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.

Cost-effective HLA typing with tagging SNPs predicts celiac disease risk haplotypes in the Finnish, Hungarian, and Italian populations.

Human leukocyte antigen (HLA) genes, located on chromosome 6p21.3, have a crucial role in susceptibility to various autoimmune and inflammatory diseases, such as celiac disease and type 1 diabetes. Certain HLA heterodimers, namely DQ2 (encoded by the DQA1*05 and DQB1*02 alleles) and DQ8 (DQA1*03 and DQB1*0302), are necessary for the development of celiac disease. Traditional genotyping of HLA genes is laborious, time-consuming, and expensive. A novel HLA-genotyping method, using six HLA-tagging single-nucleotide polymorphisms (SNPs) and suitable for high-throughput approaches, was described recently. Our aim was to validate this method in the Finnish, Hungarian, and Italian populations. The six previously reported HLA-tagging SNPs were genotyped in patients with celiac disease and in healthy individuals from Finland, Hungary, and two distinct regions of Italy. The potential of this method was evaluated in analyzing how well the tag SNP results correlate with the HLA genotypes previously determined using traditional HLA-typing methods. Using the tagging SNP method, it is possible to determine the celiac disease risk haplotypes accurately in Finnish, Hungarian, and Italian populations, with specificity and sensitivity ranging from 95% to 100%. In addition, it predicts homozygosity and heterozygosity for a risk haplotype, allowing studies on genotypic risk effects. The method is transferable between populations and therefore suited for large-scale research studies and screening of celiac disease among high-risk individuals or at the population level.

Lower economic status and inferior hygienic environment may protect against celiac disease.

BACKGROUND: The populations in adjacent Russian Karelia and Finland are equally exposed to grain products and share partly the same ancestry, but live in completely different socioeconomic environments. AIM: This creates an ideal epidemiological setting to study gene-environmental interactions in pathogenesis of celiac disease. METHODS: The prevalence of celiac disease and predisposing human leukocyte antigen (HLA) alleles was compared between Russian Karelia and Finland. Tissue transglutaminase antibodies and HLA-DQ alleles were screened from 1988 schoolchildren from Karelia and 3654 children from Finland. Children with transglutaminase antibodies were invited to small-bowel biopsy. Results. Transglutaminase antibodies were less frequent in Russian Karelia than in Finland (0.6% versus 1.4%, P = 0.005). Immunoglobulin class G (IgG) antigliadin antibodies were also less frequent in Russian Karelia (10.2% versus 28.3%, P<0.0001). Celiac disease was confirmed by duodenal biopsy in four of the eight transglutaminase antibody-positive Karelian children, giving a prevalence of 1 in 496 compared to 1 in 107 children in Finland. The same HLA-DQ alleles were associated with celiac disease and transglutaminase antibody positivity in both populations. CONCLUSIONS: The prevalence of transglutaminase antibodies and celiac disease is lower in Russian Karelia than in Finland. This may be associated with a protective environment characterized by inferior prosperity and standard of hygiene in Karelia.

Comparison of quality of life between asthmatic and healthy school children.

There are only a few studies which have assessed the impact of asthma on the quality of life (QoL) compared to healthy children. In this study we wanted to compare QoL between asthmatic and healthy children in a population based setting. We surveyed 2159 children aged 11-15 yr with a Child Health Questionnaire; a generic QoL measure for children. This method gives a profile of the QoL consisting of 11 scales giving a range from 0 to 100. Asthma was defined based on the ISAAC questionnaire on asthma and asthma symptoms. In all, 192 children (8.9%) reported to have asthma diagnosed by a doctor and 61 of them (2.8% of all children) had been symptomatic during the previous month. Among these symptomatic children significantly impaired QoL was observed in 8 of the 11 scales compared to non-asthmatics. The most affected scales were those defining the physical part of child's QoL: Mean General Health scores were 60 for asthmatic and 74 for non-asthmatic children and mean Bodily Pain scores 71 and 86, respectively. Symptoms during longer periods were associated with an overall decreased QoL. In conclusion, a child's asthma impairs the QoL and especially the physical dimensions.

Should we screen reflux oesophagitis patients for coeliac disease?

OBJECTIVES: Oesophagitis and gastro-oesophageal reflux have been implicated recently in the manifestations of coeliac disease. The aim was to investigate this association in a primary-care setting. METHODS: First, the prevalence of coeliac disease was calculated in 1198 adults with oesophagitis, in 2541 adults with reflux symptoms and in 200 adults suffering from dysphagia; 5459 patients with a history consistent with dyspepsia and 709 patients with a suspicion of coeliac disease served as controls. Second, the prevalence of oesophagitis was estimated in 382 untreated and 232 treated coeliac patients; controls here comprised 5404 patients with dyspeptic symptoms and 2525 patients with reflux symptoms. Third, oesophagitis and oesophageal reflux symptoms were investigated before and after a gluten-free diet was followed in 67 adults with coeliac disease. The diagnosis of coeliac disease was based on small-bowel histology; histological exclusion of the disease was unambiguous in all controls. Oesophagitis was identified by endoscopic inspection. RESULTS: Altogether, 0.9% of patients with oesophagitis and 0.6% of those with oesophageal reflux symptoms had coeliac disease. The corresponding percentages were 1.0% in patients with dyspepsia and 12% with suspicion of coeliac disease. The prevalence of oesophagitis was 5.2% in untreated coeliac disease, 5.6% in treated coeliac disease, 7.0% in patients with dyspepsia, and 27% in symptomatic reflux disease. In coeliac patients, the reflux symptoms were mild but nevertheless were alleviated on a gluten-free diet. CONCLUSIONS: This study does not support the conception that patients with reflux oesophagitis should be screened vigorously for coeliac disease. The association between these two conditions is, at most, weak, but a gluten-free diet may still bring symptomatic relief for reflux symptoms in coeliac disease.

Prevalence of Celiac disease among children in Finland.

BACKGROUND: Wheat, rye, and barley proteins induce celiac disease, an autoimmune type of gastrointestinal disorder, in genetically susceptible persons. Because the disease may be underdiagnosed, we estimated the prevalence of the disease and tested the hypothesis that assays for serum autoantibodies can be used to detect untreated celiac disease and that positive findings correlate with specific HLA haplotypes. METHODS: Serum samples were collected from 3654 students (age range, 7 to 16 years) in 1994 and screened in 2001 for endomysial and tissue transglutaminase antibodies. HLA typing was also performed on stored blood samples. All antibody-positive subjects were asked to undergo small-bowel biopsy in 2001. RESULTS: Of the 3654 subjects, 56 (1.5 percent) had positive antibody tests, as determined in 2001. Results of the two antibody tests were highly concordant. As of 1994, none of the subjects had received a clinical diagnosis of celiac disease, but 10 who had positive tests for both antibodies in serum obtained in 1994 received the diagnosis between 1994 and 2001. Of the 36 other subjects with positive antibody assays who agreed to undergo biopsy in 2001, 27 had evidence of celiac disease on biopsy. Thus, the estimated biopsy-proved prevalence was 1 case in 99 children. All but two of the antibody-positive subjects had either the HLA-DQ2 or the HLA-DQ8 haplotype. The prevalence of the combination of antibody positivity and an HLA haplotype associated with celiac disease was 1 in 67. CONCLUSIONS: The presence of serum tissue transglutaminase and endomysial autoantibodies is predictive of small-bowel abnormalities indicative of celiac disease. There is a good correlation between autoantibody positivity and specific HLA haplotypes. We estimate that the prevalence of celiac disease among Finnish schoolchildren is at least 1 case in 99 children.

A new locus for coeliac disease mapped to chromosome 15 in a population isolate.

Coeliac disease is a common multifactorial disease with a strong genetic component, which is not entirely explained by the HLA association. Four previous whole-genome screens have produced somewhat inconsistent results suggesting genetic heterogeneity. We attempted to overcome this problem by performing a genome-wide scan in a Finnish sub-population, expected to be more homogeneous than the general population of Finland. The families in our study originate from the northeastern part of Finland, the Koilliskaira region, which has been relatively isolated since its founding in the 16th century. Genealogical studies have confirmed that the families share a common ancestor in the 16th century. Nine families with altogether 23 patients were genotyped for 399 microsatellite markers and the data were analysed with parametric linkage analysis using two dominant and one recessive model. A region on chromosome 15q11-q13 was implicated with a LOD score of 3.14 using a highly penetrant dominant model. Addition of more markers and one more sib-pair increased the LOD score to 3.74. This result gives preliminary evidence for existence of a susceptibility factor in this chromosomal region.

Gluten-free diet and quality of life in patients with screen-detected celiac disease.

CONTEXT: Since the advent of serologic testing for celiac disease, most persons who receive a diagnosis of celiac disease have few or no symptoms. Although pathologic changes of celiac disease resolve on a gluten-free diet, how a gluten-free diet affects the quality of life for patients with screen-detected celiac disease is unclear. OBJECTIVE: To evaluate the effect of a gluten-free diet on the quality of life of patients with screen-detected celiac disease. DESIGN: Prospective study of patients before and 1 year after initiating a gluten-free diet. PARTICIPANTS: 19 patients with screen-detected celiac disease (found by serologically testing first-degree relatives of celiac patients) and 21 consecutive patients with symptom-detected disease. In all cases, celiac diagnosis was confirmed by finding villous atrophy and crypt hyperplasia on small-bowel biopsy. INTERVENTION: Gluten-free diet (explained during a single physician visit). MAIN OUTCOME MEASURES: Gastrointestinal Symptoms Rating Scale (GSRS), in which scores range from 0 to 6 (higher scores represent worse symptoms); and quality of life measured with the Psychological General Well-Being Questionnaire (PGWB). Scores range from 22 to 132 (higher scores mean greater well-being). RESULTS: At baseline, patients with symptom-detected celiac disease had poorer quality of life and more gastrointestinal symptoms than those with screen-detected celiac disease. Reported compliance with the gluten-free diet was good. All mucosal lesions of the small bowel had resolved at the follow-up biopsy. After 1 year of following the diet, quality of life for patients with screen-detected disease significantly improved (mean PGWB score increased from 108 to 114; P <0.01). A similar increase was noted in patients with symptom-detected disease (mean PGWB score increased from 92 to 103; P <0.01). Gastrointestinal symptoms also improved in patients with screen-detected disease and in patients with symptom-detected disease (mean GSRS scores decreased from 1.8 to 1.4 and from 2.6 to 1.9, respectively; P <0.01 for both comparisons). CONCLUSIONS: Gluten-free diet was associated with improved quality of life for patients with symptom-detected celiac disease and patients with screen-detected celiac disease. Concerns about the burden of a gluten-free diet, at least over the short term, may be unfounded.

Genomewide linkage analysis of celiac disease in Finnish families.

Celiac disease (CD), or gluten-sensitive enteropathy, is a common multifactorial disorder resulting from intolerance to cereal prolamins. The only established genetic susceptibility factor is HLA-DQ, which appears to explain only part of the overall genetic risk. We performed a genomewide scan of CD in 60 Finnish families. In addition to strong evidence for linkage to the HLA region at 6p21.3 (Z(max)>5), suggestive evidence for linkage was found for six other chromosomal regions--1p36, 4p15, 5q31, 7q21, 9p21-23, and 16q12. We further analyzed the three most convincing regions--4p15, 5q31, and 7q21--by evaluation of dense marker arrays across each region and by analysis of an additional 38 families. Although multipoint analysis with dense markers provided supportive evidence (multipoint LOD scores 3.25 at 4p15, 1.49 at 5q31, and 1.04 at 7q21) for the initial findings, the additional 38 families did not strengthen evidence for linkage. The role that HLA-DQ plays was studied in more detail by analysis of DQB1 alleles in all 98 families. All but one patient carried one or two HLA-DQ risk alleles, and 65% of HLA-DQ2 carriers were affected. Our study indicates that the HLA region harbors a predominant CD-susceptibility locus in these Finnish families.