Epidemiology of celiac disease: what are the prevalence, incidence, and progression of celiac disease?

Design, synthesis and evaluation of high-affinity binders for the celiac disease associated HLA-DQ2 molecule

Celiac disease is caused by uncontrolled CD4 T-cell responses directed to wheat-derived gluten peptides bound to the disease predisposing HLA-DQ molecules. The only available treatment is a life-long gluten-free diet which is complicated by the widespread use of wheat-derived gluten in the food industry. As the binding of gluten-derived peptides is a prerequisite for the induction of the inflammatory T-cell response, blockers that would prevent gluten peptide binding to the HLA-DQ molecules might be used as an alternative to the gluten-free diet. In the present study we have analyzed the binding properties of a set of previously identified natural ligands for HLA-DQ2, the primary disease predisposing allele. An in silico method, Epibase, ranked these peptides and the top one, a peptide with a nine amino acid core FVAEYEPVL, was measured among these peptides as the peptide with the highest binding affinity for HLA-DQ2. In a stepwise approach we subsequently tested the impact of N-terminal extensions and systematic single amino acid substitutions within the core of this peptide which revealed that an N-terminal extension with the tripeptide sequence ADA increased binding affinity 5- to 6-fold. In addition the substitution analysis indicated which amino acids were most preferred at anchor residues in the lead peptide, generally leading to an increase of binding affinity with a factor of 2. Next we tested which combinations of such preferred amino acids yielded the best results. The combined results indicate that a peptide with sequence ADAYDYESEELFAA (core in bold) had superior binding properties. This peptide was chosen as a lead peptide for further optimization with non-natural amino acids at the p1 position, since molecular modeling indicated that none of the natural amino acids is able to optimally occupy the p1 pocket. A set of 8 non-proteinogenic amino acids was designed, synthesized and incorporated in the lead peptide (and in two control peptides) and tested for binding to HLA-DQ2. The results indicate that the effect of the incorporation of these non-proteinogenic amino acids depended on the peptide in which they were incorporated and that the maximum increase in binding affinity obtained was approximately 2-fold. Altogether lead sequences were obtained that have a binding affinity for HLA-DQ2 that is 100- to 200-fold higher compared to that of the gluten-derived peptide that has the highest affinity for HLA-DQ2. Such peptides are candidate lead peptides for further optimization. Our results, however, also indicate that in order to obtain further significant increases in binding affinity alternative approaches will have to be explored.

The changing face of childhood celiac disease in north america: impact of serological testing

OBJECTIVE

The goal was to evaluate the impact of immunoglobulin A endomysial antibody testing on the incidence and clinical presentation of childhood celiac disease.

METHODS

The incidence and clinical presentation of celiac disease in patients <18 years of age in 1990-1996 (pretesting group) versus 2000-2006 (testing group) were compared.

RESULTS

The median age at diagnosis was 2 years (95% confidence interval: 2-4 years) in the pretesting group (N = 36), compared with 9 years (95% confidence interval: 8-10 years) in the testing group (N = 199; P < .001); the female/male ratios (1.6:1) were similar (P = .982). The incidence of celiac disease increased from 2.0 cases per 100000 children (pretesting group) to 7.3 cases per 100000 children (testing group; P = .0256). The frequency of classic celiac disease presentations decreased from 67% (pretesting group) to 19% (testing group; P < .001), but the incidence of classic celiac disease did not differ (0.8 vs 1.6 cases per 100000; P = .154). In the testing group, 13 previously unrecognized clinical presentations were observed in 98 children, including 35 with family history, 18 with abdominal pain, and 14 with type 1 diabetes mellitus. The frequency of Marsh IIIc lesions decreased from 64% (pretesting group) to 44% (testing group; P = .0403). In the testing group, classic celiac disease remained predominant (67%) in young children (<3 years), whereas atypical gastrointestinal and silent presentations predominated in older children.

CONCLUSIONS

Antibody testing for celiac disease tripled the incidence of celiac disease and quadrupled the median age at diagnosis.

Metabolic osteopathy in celiac disease: importance of a gluten-free diet

Reduced bone mineral density (BMD) is frequently found in individuals with untreated celiac disease (CD), possibly due to calcium and vitamin D malabsorption, release of pro-inflammatory cytokines, and misbalanced bone remodeling. A gluten-free diet (GFD) promotes a rapid increase in BMD that leads to complete recovery of bone mineralization in children. Children may attain normal peak bone mass if the diagnosis is made and treatment is given before puberty, thereby preventing osteoporosis in later life. A GFD improves, but rarely normalizes, BMD in patients diagnosed with CD in adulthood. In some cases, nutritional supplementation may be necessary. More information on therapeutic alternatives is needed.

Anti-microbial antibodies in celiac disease: Trick or treat?

AIM: To determine the prevalence of a new set of anti-glycan and anti-outer membrane protein (anti-OMP) antibodies in a Hungarian cohort of adult Celiac disease (CD) patients.

METHODS: 190 consecutive CD patients [M/F: 71/119, age:39.9 (SD:14.1) years], 100 healthy, and 48 gastrointestinal controls were tested for glycan anti-Saccharomyces cerevisiae (gASCA), anti-laminaribioside (ALCA), anti-chitobioside, anti-mannobioside, anti-OMP antibodies and major NOD2/CARD15 mutations. Thirty out of 82 CD patients enrolled at the time of diagnosis were re-evaluated for the same antibodies after longstanding gluten-free diet (GFD).

RESULTS: 65.9% of the CD patients were positive for at least one of the tested antibodies at the time of the diagnosis. Except anti-OMP and ALCA, anti-microbial antibodies were exclusively seen in untreated CD; however, the overall sensitivity was low. Any glycan positivity (LR+: 3.13; 95% CI: 2.08-4.73) was associated with an increased likelihood ratio for diagnosing CD. Significant correlation was found between the levels of anti-glycan and anti-endomysial or anti-transglutaminase antibodies. Anti-glycan positivity was lost after longstanding GFD. Anti-glycan antibody titers were associated with symptoms at presentation, but not the presence of NOD2/CARD15 mutations. Patients with severe malabsorption more frequently had multiple antibodies at diagnosis (P = 0.019).

CONCLUSION: The presence of anti-glycan antibodies in CD seems to be secondary to the impaired small bowel mucosa which can lead to increased antigen presentation. Furthermore, anti-glycan positivity may be considered an additional marker of CD and dietary adherence.

Headache in pediatric patients with celiac disease and its prevalence as a diagnostic clue

OBJECTIVES

To establish the prevalence of headache in children with celiac disease (CD), the response to a gluten-free diet, and the prevalence of CD in children affected by headache.

METHODS

This hospital-based study included 2 steps. In the retrospective part, 354 children with CD answered a questionnaire investigating the presence of headache before and after the gluten-free diet. The same questionnaire was administered to 200 healthy children matched for sex and age. In the prospective part, 79 children affected by headache were screened for CD by antitransglutaminase IgA. Diagnosis of CD was confirmed by duodenal biopsy; before starting a gluten-free diet patients underwent a brain positron emission tomography study. After 6 months of follow-up children were reevaluated for the presence of headache.

RESULTS

Overall, 88 patients with CD complained of headaches before the diagnosis of CD as compared with 16 in the control group (24.8% vs 8%, P < 0.001). After the institution of a gluten-free diet, the headaches significantly improved in 68 children (77.3%), of whom 24 (27.3%) were headache-free during the study period. Four of 79 (5%) headache patients were found to have CD compared with 0.6% of the general population (P = 0.005). The brain positron emission tomography studies did not show any anomalies. During the follow-up, headaches improved in all 4 children with CD.

CONCLUSIONS

We recorded -- in our geographical area -- a high frequency of headaches in patients with CD and vice versa with a beneficial effect of a gluten-free diet. Screening for CD could be advised in the diagnostic work-up of patients with headache.

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.

Prevalence of celiac disease in the Asia-Pacific region

The development of sensitive and specific serological assays for celiac disease has led to a revision of the prevalence of this disease in many countries. In the Asia-Pacific region, prevalence has been determined in only a minority of countries but those with prevalence rates of 1:50-1:500 adults include Australia, Iran, Israel, New Zealand, Syria and Turkey. In contrast, celiac disease appears to be extremely rare in Japan and may be rare in China. In India, prevalence rates are high in the northern states but much lower in the southern states. In individual countries, important determinants of prevalence include the per capita consumption of wheat and the frequency of a specific human leukocyte antigen (HLA) type genetically defined as HLA-DQB1*02 (*0201 or *0202) and serologically defined as HLA-DQ2. These determinants predict low prevalence rates for celiac disease in the Pacific Islands, South-East Asia and eastern China but higher rates in countries west of India and China. There is also the potential for a rising incidence of celiac disease if traditional rice-based diets are replaced by Western-style diets with a higher content of wheat products.

Enteroscopy in the diagnosis and management of celiac disease

Esophagogastroduodenoscopy (EGD) with 3 to 6 biopsies in the descending duodenum is the gold standard for the diagnosis of celiac disease. At the time of the first diagnosis of celiac disease, an extensive evaluation of the small bowel is not recommended. However, video capsule endoscopy, because of its good sensitivity and specificity in recognizing the Endoscopic features of celiac disease, can be considered a valid alternative to EGD in patients unable or unwilling to undergo EGD with biopsies. Capsule endoscopy is also a possible option in selected cases with strong suspicion of celiac disease but negative first-line tests. In evaluating patients with refractory or complicated celiac disease, in whom a complete evaluation of the small bowel is mandatory (at least in refractory celiac disease type II patients) because of the possible presence of complications beyond the reach of conventional endoscopes, both capsule endoscopy and balloon-assisted enteroscopy have been found to be helpful. In these patients, capsule endoscopy offers several advantages: it is well tolerated, it allows inspection of the entire small bowel, and it is able to recognize subtle mucosal changes. However, in this setting, capsule endoscopy should ideally be coupled with imaging techniques that provide important information about the thickness of the wall of the intestine and about extraluminal abnormalities. Although deep enteroscopy (such as balloon enteroscopy) is expensive, time-consuming, and potentially risky in these frail patients, they may have a key role, because they make it possible to take tissue samples from deep in the small intestine.

Inflammatory Disease Processes and Interactions with Nutrition

Inflammation is a stereotypical physiological response to infections and tissue injury; it initiates pathogen killing as well as tissue repair processes and helps to restore homeostasis at infected or damaged sites. Acute inflammatory reactions are usually self-limiting and resolve rapidly, due to the involvement of negative feedback mechanisms. Thus, regulated inflammatory responses are essential to remain healthy and maintain homeostasis. However, inflammatory responses that fail to regulate themselves can become chronic and contribute to the perpetuation and progression of disease. Characteristics typical of chronic inflammatory responses underlying the pathophysiology of several disorders include loss of barrier function, responsiveness to a normally benign stimulus, infiltration of inflammatory cells into compartments where they are not normally found in such high numbers, and overproduction of oxidants, cytokines, chemokines, eicosanoids and matrix metalloproteinases. The levels of these mediators amplify the inflammatory response, are destructive and contribute to the clinical symptoms. Various dietary components including long chain ω-3 fatty acids, antioxidant vitamins, plant flavonoids, prebiotics and probiotics have the potential to modulate predisposition to chronic inflammatory conditions and may have a role in their therapy. These components act through a variety of mechanisms including decreasing inflammatory mediator production through effects on cell signaling and gene expression (ω-3 fatty acids, vitamin E, plant flavonoids), reducing the production of damaging oxidants (vitamin E and other antioxidants), and promoting gut barrier function and anti-inflammatory responses (prebiotics and probiotics). However, in general really strong evidence of benefit to human health through anti-inflammatory actions is lacking for most of these dietary components. Thus, further studies addressing efficacy in humans linked to studies providing greater understanding of the mechanisms of action involved are required.

Capsule endoscopy findings in celiac disease

Capsule endoscopy (CE) is a noninvasive imaging method used to evaluate intestinal mucosa. We aimed to examine intestinal mucosal changes in celiac disease (CD) with CE. Eight untreated patients who had anti-endomysial antibody-positive duodenal biopsy results consistent with CD were included in the study. Villous atrophy, scalloping, fissuring, and mosaic pattern (consistent with CD) were detected in seven patients; one patient was excluded for early meal consumption. No patchy involvement was found in the intestine or distal region of the intestine (ileum) in any of the patients. The common feature of all patients was that villous atrophy, scalloping, fissuring, and mosaic patterns detected in the proximal intestine gradually decreased towards the distal intestine. CE provided no diagnostic contribution to CD when compared with duodenal biopsy. It can be used to show villous atrophy in selected cases and to evaluate the extension of intestinal involvement in CD.

The epidemiology and pathogenesis of neoplasia in the small intestine

PURPOSE

The mucosa of the small intestine encompasses about 90% of the luminal surface area of the digestive system, but only 2% of the total annual gastrointestinal cancer incidence in the United States.

METHODS

The remarkable contrast in age-standardized cancer incidence between the small and large intestine has been reviewed with respect to the cell type patterns, demographic features, and molecular characteristics of neoplasms.

RESULTS

Particularly noteworthy is the predominance of adenocarcinoma in the colon, which exceeds 98% of the total incidence by cell type, in contrast to that of 30% to 40% in the small intestine, resulting in an age-standardized ratio of rates exceeding 50-fold. The prevalence of adenomas and carcinomas is most prominent in the duodenum and proximal jejunum. The positive correlation in global incidence rates of small and large intestinal neoplasms and the reciprocal increases in risk of second primary adenocarcinomas suggest that there are common environmental risk factors. The pathophysiology of Crohn inflammatory bowel disease and the elevated risk of adenocarcinoma demonstrate the significance of the impaired integrity of the mucosal barrier and of aberrant immune responses to luminal indigenous and potentially pathogenic microorganisms.

CONCLUSION

In advancing a putative mechanism for the contrasting mucosal susceptibilities of the small and large intestine, substantial differences are underscored in the diverse taxonomy, concentration and metabolic activity of anaerobic organisms, rate of intestinal transit, changing pH, and the enterohepatic recycling and metabolism of bile acids. Experimental and epidemiologic studies are cited that suggest that the changing microecology, particularly in the colon, is associated with enhanced metabolic activation of ingested and endogenously formed procarcinogenic substrates.

Tetraploid and hexaploid wheat varieties reveal large differences in expression of alpha-gliadins from homoeologous Gli-2 loci

BACKGROUND

Alpha-gliadins form a multigene protein family encoded by multiple alpha-gliadin (Gli-2) genes at three genomic loci, Gli-A2, Gli-B2 and Gli-D2, respectively located on the homoeologous wheat chromosomes 6AS, 6BS, and 6DS. These proteins contain a number of important celiac disease (CD)-immunogenic domains. The alpha-gliadins expressed from the Gli-B2 locus harbour fewer conserved CD-epitopes than those from Gli-A2, whereas the Gli-D2 gliadins have the highest CD-immunogenic potential. In order to detect differences in the highly CD-immunogenic alpha-gliadin fraction we determined the relative expression level from the homoeologous Gli-2 loci in various tetraploid and hexaploid wheat genotypes by using a quantitative pyrosequencing method and by analyzing expressed sequence tag (EST) sequences.

RESULTS

We detected large differences in relative expression levels of alpha-gliadin genes from the three homoeologous loci among wheat genotypes, both as relative numbers of expressed sequence tag (EST) sequences from specific varieties and when using a quantitative pyrosequencing assay specific for Gli-A2 genes. The relative Gli-A2 expression level in a tetraploid durum wheat cultivar ('Probstdorfer Pandur') was 41%. In genotypes derived from landraces, the Gli-A2 frequency varied between 12% and 58%. In some advanced hexaploid bread wheat cultivars the genes from locus Gli-B2 were hardly expressed (e.g., less than 5% in 'Lavett') but in others they made up more than 40% (e.g., in 'Baldus').

CONCLUSION

Here, we have shown that large differences exist in relative expression levels of alpha-gliadins from the homoeologous Gli-2 loci among wheat genotypes. Since the homoelogous genes differ in the amount of conserved CD-epitopes, screening for differential expression from the homoeologous Gli-2 loci can be employed for the pre-selection of wheat varieties in the search for varieties with very low CD-immunogenic potential. Pyrosequencing is a method that can be employed for such a 'gene family-specific quantitative transcriptome profiling'.

Emerging technologies in upper gastrointestinal endoscopy and celiac disease

Despite advances in our knowledge of celiac disease, the most current and authoritative recommendations conclude that diagnosis requires at least four biopsy specimens to be taken from the duodenal area. These recommendations are based on the perception that classic endoscopic markers are not adequate to target biopsy sampling to sites of villous damage in the duodenum. In the past few years, newly developed procedures and technologies have improved endoscopic recognition of the duodenum. These advances make possible the real-time recognition of the duodenal villous pattern during an upper endoscopy procedure, and thereby have the potential to optimize diagnostic accuracy. It is, therefore, reasonable to hypothesize that upper endoscopy might have a more incisive role in the diagnosis of celiac disease than merely providing a means of obtaining biopsy specimens for histological analysis. This Review highlights the new technologies in the field of upper endoscopy that could be helpful for the diagnosis of celiac disease, including the water-immersion technique, chromoendoscopy, high-resolution magnification endoscopy, optimal band imaging, optical coherence tomography and confocal endomicroscopy.

Antigliadin immunoglobulin A best in finding celiac disease in children younger than 18 months of age

OBJECTIVES

The aim was to investigate age-dependent serum levels and occurrence of elevated celiac disease (CD)-related antibodies in young children, to define the optimal serological procedure when selecting for small intestinal biopsy.

PATIENTS AND METHODS

Included were 428 children with biopsy verified CD (median age 16 months; range 7.5 months-14 years) and 216 controls (median age 2.7 years; range 8.5 months-14.6 years). Immunoglobulin (Ig) A antibodies against gliadin (AGA-IgA), tissue transglutaminase (tTG-IgA), and endomysium (EMA-IgA) were analysed.

RESULTS

Increased serum AGA-IgA levels were found in 411 of 428 CD cases, tTG-IgA in 385 of 428, and EMA-IgA in 383 of 428. In the control group, 11 of 216 had increased levels of AGA-IgA, 5 of 216 of tTG-IgA, and 8 of 216 of EMA-IgA. In CD children younger than 18 months, elevated AGA-IgA occurred in 97% and elevated tTG-IgA and EMA-IgA were found in 83% of the cases. Conversely, in CD children older than 18 months, elevated AGA-IgA occurred in 94%, and elevated tTG-IgA and EMA-IgA were found in 99% of the cases.

CONCLUSIONS

In children older than 18 months, both tTG-IgA and EMA-IgA are sufficiently accurate to be used as a single antibody marker, whereas a large proportion of younger children with CD lack these antibodies. Therefore, when selecting children for small intestinal biopsy, the detection of a combination of AGA-IgA and tTG-IgA is optimal for identifying untreated CD in children younger than 18 months.

Gluten-free and regular foods: a cost comparison

PURPOSE

The treatment of celiac disease is a strict gluten-free diet for life. This diet is assumed to be more expensive, although no studies confirm this assumption. In the current study, the prices of gluten-free foods and regular (gluten-containing) foods were compared to determine if and to what extent gluten-free products are more expensive.

METHODS

Prices were compared for all food products labelled "gluten-free" and comparable gluten-containing food items in the same group available at two large-chain general grocery stores. The unit cost of each food, calculated as the price in dollars per 100 grams of each product, was calculated for purposes of comparison.

RESULTS

All 56 gluten-free products were more expensive than regular products. The mean (+/- standard deviation) unit price for gluten-free products was $1.71 (+/- 0.93) compared with $0.61 (+/- 0.38) for regular products (p<0.0001). On average, gluten-free products were 242% more expensive than regular products (+/- 212; range, 5% to 1,000%).

CONCLUSIONS

All the commercially available products labelled gluten-free were significantly more expensive than comparable products. This information will be useful to dietitians who counsel individuals and families with celiac disease, and to celiac advocacy groups for lobbying the government about financial compensation.

Use of selected sourdough strains of Lactobacillus for removing gluten and enhancing the nutritional properties of gluten-free bread

Forty-six strains of sourdough lactic acid bacteria were screened for proteolytic activity and acidification rate in gluten-free (GF) flours. The sourdough cultures consisted of Lactobacillus sanfranciscensis LS40 and LS41 and Lactobacillus plantarum CF1 and were selected and used for the manufacture of GF bread. Fermentation occurred in two steps: (i) long-time fermentation (16 h) and (ii) fast fermentation (1.5 h) using the previous fermented sourdough as inoculum (ca. 43%, wt/wt) with Saccharomyces cerevisiae (baker's yeast). GF bread started with baker's yeast alone was used as the control. Gluten was added to ingredients before fermentation to simulate contamination. Initial gluten concentration of 400 ppm was degraded to below 20 ppm only in the sourdough GF bread. Before baking, sourdough GF bread showed phytase activity ca. sixfold higher than that of GF bread started with baker's yeast alone. Atomic absorption spectrophotometric analysis revealed that the higher phytase activity resulted in an increased availability of free Ca2+, Zn2+, and Mg2+. The concentration of free amino acids also was the highest in sourdough GF bread. Sourdough GF bread had a higher specific volume and was less firm than GF bread started with baker's yeast alone. This study highlighted the use of selected sourdough cultures to eliminate risks of contamination by gluten and to enhance the nutritional properties of GF bread.

Imbalance in the composition of the duodenal microbiota of children with coeliac disease

Coeliac disease (CD) is the most common immune-mediated enteropathy characterized by chronic inflammation of the small intestinal mucosa. The ingestion of gluten is responsible for the symptoms of CD, but other environmental factors are also thought to play a role in this disorder. In this study, the composition of the duodenal microbiota of coeliac children with active disease, symptom-free CD patients on a gluten-free diet and control children was determined. Bacteriological analyses of duodenal biopsy specimens were carried out by fluorescent in situ hybridization coupled with flow cytometry. The proportions of total bacteria and Gram-negative bacteria were significantly higher in CD patients with active disease than in symptom-free CD patients and controls. Bacteroides and Escherichia coli groups were significantly more abundant in CD patients with active disease than in controls, whilst these bacterial deviations were normalized in symptom-free CD patients. The ratio of Lactobacillus--Bifidobacterium to Bacteroides--E. coli was significantly reduced in coeliac patients with either active or inactive disease compared with controls. The differences in Atopobium, Eubacterium rectale--Clostridium coccoides, Clostridium histolyticum, Clostridium lituseburense, sulphate-reducing bacteria and Faecalibacterium prausnitzii populations among the three groups of children were less relevant. Overall, the higher incidence of Gram-negative and potentially pro-inflammatory bacteria in the duodenal microbiota of coeliac children was linked to the symptomatic presentation of the disease and could favour the pathological process of the disorder.

Vitamin D status in gastrointestinal and liver disease

PURPOSE OF REVIEW

The purpose of this review is to report on the vitamin D status and its relationship with bone health in individuals with gastrointestinal and liver disorders. In addition, recommendations regarding replacement and maintenance of optimal vitamin D stores, as well as the state of knowledge regarding its effect on the disease through its actions on the immune system, will be reviewed.

RECENT FINDINGS

The scientific community has revised upward the serum levels of vitamin D considered optimal, and doses of vitamin D much larger than those currently recommended may be needed to maintain these levels, especially in individuals with gastrointestinal and liver disorders. The relationship between vitamin D and bone health in this population is controversial. The role of vitamin D in the regulation of the immune system continues to be elucidated.

SUMMARY

Hypovitaminosis D is prevalent among individuals with gastrointestinal and liver disease. Although replacement and supplementation guidelines have not been well defined, practitioners should aim for a serum 25-hydroxyvitamin D level of at least 32 ng/ml. The contribution of vitamin D to the bone health of these individuals and its role in altering disease course through its actions on the immune system remain to be elucidated.

A non-human primate model for gluten sensitivity

BACKGROUND AND AIMS

Gluten sensitivity is widespread among humans. For example, in celiac disease patients, an inflammatory response to dietary gluten leads to enteropathy, malabsorption, circulating antibodies against gluten and transglutaminase 2, and clinical symptoms such as diarrhea. There is a growing need in fundamental and translational research for animal models that exhibit aspects of human gluten sensitivity.

METHODS

Using ELISA-based antibody assays, we screened a population of captive rhesus macaques with chronic diarrhea of non-infectious origin to estimate the incidence of gluten sensitivity. A selected animal with elevated anti-gliadin antibodies and a matched control were extensively studied through alternating periods of gluten-free diet and gluten challenge. Blinded clinical and histological evaluations were conducted to seek evidence for gluten sensitivity.

RESULTS

When fed with a gluten-containing diet, gluten-sensitive macaques showed signs and symptoms of celiac disease including chronic diarrhea, malabsorptive steatorrhea, intestinal lesions and anti-gliadin antibodies. A gluten-free diet reversed these clinical, histological and serological features, while reintroduction of dietary gluten caused rapid relapse.

CONCLUSIONS

Gluten-sensitive rhesus macaques may be an attractive resource for investigating both the pathogenesis and the treatment of celiac disease.

Haptoglobin polymorphism: a novel genetic risk factor for celiac disease development and its clinical manifestations

BACKGROUND

Haptoglobin (Hp) alpha-chain alleles 1 and 2 account for 3 phenotypes that may influence the course of inflammatory diseases via biologically important differences in their antioxidant, scavenging, and immunomodulatory properties. Hp1-1 genotype results in the production of small dimeric, Hp2-1 linear, and Hp2-2 cyclic polymeric haptoglobin molecules. We investigated the haptoglobin polymorphism in patients with celiac disease and its possible association to the presenting symptoms.

METHODS

We studied 712 unrelated, biopsy-proven Hungarian celiac patients (357 children, 355 adults; severe malabsorption 32.9%, minor gastrointestinal symptoms 22.8%, iron deficiency anemia 9.4%, dermatitis herpetiformis 15.6%, silent disease 7.2%, other 12.1%) and 384 healthy subjects. We determined haptoglobin phenotypes by gel electrophoresis and assigned corresponding genotypes.

RESULTS

Hp2-1 was associated with a significant risk for celiac disease (P = 0.0006, odds ratio [OR] 1.54, 95% CI 1.20-1.98; prevalence 56.9% in patients vs 46.1% in controls). It was also overrepresented among patients with mild symptoms (69.2%) or silent disease (72.5%). Hp2-2 was less frequent in patients than in controls (P = 0.0023), but patients having this phenotype were at an increased risk for severe malabsorption (OR 2.21, 95% CI 1.60-3.07) and accounted for 45.3% of all malabsorption cases. Celiac and dermatitis herpetiformis patients showed similar haptoglobin phenotype distributions.

CONCLUSIONS

The haptoglobin polymorphism is associated with susceptibility to celiac disease and its clinical presentations. The predominant genotype in the celiac population was Hp2-1, but Hp2-2 predisposed to a more severe clinical course. The phenotype-dependent effect of haptoglobin may result from the molecule's structural and functional properties.

The incidence of coeliac disease in adult first degree relatives

BACKGROUND AND AIMS

Although prevalence of coeliac disease among first degree relatives of coeliac patients is well-known, only four studies are available about its incidence. We investigated whether first degree relatives found to be negative at a first serological screening can subsequently develop coeliac disease.

PATIENTS AND METHODS

In the last 6 years, endomysial antibodies were tested in 158 adult first degree relatives referred to our coeliac out-patient clinic. After at least a year, negative subjects were offered a second testing. Sixty-three accepted.

RESULTS

130/158 first degree relatives tested negative initially. Although one of them had developed coeliac disease after the first testing, at the second testing none of the 63 endomysial antibody negative first degree relatives proved positive. Incidence of coeliac disease among first degree relatives was 1/64 in 51 months, 0.437% year (95%CI 0.05-2.62). An analysis of the sample size showed that 10,000 first degree relatives must be followed up to significantly reduce the CI.

CONCLUSIONS

Although we confirmed the high prevalence of coeliac disease among first degree relatives (28/158, 17.7%), we found that the low incidence suggests that further studies are required to understand whether endomysial antibody negative first degree relatives need to be followed up.

A tale of two cities: typical celiac sprue presenting symptoms are significantly more common in Turkish than in US Patients

GOAL

Recent studies suggest an increasing prevalence of atypical initial symptoms in patients with celiac disease (CD). The aim of this study was to compare the presenting symptoms of CD at 2 comparable referral institutions in South Florida, and in Ankara, Turkey. We retrospectively reviewed the records of patients with an initial diagnosis of CD by small bowel biopsy during the same (1991 to 2001) 10-year period at Cleveland Clinic Florida and University of Ankara, Turkey. A numerical score was assigned to presenting symptom and signs.

RESULTS

There were 28 patients in the South Florida group (51% men) and 40 patients in the Turkish group (35% men) (P=NS). The Turkish patients were significantly younger at diagnosis (36+/-2 y vs. US patients 66+/-3 y) (P<0.0001). Typical celiac symptom scores were similar (Turkey 1.1+/-0.2 vs. South Florida 1.3+/-0.3) (P=NS). Atypical symptom scores were significantly higher in the US patients (1.9+/-0.2) versus those from Turkey (1.2+/-0.1) (P<0.01). The Turkish patients were significantly more likely (P<0.01) to present with chronic diarrhea, hypoalbuminemia, and mactocytosis at the time of diagnosis.

CONCLUSIONS

Although retrospective, this study points to striking differences in the clinical presentation of CD in individuals in South Florida, United States, and Ankara, Turkey, diagnosed during the same time period at both institutions. Turkish patients were younger, and more likely to present with chronic diarrhea, hypoalbuminemia, and microcytosis-as was more commonly seen in the United States in the 1960s and 70s. These findings raise the question of an interplay of demographics with diet and genetics in the presenting symptoms of CD in these 2 distant geographic areas.

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.

Long-term follow-up of individuals with celiac disease: an evaluation of current practice guidelines

INTRODUCTION

Celiac disease can be treated by following a strict gluten-free diet for life. If properly followed, the diet resolves symptoms and nutritional deficiencies. It is generally recommended that individuals with celiac disease have careful long-term follow-up. However, it is not clear which elements of disease status evaluation, laboratory investigations and self-management support should be included in follow-up.

OBJECTIVES

To examine the current practice guidelines and recommendations regarding follow-up of individuals with celiac disease.

METHODS

Guidelines issued by gastroenterological societies and associations, and recommendations by experts were retrieved using Medline and other Internet search engines.

RESULTS

Practice guidelines were available from the American Gastroenterological Association; the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition; the National Institutes of Health Consensus Development Conference 2004; the World Gastroenterology Organization; the British Society for Gastroenterology and the United Kingdom-based Primary Care Society for Gastroenterology. Most guidelines recommended a scheduled annual review and regular measurements of body mass index. The British Society for Gastroenterology recommended dietary review only at times of stress, while others recommended dietary review with a nutritionist. All associations recommended serial tissue transglutaminase antibody testing. The American Gastroenterological Association and the Primary Care Society for Gastroenterology recommended annual hemoglobin, ferritin and folate checks. One guideline recommended annual hemoglobin, electrolyte, calcium, albumin, ferritin, folate, fat-soluble vitamin, liver function test, parathyroid hormone and bone density measurements (approximately $400 per patient).

CONCLUSIONS

The current practice guidelines regarding the follow-up of patients with celiac disease varied greatly in their recommendations and many were not evidence-based. Prospective studies are required to develop rational, cost-effective and risk-stratified guidelines for long-term follow-up of these patients.

Clinical presentation and incidence of complications in patients with coeliac disease diagnosed by relative screening

BACKGROUND

There is an increased prevalence of coeliac disease (CD) among relatives of those with the disease.

AIMS

To compare the clinical features in patients with CD detected via family screening with those in patients diagnosed routinely.

METHODS

Information on screening was provided to relatives of patients. Those who wished to be screened were tested for endomysial and/or tissue transglutaminase antibodies. Duodenal biopsy was performed in those with positive antibodies. The clinical details of the relative screening group were compared with those of 105 patients diagnosed routinely.

RESULTS

183 relatives underwent screening, of whom 32 had positive serology, 24 had histology diagnostic of CD, six had normal biopsies and two declined duodenal biopsy. Patients in the relative screening group were younger with a median age of 33 years (range 17-72 years) compared to the routine group which had a median age of 54 years (range 25-88 years). In the relative screening group, there was a male preponderance (M:F ratio 16:8), anaemia at presentation was significantly less common (13% v 58%; p<0.001) and osteoporosis was less frequent (9% v 22%; p<0.244) compared with the routine group. 65% of the relative screening group had gastrointestinal symptoms or anaemia at diagnosis.

CONCLUSIONS

Patients detected by family screening are younger with a male preponderance, but fewer had anaemia and osteoporosis.

Video capsule enteroscopy in the diagnosis of celiac disease: a multicenter study

OBJECTIVES

Duodenal biopsy is the current gold standard for diagnosis of celiac disease. Videocapsule endoscopy examines the entire small bowel and allows visualization of mucosal villi. We evaluated the potential of videocapsule endoscopy in assessing the severity and extent of mucosal changes in patients with suspected celiac disease.

METHODS

Consecutive patients with signs/symptoms suggesting celiac disease and positive anti-gliadin and/or anti-endomysial and/or anti-tissue transglutaminase antibodies underwent upper gastrointestinal endoscopy and videocapsule endoscopy. Duodenal biopsies were classified according to modified Marsh's criteria. Capsule findings were evaluated for the presence of lesions compatible with celiac disease (scalloping of duodenal folds, fissures, flat mucosa, and mosaic appearance).

RESULTS

Forty-three patients were studied. Duodenal histology was normal in 11 and compatible with celiac disease in 32. Using duodenal histology as the gold standard, the performance characteristics of capsule endoscopy for the diagnosis of celiac disease were: sensitivity 87.5% (95% CI 76.1-98.9%), specificity 90.9% (95% CI 81.0-100%), positive predictive value 96.5% (95% CI 90.1-100%), negative predictive value 71.4% (95% CI 55.8-87%), positive and negative likelihood ratios 9.6 and 0.14, respectively. Eighteen patients had mucosal changes extending beyond the duodenum, involving the entire small bowel in three. These patients tended to have more severe symptoms, but the difference was not statistically significant. Interobserver agreement for the diagnosis of celiac disease by capsule endoscopy ranged between 79.2 and 94.4%; kappa values ranged between 0.56 and 0.87.

CONCLUSIONS

Videocapsule endoscopy shows good sensitivity and excellent specificity for the detection of villous atrophy in patients with suspected celiac disease.

Highly efficient gluten degradation by lactobacilli and fungal proteases during food processing: new perspectives for celiac disease

Presently, the only effective treatment for celiac disease is a life-long gluten-free diet. In this work, we used a new mixture of selected sourdough lactobacilli and fungal proteases to eliminate the toxicity of wheat flour during long-time fermentation. Immunological (R5 antibody-based sandwich and competitive enzyme-linked immunosorbent assay [ELISA] and R5 antibody-based Western blot), two-dimensional electrophoresis, and mass spectrometry (matrix-assisted laser desorption ionization-time of flight, strong-cation-exchange-liquid chromatography/capillary liquid chromatography-electrospray ionization-quadrupole-time of flight [SCX-LC/CapLC-ESI-Q-TOF], and high-pressure liquid chromatography-electrospray ionization-ion trap mass spectrometry) analyses were used to determine the gluten concentration. Assays based on the proliferation of peripheral blood mononuclear cells (PBMCs) and gamma interferon production by PBMCs and intestinal T-cell lines (iTCLs) from 12 celiac disease patients were used to determine the protein toxicity of the pepsin-trypsin digests from fermented wheat dough (sourdough). As determined by R5-based sandwich and competitive ELISAs, the residual concentration of gluten in sourdough was 12 ppm. Albumins, globulins, and gliadins were completely hydrolyzed, while ca. 20% of glutenins persisted. Low-molecular-weight epitopes were not detectable by SCX-LC/CapLC-ESI-Q-TOF mass spectrometry and R5-based Western blot analyses. The kinetics of the hydrolysis of the 33-mer by lactobacilli were highly efficient. All proteins extracted from sourdough activated PBMCs and induced gamma interferon production at levels comparable to the negative control. None of the iTCLs demonstrated immunoreactivity towards pepsin-trypsin digests. Bread making was standardized to show the suitability of the detoxified wheat flour. Food processing by selected sourdough lactobacilli and fungal proteases may be considered an efficient approach to eliminate gluten toxicity.

Correlation of duodenal histology with tissue transglutaminase and endomysial antibody levels in pediatric celiac disease

BACKGROUND & AIMS

IgA antibodies against tissue transglutaminase (TTGA) and endomysium (EMA) are sensitive and specific markers for celiac disease (CD). Data correlating TTGA and EMA levels with degree of villous atrophy are limited. We compared duodenal histopathology in pediatric CD patients with TTGA and EMA serologies, symptoms, height, and weight.

METHODS

We identified 117 pediatric patients retrospectively who had serologic testing for IgA TTGA and IgA EMA and duodenal biopsies graded by modified Marsh criteria as 0-3c. Data were analyzed with Spearman rank correlation and multinomial logistic regression.

RESULTS

IgA TTGA (r = .704, P < .001) and IgA EMA (r = 0.740, P < .001) correlated with intestinal villous atrophy in pediatric CD patients by Spearman rank correlation. Similar correlations were found in a subset of 23 patients younger than 3 years of age. Multinomial logistic regression revealed increased probability of Marsh 3a or greater changes with increasing TTGA or EMA levels. Strongly positive antibody levels (TTGA >100 units or EMA titer >1:1280) were highly specific (>98%) for Marsh 3a or greater lesions. Among symptoms, abdominal distention and diarrhea were associated with abnormal histology.

CONCLUSIONS

IgA TTGA and EMA levels correlate with duodenal villous atrophy in pediatric CD patients. IgA TTGA >100 or EMA >1:1280 were nearly always associated with CD histopathology. With further validation of this observation, strongly positive titers might be considered sufficient for diagnosis of pediatric patients at risk for CD. Symptoms, height, and weight are not reliable predictors of CD.

Population screening for coeliac disease in a low prevalence area in Italy

OBJECTIVE

A screening program was proposed for the village of Carcare (population 5700), located in a region of Italy with an apparently low prevalence of coeliac disease (CD): only 1 patient diagnosed out of 2557 inhabitants. The study group comprised 1002 individuals (568 F, 434 M, age range 13-90 years) recruited from blood donors, secondary school pupils and people referred to the local outpatient facilities for routine blood chemistry.

MATERIAL AND METHODS

Total IgA, IgA anti-tissue transglutaminase (tTG) (ELISA, recombinant human antigen) and IgA antiendomysium (EMA) (IFI, umbilical cord substrate) antibodies were measured in the serum of all participants. All patients with IgA deficiency were investigated for IgG tTG antibodies, and in the case of disagreement between tTG and EMA, they were typed for HLA DQ2-DQ8 haplotypes.

RESULTS

Thirteen subjects were positive and 988 negative for autoantibodies (3/988 had IgA deficiency). One serum sample was positive for tTG antibodies but negative for EMA. Ten out of 13 positive subjects consented to undergo duodenal biopsy, which invariably produced evidence of CD despite the absence of clinical signs/symptoms. A post-diagnostic clinical investigation provided evidence showing mild iron deficiency (4 subjects) and osteoporosis (2 subjects). After counselling, all subjects accepted a gluten-free diet.

CONCLUSIONS

The prevalence of CD in the study group was 1:100 (1.0%; 95% CI: 0.5-1.8%): this indicates that CD is largely underdiagnosed in Carcare. Our results suggest that the low prevalence of CD observed in some regions is likely to be due to underdiagnosis.

Gastroduodenal diseases of childhood

PURPOSE OF REVIEW

This paper will review new developments in the etiology and management of gastric and duodenal diseases affecting children.

RECENT FINDINGS

Despite dropping prevalence rates in developed nations, most new Helicobacter pylori infections are primarily acquired during childhood. Resistance to standard triple therapy and falling eradication rates are increasing problems for clinicians, necessitating the study of alternative treatment strategies. Eosinophilic diseases of the gastrointestinal tract are being increasingly recognized. Although population-based epidemiology and the natural history of eosinophilic diseases are not yet fully characterized, biologic therapies are in development for the treatment of these chronic, often refractory, conditions. A recent US National Institutes of Health celiac disease consensus conference suggested that infants' diet constituents and timing of solid food introduction are potential environmental influences in the development of celiac disease.

SUMMARY

New methods of diagnosis and treatment are greatly impacting care of pediatric patients with gastric and duodenal diseases. Less invasive but highly accurate tools for diagnosis are becoming better validated. Early diagnosis and effective intervention in most gastroduodenal disorders of childhood can alter natural history and improve overall quality of life.

Consumption of gluten-free products: should the threshold value for trace amounts of gluten be at 20, 100 or 200 p.p.m.?

OBJECTIVE

The threshold of gluten contamination in gluten-free products of both dietary and normal consumption is under debate. The objective of this study was to gather information on consumption of gluten-free products intended for dietary use of people under a gluten-free diet. This information is essential to ascertain the exposure of coeliac patients to gluten through their diet and deduce the maximum gluten content that these products should contain to guarantee a safe diet.

METHODS

A diet diary of consumption of gluten-free products intended for dietary use was distributed to the coeliac societies of two typical Mediterranean countries (Italy and Spain) and two Northern countries (Norway and Germany). The diet diary included a self-weigh table of the selected food items and a 10-day consumption table. Results were reported in percentiles as distributions were clearly right skewed.

RESULTS

The respondents included in the study accounted for 1359 in Italy, 273 in Spain, 226 in Norway and 56 in Germany. Gluten-free products intended for dietary use contributed significantly to the diet of coeliac patients in Italy, Germany and Norway and to a lesser degree in Spain. The most consumed gluten-free product in all countries was bread, and it was double consumed in the Northern countries (P<0.001). Mediterranean countries showed consumption of a wider variety of gluten-free foods and pasta was eaten to a large degree in Italy.

CONCLUSIONS

The differences between Northern and Mediterranean countries were not in the total amount of gluten-free products but in the type of products consumed. The observed daily consumption of gluten-free products results in the exposure to rather large amounts of gluten, thus the limit of 200 p.p.m. should be revised. A limit of 20 p.p.m. for products naturally gluten-free and of 100 p.p.m. for products rendered gluten-free is proposed to guarantee a safe diet and to enable coeliac patients to make an informed choice. These limits should be revised as new data become available.

Rotavirus infection frequency and risk of celiac disease autoimmunity in early childhood: a longitudinal study

OBJECTIVE

Few studies have assessed the role of specific gastrointestinal infections in celiac disease. We investigated whether increased frequency of rotavirus infection, a common cause of gastrointestinal infection and inflammation, predicts increased risk of celiac disease autoimmunity.

METHODS

A cohort of 1,931 children from the Denver metropolitan area who carried celiac disease human leukocyte antigen (HLA) risk alleles were followed from infancy for development of celiac disease autoimmunity, defined as positivity at two or more subsequent clinic visits for tissue transglutaminase (tTG) autoantibodies measured using a radioimmunoassay with human recombinant tTG. Blood samples were obtained at ages 9, 15, and 24 months, and annually thereafter. Rotavirus antibodies were assayed using an indirect enzyme immunoassay in serial serum samples from each case and two matched controls. Frequency of infections were estimated by the number of increases (> 2 assay coefficient of variation) in rotavirus antibody between clinic visits.

RESULTS

Fifty-four cases developed celiac disease autoimmunity at a median age of 4.4 yr. Thirty-six had an intestinal biopsy, of which 27 (75%) were positive for celiac disease. Frequent rotavirus infections predicted a higher risk of celiac disease autoimmunity (compared with zero infections, rate ratio 1.94, 95% confidence interval [CI] 0.39-9.56, for one infection and rate ratio 3.76, 95% CI 0.76-18.7, for > or = 2 infections, rate ratio for trend per increase in number of infections = 1.94, 95% CI 1.04-3.61, p = 0.037). The result was similar after adjustment for gender, ethnic group, maternal education, breast-feeding, day-care attendance, number of siblings, season of birth, and number of HLA DR3-DQ2 haplotypes.

CONCLUSIONS

This prospective study provides the first indication that a high frequency of rotavirus infections may increase the risk of celiac disease autoimmunity in childhood in genetically predisposed individuals.

Occurrence of overt celiac disease in the elderly following total thyroidectomy

We report the case of a female patient in whom gluten-induced entheropathy was revealed at the age of 71 yr by resistance to treatment with levothyroxine (L-T4), calcium carbonate and alfacalcidol. Hypothyroidism and hypoparathyroidism were the consequence of a total thyroidectomy performed at the age of 65 yr for a large multinodular goiter. Six months after thyroid ablation the patient started to complain of abdominal pain, diarrhea and weight loss. Following, anemia and osteopenia were documented. A progressive increase of replacement therapy for hypothyroidism and hypoparathyroidism was necessary. The clinical presentation suggested a malabsorption syndrome: celiac disease (CD) was diagnosed by serological markers and duodenal biopsy. Following gluten-free diet a normalization of clinical and serological findings was observed, bone mass density improved and a reduction of L-T4, calcium and vitamin D requirements was observed.

Celiac disease could be a frequent disease in Mexico: prevalence of tissue transglutaminase antibody in healthy blood donors

INTRODUCTION/AIM

In North America and Europe, the prevalence of celiac disease (CD) might be much greater than expected in previous estimates. Until recently, the prevalence of CD in Latin America remained largely unknown. So far, information regarding CD in Mexico is limited, and it is still considered a rare disease. Our aim was to determine the prevalence of tTGA in a large group of apparently healthy blood donors.

SUBJECTS AND METHODS

Serum samples from 1009 consecutive blood donors, who attended a third level referral center in Mexico City, were collected between June 2004 and December 2004. Only Mexican Mestizo individuals were included. All sera were tested with a new generation human recombinant protein based tTGA-IgA ELISA commercial kit (Aeskulisa tTG-IgA, Wendelsheim, Germany). The cut-off value provided by the manufacturer was 15 U/mL.

RESULTS

The mean age of the blood donors was 34+/-10 years and 68% (n=683) were men. Six hundred fifty two subjects (65%) were born in Mexico City; and from the remaining 357 subjects, at least one was born in each of the 31 different states in our country. Twenty-seven (2.7%) blood donors were positive for tTGA-IgA; all of them with tTGA-IgA values above 30 U/mL (range 36 to 1639). Overall prevalence was 1:37 [27/1009, 95% confidence interval (CI)=1.6-3.7]. The prevalence among women was 1:33 (10/326, 95% CI=1.04-5.09) and for men 1:40 (17/683, 95% CI=1.24-3.73).

CONCLUSIONS

On the basis of a well-recognized serologic screening method performed to blood donor samples, we demonstrated an unexpectedly high prevalence of tTGA positivity (2.6%) in the adult Mexican Mestizo population. Thus, the prevalence of CD in Mexico could be higher or similar to that observed in other countries. This observation contributes to increase the awareness for this under diagnosed disease in clinical practice and to consider CD as a global health problem.

In celiac disease, a subset of autoantibodies against transglutaminase binds toll-like receptor 4 and induces activation of monocytes

BACKGROUND

Celiac disease is a small intestine inflammatory disorder with multiple organ involvement, sustained by an inappropriate immune response to dietary gluten. Anti-transglutaminase antibodies are a typical serological marker in patients with active disease, and may disappear during a gluten-free diet treatment. Involvement of infectious agents and innate immunity has been suggested but never proven. Molecular mimicry is one of the mechanisms that links infection and autoimmunity.

METHODS AND FINDINGS

In our attempt to clarify the pathogenesis of celiac disease, we screened a random peptide library with pooled sera of patients affected by active disease after a pre-screening with the sera of the same patients on a gluten-free diet. We identified a peptide recognized by serum immunoglobulins of patients with active disease, but not by those of patients on a gluten-free diet. This peptide shares homology with the rotavirus major neutralizing protein VP-7 and with the self-antigens tissue transglutaminase, human heat shock protein 60, desmoglein 1, and Toll-like receptor 4. We show that antibodies against the peptide affinity-purified from the sera of patients with active disease recognize the viral product and self-antigens in ELISA and Western blot. These antibodies were able to induce increased epithelial cell permeability evaluated by transepithelial flux of [(3)H] mannitol in the T84 human intestinal epithelial cell line. Finally, the purified antibodies induced monocyte activation upon binding Toll-like receptor 4, evaluated both by surface expression of activation markers and by production of pro-inflammatory cytokines.

CONCLUSIONS

Our findings show that in active celiac disease, a subset of anti-transglutaminase IgA antibodies recognize the viral protein VP-7, suggesting a possible involvement of rotavirus infection in the pathogenesis of the disease, through a mechanism of molecular mimicry. Moreover, such antibodies recognize self-antigens and are functionally active, able to increase intestinal permeability and induce monocyte activation. We therefore provide evidence for the involvement of innate immunity in the pathogenesis of celiac disease through a previously unknown mechanism of engagement of Toll-like receptor 4.

[Clinical features and diagnosis of celiac disease]

Celiac disease is a life-long enteropathy caused by an intolerance to gluten. The pathologic lesion of the small intestinal mucosa is characterized by the loss of absorptive villi, crypt cell hyperplasia, and infiltration of the lamina propria with inflammatory cells. The clinical presentation of celiac disease varies greatly depending on patient's age, duration and extent of the disease, and the presence of extraintestinal manifestations. The classical symptoms like diarrhea, weight loss and abdominal pain are seen less common. Unfortunately, most patients with celiac disease have either silent or atypical presentations, thus escaping diagnosis for several years. The pathologic changes and symptoms resolve when gluten is excluded from the diet for a sustained period. Untreated celiac disease is associated with significant risk of the development of enteropathy-associated intestinal lymphoma.

Screening for celiac disease in Tunisian patients with Graves’ disease using anti-endomysium and anti-tissue transglutaminase antibodies

OBJECTIVE

Celiac disease (CD) can be associated with autoimmune thyroid diseases. The aim of this study was to screen for CD in patients with Graves' disease in Tunisia.

PATIENTS AND METHODS

Sera from 161 patients with Graves' disease were tested for IgA class anti-endomysium antibodies (AEA) using indirect immunofluorescence on cryostat sections of human umbilical cord and for IgA class anti-human tissue transglutaminase antibodies (AtTG) by ELISA.

RESULTS

AEA were positive in 6 out of 161 (3.7%) patients with Graves' disease and all 6 patients were also positive for AtTG. Four of these 6 patients with positive serological markers of CD underwent duodenal biopsy; three had marked villous atrophy, one has normal histological picture and two did not agree to undergo biopsy. The prevalence of biopsy confirmed CD in patients with Graves' disease was 1.86% (3/161).

CONCLUSION

Patients with Graves' disease are at substantial risk of CD and therefore antibody screening for CD may be included in the work-up of these patients. Either AEA or AtTG may be used.

Health-related quality of life in adult coeliac disease in Germany: results of a national survey

OBJECTIVE

No national survey on the present clinical spectrum and health-related quality of life (HRQOL) in people with coeliac disease has been conducted in Germany until now.

METHODS

The German Coeliac Society DZG posted a set of questionnaires (self-developed socio-demographic and medical questionnaire, the Short Form Health Survey, the Hospital Anxiety and Depression Scale and the Giessen Symptom Check List) to 1000/18 355 of their members who were >/=18 years (every 18th member following consecutive postal codes of the membership directory).

RESULTS

Four hundred and forty-six usable questionnaires were returned (diagnosis proven by biopsy; 78% female, median age 45.5 years). The median interval between the first medical examination due to symptoms of coeliac disease and the final diagnosis was 1 year. Ninety-eight percent reported a reduction of initial symptoms, 85% an improvement of HRQOL with a median gain in weight of 8 kg after starting a gluten-free diet (median duration of 6 years). Sixty-seven percent adhered all the time to the dietary regimen and 26% adhered most of the time. The most frequent diseases associated with coeliac disease were osteoporosis (15%), oral aphtae (12%) and dermatitis herpetiformis (9%). Because of the presence of gastrointestinal symptoms 26% of the patients met the modified Rome I criteria for irritable bowel symptom. Compared to representative samples from the German population, coeliac disease patients had higher scores for anxiety , fatigue, dyspeptic and musculoskeletal pain, and a reduced HRQOL in 9/10 scales of the SF-36 (all P<0.001).

CONCLUSION

Despite being on a gluten-free diet German coeliac disease patients suffer from a high burden of general and extra-intestinal symptoms and a reduced HRQOL.

Celiac disease--sandwiched between innate and adaptive immunity

Celiac disease (CD) patients are intolerant to gluten, proteins in wheat, and related cereals. Virtually all patients are human leukocyte antigen (HLA)-DQ2 or HLA-DQ8 positive and several studies have demonstrated that CD4 T cells specific for (modified) gluten peptides bound to these HLA-DQ molecules are found in patients but not in control subjects. These T cell responses are therefore thought to be responsible for disease development. Many immunogenic gluten peptides which may relate to the disease-inducing properties of gluten have now been identified. In addition, gluten can stimulate IL-15 production that ultimately leads to NKG2D-mediated epithelial cell killing. However, CD develops in only a minority of HLA-DQ2 and HLA-DQ8 individuals. This may be attributed to the default setting of the intestinal immune system: induction and maintenance of tolerance to dietary components and commensal flora. Although at present it is unknown why tolerance in CD is not established or broken, both environmental and genetic factors have been implicated. There is strong evidence for the existence of genes or gene variants on chromosomes 5, 6, and 19 that predispose to CD. In addition, type I interferons have been implicated in development of several autoimmune disorders, including CD. Thus, viral infection and/or tissue damage in the intestine may cause inflammation and induce protective Th1-mediated immunity leading to loss of tolerance for gluten. Once tolerance is broken, a broad gluten-reactive T cell repertoire may develop through determinant spreading. This may be a critical step toward full-blown disease.

The role of ultrasonography in patients with celiac disease

The aim of the present review was to summarize the current evidence on the role of ultrasonography (US) and doppler-US in the diagnosis of celiac disease.

Several ultrasonographic signs have been reported in the association with celiac disease in studies using real-time US. Firstly, case control studies identified some of these US signs and then in a prospective series some of these parameters, due to their high specificity, have been shown to be of value in confirming CD diagnosis, whereas others, due to their high sensitivity, have been demonstrated to be useful in excluding the presence of the disease.

The pattern of splanchnic circulation in CD have extensively been investigated by several studies all of which reported similar results and identified a hy-perdynamic mesenteric circulation that reverts to no-rmal values after successful a gluten-free regimen.

The last part of this review will deal with the possible role of US in identyfing the most severe and common intestinal complication of CD, i.e. the enteropathy-associated T cell non-Hodgkin lymphoma.

Understanding the molecular basis of celiac disease: what genetic studies reveal

Celiac disease (CD) is characterized by a chronic immune reaction in the small intestine to the gluten proteins that are present in a (Western) daily diet. Besides the well known involvement of the HLA class II histocompatibility antigen (HLA)-DQ2.5 and -DQ8 heterodimers (encoded by particular combinations of the HLA-DQA1 and -DQB1 gene) in CD and the minor contribution of the CTLA-4 gene, recently the myosin IXB (MYO9B) gene has also been found to be genetically associated. This review covers the general aspects of CD as well as current insight into important molecular aspects. We evaluate the role of susceptibility genes in CD by following gluten along its path from ingestion to uptake in the body, which leads us through the three aspects of CD's pathology. The first is the presence of gluten in the lumen of the intestine, where it is broken down by several enzymes. The second is the intestinal barrier through which gluten peptides pass. The third is the reaction of the immune system in response to gluten peptides, in which both the innate and the adaptive immune systems play a role. Our main conclusion, based on the current genetic and functional studies, is that we should look for causal genes in the barrier function as well as in the immune systems.

Celiac disease: current concepts in diagnosis and treatment

Celiac disease is a complex autoimmune enteropathy that affects the small bowel in genetically predisposed individuals. It is thought that celiac disease is the result of an inappropriate T cell-mediated immune response against ingested gluten protein. The characteristic lesion of the small intestinal mucosa includes loss of absorptive villi and infiltration of the lamina propria with inflammatory cells. The clinical presentation of celiac disease varies greatly depending on patient's age, duration and extent of the disease, and the presence of extraintestinal manifestations. Unfortunately, most patients with celiac disease have either silent or atypical presentations, thus escaping diagnosis for several years. Medical nutrition therapy with lifelong adherence to a strict gluten-free diet is the only accepted treatment of celiac disease. Individuals at risk for this entity should undergo appropriate serologic testing, but there is no evidence to support mass screening.