recent advances in the understanding of the pathogenesis of CD, different targets have been identified and have motivated the development of several experimental therapeutic strategies. The main goal of this review is to discuss the mechanisms that can be exploited therapeutically to prevent or delay CD, disease associations and its complications. Current treatments for complications of CD, including refractory CD and malignancy, are beyond the scope of this review.

Effect of the timing of gluten introduction on the development of celiac disease

Celiac disease (CD) is a permanent auto-immune enteropathy, triggered in genetically predisposed individuals by the ingestion of dietary gluten. Gluten is the alcohol-soluble protein component of the cereals wheat, rye and barley. CD is a multifactorial condition, originating from the interplay of genetic and environmental factors. The necessary environmental trigger is gluten, while the genetic predisposition has been identified in the major histocompatibility complex region on chromosome 6p21, with over 90% of CD patients expressing HLA DQ2 and the remaining celiac patients express DQ8. The fact that only about 4% of DQ2/8-positive individuals exposed to gluten develop CD, has led to the recognition that other genetic and environmental factors are also necessary. In the last few years, several epidemiological studies have suggested that the timing of the introduction of gluten, as well as the pattern of breastfeeding, may play an important role in the subsequent development of CD. Here, we present and review the most recent evidences regarding the effect of timing of gluten introduction during weaning, the amount of gluten introduced and simultaneous breastfeeding, on the development of CD.

Symptomless celiac disease in type 1 diabetes: 12-year experience in Estonia

BACKGROUND

We aimed to determine the prevalence and characteristics of celiac disease in children with type 1 diabetes in Estonia, a country with a formerly low frequency of both diseases.

METHODS

Altogether, 271 patients with diabetes were studied over 12 years (1995-2006): 122 at diagnosis and 149 patients 0.1-14.8 years after diagnosis. In addition, 73 patients were followed up over 1-6 years. Immunoglobulin A type endomysium and tissue transglutaminase antibodies were determined. Patients with antibodies and/or with celiac-disease-related symptoms were invited for a small-intestinal biopsy.

RESULTS

At the primary screening, celiac disease was histologically confirmed in nine patients (all without symptoms), that is, in 3.3% (95% confidence interval: 1.63-6.42) of type 1 diabetes cases. At follow up, celiac disease was additionally detected in two (2.7%) of 73 diabetic patients, that is, in 0.016 (95% confidence interval: 0-0.072) celiac disease cases per follow-up year.

CONCLUSION

The prevalence of celiac disease among type 1 diabetes patients in Estonia is similar to that in countries with a high incidence of celiac disease and type 1 diabetes. As celiac disease is mostly symptomless, all children with type 1 diabetes, irrespective of their geographic origin, should be regularly screened for celiac disease.

Infant nutritional factors and functional constipation in childhood: the Generation R study

OBJECTIVES

Food allergy and celiac disease may lead to childhood constipation. Early introduction of food allergens and gluten in the first year of life has been suggested to have a function in these food intolerances, but it is unclear whether this also holds true for development of childhood constipation. The aim of this study was to assess the association between the timing of introduction of food allergens and gluten early in life and functional constipation in childhood.

METHODS

This study was embedded in the Generation R study, a population-based prospective cohort study from fetal life until young adulthood. Functional constipation at 24 months of age was defined in 4,651 children according to the Rome II criteria of defecation frequency <3 times a week or the presence of mainly hard feces for at least 2 weeks.

RESULTS

At the age of 24 months, 12% of the children had functional constipation. Children with functional constipation got introduced to gluten more often before or at the age of 6 months than children without functional constipation (37% and 27%, respectively). After adjustment for birth weight, gestational age, gender, ethnicity, maternal education, and family history of atopy and chronic intestinal disorders, functional constipation was significantly associated with early gluten introduction (odds ratio (OR): 1.35; 95% confidence interval (CI): 1.10-1.65). No association was found between timing of introduction of cow's milk, hen's egg, soy, peanuts, and tree nuts with functional constipation. A history of cow's milk allergy in the first year of life was significantly associated with functional constipation in childhood (OR: 1.57; 95% CI: 1.04-2.36).

CONCLUSIONS

These results suggest that early gluten introduction in the first year of life provide a trigger for functional constipation in a subset of children. In case of functional constipation, there also might be a role for cow's milk allergy initiated in the first year of life.

Screening detects a high proportion of celiac disease in young HLA-genotyped children

BACKGROUND AND AIMS

Celiac disease is associated with tissue transglutaminase autoantibodies (tTGAb) and the human leukocyte antigen (HLA)-risk alleles DQB1*02 and DQB1*0302. The aim was to estimate the proportion of undiagnosed celiac disease in children with HLA risk at 3 years of age.

PATIENTS AND METHODS

From a population-based HLA-DQ screening study of newborns born between June 2001 and August 2004 in the southern part of Sweden, 6206 children with HLA-risk alleles were identified and asked to participate at a mean 3.3 +/- 0.4 years of age. As controls, 7654 children with HLA-nonrisk alleles were asked to participate. In all, 1620 (26.1%) children with HLA risk and 1815 (23.7%) controls were screened for tTGAb using radioligand-binding assays. Celiac disease was established by intestinal biopsy in children with a confirmed positive tTGAb test.

RESULTS

Twenty-three children reported already having clinically diagnosed celiac disease and did not participate further. In children with HLA-risk genotypes, 73 of 1620 (4.5%, 95% CI 3.5%-5.5%) were tTGAb-positive compared with none of 1815 from the controls (P < 0.0001). Seventy-one children underwent biopsy (1 refused biopsy and 1 biopsy failed), of whom 56 of 1618 (3.5%, 95% CI 2.6%-4.4%) had damaged intestinal mucosa classified as celiac disease. The ratio between clinically and screening detected celiac disease in this study was 1:2.4 (23:56).

CONCLUSIONS

The proportion of clinically undetected celiac disease may be particularly high among 3-year-old children with HLA-DQB1*02 and DQB1*0302 in Sweden, where these 2 HLA-risk alleles frequently occur.

Celiac disease revealed in 3% of Swedish 12-year-olds born during an epidemic

OBJECTIVE

Sweden experienced a marked epidemic of celiac disease between 1984 and 1996 in children younger than 2 years of age, partly explained by changes in infant feeding. The objective of this study was to determine the prevalence of celiac disease in 12-year-olds born during the epidemic (1993), including both symptomatic and screening detected cases.

PATIENTS AND METHODS

All sixth-grade children in participating schools were invited (n = 10,041). Symptomatic and, therefore, previously diagnosed celiac disease cases were ascertained through the National Swedish Childhood Celiac Disease Register and/or medical records. All serum samples were analyzed for antihuman tissue transglutaminase (tTG)-IgA (Celikey), and serum-IgA, and some for tTG-IgG and endomysial antibodies. A small intestinal biopsy was recommended for all children with suspected undiagnosed celiac disease.

RESULTS

Participation was accepted by 7567 families (75%). Previously diagnosed celiac disease was found in 67 children; 8.9/1000 (95% confidence interval [CI] 6.7-11). In another 192 children, a small intestinal biopsy was recommended and was performed in 180. Celiac disease was verified in 145 children, 20/1000 (95% CI 17-23). The total prevalence was 29/1000 (95% CI 25-33).

CONCLUSIONS

The celiac disease prevalence of 29/1000 (3%)-with two thirds of cases undiagnosed before screening-is 3-fold higher than the usually suggested prevalence of 1%. When these 12-year-olds were infants, the prevailing feeding practice was to introduce gluten abruptly, often without ongoing breast-feeding, which might have contributed to this unexpectedly high prevalence.

Celiac disease

PURPOSE OF REVIEW

Research in celiac disease is unraveling new findings at a high rate, and major advances seem to occur in all areas such as genetics, environmental factor, pathophysiology, and even prospective therapeutic implications.

RECENT FINDINGS

New insight is being gained into the interplay between genetic and environmental factors causing celiac disease. In addition to the known human leukocyte antigen haplotypes, genome-wide studies have now identified additional susceptibility loci and the majority of newly discovered risk regions harbor genes controlling immune pathways. The mechanism of translocation of gliadin peptides across the intestinal barrier has been the subject of much investigation, and there is now evidence that the toxic 33-mer peptide can also be translocated transcellularly. As for the paracellular route, this appears to be enhanced by gliadin's stimulation of zonulin release. The growing role of the innate immunity is being recognized and the increased expression of some Toll-like receptors appears to delineate a new inherent defect in this branch of innate immunity. Finally, new perspectives are opening in the treatment of celiac disease based on new detoxified grains, enzymatic degradation of gluten, and prevention of its crossing the mucosal barrier.

SUMMARY

The pace of new knowledge in this 'ancient' disease is very fast, and this review outlines the principal lines of such exciting developments.

Difference in celiac disease risk between Swedish birth cohorts suggests an opportunity for primary prevention

OBJECTIVES

Sweden experienced a unique epidemic of celiac disease in children <2 years of age. The epidemic was partly explained by changes in infant feeding over time and indicated a multifactorial pathogenesis. The main aim of this study was to analyze celiac disease risk in epidemic and postepidemic birth cohorts up to preschool age, to explore further the opportunity for primary prevention.

METHODS

A population-based incidence register of celiac disease in children covering the entire nation from 1998 to 2003 and part of the country back to 1973 was analyzed. European Society for Pediatric Gastroenterology, Hepatology, and Nutrition diagnostic criteria for celiac disease were used. The annual incidence rate for each age group and the cumulative incidence according to age for each birth cohort were calculated.

RESULTS

A considerable difference in cumulative incidences of celiac disease at comparable ages was demonstrated between birth cohorts from the epidemic and postepidemic periods. The difference persisted during the preschool years, although it decreased somewhat with age. During the last years of the follow-up period, there was again a successive increase in incidence rate among children <2 years of age.

CONCLUSIONS

The difference in celiac disease risk between birth cohorts at comparable ages suggests an opportunity for primary prevention. This highlights the importance of further exploring the role of infant feeding and exogenous factors besides dietary gluten that might initiate or prevent disease development. Moreover, on the basis of postepidemic incidence trends, we speculate that the Swedish epidemic might not have been as unique as thought previously, although its magnitude was striking.

Prevalence of celiac disease in children with type 1 diabetes mellitus increased in the mid-1990 s: an 18-year longitudinal study based on anti-endomysial antibodies

Between 1987 and 2004, 331 consecutive children, all newly diagnosed with type 1 diabetes mellitus in our pediatric clinic, underwent repeated serological screening for celiac disease (CD) by means of anti-endomysial antibodies, measured prospectively between 1994 and 2004, and retrospectively, using frozen banked serum, between 1987 and 1993. There were 22 cases (6.6%) of biopsy-proven CD among the 331 diabetic children. The prevalence of CD was significantly (P = 0.015) higher after 1994 (10.6%) than before 1994 (3.3%). The rapid change in the risk of CD among Italian diabetic children that occurred in the mid-1990 s could be related to changes in environmental factors, namely, eating habits and viral infections.

Complementary feeding: a commentary by the ESPGHAN Committee on Nutrition

This position paper on complementary feeding summarizes evidence for health effects of complementary foods. It focuses on healthy infants in Europe. After reviewing current knowledge and practices, we have formulated these conclusions: Exclusive or full breast-feeding for about 6 months is a desirable goal. Complementary feeding (ie, solid foods and liquids other than breast milk or infant formula and follow-on formula) should not be introduced before 17 weeks and not later than 26 weeks. There is no convincing scientific evidence that avoidance or delayed introduction of potentially allergenic foods, such as fish and eggs, reduces allergies, either in infants considered at increased risk for the development of allergy or in those not considered to be at increased risk. During the complementary feeding period, >90% of the iron requirements of a breast-fed infant must be met by complementary foods, which should provide sufficient bioavailable iron. Cow's milk is a poor source of iron and should not be used as the main drink before 12 months, although small volumes may be added to complementary foods. It is prudent to avoid both early (<4 months) and late (>or=7 months) introduction of gluten, and to introduce gluten gradually while the infant is still breast-fed, inasmuch as this may reduce the risk of celiac disease, type 1 diabetes mellitus, and wheat allergy. Infants and young children receiving a vegetarian diet should receive a sufficient amount ( approximately 500 mL) of breast milk or formula and dairy products. Infants and young children should not be fed a vegan diet.