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Background The frequency of HLA‐DQ2 and DQ8 predisposing genotypes for celiac disease (CD) has shown significant variation among different world regions and has not been previously determined among the highly interbred Brazilian population. The aim of this study was to investigate the frequency of these genotypes among Brazilian newborns (NB). Methods We typed DQA1*05 ‐ DQB1*02 (DQ2.5) and DQA1*03 ‐ DQB1*03:02 (DQ8) alleles in 329 NB using qPCR technique. Subsequently we confirmed our results by PCR‐SSP using a reference kit which further identified DQ2.2 (DQA1*02:01 ‐ DQB1*02). Results Among the 329 NB, using qPCR technique: 5 (1.52%) carried both DQ2.5 and DQ8 variants; 58 (17.63%) carried only DQ2.5 (DQA1*05 and DQB1*02) and 47 (14.29%) carried only the DQ8 (DQA1*03 and DQB1*03:02) variant. The use of the PCR‐SSP method yielded further information; among the 329 samples: 34 (10.34%) tested positive for DQ2.2 and among the 47 previously DQ8 positives samples, we found 10 (3.04%) that also tested positives for DQ2.2. Conclusion 43.7% of the analyzed individual tested positive for at least one of the CD predisposing HLA‐DQ genotypes in our group of Brazilian NB. The highest frequency was found for DQ2.5 positive subjects (17.6%) followed by DQ8 (11.3%); DQ2.2 (10.3%); DQ8 and DQ2.2 (3.0%); DQ2.5 and DQ8 (1.5%). We found no positive sample for DQ2.5 associated with DQ2.2.

CONTEXTO: A doença celíaca é uma enteropatia autoimune, desencadeada pela ingestão do glúten em indivíduos geneticamente predispostos. Quase todos os pacientes celíacos possuem genes que codificam os heterodímeros HLA-DQ2.5 e DQ8. Nos últimos anos, mesmo com algumas controvérsias a respeito, tem se dado grande importância ao HLA-DQ2.2 como outra provável variante predisponente para doença celíaca. OBJETIVO: O objetivo do nosso trabalho foi determinar a provável associação entre HLA-DQ2.2 e a doença celíaca em crianças brasileiras, mediante a análise da prevalência das variantes predisponentes para doença celíaca em um grupo representativo desta população que ainda carece de dita informação. MÉTODOS: A genotipagem das variantes HLA-DQ foi realizada em populações de crianças celíacas (n=100) e não celíacas (n=110). A presença das seguintes variantes foi testada em todas as amostras: DQA1*05-DQB1*02 (DQ2.5), DQA1*03-DQB1*03:02 (DQ8) e DQA1*02:01-DQB1*02:02 (DQ2.2). A análise estatística foi realizada utilizando o teste exato de Fisher. RESULTADOS: No grupo de 100 crianças celíacas, 78 (78%) foram positivas para DQ2, 13 (13%) para DQ2/DQ8 e 6 (6%) foram DQ8 positivas. O padrão de variantes predisponentes no grupo de 110 crianças não celíacas foi: 33 (29.9%) amostras positivas para DQ2, 2 (1.8%) DQ2/DQ8 positivas e 15 (13.6%) DQ8 positivas. Quando as prevalências de ambos grupos foram compradas, foram achadas diferenças significativas entre algumas, mas não todas as variantes predisponentes. CONCLUSÃO: A genotipagem das variantes HLA-DQ predisponentes para doença celíaca mostrou um padrão similar ao achado em populações europeias e não-europeias, o qual pode ser resultado da miscigenação que deu origem à população brasileira atual. Nosso trabalho não mostrou associação significativa entre a variante DQ2.2 e a doença celíaca na população estudada. BACKGROUND: Celiac disease is an autoimmune enteropathy triggered by the ingestion of gluten in genetically susceptible individuals. Almost all celiac patients carry immune recognition genes coding for HLA-DQ2.5 and DQ8 heterodimers. Over the last few years, great importance has been given to HLA-DQ2.2 as probable predisposing variant, although controversies still exist regarding its relevance. OBJECTIVE: The aim of our study was to determine the possible existence of an association between HLA-DQ2.2 and celiac disease in Brazilian children by analyzing the prevalence of the predisposing variants for celiac disease in a representative group of children of a population in which this determination is still missing. METHODS: HLA-DQ typing was performed in samples from a group of celiac (n=100) and non-celiac children (n=110). All samples were tested for the presence of the following variants: DQA1*05-DQB1*02 (DQ2.5), DQA1*03-DQB1*03:02 (DQ8) and DQA1*02:01-DQB1*02:02 (DQ2.2). Fisher`s exact test was used for statistical analysis. RESULTS: In the group of 100 celiac children, 78 (78%) were positive for DQ2, 13 (13 %) were DQ2/DQ8 and 6 (6%) were DQ8 positives. The HLA-DQ pattern in the 110 non-celiac children was as follows: positive for DQ2 in 33 (29.9%) samples, in 2 (1.8 %) was positive for DQ2/DQ8 and in 15 (13.6%) was positive for DQ8. We found significant differences between the distribution of some but not all of the analyzed alleles when comparing celiac and non-celiac children. CONCLUSION: The genotyping of celiac disease HLA-DQ predisposing alleles showed similarities with HLA-DQ patterns found in both European and non-European populations, which may be a reflection of the miscegenation, which gave origin to the current Brazilian population. No significant association was found between DQ2.2 variant and celiac disease in the studied population.

Objective: To evaluate the possible association between celiac disease (CD) and/or gluten sensitivity (GS) and autism spectrum disorder (ASD). Methods: Occurrences of CD were determined in a group of children and adolescents affected by ASD and, conversely, occurrences of ASD were assessed in a group of biopsy-proven celiac patients. To detect the possible existence of GS, the levels of antigliadin antibodies in ASD patients were assessed and compared with the levels in a group of non-celiac children. Results: The prevalence of CD or GS in ASD patients was not greater than in groups originating from the same geographical area. Similarly the prevalence of ASD was not greater than in a group of biopsy-proven CD patients. Conclusion: No statistically demonstrable association was found between CD or GS and ASD. Consequently, routine screening for CD or GS in all patients with ASD is, at this moment, neither justifed nor cost-effective. ___________________________________________________________________________________ RESUMO Objetivo: Avaliar a possível associação entre doença celíaca (DC) e/ou sensibilidade ao glúten (SG) e transtorno do espectro autista (TEA). Métodos: Ocorrências de DC foram determinadas em um grupo de crianças e adolescentes afetados pelo TEA e a ocorrência d TEA foi avaliada em um grupo de pacientes com DC comprovada por biópsia. Para detectar a possível existência de SG, foram determinados níveis de anticorpos antigliadina em pacientes com TEA e comparados ao grupo de crianças sem a doença celíaca. Resultados: A prevalência de DC ou SG não foi maior no grupo de pacientes com TEA quando comparada a grupos de indivíduos originários da mesma região geográfca. De modo similar, a prevalência do TEA não foi maior ao ser comparada ao grupo de pacientes com DC. Conclusão: Não houve associação estatisticamente demonstrável entre DC ou SG e TEA. Consequentemente, não são justifcáveis, no momento, exames de rotina para detecção de DC ou SG em pacientes com TEA.

Contexto - Doença celíaca é uma enteropatia autoimmune desencadeada pela ingestão de gluten em indivíduos geneticamente suscetíveis. Essa suscetibilidade genética está associada a dois conjuntos de alelos, DQA1*05 - DQB1*02 e DQA1*03 - DQB1*03:02, que codificam moléculas MHC de classe II DQ2 e DQ8, respectivamente. Aproximadamente 90%-95% dos pacientes celíacos são HLA-DQ2 positivos, e metade dos restantes são HLA-DQ8 positivos. No diagnóstico da doença celíaca, a ausência desses alelos DQA e DQB específicos possui um elevado valor preditivo negativo. Objetivo - Nosso objetivo foi melhorar a detecção de alguns alelos predisponentes para doença celíaca, combinando a simplicidade e sensibilidade da técnica de PCR em tempo real (qPCR) e análise da curva de melting com a especificidade dos primers de sequência específica. Métodos - Primers de sequência específica para DQA1*05 (DQ2), DQB1*02 (DQ2), e DQA1*03 (DQ8) foram usados para testar a presença de cada alelo em reações independentes. Primers para Hormônio de Crescimento Humano foram usados como controle interno. Em paralelo, foi usado um protocolo de PCRSSP como um método de referência para validar nossos resultados positivos. Resultados - Das 329 amostras testadas, 187 (56.8%) foram positivas para os alelos HLA predisponentes, usando as duas técnicas. Essas 187 amostras positivas foram subdivididas em 114 (61.0%) positivas para apenas um alelo, 68 (36.3%) para dois alelos e apenas 5 (2.7%) para os três alelos. Conclusão - Os resultados obtidos pela técnica de qPCR mostraram-se altamente confiáveis, sem resultados discordantes quando comparados àqueles obtidos pelo método PCR-SSP. Background - Celiac disease is an autoimmune enteropathy triggered by the ingestion of gluten in genetically susceptible individuals. Genetic susceptibility is associated with two sets of alleles, DQA1*05 - DQB1*02 and DQA1*03 - DQB1*03:02, which code for class II MHC DQ2 and DQ8 molecules, respectively. Approximately 90%-95% of celiac patients are HLA-DQ2 positive, and half of the remaining patients are HLA-DQ8 positive. In fact, during a celiac disease diagnostic workup, the absence of these specific DQA and DQB alleles has a near perfect negative predictive value. Objective - Improve the detection of celiac disease predisposing alleles by combining the simplicity and sensitivity of real-time PCR (qPCR) and melting curve analysis with the specificity of sequence-specific primers (SSP). Methods - Amplifications of sequence-specific primers for DQA1*05 (DQ2), DQB1*02 (DQ2), and DQA1*03 (DQ8) were performed by the real time PCR method to determine the presence of each allele in independent reactions. Primers for Human Growth Hormone were used as an internal control. A parallel PCR-SSP protocol was used as a reference method to validate our results. Results - Both techniques yielded equal results. From a total of 329 samples the presence of HLA predisposing alleles was determined in 187 (56.8%). One hundred fourteen samples (61%) were positive for a single allele, 68 (36.3%) for two alleles, and only 5 (2.7%) for three alleles. Conclusion - Results obtained by qPCR technique were highly reliable with no discordant results when compared with those obtained using PCR-SSP.

Background Although it is known that first degree relatives of celiac patients have an increased risk for celiac disease few studies are available on its incidence. We investigated the incidence of serologic conversion and of new cases of celiac disease among first degree relatives with negative results at a first screening. Methods From a total of 634 first degree relatives of 186 biopsy-proven celiac disease patients diagnosed between October 2000 and October 2010, 450 subjects agreed to participate in the study (Group I), and underwent serologic screening. Between January 2010 and October 2012, out of the initial group of 450, 205 previously sero-negative subjects consented to participate in a second stage of the study and undergo new serologic testing (Group II). All serologically positive individuals of both groups (I and II) were genotyped for celiac disease-predisposing alleles (HLA-DQ2/DQ8). Results 19 subjects (4.2%) out of the 450 subjects of Group I disclosed positive serologic results, presence of DQ2 and/or DQ8 alleles and celiac disease-compatible mucosal abnormalities. The 205 previously negative first degree relatives from Group II that underwent new serologic testing disclosed eight sero-converted subjects. Mucosal abnormalities in five of these patients confirmed the diagnosis of celiac disease. During the 10-year period of the study the incidence of sero-conversion was 8/205 and the incidence of biopsy-proven celiac disease cases was 5/205. Conclusions Our data are coincident with other works on this subject and confirm once again that relatives of celiac patients, especially first degree relatives are at high risk of developing celiac disease. In view of the relatively low incidence further studies are needed to try to establish a useful and cost-effective algorithm for follow-up of relatives of celiac patients.

AIM: To evaluate the prevalence of celiac disease in a group of Brazilian individuals over 60 years of age and compare it with the previously known prevalence in a pediatric group living in the same geographical area. METHODS: The research protocol was approved by the Ethics Committee of the University of Brasilia School of Medicine, Brasilia, Brazil. Blood samples from 946 individuals (295 male and 651 female) aged 60 years or older were collected between May 2010 and July 2011. The study subjects’ mean and median ages were 68.1 and 67 years, respectively, ranging from 60 to 92 years. That age distribution closely corresponded to the age distribution of the Brazilian population according to the Brazilian 2010 census. The participants were consecutive and unselected outpatients undergoing blood tests at the University of Brasilia Hospital’s Clinical Pathology Laboratory. All sera were tested for immunoglobulin A anti-transglutaminase antibodies (IgA-tTG) by enzyme- linked immunosorbent assay, and those that were positive were further tested for immunoglobulin A anti-endomysium antibodies (IgA-EMA). Human leukocyte antigen (HLA) genotyping was performed for all individuals who exhibited positive serologic results for IgA-tTG and/or IgA-EMA. RESULTS: Out of the 946 studied patients, only one previously diagnosed case of biopsy-proven celiac disease was detected. For the remaining subjects, nine serum samples tested positive for IgA-tTG antibodies; however, none of them tested positive for IgA-EMA antibodies. The HLA genotyping of those nine subjects revealed that one was carrying DQA1*0501 and two were carrying DQB1*0201 alleles. These data showed that, among those 946 elderly individuals, the prevalence of celiac disease (CD) was 0.1% (95%CI: 0.00-0.59). The prevalence of CD for the elderly group was compared with that observed for the group of 2034 children younger than 15 years (age range, 1-14 years; mean age, 8 years) who took part in our previous CD prevalence screening study. All the children came from the same geographical region and shared a similar ethnic and low-income background. As in the elderly group in the current study, the younger group was made up of consecutive outpatients who underwent blood evaluation at the University of Brasilia Hospital’s Clinical Laboratory. The prevalence of biopsy-proven CD among those children was 0.54% (95%CI: 0.27-0.57). The comparative analysis between the two groups resulted in the following values: odds ratio = 0.19 (95%CI: 0.01-1.45) Fisher test P = 0.06. CONCLUSION: The prevalence of CD among the children of our previous study was 5.4 times higher than that found in the present elderly group.