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

Decreasing incidence of celiac disease in Southern Sweden

BACKGROUND

The incidence of celiac disease (CD) has increased rapidly in the late 20th and early 21st centuries, but there are recent reports of rates levelling off in countries with a high prevalence. The aim of this study was to investigate current trends in CD in southern Sweden.

PATIENTS AND METHODS

Children and adults diagnosed with CD by biopsy or serology in the region of Skåne, southern Sweden, from 2010-2022 were included. The home address was identified through registers to analyze temporal and geographical trends.

RESULTS

A total of 3218 CD-patients were identified (52.2% children), the vast majority detected in clinical care but a few children by screening studies. The age-standardized incidence rate was 18.6 cases/105. The incidence decreased at a rate of -0.75 cases/105 (95% CI -1.14 to -0.35, p 0.002). The incidence among girls under 18 years almost halved throughout the study period, decreasing by -2.94 cases/105 (95% CI -4.59 to -1.29, p 0.002), while there only were small changes among men. The most common age of onset was 3-9 years. CD incidence varied by place of living and was more common in small towns than urban or rural areas.

CONCLUSIONS

The incidence of CD in southern Sweden is decreasing, primarily in children and women who traditionally have had the highest risk of CD. CD was diagnosed most frequently in children 3-9 years old. There were regional variations in incidence. CD was most common in small towns, pointing to the importance of environmental factors in CD etiology.

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.

Review article: Becoming and being coeliac-special considerations for childhood, adolescence and beyond

Classically considered a disease of early childhood characterised by malabsorption and failure to thrive, coeliac disease is now recognised to arise in genetically susceptible individuals at any age. Although permissive HLA genotypes are the strongest predictor of coeliac disease, they are not sufficient. Several prospective cohort studies enrolling genetically at-risk infants have investigated the role of potential triggers of coeliac disease autoimmunity, such as timing of gluten introduction, viral infections and dietary patterns. Much less is known about triggers of coeliac disease in adulthood. Better understanding of factors leading to coeliac disease may be helpful in the management of those with potential coeliac disease (elevated serum celiac antibodies without villous atrophy in the small intestine), many of whom initiate a gluten-free diet without demonstration of villous atrophy. There are a range of clinical presentations of celiac disease in childhood and patterns of coeliac serology, including fluctuation and spontaneous reversion on a gluten-containing diet, vary. There is a current debate over best strategies to manage adults and children with potential coeliac disease to avoid over-treatment and under-treatment. Childhood and adolescence carry unique issues pertaining to the diagnosis and management of coeliac disease, and include nutrition and growth, rescreening, repeat biopsy, dietary adherence concerns and transition to adult care. In conclusion, while coeliac disease has similar pathogenesis and general clinical manifestations in paediatric and adult populations, diagnostic and management approaches need to adapt to the developmental stages.

Community-Based Study of Celiac Disease Autoimmunity Progression in Adults

BACKGROUND & AIMS

Celiac disease can develop at any age, but outcomes of adults with positive results from serologic tests for tissue transglutaminase antibodies (tTGA) without endoscopic determination of celiac disease (called celiac autoimmunity) have not been thoroughly evaluated. We investigated the proportion of adults with celiac autoimmunity at a community medical center and their progression to celiac disease.

METHODS

We analyzed waste blood samples from a community clinic from 15,551 adults for tTGA and, if titer results were above 2 U/mL, for endomysial antibody. The blood samples had been collected at 2 time points (median interval, 8.8 years) from 2006 through 2017. We collected data from the clinic on diagnoses of celiac disease based on duodenal biopsy analysis.

RESULTS

Of the serum samples collected at the first time point, 15,398 had negative results for tTGA, and 153 had positive results for tTGA (>4 U/mL). Based on medical records, 6 individuals received a diagnosis of celiac disease, for a cumulative incidence of celiac disease diagnosis of 0.06% (95% confidence interval, 0.01-0.11). Forty-nine (0.32%) individuals with a negative result from the first serologic test for tTGA had a positive result from the second test. Among the 153 adults who were tTGA positive at the first time point, 31 (20%) had a subsequent diagnosis of celiac disease, 81 (53%) remained positive for tTGA without a clinical diagnosis of celiac disease, and 41 (27%) had negative test results for tTGA at the second time point. Higher initial tTGA titers, female sex, and a history of hypothyroidism and autoimmune disease were associated with increased risks of subsequent diagnosis of celiac disease. Interestingly, adults whose first blood sample had a positive test result but second blood sample had a negative result for tTGA were older, had lower-than-average initial tTGA titer results, and had a higher mean body mass index than adults whose blood samples were positive for tTGA at both time points and adults later diagnosed with celiac disease.

CONCLUSIONS

In an analysis of serum samples collected from a community clinic an average of 8.8 years apart, we found that fewer than 1% of adults with negative results from an initial test for tTGA have a positive result on a second test. Of adults with positive results from the test for tTGA, only 20% are later diagnosed with celiac disease; the remaining individuals maintain persistent increases in tTGA without diagnoses of celiac disease or have negative results from second tests.

Immunopathology of childhood celiac disease-Key role of intestinal epithelial cells

BACKGROUND & AIMS

Celiac disease is a chronic inflammatory disease of the small intestine mucosa due to permanent intolerance to dietary gluten. The aim was to elucidate the role of small intestinal epithelial cells in the immunopathology of celiac disease in particular the influence of celiac disease-associated bacteria.

METHODS

Duodenal biopsies were collected from children with active celiac disease, treated celiac disease, and clinical controls. Intestinal epithelial cells were purified and analyzed for gene expression changes at the mRNA and protein levels. Two in vitro models for human intestinal epithelium, small intestinal enteroids and polarized tight monolayers, were utilized to assess how interferon-γ, interleukin-17A, celiac disease-associated bacteria and gluten influence intestinal epithelial cells.

RESULTS

More than 25 defense-related genes, including IRF1, SPINK4, ITLN1, OAS2, CIITA, HLA-DMB, HLA-DOB, PSMB9, TAP1, BTN3A1, and CX3CL1, were significantly upregulated in intestinal epithelial cells at active celiac disease. Of these genes, 70% were upregulated by interferon-γ via the IRF1 pathway. Most interestingly, IRF1 was also upregulated by celiac disease-associated bacteria. The NLRP6/8 inflammasome yielding CASP1 and biologically active interleukin-18, which induces interferon-γ in intraepithelial lymphocytes, was expressed in intestinal epithelial cells.

CONCLUSION

A key factor in the epithelial reaction in celiac disease appears to be over-expression of IRF1 that could be inherent and/or due to presence of undesirable microbes that act directly on IRF1. Dual activation of IRF1 and IRF1-regulated genes, both directly and via the interleukin-18 dependent inflammasome would drastically enhance the inflammatory response and lead to the pathological situation seen in active celiac disease.

Simultaneous detection of IgA and IgG antibodies against tissue transglutaminase: The preferred pre-biopsy test in childhood celiac disease

OBJECTIVES

IgA antibodies against tissue transglutaminase (anti-TG2) is a reliable marker of celiac disease (CD). However, IgA-deficient patients are not identified and young children may lack IgA anti-TG2. Combined detection of IgA and IgG (IgA/IgG) against deamidated gliadin peptides (DGP) has shown a high diagnostic performance for untreated CD. Here we examined the utility of IgA/IgG anti-TG2, IgA/IgG anti-DGP and IgA/IgG against a mix of TG2 and DGP (anti-TG2/DGP) in finding CD among children.

METHODS

Serum antibodies against TG2, DGP, and TG2/DGP were determined with ELISA in 242 children referred to a paediatric gastroenterologist. Fifty had untreated CD verified by an intestinal biopsy and 192/242 children had other diseases than CD.

RESULTS

Forty-eight untreated CD children had increased IgA/IgG anti-TG2, 47/50 had increased IgA/IgG anti-DGP and 46/50 had increased IgA/IgG anti-TG2/DGP. One control subject had increased IgA/IgG anti-TG2 and IgA/IgG anti-TG2/DGP, whereas 7/192 control subjects had increased IgA/IgG anti-DGP. The IgA/IgG anti-TG2 assay had the best performance with a sensitivity of 96%, a specificity of 99.5% and the area under the ROC-curve was 0.996 (95% CI 0.992-1, p < 0.0001).

CONCLUSIONS

Detection of one antibody is not sufficient when screening for untreated CD among children due to cases of IgA deficiency. The inclusion of DGP antigens in the IgA/IgG combination assays seems to affect the sensitivity and specificity negatively, whereas detection of IgA/IgG anti-TG2 has the potential of finding most untreated CD patients, including those with IgA deficiency.

Do we need to worry about eating wheat?

Wheat is a staple food throughout the temperate world and an important source of nutrients for many millions of people. However, the last few years have seen increasing concerns about adverse effects of wheat on health, particularly in North America and Europe, with the increasing adoption of wheat‐free or gluten‐free diets. This relates to two concerns: that wheat products are disproportionally responsible for increases in obesity and type 2 diabetes and that wheat gluten proteins cause a range of adverse reactions, including allergies, coeliac disease and ‘non‐coeliac gluten sensitivity’. The first concern has been refuted in previous publications, and we therefore focus on the second here. Current evidence indicates that allergy to ingested wheat and coeliac disease (and related intolerances) each occur in up to 1% of the population. The extent to which their prevalence has increased is difficult to quantify due to improved diagnosis and increased awareness. However, neither appears to be increasing disproportionally when compared with other immunologically mediated adverse reactions to food. Other adverse reactions to wheat are more difficult to define as their mechanisms are not understood and they are therefore difficult to diagnose. In particular, ‘non‐coeliac wheat sensitivity’ has been reported to occur in 6% or more of the population in the US. However, the application of more rigorous diagnostic criteria is likely to give substantially lower estimates of prevalence. It is therefore unlikely that the health of more than a small proportion of the population will be improved by eliminating wheat or gluten from the diet. In fact, the opposite may occur as wheat is an important source of protein, B vitamins, minerals and bioactive components.

Unusually High Incidence of Paediatric Coeliac Disease in Sweden during the Period 1973 - 2013

OBJECTIVE

The prevalence of coeliac disease in Sweden during the "epidemic period" (1984-1996) was one of the highest in the world. The aim of this study was to assess the coeliac disease incidence in our region over the 41-year period, and how diagnostic activity and diagnostic accuracy were affected by the introduction of antibody testing. We also looked into how patients with mild enteropathy were evaluated.

METHODS

In the county of Östergötland in Sweden, 2790 paediatric patients were investigated for suspected coeliac disease between 1973 and 2013. Notes were scrutinised for data on sex, age, histopathological reports and final diagnosis. For comparative purposes this period was divided into three sub-periods (1973-1983, 1984-1996 and 1997-2013) named pre-epidemic, epidemic and post-epidemic.

RESULTS

Coeliac disease diagnosis was received by 1,030 patients. The peak incidence rate, 301 cases/100,000 in 1994 for the age group 0-1.9 years is the highest figure ever reported. The other age groups, 2-4.9, 5-14.9, and 15-17.9 years, also had high incidence rates. After the 1984-1996 "epidemic period" the incidence decreased for the youngest group but continued to increase for the other groups. The cumulative incidence at 18 years-of-age for children born during the epidemic reached 14 cases/1000 births, the highest figure hitherto reported. Diagnostic activity differed significantly between the three sub-periods (p<0.001) increasing gradually from 1984 and reaching a peak value of 0.87 in 2012. Cases of mild enteropathy were more frequently regarded as non-coeliac disease cases, decreasing significantly in the "post-epidemic" period (p<0.001).

CONCLUSIONS

The incidence rate and cumulative incidence of coeliac disease were possibly the highest ever reported. Changes in diagnostic activity and accuracy could not be attributed to the introduction of new antibody tests, possibly because of other changes e.g. variations in the symptoms at presentation and improved knowledge of the disease among parents and health professionals.

[The introduction of gluten into the infant diet. Expert group recommendations]

At present there is a degree of uncertainty regarding when, how and in what form gluten should be introduced into the infant diet. For years the recommendations of the ESPGHAN Committee on Nutrition have prevailed, which include avoiding early introduction, before 4 months, and late, after 7 months, and gradually introducing gluten into the diet while the infant is being breastfed, with the aim of reducing the risk of celiac disease, diabetes and gluten allergy. However, 2 independent studies published in The New England Journal of Medicine in October 2014 reached the conclusion that the age of introduction of gluten does not modify the risk of developing celiac disease, and that breastfeeding at any age does not confer protection against celiac disease development. On the other hand, according to available scientific evidence, the introduction of foods other than breast milk or formula into the infants diet is generally recommended around 6 months of age, since the introduction before 4 months could be associated with an increased risk of food allergy and autoimmune diseases, and delaying it beyond 7 months would not have a protective effect. In this context, a group of experts has considered it appropriate to produce a consensus document based on the current scientific evidence and present general recommendations for daily clinical practice on the introduction of gluten into the diet.

Spanish national registry of celiac disease: incidence and clinical presentation

OBJECTIVES

The aim of this study was to assess the incidence and clinical pattern of celiac disease (CD) presently diagnosed in Spanish children.

METHODS

A prospective, multicenter, nationwide registry of new cases of CD in children <15 years was conducted from June 1, 2006 to May 31, 2007. The parameters studied were age at diagnosis, sex, clinical symptoms, associated diseases, nutritional status, CD serology, histological lesions, and HLA-DQ2/-DQ8. The crude incidence rate of CD was calculated as new cases per 1000 live births and as new cases per 100,000 person-years <15 years of age.

RESULTS

A total of 974 new cases of CD were included. The median age at diagnosis was 2.3 years; 39.5% of CD diagnoses occurred in the first 2 years, 42% between 2 and 6, and 18.4% from 6 to 15. Total number of cases in each age group was 385, 409, and 180, respectively. Regarding clinical presentation 70.9% showed classical symptoms, 21.9% were nonclassical, and 7% were asymptomatic. A total of 95.7% of 931, 94.7% of 611, and 86.7% of 651 children tested positive, respectively, for immunoglobulin A (IgA) anti-transglutaminase type 2 antibodies, IgA endomysial antibodies, and IgA anti-gliadin antibodies. Villous atrophy was observed in 92.4% and increased intraepithelial lymphocytes with crypt hyperplasia in 3.3%. Of the children, 55% had normal growth, and 3.4% were overweight. The HLA phenotype was DQ2: 88.3%, DQ2/DQ8: 8.4%, and DQ8: 2.3%. The incidence rate was 7.9 cases of CD per 1000 live births and 54 cases per 100,000 person-years.

CONCLUSIONS

In Spain, the most frequent clinical presentation of CD is the classical form, mainly diagnosed during the first 2 years of life. The observed incidence of CD in Spanish children is much higher than the present CD incidence rates observed in other European countries.

Neighborhood conditions and celiac disease risk among children in Sweden

Aim: To investigate celiac disease (CD) clustering at different geographical levels and to examine the association between neighborhood demographic and socioeconomic conditions and the risk of neighborhood CD. Methods: We included 2080 children diagnosed with CD between 1998 and 2003, identified from 43 of the 47 reporting hospitals in Sweden. A total of 8036 small area market statistics (SAMS) areas were included; these were nested in 253 municipalities that were further nested into eight ‘nomenclature of territorial units for statistics’ (NUTS) 2 regions. We performed multilevel logistic regression analyses. Results: We found the highest geographical variation in CD incidence at the municipality level, compared to the region level. The probability of having CD increased in the statistical areas of (SAMS) areas with higher average annual work income, with an odds ratio (OR) of 2.24 and 95% CI of 1.76–2.85. Reduced CD risk in neighborhoods was associated with higher average age (OR 0.96; 95% CI 0.95–0.97), higher proportion of residents with a university education (OR 0.98; 95% CI 0.97–0.99), and higher level of industrial and commercial activity (OR 0.59; 95% CI 0.44–0.82). We found no significant association between CD risk and population density, proportion of Nordic to non-Nordic inhabitants, nor share of the population with only a compulsory education. Conclusions: Neighborhood composition influences CD risk. This is one of the first attempts to identify factors explaining geographical variation in CD.

Celiac disease risk varies between birth cohorts, generating hypotheses about causality: evidence from 36 years of population-based follow-up

Background

Celiac disease (CD) is a major public health problem with estimated 1-3% prevalence in the general population. In recent years an increase in CD prevalence has been reported both in Sweden and worldwide. This study aimed at examining the annual incidence rate of biopsy-proven celiac disease among children in Sweden over a 36-year period, to assess variations by age, sex and birth cohort, and to assess the clinical impact of these changes.

Methods

The National Swedish Childhood CD Register was used to identify 9107 children aged 0–14.9 years who were diagnosed with CD during the period 1973 to 2009. From 1973 to 1990 the register covered 15% of the nation, this increased to 40% during 1991–1997; a full national coverage was obtained from 1998 onwards. Estimations for the annual incidence rate, cumulative incidence and clinical impact by age groups, calendar month and birth cohorts were made.

Results

CD incidence is continuing to increase in the child population aged 2–14.9 years. A continued variation in CD incidence was observed in children aged 0–1.9 years, characterized by a marked decrease in most recent years. The median age at diagnosis has increased from 1.0 year in the 1970s to 6.8 years in 2009. The average number of new cases has risen from ~200 during 1973–1983 to ~600 during 2004–2009. In the birth cohorts of 2000–2002 the cumulative incidence even exceeded that of the epidemic cohorts at comparable ages. The highest cumulative incidence was observed in the birth cohorts of 1985–1995 and 2000–2002.

Conclusions

CD risk varies between birth cohorts, suggesting cyclic environmental and/or lifestyle risk factors in CD etiology. More research on underlying risk factors is required in order to move forward with preventive strategies.

What happens to food choices when a gluten-free diet is required? A prospective longitudinal population-based study among Swedish adolescent with coeliac disease and their peers

A dietary survey was performed during a large screening study in Sweden among 13-year-old adolescents. The aim was to study how the intake of food groups was affected by a screening-detected diagnosis of coeliac disease (CD) and its gluten-free (GF) treatment. Food intake was reported using a FFQ, and intake reported by the adolescents who were diagnosed with CD was compared with the intake of two same-aged referent groups: (i) adolescents diagnosed with CD prior to screening; and (ii) adolescents without CD. The food intake groups were measured at baseline before the screening-detected cases were aware of their CD, and 12–18 months later. The results showed that food intakes were affected by screen-detected CD and its dietary treatment. Many flour-based foods were reduced such as pizza, fish fingers and pastries. The results also indicated that bread intake was lower before the screened diagnosis compared with the other studied groups, but increased afterwards. Specially manufactured GF products (for example, pasta and bread) were frequently used in the screened CD group after changing to a GF diet. The present results suggest that changing to a GF diet reduces the intake of some popular foods, and the ingredients on the plate are altered, but this do not necessarily include a change of food groups. The availability of manufactured GF replacement products makes it possible for adolescents to keep many of their old food habits when diagnosed with CD in Sweden.

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.

The rising incidence of celiac disease in Scotland

BACKGROUND AND OBJECTIVES

Although the incidence of pediatric celiac disease (CD) is increasing globally, it is uncertain whether this is attributed to improved case ascertainment or signifies a true rise. We aimed to identify all incident cases of childhood CD in southeast Scotland over the period 1990 to 2009 to assess trends in total incidence and cases diagnosed as a result of (1) a classic presentation, (2) a nonclassic presentation, or (3) targeted screening.

METHODS

Twenty-year retrospective cohort study of case notes, pathology databases, endoscopy, and patient records for all children (<16 years of age) diagnosed with CD on biopsy in southeast Scotland (at-risk population of 225000-233000). Data were age-gender standardized and Poisson regression models used to calculate changes in incidence over time.

RESULTS

A total of 266 children were diagnosed from 1990 to 2009 with an increase in incidence from 1.8/100000 (95% confidence interval [CI] 1.1-2.7) to 11.7/100000 (95% CI 9.8-13.9) between the epochs 1990 to 1994 and 2005 to 2009, respectively (P < .0001). The incidence of nonclassic presentation (children with a monosymptomatic presentation and those with extraintestinal symptoms) and actively screened cases increased by 1566% (P < .05) and 1170% (P < .001) from 1990 to 1999 to 2000 to 2009, respectively. However, a rise in the incidence of Oslo classic cases from 1.51/100000 (95% CI 0.91-2.38) in 1990 to 1994 to 5.22/100000 (95% CI 3.98-6.75) in 2005 to 2009 (P < .01) remained evident.

CONCLUSIONS

The incidence of pediatric CD increased 6.4-fold over the 20 years. This study demonstrates that this rise is significant for classic CD, indicating a true rise in the incidence of pediatric CD.

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.

Prevotella jejuni sp. nov., isolated from the small intestine of a child with coeliac disease

Five obligately anaerobic, Gram-stain-negative, saccharolytic and proteolytic, non-spore-forming bacilli (strains CD3 : 27, CD3 : 28(T), CD3 : 33, CD3 : 32 and CD3 : 34) are described. All five strains were isolated from the small intestine of a female child with coeliac disease. Cells of the five strains were short rods or coccoid cells with longer filamentous forms seen sporadically. The organisms produced acetic acid and succinic acid as major metabolic end products. Phylogenetic analysis based on comparative 16S rRNA gene sequence analysis revealed close relationships between CD3 : 27, CD3 : 28(T) and CD3 : 33, between CD3 : 32 and Prevotella histicola CCUG 55407(T), and between CD3 : 34 and Prevotella melaninogenica CCUG 4944B(T). Strains CD3 : 27, CD3 : 28(T) and CD3 : 33 were clearly different from all recognized species within the genus Prevotella and related most closely to but distinct from P. melaninogenica. Based on 16S rRNA, RNA polymerase β-subunit (rpoB) and 60 kDa chaperonin protein subunit (cpn60) gene sequencing, and phenotypic, chemical and biochemical properties, strains CD3 : 27, CD3 : 28(T) and CD3 : 33 are considered to represent a novel species within the genus Prevotella, for which the name Prevotella jejuni sp. nov. is proposed. Strain CD3 : 28(T) ( = CCUG 60371(T) = DSM 26989(T)) is the type strain of the proposed novel species. All five strains were able to form homologous aggregates, in which tube-like structures were connecting individual bacteria cells. The five strains were able to bind to human intestinal carcinoma cell lines at 37 °C.

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.

Early infections are associated with increased risk for celiac disease: an incident case-referent study

BACKGROUND

Celiac disease is defined as a 'chronic small intestinal immune-mediated enteropathy precipitated by exposure to dietary gluten in genetically predisposed individuals'. Sweden has experienced an "epidemic" of celiac disease in children below two years of age. Celiac disease etiology is considered multifactorial; however, little is known regarding potential risk- or protecting factors. We present data on the possible association between early infectious episodes and celiac disease, including their possible contribution to the Swedish celiac disease epidemic.

METHODS

A population-based incident case-referent study (475 cases, 950 referents) with exposure information obtained via a questionnaire (including family characteristics, infant feeding, and the child's general health) was performed. Celiac disease cases were diagnosed before two years of age, fulfilling the diagnostic criteria of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition. Referents were randomly selected from the national population register after fulfilling matching criteria. The final analyses included 954 children, 373 (79%) cases and 581 (61%) referents, with complete information on main variables of interest in a matched set of one case with one or two referents.

RESULTS

Having three or more parental-reported infectious episodes, regardless of type of infection, during the first six months of life was associated with a significantly increased risk for later celiac disease, and this remained after adjusting for infant feeding and socioeconomic status (odds ratio [OR] 1.5; 95% confidence interval [CI], 1.1-2.0; P=0.014). The celiac disease risk increased synergistically if, in addition to having several infectious episodes, infants were introduced to dietary gluten in large amounts, compared to small or medium amounts, after breastfeeding was discontinued (OR 5.6; 95% CI, 3.1-10; P<0.001).

CONCLUSION

This study suggests that having repeated infectious episodes early in life increases the risk for later celiac disease. In addition, we found a synergistic effect between early infections and daily amount of gluten intake, more pronounced among infants for whom breastfeeding had been discontinued prior to gluten introduction. Regarding contribution to the Swedish celiac disease epidemic, which partly was attributed to concurrent changes in infant feeding, early infections probably made a minor contribution via the synergistic effect with gluten amount.

Systematic review: early infant feeding and the prevention of coeliac disease

BACKGROUND

PREVENTCD, Prevent Coeliac Disease, is an international project investigating the hypothesis of possible induction of tolerance to gluten in genetically predisposed children through introducing small quantities of gluten during the period of breastfeeding.

AIM

To summarise current knowledge on the possible relationship between early feeding practices and the risk of coeliac disease (CD).

METHODS

The Cochrane Library, MEDLINE, and EMBASE databases were searched in May 2011, and the search was updated in January 2012, and again in July 2012.

RESULTS

Breastfeeding (BF) and CD: some studies show a protective effect of BF, while others show no effect. No studies have shown a long-term preventive effect. BF at the time of gluten introduction and CD: Results from a meta-analysis of five observational case-control studies suggest that BF at gluten introduction is associated with a lower risk of CD compared with formula feeding. It is unclear whether BF provides a permanent protection or only delays the onset of CD. Timing of gluten introduction: The data suggest that both early (≤4 months) and late (≥7 months) introduction of gluten may increase the risk of CD. Amount of gluten at weaning (and later) and CD: One incident case-referent study documented that the introduction of gluten in large amounts compared with small or medium amounts increased the risk of CD.

CONCLUSIONS

In the absence of clear evidence, in order to decrease the risk of later coeliac disease, it is reasonable to avoid both early (<4 months) and late (≥7 months) introduction of gluten, and to introduce gluten while the infant is still being breastfed. Future studies may clarify the remaining uncertainties.

The incidence and risk of celiac disease in a healthy US adult population

OBJECTIVES

Celiac disease (CD) is an increasingly common disease that may affect as many as 1% of the North American population. Recent population-based data suggest a substantial increase in the prevalence of CD over the last several decades. Several factors are hypothesized as possible disease triggers including intercurrent illnesses, such as gastroenteritis, surgeries, and trauma. We used the active duty US military, a unique healthy worker population with essentially complete medical diagnostic coding, as an opportunity to describe trends in CD and deployment-related risk factors.

METHODS

Using electronic medical encounter data (1999-2008) on active duty US military (over 13.7 million person-years), a matched, nested case-control study describing the epidemiology and risk determinants of CD (based on ≥2 ICD-9 medical encounters) was conducted. Incidence and duration of CD-related medical care were estimated, and conditional logistic regression was utilized to evaluate CD risk following infectious gastroenteritis (IGE) occurring within 3 years before CD diagnosis while controlling for other risk factors.

RESULTS

A total of 455 incident cases of CD were identified and age, gender, and time matched to 1,820 controls. The incidence of CD increased five-fold from 1.3 per 100,000 in 1999 to 6.5 per 100,000 in 2008, with the highest rates of increase among those over 34 years of age (average annual increase of 0.8 cases per 100,000). A total of 172 IGE episodes, predominately of "viral etiology" (60.5%), were documented. In multivariate models, a significant association between IGE and CD was found (Odds ratio (OR): 2.06, 95% confidence interval (CI) 1.43, 2.97). Risk generally increased with temporal proximity to, and non-viral etiology of, exposure. Other notable risk factors for CD in multivariate models were Caucasian race (OR: 3.1, P<0.001), non-Army service (OR: 1.5, P=0.001), and greater than a high-school education (OR: 1.3, P=0.05).

CONCLUSIONS

Incidence of CD diagnosis in the US military is increasing, particularly among those in the fourth and fifth decades of life and appears higher than other population-based estimates. An association between antecedent IGE and risk of CD was noted, but the potential for exposure misclassification cannot be ruled out and further study is needed to link pathogen-specific exposure to incident CD anti-gluten antibody development or symptom onset.

Early vaccinations are not risk factors for celiac disease

OBJECTIVES

To investigate if changes in the national Swedish vaccination program coincided with changes in the celiac disease (CD) incidence rate in infants (ie, the Swedish CD Epidemic), and to assess the potential association between these vaccinations and CD risk.

METHODS

All studies were based on the National Swedish Childhood Celiac Disease Register. Using an ecological approach, we plotted changes over time in the national vaccination program in the graph displaying CD incidence rate. A population-based incident case-referent study of invited infants was performed. Exposure information was received through a questionnaire and child health clinic records. Vaccines explored were diphtheria/tetanus, pertussis (acellular), polio (inactivated), Haemophilus influenzae type b (conjugated), measles/mumps/rubella, and live attenuated bacillus Calmette-Guérin (BCG) in children with increased tuberculosis risk. Findings were subjected to a birth cohort analysis.

RESULTS

Introduction of pertussis vaccine coincided in time with decreasing CD incidence rates. In the infant case-referent study, however, neither vaccination against pertussis (odds ratio 0.91; 95% confidence interval 0.60-1.4), nor against Haemophilus influenzae type b or measles/mumps/rubella was associated with CD. Coverage for the diphtheria/tetanus and polio vaccines was 99%. BCG was associated with reduced risk for CD (adjusted odds ratio 0.54; 95% confidence interval 0.31-0.94). Discontinuation of general BCG vaccination did not affect the cumulative incidence of CD at age 15 years.

CONCLUSIONS

Early vaccinations within the national Swedish program were not associated with CD risk, nor could changes in the program explain the Swedish epidemic. A protective effect by BCG was suggested, which could be subject to further studies.

A 10-year serological follow-up of celiac disease in an Estonian population

BACKGROUND

Celiac disease (CD) is induced by wheat gluten and related prolamines. Its prevalence may be underestimated in many geographic regions and populations, and has recently increased in several countries. In 1998 and 1999, a random sample of Estonian schoolchildren was screened with IgA-type tissue transglutaminase antibodies (IgA-tTG) for CD. The results revealed a CD prevalence of 0.34%, which is lower compared with many other European countries.

OBJECTIVE

We rescreened the same population for CD using IgA-tTG after a 10-year interval.

MATERIALS AND METHODS

A total of 891 patients from the initial sample were rescreened using the IgA-tTG assay for a participation rate of 76.8% (median age, 24.3 years). As in the initial study, the IgA-tTG results were evaluated by ImmunoCAP EliA Celikey using an IgG-tTG and deamidated gliadin antibody assay for IgA-deficient cases.

RESULTS

No new cases of CD were found in this follow-up study. Of note, 75% of patients with initial IgA-tTG-positive results and biopsy-proven CD remained seropositive. One patient with a negative seroconversion at the time of rescreening followed a strict gluten-free diet during the follow-up years.

CONCLUSION

In a 10-year follow-up period, no new cases of CD were found in this Estonian population of school-children and young adults. Therefore, we presume no increase in CD during the last decade among this age group in Estonia. Additional studies are needed to determine whether similar results would be obtained in other age groups, because of differences in the CD prevalence between Estonian and other European populations.

The introduction of allergenic foods and the development of reported wheezing and eczema in childhood: the Generation R study

OBJECTIVE

To examine whether the timing of introduction of the allergenic foods cow's milk, hen's egg, peanuts, tree nuts, soy, and gluten is associated with eczema and wheezing in children 4 years of age or younger.

DESIGN

Population-based prospective cohort study from fetal life until young adulthood.

SETTING

Rotterdam, the Netherlands, from April 2002 through January 2006.

PARTICIPANTS

A total of 6905 preschool children participating in the Generation R study.

MAIN EXPOSURE

Timing of introduction of cow's milk, hen's egg, peanuts, tree nuts, soy, and gluten collected by questionnaires at 6 and 12 months of age.

MAIN OUTCOME MEASURES

Information on the outcomes eczema and wheezing were obtained by questions from the age-adapted version of the "International Study of Asthma and Allergies in Childhood" core questionnaire and questionnaire data on parentally reported physician diagnosis for eczema.

RESULTS

Of 6905 children, wheezing was reported in 31% at age 2 years and in 14% at ages 3 and 4 years. Eczema was reported in 38%, 20%, and 18% of children at the ages of 2, 3, and 4 years, respectively. The introduction of cow's milk, hen's egg, peanuts, tree nuts, soy, and gluten before the age of 6 months was not significantly associated with eczema or wheezing at any age after adjustment for potential confounders (P > .10 for all comparisons). The results did not alter after stratification according to the child's history of cow's milk allergy and parental history of atopy.

CONCLUSION

This study does not support the recommendation for delayed introduction of allergenic foods after age 6 months for the prevention of eczema and wheezing.

Influence of early feeding practices on celiac disease in infants

AIM

To investigate whether duration of breastfeeding and timing of gluten introduction influence the age at diagnosis and severity of celiac disease.

METHODS

Medical records of 89 infants (59 girls and 30 boys; mean age of 14.2 months, standard deviation 4.80) diagnosed with classic celiac disease at the University Children's Hospital in Belgrade from 2000 to 2008 were retrospectively analyzed to determine the duration of breastfeeding and timing of gluten introduction. The severity of celiac disease was assessed based on weight loss, longitudinal growth retardation, anemia, and secondary lactose intolerance.

RESULTS

Longer breastfeeding significantly reduced the risk that celiac disease would manifest in the first year of life (odds ratio, 0.655; 95% confidence interval, 0.481-0.891; P=0.007), and duration of breastfeeding was the most significant predictor of developing celiac disease (B=0.49; 95% confidence interval, 0.131-0.768; P=0.007). There were no significant differences in age at diagnosis between infants who had started consuming gluten before the fourth month and those who had started between the fourth and sixth month. Neither breastfeeding nor timing of gluten introduction affected the severity of the disease.

CONCLUSION

Longer breastfeeding and continuation of breastfeeding after gluten introduction delay the onset of classic celiac disease. On the other hand, neither breastfeeding nor the timing of gluten introduction affects the severity of celiac disease.

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.

Natural history of celiac disease autoimmunity in a USA cohort followed since 1974

BACKGROUND

The natural history and the possible changes of celiac disease (CD) prevalence over time are still unclear.

OBJECTIVES

1) To establish whether loss of tolerance to gluten may occur at any age; 2) to investigate possible changes of CD prevalence over time; and 3) to investigate CD-related co-morbidities.

METHODS

We analyzed 3,511 subjects with matched samples from 1974 (CLUE I) and 1989 (CLUE II). To avoid a selection bias regarding survival, we also screened 840 CLUE I participants who deceased after the 1974 survey. Outcome measure. CD autoimmunity (positivity to auto-antibodies) over time.

RESULTS

CD autoimmunity was detected in seven subjects in 1974 (prevalence 1:501) and in an additional nine subjects in 1989 (prevalence 1:219). Two cases of CD autoimmunity were found among the 840 subjects deceased after CLUE I. Compared to controls, untreated CD subjects showed increased incidence of osteoporosis and associated autoimmune disorders, but they did not reach statistical significance.

CONCLUSIONS

During a 15-year period CD prevalence increased 2-fold in the CLUE cohort and 5-fold overall in the US since 1974. The CLUE study demonstrated that this increase was due to an increasing number of subjects that lost the immunological tolerance to gluten in their adulthood.

Time trends of Helicobacter pylori resistance to antibiotics in children living in Vienna, Austria

BACKGROUND

Increase of antibiotic resistance is a worldwide problem. Within the 4 years before the turn of the millennium Helicobacter pylori strains isolated in children living in Vienna, Austria, showed a primary clarithromycin and metronidazole resistance of 20% and 16%, respectively. The aim of this retrospective follow-up survey was to assess the further development and current antimicrobial resistance status.

METHODS

Children having undergone upper endoscopy between March 2002 and March 2008 at the same two co-operating pediatric gastroenterology units which had also been collaborating on the prior assessment were included. H. pylori infection was diagnosed by rapid urease test, histology, and culture. If the latter was positive, susceptibility testing to amoxicillin, clarithromycin and metronidazole by E-test followed. From March 2004 onwards, susceptibility to levofloxacin, tetracycline and rifampin was additionally assessed.

RESULTS

Out of 897 children, 153 had a proven infection with H. pylori and no history of prior eradication treatment. Their median age was 11.5 years (range 0.5-20.9 years). Primary resistance to clarithromycin and metronidazole were 34% and 22.9%, respectively; dual resistance was found in 9.8% of the strains; 0.9% was resistant to tetracycline and rifampin, respectively. No case of amoxicillin resistance was detected. The only independent risk factor for clarithromycin resistance turned out to be the origin of a child from Austrian parents.

CONCLUSIONS

In the last decade, the rate of primary resistance of H. pylori to clarithromycin continued to rise. No significant change was found regarding primary resistance to metronidazole or dual resistance to metronidazole and clarithromycin, respectively.

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.

Celiac disease

PURPOSE OF REVIEW

To summarize recent advances in celiac disease published between August 2008 and July 2009.

RECENT FINDINGS

Celiac disease affects nearly 1% of most populations but remains largely unrecognized. In the last year, work has shown that the prevalence of celiac disease has increased dramatically, not simply due to increased detection. Also, undiagnosed celiac disease may be associated with increased mortality. Significant progress has been made in understanding how gliadin peptides can cross the intestinal border and access the immune system. New genetic loci and candidate genes that may contribute to the risk of celiac disease and its overlap with type 1 diabetes mellitus have been identified. Novel deamidated gliadin peptides antibodies have better diagnostic accuracy over native gliadin-based tests. The inclusion of duodenal bulb biopsy specimens may increase the rate of celiac disease detection. The spectrum of celiac disease likely includes a minority of patients with mild enteropathy. A practical seven-item instrument may facilitate standardized evaluation of gluten-free diet adherence. Finally, refractory celiac disease, although rare, is associated with a poor prognosis.

SUMMARY

Celiac disease is a global health problem that requires a multidisciplinary and increasingly cooperative multinational research effort.

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.

Proximal small intestinal microbiota and identification of rod-shaped bacteria associated with childhood celiac disease

OBJECTIVES

Alterations in the composition of the microbiota in the intestine may promote development of celiac disease (CD). Using scanning electron microscopy (SEM) we previously demonstrated that rod-shaped bacteria were present on the epithelium of proximal small intestine in children with CD but not in controls. In this study we characterize the microbiota of proximal small intestine in children with CD and controls and identify CD-associated rod-shaped bacteria.

METHODS

Proximal small intestine biopsies from 45 children with CD and 18 clinical controls were studied. Bacteria were identified by 16S rDNA sequencing in DNA extracted from biopsies washed with buffer containing dithiothreitol to enrich bacteria adhering to the epithelial lining, by culture-based methods and by SEM and transmission electron microscopy.

RESULTS

The normal, mucosa-associated microbiota of proximal small intestine was limited. It was dominated by the genera Streptococcus and Neisseria, and also contained Veillonella, Gemella, Actinomyces, Rothia, and Haemophilus. The proximal small intestine microbiota in biopsies from CD patients collected during 2004-2007 differed only marginally from that of controls, and only one biopsy (4%) had rod-shaped bacteria by SEM (SEM+). In nine frozen SEM+ CD biopsies from the previous study, microbiotas were significantly enriched in Clostridium, Prevotella, and Actinomyces compared with SEM- biopsies. Bacteria of all three genera were isolated from children born during the Swedish CD epidemic. New Clostridium and Prevotella species and Actinomyces graevenitzii were tentatively identified.

CONCLUSIONS

Rod-shaped bacteria, probably of the indicated species, constituted a significant fraction of the proximal small intestine microbiota in children born during the Swedish CD epidemic and may have been an important risk factor for CD contributing to the fourfold increase in disease incidence in children below 2 years of age during that time.

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.

Regional variation in celiac disease risk within Sweden revealed by the nationwide prospective incidence register

AIM

To determine if there is any regional celiac disease (CD) risk variation in the Swedish childhood population.

METHODS

Prospective nationwide Swedish incidence register of CD in children 0-15 years of age, with the present analysis covering the period from 1998 to 2003. ESPGHAN diagnostic criteria for CD were used. Regions were classified according to the Nomenclature of Territorial Units for Statistics. The incidence rate for each region, gender, age group and year of diagnosis was calculated.

RESULTS

A regional variation in CD risk was demonstrated. The childhood populations in 'West Sweden' and 'Småland and the islands', situated in the southern part of the country, had a significantly higher incidence rate compared to in 'North Middle Sweden' and 'Stockholm', situated in the central part. This regional variation was not explained by variations in risk by gender, age at diagnosis or year of diagnosis.

CONCLUSION

The Swedish regional variation in CD risk supports multifactorial disease aetiology. Continued efforts are warranted to define factors, besides gluten exposure, that modulate CD risk.