The prevalence of coeliac disease-associated human leukocyte antigens in South African transplant donors and recipients.

BACKGROUND: Coeliac disease (CD) is an autoimmune condition occurring in genetically predisposed individuals exposed to an environmental trigger. The human leukocyte antigen (HLA) haplotypes HLA-DQ2.5 and HLA-DQ8 have the strongest association with CD, and 90 - 95% of CD patients bear these haplotypes. The susceptibility of the South African (SA) population to CD has not been studied previously. OBJECTIVES: To describe the genetic propensity of the SA population to CD. METHODS: The South African National Blood Service database was used to analyse the prevalence of HLA-DQ2.5 and HLA-DQ8 in potential donors and recipients of organ transplants. Self-reported ethnic group was used to estimate the prevalence among different population groups. RESULTS: The overall prevalence of HLA-DQ2.5 and HLA-DQ8 was 19.8%. The prevalence was lower in black participants (15.9%) than in whites (28.6%). Coloured (22.0%) and Indian (17.4%) participants had an intermediate prevalence. There was no significant difference between potential transplant donors and recipients. CONCLUSIONS: The prevalence of HLA-DQ2.5 and HLA-DQ8 differed among SA study participants of different ethnicities. However, the notion that CD does not occur in black South Africans owing to lack of a genetic predisposition is incorrect.

TagSNP approach for HLA risk allele genotyping of Saudi celiac disease patients: effectiveness and pitfalls.

BACKGROUND: Celiac disease (CD) is a genetically complex autoimmune disease which is triggered by dietary gluten. Human leukocyte antigen (HLA) class II genes are known to act as high-risk markers for CD, where >95% of CD patients carry (HLA), DQ2 and/or DQ8 alleles. Therefore, the present study was conducted to investigate the distribution of HLA haplotypes among Saudi CD patients and healthy controls by using the tag single nucleotide polymorphisms (SNP). METHODS: HLA-tag SNPs showing strong linkage value (r2>0.99) were used to predict the HLA DQ2 and DQ8 genotypes in 101 Saudi CD patients and in 103 healthy controls by using real-time polymerase chain reaction technique. Genotype calls were further validated by Sanger sequencing method. RESULTS: A total of 63.7% of CD cases and of 60.2% of controls were predicted to carry HLA-DQ2 and DQ8 heterodimers, either in the homozygous or heterozygous states. The prevalence of DQ8 in our CD patients was predicted to be higher than the patients from other ethnic populations (35.6%). More than 32% of the CD patients were found to be non-carriers of HLA risk haplotypes as predicted by the tag SNPs. CONCLUSION: The present study highlights that the Caucasian specific HLA-tag SNPs would be of limited value to accurately predict CD specific HLA haplotypes in Saudi population, when compared with the Caucasian groups. Prediction of risk haplotypes by tag SNPs in ethnic groups is a good alternate approach as long as the tag SNPs were identified from the local population genetic variant databases.

Celiac Disease: Fallacies and Facts.

Our understanding of the pathophysiology of celiac disease has progressed greatly over the past 25 years; however, some fallacies about the clinical characteristics and management persist. Worldwide epidemiologic data are now available showing that celiac disease is ubiquitous. An elevated body mass index is common at the time of the diagnosis. The gluten-free diet (GFD) is an imperfect treatment for celiac disease; not all individuals show a response. This diet is widely used by people without celiac disease, and symptomatic improvement on a GFD is not sufficient for diagnosis. Finally, the GFD is burdensome, difficult to achieve, and thus has an incomplete efficacy, opening exciting opportunities for novel, nondietary treatments.

Prevalence of coeliac disease in Northwest China: heterogeneity across Northern Silk road ethnic populations.

BACKGROUND: Epidemiological data of coeliac disease are lacking from the central Asian region. AIMS: To verify the occurrence of coeliac disease amongst four major ethnic groups of Xinjiang Uyghur Autonomus Region, China. METHODS: 2277 in-patients with gastrointestinal symptoms (1391 Han, 608 Uyghur, 146 Kazakh and 132 Hui; mean age: 54 ± 12.8 years) were included. Total IgA, anti-deamidated gliadin peptide (DGP)-IgG, and anti-tissue transglutaminase (anti-tTG)-IgA were analysed. All antibody-positive subjects were further tested for endomysial (EMA) antibodies and were HLA genotyped. All subjects with antibody positivity were asked to undergo intestinal biopsy. In addition, a subset of antibody-negative subjects were tested for HLA-DQA1and DQB1. RESULTS: Among the 2277 subjects, 29 subjects were defined as coeliac disease autoimmune (positive results for anti-tTG IgA and EMA-IgA) (1.27%; 95% confidence interval, 0.81%-1.73%), eight of them underwent biopsy and all showed coeliac disease histology (0.35%; 95% Cl, 0.11%-0.59%). The frequency of coeliac disease autoimmunity was lowest among the Han (0.79%), followed by the Uyghur (1.81%), the Kazakh (2.05%) and the Hui (3.03%). The frequency of the HLA-DQ2 and/or DQ8 haplotype was highest in the Uyghur (52.1%), followed by the Hui (44.4%), the Kazakh (40.0%) and the Han (39.4%). Besides, a three times higher frequency of coeliac disease autoimmunity was found among rural living subjects with significantly higher wheat consumption compared to urban living subjects (3.16% vs 0.97%, P < 0.01). CONCLUSIONS: In Xinjiang, coeliac disease does occur, especially in the rural area. The HLA haplotype and environment play key roles in the development of coeliac disease.

Celiac Disease in Kosovar Albanian Children: Evaluation of Clinical Features and Diagnosis.

BACKGROUND: Celiac disease is an immune-mediated disorder characterized by variable clinical manifestations, specific antibodies, HLA-DQ2/DQ8 haplotypes, and enteropathy. OBJECTIVES: The aim of this study was to present the clinical spectrum and patterns of celiac disease in Kosovar Albanian children. METHODS: A cross-sectional retrospective study was performed with Albanian children aged 0-18 years, treated for celiac disease in the Pediatric Clinic, University Clinical Center of Kosovo from 2005 to 2016. RESULTS: During the study period, 63 children were treated for celiac disease. The mean age at diagnosis was 5.5 years (SD ± 3.31). The mean age at celiac disease onset was 3.3 years (SD ± 2.02), while the mean delay from the first symptoms indicative of celiac disease to diagnosis was 2.2 years (SD ± 2.09). More than 70% of the patients were diagnosed in the first 7 years of life, mainly presented with gastrointestinal symptoms, while primary school children and adolescents mostly showed atypical symptoms (p<0.001). The classical form of celiac disease occurred in 78% of the cases. Sixty (95%) patients carried HLA-DQ2.5, DQ2.2 and/or HLA-DQ8 heterodimers, and only three of them tested negative. CONCLUSION: Kosovo, as the majority of developing countries, is still facing the classical form of celiac disease as the dominant mode of presentation; as a result, most children with other forms of the celiac disease remain undiagnosed. Physicians should be aware of the wide range of clinical presentations and utilize low testing thresholds in order to prevent potential long-term problems associated with untreated celiac disease.

Association study identified biologically relevant receptor genes with synergistic functions in celiac disease.

Receptors are essential mediators of cellular physiology, which facilitate molecular and cellular cross-talk with the environment. Nearly 20% of the all known celiac disease (CD) genes are receptors by function. We hypothesized that novel biologically relevant susceptibility receptor genes act in synergy in CD pathogenesis. We attempted to identify novel receptor genes in CD by re-analyzing published Illumina Immunochip dense genotype data for a north Indian and  a European (Dutch) cohort. North Indian dataset was screened for 269 known receptor genes. Association statistics for SNPs were considered with minor allele frequency >15% and association P ≤ 0.005 to attend desired study power. Identified markers were tested for cross-ethnic replication in a European CD dataset. Markers were analyzed in-silico to explain their functional significance in CD. Six novel SNPs from MOG (rs29231, p = 1.21e-11), GABBR1 (rs3025643, p = 1.60e-7), OR2H2 (rs1233388, p = 0.0002), ABCF1 (rs9262119, p = 0.0005), ADRA1A (rs10102024, p = 0.003), and ACVR2A (rs7560426, p = 0.004) were identified in north Indians, of which three genes namely, GABBR1 (rs3025643, p = 5.38e-8), OR2H2 (rs1233388, p = 3.29e-5) and ABCF1 (rs9262119, p = 0.0002) were replicated in Dutch. Tissue specific functional annotation, potential epigenetic regulation, co-expression, protein-protein interaction and pathway enrichment analyses indicated differential expression and synergistic function of key genes that could alter cellular homeostasis, ubiquitination mediated phagosome pathway and cellular protein processing to contribute for CD. At present multiple therapeutic compounds/drugs are available targeting GABBR1 and ADRA1A, which could be tested for their effectiveness against CD in controlled drug trials.

Fibrillar-type dermatitis herpetiformis.

Dermatitis herpetiformis (DH) is a pruritic papulovesicular disease that is relatively common in Caucasian populations, and was first reported by Louis Duhring. It is characterized by granular IgA deposition in the dermal-epidermal junction and gluten-sensitive enteropathy (GSE) associated with human leukocyte antigen-DQ2/DQ8 haplotype. In contrast, DH is rare in Japan, and Japanese DH patients occasionally show unique features, including a high frequency of fibrillar IgA deposition in the papillary dermis, and rare occurrence of GSE. We refer to this condition in Japanese patients as "fibrillar-type DH", while the DH that is typically observed in the Caucasian population is referred to as "granular-type DH". In patients with typical fibrillar-type DH, IgA antibodies to epidermal transglutaminase are the only antibodies detected. In addition, Th2-type cytokines, such as interleukin (IL)-4, IL-5 and IL-13, may be important in the development of skin lesions in fibrillar-type DH (especially in the infiltration of tissue by eosinophils), as in granular-type DH. The pathogenesis of fibrillar-type DH may differ from that of granular-type DH, which is dependent on gluten and in which IgA antibodies to tissue transglutaminase (the main antigen in GSE) are detected. We herein review the clinical, histological, and immunological findings of fibrillar-type DH.

Diet patterns in an ethnically diverse pediatric population with celiac disease and chronic gastrointestinal complaints.

INTRODUCTION: Celiac disease (CD) is an autoimmune disease requiring lifelong adherence to the gluten-free diet (GFD). The GFD has significant nutritional limitations which may result in poor diet quality (DQ). We hypothesized that biopsy-proven children with CD (CCD) would have dietary patterns characterized by high saturated fat/simple sugar intake with a low micronutrient density contributing to lower DQ when compared to children with mild-gastrointestinal complaints (GI-CON). In addition, we hypothesized that ethnicity may further impact DQ. METHODS: Socio-demographic (age, CD duration, parent/child ethnicity, education), household characteristics, anthropometric, dietary intake (24-h recalls), gastrointestinal pain and adherence was collected in CCD (n = 243) and GI-CON (n = 148). Dietary patterns were determined using k-mean Cluster Analysis. RESULTS: GI-CON had significantly lower DQ than CCD (p < 0.001). Most CCD and GI-CON (>80%) had dietary patterns characterized by1) Western Diet (Cluster 1: %BMR: 110-150, low DQ, high fat, moderate CHO, high sodium) and 2) High Fat-Western Diet (Cluster 2: %BMR:130-150, low DQ, high Fat, high processed meats, high fat dairy products, CHO. Fewer children (<20%) had Prudent, Lower Fat/High Carbohydrate dietary patterns (% BMR:100-150, higher DQ, lower fat/sodium, higher CHO) with a greater proportion of non-Caucasian CCD consuming a Prudent dietary pattern. Seventy-seven percent and 37.5% of CCD and GI-CON, respectively, did not meet estimated average requirements for folate (p < 0.001). CONCLUSIONS: CCD and GI-CON have predominantly Western dietary patterns with low DQ, particularly GI-CON. Non-caucasian CCD consume more prudent dietary patterns with higher DQ. Nutrition education is warranted to ensure optimal DQ in children with chronic gastrointestinal diseases.

Coeliac disease in Caucasian and South Asian patients in the North West of England.

BACKGROUND: Coeliac disease is an autoimmune enteropathy characterised by mucosal inflammation subsequent to gluten exposure, leading to malabsorption. Treatment is strict dietary control, relying on the patient's ability to maintain lifestyle modifications. The present study aimed to compare clinical presentation and adherence to a gluten-free diet between South Asian and Caucasian patients with coeliac disease in East Lancashire METHODS: In total, 33 South Asian and 113 Caucasian adult patients diagnosed with coeliac disease under the care of the Dietetics Department at East Lancashire Hospitals NHS Trust were selected using a convenience sampling method and then allocated to the South Asian or Caucasian group. A subjective assessment of dietetic notes from follow-up visits within 1 year of the first appointment was undertaken by two investigators who subsequently allocated the patients to one of the three categories: (i) fully-adherent; (ii) partly-adherent; and (iii) non-adherent. Presenting complaint, vitamin D, vitamin B12 , folate and ferritin levels were also compared. RESULTS: There was a significant difference in adherence to gluten-free diet between the groups, with a larger proportion of Caucasian patients being fully adherent to gluten-free diet compared to South Asian patients (64.6% versus 12.1%, P < 0.001). In addition, a significantly higher proportion of South Asian patients were vitamin D deficient compared with Caucasian patients (70.8% versus 32.8%, P = 0.002). CONCLUSIONS: The rates of strict adherence to gluten-free diet and vitamin D levels were significantly lower in South Asian patients with coeliac disease compared to the Caucasian coeliac population. Further studies are required to investigate the causes and improve adherence in the South Asian population.

Prevalence and characteristics of celiac disease in South African patients with type 1 diabetes mellitus: Results from the Durban Diabetes and Celiac Disease Study.

BACKGROUND AND AIM: The aim of this study was to assess the prevalence and characteristics of celiac disease (CD) in all patients with type 1 diabetes mellitus attending a tertiary adult diabetes clinic in Durban, South Africa. METHODS: This was a cross-sectional observational study that screened 202 patients; of these, 56.4% were African (Black), 31.7% Asian Indian, 4.5% White, and 7.4% mixed race. Demographic data, symptoms, and anthropometry were documented. Blood tests included anti-tissue transglutaminase antibody (tTG), anti-endomysial antibody (EMA), and anti-gliadin antibody (AGA). Endoscopy and duodenal biopsy were performed in patients with celiac antibodies. Diagnosis of CD was based on the modified Marsh classification. RESULTS: Mean age and mean duration of diabetes were 26.4 ± 11.4 and 10.7 ± 9.1 years, respectively. Celiac antibodies were found in 65 (32.2%) patients: EMA 7.4%, tTG immunoglobulin A (IgA) 8.4%, tTG immunoglobulin G 1.9%, AGA IgA 18.3%, and AGA immunoglobulin G 21.8%. Histological evidence of CD was found in 5.9% (n = 12/202): 2.5% were classed as definite CD (Marsh 3) and 3.4% as potential CD (Marsh 1). None of the patients with CD were symptomatic. The sensitivity of AGA IgA, EMA, and tTG IgA antibodies for detecting histologically proven CD was 66.7%, 50.0%, and 41.7%, respectively. CONCLUSION: The prevalence of CD was similar to reports from western countries. No ethnic specific differences were noted. CD was silent in all patients in this study. The sensitivity of EMA and tTG antibodies was poor and merits further evaluation as screening tools for CD in South African patients with type 1 diabetes mellitus.

Unexplained Infertility and Undiagnosed Celiac Disease: Study of a Multiethnic Canadian Population.

OBJECTIVE: The aims of this study were to examine the prevalence of Celiac disease (CD) in Canadian women with unexplained infertility versus women with an identifiable cause of infertility and to assess the sensitivity of the point-of-care Biocard Celiac Test Kit versus standard serum serologic testing. METHODS: In this prospective cohort study, women aged 18 to 44 who were evaluated for infertility between February 2010 and May 2012 at a tertiary academic care fertility clinic in Toronto, ON, were invited to participate. They were categorized as having unexplained infertility (Cases) or infertility secondary to a known cause (Controls). Women on a gluten-free diet or previously diagnosed with CD were excluded. Outcome measures were the Celiac Questionnaire, serum testing for tissue transglutaminase IgA antibody (anti-tTG IgA), serum IgA levels, and Biocard Celiac Test Kit. RESULTS: Of 685 women approached, 1.2% (4/326) with unexplained infertility and 1.1% (4/359) with an identifiable infertility cause were newly found to have CD. Biocard testing revealed the same results as standard serologic IgA and anti-tTG IgA testing. CONCLUSION: CD was not more common in women with unexplained infertility than those with an identifiable cause of infertility. These results do not support the routine screening of Canadian women with infertility for CD.

Ethnic differences in coeliac disease autoimmunity in childhood: the Generation R Study.

OBJECTIVE: The aim was to identify whether ethnic differences in coeliac disease autoimmunity (CDA) in children at 6 years of age exist, and when present, to evaluate how these differences may be explained by sociodemographic and environmental factors. DESIGN: This study was embedded within a multi-ethnic population-based prospective cohort study. SETTING AND PATIENTS: 4442 six-year-old children born between 2002 and 2006 were included. Information on ethnicity, environmental and lifestyle characteristics was assessed by questionnaires. Ethnicity was categorised into Western (Dutch, European, Indonesian, American, Oceanian) and non-Western (Turkish, Moroccan, Cape Verdean, Antillean, Surinamese). Serum transglutaminase type 2 antibody (TG2A) levels were measured with fluorescence enzyme immunoassay. Serum IgG levels against cytomegalovirus (CMV) were measured by ELISA. MAIN OUTCOME MEASURES: TG2A positivity was defined as TG2A ≥7 U/mL, strong TG2A positivity as TG2A ≥10 upper limit normal (70 U/mL). RESULTS: Of 4442 children, 60 (1.4%) children were TG2A positive, of whom 31 were strong positive. 66% of children were Western, 33% non-Western. Western ethnicity, high socioeconomic position and daycare attendance were positively associated with strong TG2A positivity (odds ratio (OR) 6.85 (1.62 to 28.8) p<0.01, OR 3.70 (1.40 to 9.82) p<0.01, OR 3.90 (1.38 to 11.0) p=0.01 resp.), whereas CMV seropositivity was inversely related to strong TG2A positivity (OR 0.32 (0.12 to 0.84) p=0.02). Together, these factors explained up to 47% (-67 to -17; p=0.02) of the ethnic differences in TG2A positivity between Western and non-Western children. CONCLUSIONS: Ethnic differences in children with CDA are present in childhood. Socioeconomic position, daycare attendance and CMV seropositivity partly explained these differences, which may serve as targets for prevention strategies for CDA.

Prevalence of Self-Reported Gluten Sensitivity and Adherence to a Gluten-Free Diet in Argentinian Adult Population.

BACKGROUND: Previous studies suggest that the prevalence of wheat/gluten sensitivity and adherence to a gluten-free diet (GFD) are high in Latin population despite a poor diagnosis of celiac disease. However, these prevalence rates still remain unknown in most Latin American countries. METHODS: A cross-sectional survey study was conducted in Santa Fe, Argentina. RESULTS: The estimated self-reported prevalence rates were (95% Confidence Interval [CI]): self-reported gluten sensitivity (SR-GS) 7.61% (6.2-9.2), SR-GS currently following a GFD 1.82% (1.2-2.7), celiac disease 0.58% (0.3-1.2), wheat allergy 0.33% (0.12-0.84), self-reported non-celiac gluten sensitivity (SR-NCGS) 6.28% (5.1-7.8), SR-NCGS currently following a GFD 0.91% (0.5-1.6), and adherence to a GFD 6.37% (5.1-7.9). SR-GS was more common in women (6.0%; p < 0.001) and associated with irritable bowel syndrome (p < 0.001). Among the GFD followers, 71.4% were doing it for reasons other than health-related benefits and 50.6% without medical/dietitian advice. In the non-SR-GS group, the main motivations for following a GFD were weight control and the perception that a GFD is healthier. CONCLUSION: In Argentina, gluten sensitivity is commonly reported and it seems that physicians/gastroenterologists are aware of celiac disease diagnosis. Trustable information about the benefits and potential consequences of following a GFD should be given to the general population.

[An analysis of clinical features of celiac disease patients in different ethnic].

OBJECTIVE: To summarize the clinical features of different racial patients with celiac disease (CD) and analyze the disease prevalence, diagnosis and treatment in Chinese population. METHODS: All the patients were diagnosed as CD and enrolled in Beijing United Family Hospital between January 2005 and July 2015.Clinical data including nationality, age, symptoms, endoscopic and pathological findings, outcome were collected and compared in patients from different countries. RESULTS: A total of 87 patients were enrolled including 63 Caucasians, 18 Asian patients and 6 Middle East patients.The peak age of disease onset was 40-60 years old.Patients with typical symptoms such as chronic diarrhea and weight loss only accounted for 20.7%(18/87) and 9.2%(8/87) respectively.Some patients presented with nonspecific symptoms such as abdominal pain and bloating [32.2%(28/87)], even constipation [5.7%(5/87)].13.8%(12/87) patients were previously diagnosed as irritable bowel syndrome.The incidence of abdominal pain, bloating, diarrhea and constipation between Asians and Caucasians had no statistical significance (P>0.05); but the proportions of weight loss, growth retardation, iron deficiency anemia and dermatitis herpetiformis in Asian group were significantly higher than that in Caucasian group (P<0.05). IgA type of anti-gliadin antibody (AGA), endomysium antibody (EMA) and tissue transglutaminase antibody (tTGA) were dominant autoimmune antibodies in patients with CD, which accounted for 58.6%(51/87), 44.8%(39/87) and 36.8%(32/87) respectively.The endoscopy showed that the lesion of CD was mainly located in small intestine, with reducing severity from the proximal to the distal small intestine.The lesions of duodenal bulb and descending duodenum appeared more significant in Asian group.Accordingly pathological intestinal atrophy and the degree of intraepithelial lymphocytosis were more severe in Asian patients.All 87 cases took the gluten-free diet (GFD). Eighty-one cases received serological follow up and 8 with endoscopic intestinal biopsy.The celiac disease antibodies in 47 patients turned negative from 6-9 months after GFD treatment, while 34 patients turned negative from 12-18 months after GFD.All patients reported disease remission to some extent.After 1 year GFD treatment, the pathology of endoscopic intestinal biopsy in 8 patients showed significant improvement of villous atrophy and lymphocyte infiltration. CONCLUSIONS: CD patients with typical clinical manifestations are not the majority.Serological celiac disease antibodies (AGA, EMA and tTGA) have a high diagnostic value.GFD treatment is effective on majority of celiac patients.Clinical manifestations, endoscopy, intestinal pathology, and response to GFD in Chinese patients are not the same as Caucasians.Clinicians need to pay attention to the differential diagnosis.

Health-Related Quality of Life in Spanish Children With Coeliac Disease.

OBJECTIVES: The aim of the study was to assess health-related quality of life (HRQOL) using the Coeliac Disease Dutch Questionnaire (CDDUX) in Spanish children with coeliac disease. METHODS: The CDDUX was cross-culturally adapted according to international consensus guidelines. HRQOL was assessed in coeliac members of the Madrid Coeliac Association ages 8 to 18 years using the adapted CDDUX. Cronbach α coefficient was determined as a measure of intraquestionnaire reliability and intraclass correlation coefficients as a measure of reliability between scores awarded by children and parents. Demographic and clinical variables associated with HRQOL were also assessed. RESULTS: A total of 1602 children of 3122 registered Madrid Coeliac Association members ages 8 to 18 years were invited to participate. The questionnaire was completed by 480 families (30%): 214 only by parents, 214 by parents and their children, and 52 only by children. Cronbach α coefficient for the total score for parents was 0.90, and for children 0.88 (0.75-0.90 by scales). Mean total (standard deviation [SD]) HRQOL scores in children and parents were 55.5 (SD 12.7) and 53.89 (SD 12.19), respectively, with no differences detected in paired comparisons between the 2 groups. Significantly worse HRQOL scores were recorded in children showing a nonclassical clinical presentation, in those not adhering to treatment and in those reporting difficulties in following the diet. CONCLUSIONS: The CDDUX questionnaire emerged as reliable for use in Spanish children with celiac disease. Overall, both children and parents felt the disease had no substantial negative impacts on patient HRQOL.

Central America in Transition: From Maize to Wheat Challenges and Opportunities.

The Central American countries: Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama are in transition from a dietary culture based mainly on maize to a wheat-containing diet. Several other changes are occurring, such as a decrease of parasitic and infectious diseases. The environmental changes permit a prediction of an increase of celiac disease and other autoimmune diseases such as type I diabetes and thyroid disease in these genetically heterogeneous countries. At present, celiac disease and gluten-related disorders are considered to be of no relevance at the level of public health in these nations. This review documents the presence of celiac disease in Central America. It draws attention to some of the challenges in planning systematic studies in the region since up until recently celiac disease was unknown. The aim of this review is to disseminate knowledge obtained with preliminary data, to stimulate clinical and basic scientists to study these diseases in Central America and to alert authorities responsible for the planning of education and health, to find possibilities to avoid a rise in these disorders before the epidemics start, as has occurred in the Mediterranean countries.

Prevalence of celiac disease and celiac autoimmunity in the Toba Native Amerindian community of Argentina.

BACKGROUND: Celiac disease (CD) is mostly recognized among subjects with a Caucasian ethnic ancestry. No studies have explored conditions predisposing Amerindians to CD. OBJECTIVE: To prospectively assess environmental, genetic and serological conditions associated with CD among members of the Toba native population attending a multidisciplinary sanitary mission. METHODS: An expert nutritionist determined daily gluten intake using an established questionnaire. Gene typing for the human leukocyte antigen (HLA) class II alleles was performed on DNA extracted from peripheral blood (HLA DQ2/DQ8 haplotype). Serum antibodies were immunoglobulin (Ig) A tissue transglutaminase (tTG) and the composite deamidated gliadin peptides/tTG Screen test. Positive cases were tested for IgA endomysial antibodies. RESULTS: A total of 144 subjects (55% female) were screened. The estimated mean gluten consumption was 43 g/day (range 3 g/day to 185 g/day). Genetic typing showed that 73 of 144 (50.7%) subjects had alleles associated with CD; 69 (94.5%) of these subjects had alleles for HLA DQ8 and four had DQ2 (5.5%). Four and six subjects had antibody concentrations above the cut-off established by the authors' laboratory (>3 times the upper limit of normal) for IgA tTG and deamidated gliadin peptides/tTG screen, respectively. Four of these had concomitant positivity for both assays and endomysial antibodies were positive in three subjects who also presented a predisposing haplotype. CONCLUSION: The present study was the first to detect CD in Amerindians. The native Toba ethnic population has very high daily gluten consumption and a predisposing genetic background. We detected subjects with persistent CD autoimmunity and, at least, three of them fulfilled serological criteria for CD diagnosis.