Celiac disease in a Chilean population carrying Amerindian traits

Frequency of celiac disease and distribution of HLA-DQ2/DQ8 haplotypes among siblings of children with celiac disease

BACKGROUND

Celiac disease (CD) is a multifactorial disease, but genetic factors play a major role in its etiology. It has been known that human leucocyte antigen (HLA)-DQ2/DQ8 haplotypes are one of the most important predisposing genetic factors. The risk of developing CD in first-degree relatives and especially siblings of celiac patients is quite high because of having the same HLA haplotypes.

AIM

To evaluate the frequency of CD and the distribution of the HLA-DQ2/DQ8 haplotypes in siblings of celiac patients.

METHODS

Patients with biopsy-proven CD and their siblings were included in the study; those who did not have HLA genotyping were excluded from the study. All siblings were on a gluten-containing diet. The HLA genotyping, tissue transglutaminase antibody IgA antibody test, and total IgA test were performed in all participants.

RESULTS

A total of 57 celiac patients and their 112 siblings were included in the study. The mean age of celiac patients and siblings were 10.30 ± 3.87 years and 9.90 ± 6.11 years, respectively. HLA-DQ2/DQ8 alleles were detected in 98.2% of patients with CD and 90.2% of siblings of celiac patients. HLA-DQ genotypes were present in all siblings diagnosed with CD. Tissue transglutaminase antibody IgA test was found to be positive in 16 siblings. CD was diagnosed in 12 siblings (10.7%) by intestinal biopsy.

CONCLUSION

The prevalence of CD was found to be 10.7% in siblings of celiac patients in our study. One-third of the siblings diagnosed with CD were asymptomatic. We detected HLA-DQ alleles in 98.2% of celiac patients and 100% in siblings diagnosed with CD. In addition, 1 of the 2 siblings was diagnosed with CD 1 year later and the other 4 years later. Therefore, we suggest that siblings of celiac patients should be followed up with clinical findings as well as HLA analysis and serological examination. Since the risk of developing CD is much higher in asymptomatic siblings, we recommend that siblings should be screened for CD even if they are asymptomatic.

Distribution of celiac disease predisposing genes HLA-DQ2 and HLA-DQ8 in the native population of southern India

BACKGROUND

Celiac disease (CD) is an intestinal inflammatory condition caused by the ingestion of gluten peptides in wheat and related grains in individuals carrying HLA-DQ2 and/or HLA-DQ8 genes. In comparison to HLA-DQ8, a higher HLA-DQ2 prevalence is reported in European population where wheat has been the staple food for thousands of years. In non-European population, this pattern of HLA-DQ CD-predisposing gene distribution has not always been found. The aim of this study was to evaluate the HLA-DQ2 and HLA-DQ8 distribution in the native low-gluten consuming southern Indian population.

METHODS

Overall, 211 dried blood spots (DBS) were collected from native southern Indian individuals. HLA-DQ characterization and the determination of homozygous/heterozygous status were performed using commercially available HLA-DQ typing kits.

RESULTS

Of 211 collected DBS, 88 (42%, 95% CI: 36-48) were positive for HLA-DQ2 and/or HLA-DQ8 heterodimers. Overall, 40 (19%, 95% CI: 14-24) samples typed positive for HLA-DQ2 and 48 (23%, 95% CI: 18-28) typed positive for HLA-DQ8 genotypes. Of 40 HLA-DQ2-positive individuals, only one subject tested homozygous for the DQB1*02 allele.

CONCLUSIONS

In the southern Indian native general population, the prevalence of HLA-DQ8 is higher in comparison to HLA-DQ2 prevalence. This finding could be related to the delayed introduction of wheat in the diet of the southern Indian population.

Role of HLA-DQB1 alleles in the risk, signs and symptoms, and severity of celiac disease in a Venezuelan population

INTRODUCTION AND AIMS

Celiac disease (CD) is a complex condition, whose main genetic determinant involves HLA molecules, specifically the HLA-DQ2 and/or HLA-DQ8 heterodimers. Nevertheless, the frequency of the alleles encoding those molecules has not been reported in Venezuelan celiac patients. Therefore, the aim of our study was to evaluate the frequency of the HLA-DQB1 alleles in individuals with symptoms suggestive of CD and define the diagnostic markers of the condition in a Venezuelan population.

MATERIAL AND METHODS

A cross-sectional study included 516 individuals with symptoms suggestive of CD. Molecular typing of the HLA-DQB1 locus was performed using a polymerase chain reaction-sequence-specific oligonucleotide procedure (PCR-SSO).

RESULTS

A total of 58.3% of the individuals with clinical manifestations consistent with CD presented with at least one risk allele (DQB1*0201 and/or DQB1*0302), and the diagnosis was confirmed in 40 of them. The patients with CD had a higher frequency of the DQB1*0201 risk allele (26.25%), followed by the DQB1*0302 (17.5%) allele. There was an association between the presence of risk alleles and the presence of lesions characteristic of CD (P = 0.001), and a correlation was found between the genetic predisposition to develop CD and the presence of anti-tissue transglutaminase antibodies (P = 0.0127).

CONCLUSIONS

The results support the role of the DQB1*02 and DQB1*0302 alleles in CD susceptibility and the histologic alterations of the intestinal mucosa, in a Venezuelan population.

Changes in Age at Diagnosis and Nutritional Course of Celiac Disease in the Last Two Decades

The frequency of celiac disease (CD) has increased along time, with relevant changes reported in geographical variations, clinical presentation and nutritional repercussions. In recent years, some celiac patients are presenting overweight/obesity, but it is unclear how frequent this is and to what extent undernutrition remains a concern. This is relevant because CD tends to be overlooked in overweight patients. With this in mind, we assessed age at diagnosis, clinical characteristics and nutritional status of 155 celiac patients diagnosed between 1994–2017 in four pediatric hospitals in Santiago, Chile. Since 2003, the number of patients diagnosed has increased (p < 0.0033), coinciding with antitransglutaminase and antiendomysial antibodies becoming available to public health systems. In 2000, 4.5% of patients were asymptomatic at diagnosis, suggesting that active search is not routinely applied. Gastrointestinal symptoms plus failure to thrive were significantly more frequent under 2 years (p = 0.0001). Nutritional status has improved at diagnosis and during follow up, but undernutrition remains more frequent in children <2 and <5 years (p < 0.002 and p < 0.0036, respectively). Overweight at diagnosis was reported in 2002 and obesity in 2010. After initiating treatment, since 2010, patients changing from undernourishment to overweight has sometimes been observed after only 6 months on a gluten-free diet.

Relevance of HLA-DQB1*02 Allele in the Genetic Predisposition of Children with Celiac Disease: Additional Cues from a Meta-Analysis

Background and Objectives: Celiac disease (CD) is a multifactorial immune-mediated disorder, triggered by the ingestion of gluten in genetically-predisposed subjects carrying MHC-DQ2 and -DQ8 heterodimers, which are encoded by four HLA-DQ allelic variants, overall. This meta-analysis aims at providing further epidemiological support to the predominant relevance of one specific allele, namely HLA-DQB1*02, in the predisposition and genetic risk of CD. Materials and Methods: We performed a search of MEDLINE/PubMed, Embase, Web of Science, and Scopus, retrieving all publications (case-control study, cross-sectional, and retrospective cohort study) on the association between HLA class II polymorphisms and first-degree relatives (FDRs) of children with CD. After a critical reading of the articles, two investigators independently performed data extraction according to the following inclusion criteria: HLA class II genes, any DQ and DR molecules, and CD diagnosed following the current clinical guidelines. A third participant was consulted for discussion to reach an agreement concerning discrepancies. Results: Our search strategy selected 14 studies as being eligible for inclusion, and those were submitted for data extraction and analysis. These studies were published between 1999 and 2016 and, collectively, enrolled 3063 FDRs. Positive and negative likelihood ratios (LR+ and LR-, respectively) for CD diagnosis, according to the presence of the HLA-DQ genotype coding a complete MHC-DQ2 and/or MHC-DQ8 molecules, were 1.449 (CI 1.279-1.642) and 0.187 (CI 0.096-0.362), respectively. If only the isolated presence of HLA-DQB1*02 allele is considered, the pooled estimation of LR+ was 1.659 (CI 1.302-2.155) and, importantly, the LR- still showed a very good discriminatory power of 0.195 (CI 0.068-0.558). Conclusions: Through our differential meta-analysis, comparing the presence of the genotype coding the full MHC-DQ2 and/or DQ8 molecules with the isolated presence of HLA-DQB1*02 allelic variant, we found that the LR- of the latter analysis maintained the same value. This observation, along with previous evidences, might be useful to consider potential cost-effective widened screening strategies for CD in children.

Is celiac disease better identified through HLA-DQ8 than through HLA-DQ2 in Mexican subjects?

INTRODUCTION AND AIMS

A strong genetic association between celiac disease (CD) and the human leukocyte antigen (HLA) has been widely demonstrated. In Europe, the HLA-DQ2 allele is predominant. However, studies in Latin America indicate that HLA-DQ8 could be more frequent. In Mexico, the frequency of those alleles has not been reported in subjects with CD. Therefore, the aim of the present study was to evaluate the distribution of HLA-DQ2 and HLA-DQ8 in Mexican individuals with CD.

MATERIAL AND METHODS

An exploratory study was conducted on a cohort of 49 subjects with chronic diarrhea. Autoantibodies for CD, duodenal atrophy, and HLA haplotypes were determined.

RESULTS

Thirty individuals had CD (23 women, mean age 54.2 ± 15.5 years), 24 (80%) of whom expressed HLA-DQ8, 15 (50%) expressed HLA-DQ2, and 11 (37%) presented with both alleles. However, neither the HLA-DQ2 nor the HLA-DQ8 allele was found in 5 (10%) individuals. In subjects with chronic diarrhea that did not have CD, 12 (63%) presented with HLA-DQ2, and 7 (37%) with HLA-DQ8. Individuals with CD expressed the combinations of the HLA-DQ8/DQ2 alleles (37 vs. 5%) and the HLA-DR4/DQ8 alleles (60 vs. 26%) more frequently than the subjects without CD.

CONCLUSIONS

In Mexican subjects with CD, HLA-DQ8 distribution was more frequent than that of HLA-DQ2, indicating a possible similarity to the frequency reported in other Latin American countries. However, given the nature of the present study and its sample size, further conclusions could not be reached.

Understanding Celiac Disease From Genetics to the Future Diagnostic Strategies

Celiac disease (CD) is an autoimmune disorder characterized by the permanent inflammation of the small bowel, triggered by the ingestion of gluten. It is associated with a number of symptoms, the most common being gastrointestinal. The prevalence of this illness worldwide is 1%. One of the main problems of CD is its difficulty to be diagnosed due to the various presentations of the disease. Besides, in many cases, CD is asymptomatic. Celiac disease is a multifactorial disease, HLA-DQ2 and HLA-DQ8 haplotypes are predisposition factors. Nowadays, molecular markers are being studied as diagnostic tools. In this review, we explore CD from its basic concept, manifestations, types, current and future methods of diagnosis, and associated disorders. Before addressing the therapeutic approaches, we also provide a brief overview of CD genetics and treatment.

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

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

Prevalence of celiac disease in latin america: a systematic review and meta-regression

BACKGROUND

Celiac disease (CD) is an immune-mediated enteropathy triggered by the ingestion of gluten in susceptible individuals, and its prevalence varies depending on the studied population. Given that information on CD in Latin America is scarce, we aimed to investigate the prevalence of CD in this region of the world through a systematic review and meta-analysis.

METHODS AND FINDINGS

This was a two-phase study. First, a cross-sectional analysis from 981 individuals of the Colombian population was made. Second, a systematic review and meta-regression analysis were performed following the Preferred Reporting Items for Systematic Meta- Analyses (PRISMA) guidelines. Our results disclosed a lack of celiac autoimmunity in the studied Colombian population (i.e., anti-tissue transglutaminase (tTG) and IgA anti-endomysium (EMA)). In the systematic review, 72 studies were considered. The estimated prevalence of CD in Latin Americans ranged between 0.46% and 0.64%. The prevalence of CD in first-degree relatives of CD probands was 5.5%. The coexistence of CD and type 1 diabetes mellitus varied from 4.6% to 8.7%, depending on the diagnosis methods (i.e., autoantibodies and/or biopsies).

CONCLUSIONS

Although CD seems to be a rare condition in Colombians; the general prevalence of the disease in Latin Americans seemingly corresponds to a similar scenario observed in Europeans.

[Celiac disease in children from the northwest of Mexico: clinical characteristics of 24 cases]

BACKGROUND

Celiac disease (CD) is an autoimmune enteropathy induced by dietary wheat gluten that can have serious consequences if not diagnosed and treated early. It is important to be familiar with other alterations associated with gluten ingestion due to the multiplicity of clinical presentations.

OBJECTIVES

To describe the most common CD presentation patterns and alterations associated with gluten in children from the northwest region of Mexico, with an incipient knowledge of its prevalence.

PATIENTS AND METHODS

Age, sex, family history, and gastrointestinal and extraintestinal symptoms were recorded in 24 patients within the time frame of 2006 to 2010. Biochemical and hematologic data were collected. Anti-gliadin and anti-transglutaminase antibodies were analyzed in all the cases, and haplotypes (HLA-DQ2/DQ8) and duodenal biopsy were evaluated in some of the cases.

RESULTS

Of the 24 patients (14 girls and 10 boys), 13 presented with typical CD with symptoms of poor gastrointestinal absorption; 7 patients with a mean age of 5 years presented with atypical CD; 2 had disease onset with gastrointestinal and extraintestinal (neurologic) problems; and 2 with other gluten-related disorders. All of the patients had positive serology; 11/15 presented with HLA-DQ2/DQ8 and 4 with at least one allele; damaged mucosa was observed in the 6 biopsies taken. A third of the patients were anemic, 6 presented with an albumin value of<3.5g/dL, and 4 with mineral deficiencies. A total of 83% of the patients improved with a gluten-free diet.

CONCLUSIONS

The presentation patterns were: 1) typical CD, 2) atypical CD, 3) CD with gastrointestinal and extraintestinal (neurologic) symptoms, and 4) gluten-related disorders other than 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.

Celiac disease in native Indians from Brazil: A clinical and epidemiological survey

Background:

Celiac disease has been described in populations from around the world, with recent data emphasizing the occurrence of the disease in ethnic minorities. There are only a few studies evaluating celiac disease in native Indians.

Aims:

This study aimed to screen the anti-endomysial antibody (IgA-EmA) in Kaingang and Guarani Indians from southern Brazil, in order to establish a clinical serological evaluation of celiac disease in these individuals.

Material and Methods:

Serum samples from 321 individuals (125 male and 196 female; 4-86 years old) from Mangueirinha Indigenous Reserve, State of Parana, Brazil, and 180 non-Indigenous healthy individuals (62 male and 118 female; 2-81 years old) were analysed to the presence of anti-endomysial antibody class IgA by indirect immunofluorescence assay. Amongst the Indians, 158 were Kaingang, 98 Guarani and 65 of mixed race. Indians presenting complaints of diarrhea (N=12) were also evaluated to the IgG class of anti-endomisyal antibody.

Results:

None of the individuals showed positive results either to IgA or IgG anti-endomysial antibodies.

Conclusions:

Although the results indicate an absence of celiac disease in Kaingang and Guarani Indians, the authors call attention to the importance of following up indigenous children or adults presenting gastrointestinal complaints or other symptoms related to the disease. Consideration should be given to the genetic background of these individuals, allied to the inter ethnic marriages and the changing habits or occupational activities, that have gradually introduced diseases previously not described in indigenous populations.

Sex and racial disparities in duodenal biopsy to evaluate for celiac disease

BACKGROUND

Celiac disease (CD) is common but underdiagnosed in the United States. Serological screening studies indicate that, although CD occurs at the same frequency in both sexes, women are diagnosed more frequently than men (2:1). CD is less frequently diagnosed among black patients, though the seroprevalence in this group is not known.

OBJECTIVE

To measure the rates of duodenal biopsy during EGD for symptoms consistent with CD.

DESIGN

Retrospective cohort study.

SETTING

Clinical Outcomes Research Initiative National Endoscopy Database, spanning the years 2004 through 2009.

PATIENTS

Adults undergoing EGD for the indication of diarrhea, anemia, iron deficiency, or weight loss, in which the endoscopic appearance of the upper GI tract was normal.

MAIN OUTCOME MEASUREMENT

Performance of duodenal biopsy.

RESULTS

Of 13,091 individuals (58% female patients, 9% black patients) who met the inclusion criteria, duodenal biopsy was performed in 43%, 45% of female patients and 39% of male patients (P < .0001). Black patients underwent duodenal biopsy in 28% of EGDs performed compared with 44% for white patients (P < .0001). On multivariate analysis, male sex (odds ratio [OR] 0.81; 95% CI, 0.75-0.88), older age (OR for 70 years and older compared with 20-49 years, 0.51; 95% CI, 0.46-0.57), and black patients (OR 0.55; 95% CI, 0.48-0.64) were associated with decreased odds of duodenal biopsy.

LIMITATIONS

Lack of histopathologic correlation with CD prevalence.

CONCLUSIONS

In this multiregional endoscopy database spanning the period from 2004 through 2009, rates of duodenal biopsy increased modestly over time, but overall remained low in patients with possible clinical indications for biopsy. Nonperformance of duodenal biopsy during endoscopy may be contributing to the underdiagnosis of CD in the United States.

Celiac disease in the developing world

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

Epidemiology and clinical presentations of celiac disease

Evidence of the prevalence of celiac disease comes from serological screening studies. These have revealed that celiac disease is common, occurring in about 1 % of the population worldwide. There are some countries with higher prevalence rates such as Finland and others with lower rates, for example Germany. The disease is found in most continents and appears to be increasing. Most people with the disease are not currently diagnosed though women are diagnosed more frequently than men. The mode of presentation has changed both in children and adults with diarrhea and a malabsorption syndrome becoming less common. Abdominal pain and growth issues are major modes of presentation in children, while anemia, osteoporosis, and recognition at endoscopy performed for GERD are seen as modes of presentation in adults. Screening of at risk groups is a major mode of presentation for both adults and children.

Increasing incidence of enteropathy-associated T-cell lymphoma in the United States, 1973-2008

BACKGROUND

Enteropathy-associated T-cell lymphoma (EATL) is a rare lymphoma subtype that is strongly associated with celiac disease (CD), an autoimmune disease triggered by the ingestion of gluten. Because CD rates are increasing in the United States, the authors sought to determine whether the incidence rates of EATL also are increasing.

METHODS

The authors identified patients with primary, pathologically confirmed lymphoma in the Surveillance, Epidemiology, and End Results database registries from 1973 to 2008. To ensure capture of all cases of EATL, the following lymphoma subtypes, limited to the small bowel, were included: non-Hodgkin lymphoma not otherwise specified (NOS) T-cell, peripheral T-cell lymphoma NOS, and enteropathy type T-cell lymphoma, and their age-adjusted and sex-adjusted incidence rates were calculated over time. Survival was estimated using Kaplan-Meier curves.

RESULTS

In total, the authors identified 161 small bowel lymphomas that were diagnosed between 1973 and 2008. The overall age-adjusted and sex-adjusted annual incidence for all bowel lymphomas was 0.016 per 100,000 population, which increased over the study period from 0.006 to 0.024 per 100,000 population. These tumors were most common in men (age-adjusted incidence rate, 0.021 per 100,000) with the highest incidence rate in Hispanics (age-adjusted incidence rate, 0.033 per 100,000). The median overall survival was 7 months. There was no difference in survival by race/ethnicity (P = .09) or sex (P = .06).

CONCLUSIONS

The current results indicated a significant increase in the incidence of EATL in the United States, which may reflect the increasing seroprevalence of CD and better recognition of rare types of T-cell lymphomas. The incidence may continue to rise given the large ratio of undiagnosed-to-diagnosed individuals with CD in the United States.

Amerindian mtDNA haplogroups and celiac disease risk HLA haplotypes in mixed-blood Latin American patients

BACKGROUND AND OBJECTIVE

Risk haplotypes have been described in celiac disease (CD), but the influence of native genes on CD in Hispanic Americans is unknown. The aim of the study was to measure the frequency of Amerindian mitochondrial DNA (mtDNA) haplogroups (inherited by the maternal line) in mixed-blood patients with CD from Chile, Argentina, and Uruguay, and to assess the relation between these and human leukocyte antigen (HLA) alleles and haplotypes and clinical presentations.

PATIENTS AND METHODS

Clinical history, histological data, and genetic studies were conducted following 2 protocols: a case-control study of 72 Chilean patients with CD and controls, and an assessment of 43 (additional) samples of celiac patients from Chile, 96 from Argentina, and 57 from Uruguay, compared with the mtDNA frequency in the corresponding country. HLA typing was performed by a commercial kit, and mtDNA was determined by means of polymerase chain reaction and restriction fragment length polymorphisms analysis.

RESULTS

A total of 73.6% of cases had typical presentations. The most frequent HLA alleles were HLA-DQB*201 and 202. No-DQ2/DQ8 HLA haplotypes were found in 7% of cases. mtDNA frequencies for typical Amerindian haplogroups were found in 71% of cases and 64% of controls (P χ2 = 0.016); in the comparative analysis, mtDNA distribution was not different from the figures reported for the respective general country population. No relation was found between haplotypes or haplogroups and clinical presentations.

CONCLUSIONS

mtDNA haplogroups A/B/C/D were frequently found in celiac patients and controls, but no relations appeared between haplogroups, haplotypes, and clinical presentations.

Frequency distribution of HLA DQ2 and DQ8 in celiac patients and first-degree relatives in Recife, northeastern Brazil

AIMS

The aim of this study was to evaluate the frequencies of the HLA genotypes DQ2 and DQ8 and the alleles A1*05, A1*0201, B1*0201 and B1*0302 in individuals with celiac disease in Recife, northeastern Brazil.

METHODS

HLA DQ2 and DQ8 genotyping was performed for 73 individuals with celiac disease and 126 first-degree relatives with negative transglutaminase serology. The alleles DQA1*05, DQA1*0201, DQB1*02 and DQB1*0302 were identified by sequencing using specific primers and the EU-DQ kit from the Eurospital Laboratory, Trieste, Italy and double-checked by the All Set SPP kit (Dynal).

RESULTS

Among the 73 cases, 50 (68.5%) had the genotype DQ2, 13 (17.8%) had DQ8, 5 (6.8%) had DQ2 and DQ8, and 5 did not have any of these genotypes. Among the 5 negative individuals, four had the B1*02 allele and one did not have any of the alleles studied. B1*02 was the most frequent allele in both groups (94% in the patients and 89% in the control relatives).

CONCLUSIONS

In this study, celiac disease was associated with the genotypes DQ2 and DQ8. DQ2 predominated, but the distribution of the frequencies was different from what has been found in European populations and was closer to what has been found in the Americas. The high frequencies of the HLA genotypes DQ2 and DQ8 that were found in first-degree relatives would make it difficult to use these HLA genotypes for routine diagnosis of celiac disease in this group.

Functional polymorphisms of DEFB1 gene in type 1 diabetes Brazilian children

We analyzed three functional 5' un-translated region beta-defensin 1 (DEFB1) single nucleotide polymorphism (SNPs) in a group of 170 type 1 diabetes (T1D) patients. In order to evaluate the SNPs influence on the disease onset and the development of other autoimmune disorder, such as celiac disease (CD) and autoimmune thyroid disease (AITD), patients were stratified according to the presence of AITD, CD, and both AITD and CD. As control group, we studied 191 healthy children and adolescent not presenting a familiar historic of T1D, CD or AITD. DEFB1 SNPs were in Hardy-Weinberg equilibrium both in healthy controls and T1D patients, as well in the T1D patients stratified according to the presence of other autoimmune disorder(s). Allele, genotype, and haplotype frequencies of T1D patients globally considered were comparable to healthy controls ones. No evidence of any association of DEFB1 SNPs with the onset of AIDT, CD, and both AITD and CD on T1D patients was evidenced. Only a minor trend was found for an increased frequency of the - 20 G allele in T1D patients only presenting AITD vs. T1D patients not presenting AITD or CD, as well as an increase of those haplotypes comprising the - 20 G allele when compared with the GCA haplotype. We also evaluated the influence of functional DEFB1 SNPs on the age of T1D onset: no significant statistical conclusion was achieved. Further studies are envisaged, in order to elucidate the possible role of functional DEFB1 polymorphisms in the onset of TD1 and other autoimmune-related disorders.

Celiac disease in the developing countries: A new and challenging public health problem

In the past, celiac disease was believed to be a chronic enteropathy, almost exclusively affecting people of European origin. The availability of new, simple, very sensitive and specific serological tests (anti-gliadin, anti-endomysium and anti-transglutaminase antibody assays) have shown that celiac disease is common not only in Europe and in people of European ancestry but also in the developing countries where the major staple diet is wheat (Southern Asia, the Middle East, North West and East Africa, South America), both in the general population and in the groups at risk. Gluten intolerance thus appears to be a widespread public health problem and an increased level of awareness and clinical suspicion are needed in the New World where physicians must learn to recognize the variable clinical presentations (classical, atypical and silent forms) of celiac disease. In the developing countries, both serological screening in the general population and serological testing in groups at risk are necessary for an early identification of celiac patients. The gluten-free diet poses a challenging public health problem in the developing countries, especially since commercial gluten-free products are not available.

The many faces of celiac disease: clinical presentation of celiac disease in the adult population

The major modes of presentation of patients with celiac disease are the classic diarrhea-predominant form and silent celiac disease. Those with silent celiac disease lack diarrhea, although they may present with manifestations of celiac disease that include an irritable bowel syndrome, anemia, osteoporosis, neurologic diseases, or malignancy. A significant proportion of patients are diagnosed through screening at-risk groups including relatives of patients and insulin-dependant diabetics. Nondiarrheal presentations now are seen more commonly than those with diarrhea. Patients with celiac disease have a greater burden of disease than the general population because of autoimmune diseases and malignancies. There is a need for screening studies of patients with conditions associated with celiac disease to determine whether the large numbers of people with undiagnosed celiac disease currently are seeking health care.

Epidemiological and clinical features in immigrant children with coeliac disease: an Italian multicentre study

BACKGROUND

There are no available data concerning the incidence and the clinical pattern of coeliac disease in immigrant children coming to Italy from developing countries.

AIMS

To evaluate the epidemiological and clinical features of coeliac immigrant children coming to Italy.

PATIENTS AND METHODS

Hospital records of 1917 children diagnosed in 22 Italian Centres from 1999 to 2001 as having coeliac disease were retrospectively reviewed, comparing immigrant patients versus Italian ones.

RESULTS

36/1917 (1.9%) coeliac children were immigrant. This prevalence was similar to that of the immigrant children among the whole paediatric population living in Italy. Prevalence was influenced by geographical factors, being higher in Northern Italy (1.7%) and in Central Italy (2.5%) than in Southern-Insular Italy (1.5%), as consequence of a higher proportion of immigrants in these regions. The native areas of the immigrant children were East Europe (15/36), Northern Africa (14/36), Southern Asia (4/36), West Africa (1/36), East Africa (1/36) and the Middle East (1/36). The clinical spectrum and dietary habits in immigrant patients were similar to those of the Italian children.

CONCLUSIONS

Coeliac disease among the immigrant children coming from developing countries is an emerging problem, and physicians need to be fully aware of it. An important risk factor for coeliac disease in immigrant children appears to be sharing of the same dietary habits with the Italian population. The finding of coeliac disease in children coming from many countries worldwide suggests that coeliac disease is a global public health problem.

The global village of celiac disease

In the last years our knowledge on epidemiology of celiac disease has increased: there is a wide spectrum of its clinical presentation (classical, atypical, silent and latent forms of celiac disease), and of its pathological mucosal intestinal features, which range from early and mild pictures to severe villous atrophy (Marsh stages). In addition, a strong genetic component, associated with the susceptibility to the disease (HLA and non HLA genes), has been found. This knowledge, together with the availability of new high sensitive and specific serological tests (antigliadin, antiendomysium and antitransglutaminase antibodies), has led us to the realization that celiac disease is the most common food intolerance in the world, involving genetically predisposed individuals consuming gluten-containing cereals in their diet. So, today it is well known that celiac disease is a common disorder not only in Europe but also in populations of European ancestry (North and South Americas, Australia), in North Africa, in the Middle East and in South Asia, where until a few years ago it was historically considered extremely rare. Therefore, celiac disease is spread worldwide as in a common "Global Village", and greater levels of awareness and attention on gluten intolerance are needed, both in the Old and in the New World.

A prospective study of the incidence of childhood celiac disease

OBJECTIVES

To estimate the frequency of celiac disease (CD) in children in the general population of Denver, Colorado.

STUDY DESIGN

From 22,346 newborns characterized as expressing 0, 1, or 2 HLA-DR3(DQB1*0201) alleles, 987 were selected for a prospective stratified cohort study. Participants were followed for as long as 7 years with serial testing for serum IgA anti-transglutaminase antibodies and for evidence of CD (intestinal mucosal changes or persistent seropositivity).

RESULTS

Of 40 children with at least one positive serologic test, 19 had evidence of CD (10 by biopsy, 9 by persistent seropositivity). Those expressing 0, 1, or 2 HLA-DR3 alleles had, respectively, 0.3% (95% CI, 0.0-2.7), 3.4% (3.0-11.7), and 3.2% (1.0-11.0) risk for evidence of CD by age 5 years. The adjusted risk estimate for evidence of CD by age 5 years for the Denver general population was 0.9% (0.4-2.0), or 1 in 104 (1:49-221). After adjusting for number of HLA-DR3 alleles expressed, risk was higher in females: RR=3.34 (1.00-10.9, P=.048). Evidence of CD was not observed before age 2.6 years.

CONCLUSIONS

Celiac disease may affect 0.9% of Denver children by 5 years of age. Children positive for the HLA-DR3 allele and females appear to be at increased risk.

HLA-DQ determines the response to exogenous wheat proteins: a model of gluten sensitivity in transgenic knockout mice

We have investigated the genetic basis of the immune response to dietary gluten in HCD4/DQ8 and HCD4/DQ6 double transgenic mice. Mice were immunized with gluten i.p. or individual peptides s.c. and spleen or draining lymph node T cells were challenged in vitro. Strong proliferative responses to gluten were seen in the HCD4/DQ8 mice, whereas the HCD4/DQ6 mice responded to gluten poorly. A series of overlapping peptides spanning gliadin were synthesized. The HCD4/DQ8 mice reacted to many of the individual peptides of gliadin, while the HCD4/DQ6 mice were relatively unresponsive. T cells isolated from HCD4/DQ8 mice also responded well to modified (deamidated) versions of the gliadin peptides, whereas HCD4DQ6 mice did not. The T cell response to gluten was CD4 dependent and DQ restricted and led to the production of cytokines IL-6, TGF-beta, and IL-10. Finally, intestinal lymphocytes isolated from gluten-fed HCD4/DQ8 mice displayed an activated phenotype. These data suggest that this HLA class II transgenic murine model of gluten sensitivity may provide insight into the initiation of the MHC class II-restricted gluten sensitivity in celiac disease.