Análisis genético de la enfermedad celiaca

La Enfermedad Celiaca (EC) es de origen multifactorial (gluten y otros factores ambientales no bien definidos) y poligénico. La predisposición genética viene dada por la tasa de concordancia entre familiares de primer grado (10%) y la tasa de concordancia entre gemelos monocigotos de hasta un 70%. Los genes del sistema HLA (antígeno Humano de Histocompatibilidad) case II han sido identificados como factores de riego genético claves en la susceptibilidad de la EC otorgándoles un 40% del riesgo genético global. En nuestra población española (Comunidad Valenciana) se analizó la asociación entre los genes HLA clase II y EC. En nuestra muestra se han estudiado a un total de 185 pacientes (que cumplían los criterios ESPGAN 1990 para el diagnóstico de la EC) y a sus familiares en primer grado. En nuestra población hemos encontrado asociación individual entre la EC y los antígenos de sistema HLA DRB1*03, DRB1*07, DRB3*, DQB1*02:01, DQB1*02:02 y DQA1*05:01, sin embargo, no encontramos asociación con los alelos DRB1*04, DQB1*03:02 ni DQA1*03:01-03, que codificarían para la molécula heterodímera DQ8. El 92.9% de los sujetos son portadores de DQ2 y el 69.7% de los pacientes presentan el haplotipo DRB1*03:01-DQB1*02:01-DQA1*05:01 (DR3-DQ2), existiendo un número importante de pacientes con el haplotipo DRB1*07:01-DQB1*02:02-DQA1*02:01/ DRB1*11-DQB1*03:01-DQA1*05:05 (DR7-DQ2/DR5-DQ7) que codificarían para la molécula heterodímera DQ2 en trans (18.9%). El 3.7% son positivos para DQ8 y negativos para DQ2. Únicamente 1.6% de todos los pacientes no porta alguno de haplotipos asociados clásicamente a la EC. Las combinaciones de los haplotipos DR3–DQ2 con DR7–DQ2, y DR7–DQ2 con DR5–DQ7, presenta 2 veces el riesgo comparado con cada haplotipo en homocigosis. En el test de independencia para el haplotipo DR3-DQ2 mostró que la susceptibilidad para la EC no se asocia de forma primaria con ninguno de los loci estudiados sino con el haplotipo completo. Por el contrario en el caso del haplotipo DR7-DQ2 la asociación con DRB1*07 es secundaria a DQB1/DQA1. El tipaje de los alelos HLA en la EC nos reporta un alto valor predictivo negativo siendo útil como guía para el despistaje de la EC en familiares y grupos de riesgo o en aquellos casos con dudas diagnósticas. No encontramos relación entre las diversas combinaciones de haplotipos y las manifestaciones clínicas de la enfermedad, grado de lesión o momento de debut. Si realizamos el estudio HLA en los familiares como despistaje de EC en un 22,7% se excluiría la enfermedad no precisando seguimiento clínico ni serológico. En el estudio del locus CTLA-4, existe una transmisión estadísticamente significativa mayor del alelo A frente al alelo G a los individuos afectos de enfermedad celíaca en el caso del marcador +49*A/G.Coeliac Disease (CD) is a polygenic (multiple gene) and multifactorial (gluten and other still unidentified environmental factors) disease. Genetic predisposition to CD is illustrated by a high prevalence rate among first-degree relatives (10%) and a concordance rate of approximately 70% in monozygotic twins. Human leukocyte antigen (HLA) genes encoding class II molecules have been firmly identified as key genetic risk factors in CD, this region by its own is believed to confer up to 40% of the increased risk of CD. The association between HLA class II antigens and CD was analyzed in a Spanish population (Valencian Community). In our CD population (185 patients who fulfil ESPGAN criteria) we found iassociation between CD and the HLA alleles DRB1*03, DRB1*07, DRB3*, DQB1*02:01, DQB1*02:02 and DQA1*05:01 but no association with DRB1*04 and DQB1*0302 was noted. The 92.9% of the subjects were DQ2 being the main associated haplotype in a 69.7% of the cases DRB1*03–DQB1*0201–DQA1*0501(DR3–DQ2), followed by DRB1*07– DQB1*0202–DQA1*0201 (DR7–DQ2) haplotype, which is associated with DRB1*11–DQB1*0301–DQA1*0505 (DR5–DQ7) in an 18.9%. The combinations of DR3–DQ2 with DR7–DQ2, and DR7–DQ2 with DR5–DQ7, present a twofold risk compared with each haplotype in homozygosis. An independence test in DR3-DQ2 haplotype found that association with CD was attributable to the whole haplotype, but for DR7-DQ2 was secondary to DQB1/DQA1. There is no need of a double gene dosage to increase the risk. CD-associated alleles typing demonstrate a very high negative predictive value to exclude CD in risk groups. No relation between clinical manifestations, age of onset or mucosal damage degree could be related with any kind of haplotype combination. If HLA typing was performed among first degree relatives following up of 22, 5% of them could be excluded as they do not share the risks HLA haplotypes. In the evaluation of the CTLA 4 locus in our population we found a small but significant association with the SNP +49*A/G

Imbalances in faecal and duodenal Bifidobacterium species composition in active and non-active coeliac disease

<p>Abstract</p> <p>Background</p> <p>Gut bifidobacteria are believed to influence immune-related diseases. The objective of this study was to assess the possible relationships between the gut bifidobacteria composition and coeliac disease (CD) in children.</p> <p>A total of 48 faecal samples (30 and 18 samples from active and no active CD patients, respectively) and 33 duodenal biopsy specimens of CD patients (25 and 8 samples from active and non-active CD patients, respectively) were analysed. Samples (30 faecal samples and 8 biopsies) from a control age-matched group of children were also included for comparative purposes. Gut <it>Bifidobacterium </it>genus and species were analyzed by real-time PCR.</p> <p>Results</p> <p>Active and non-active CD patients showed lower numbers of total <it>Bifidobacterium </it>and <it>B. longum </it>species in faeces and duodenal biopsies than controls, and these differences were particularly remarkable between active CD patients and controls. <it>B. catenulatum </it>prevalence was higher in biopsies of controls than in those of active and non-active CD patients, whereas <it>B. dentium </it>prevalence was higher in faeces of non-active CD patients than in controls. Correlations between levels of <it>Bifidobacterium </it>and <it>B. longum </it>species in faecal and biopsy samples were detected in both CD patients and controls.</p> <p>Conclusion</p> <p>Reductions in total <it>Bifidobacterium </it>and <it>B. longum </it>populations were associated with both active and non-active CD when compared to controls. These bacterial groups could constitute novel targets for adjuvant dietary therapies although the confirmation of this hypothesis would require further investigations.</p

Intestinal dysbiosis and reduced immunoglobulin-coated bacteria associated with coeliac disease in children

<p>Abstract</p> <p>Background</p> <p>Coeliac disease is a chronic intestinal inflammatory disorder due to an aberrant immune response to dietary gluten proteins in genetically predisposed individuals. Mucosal immune response through IgA secretion constitutes a first line of defence responsible for neutralizing noxious antigens and pathogens. The aim of this study was the characterization of the relationships between immunoglobulin-coated bacteria and bacterial composition of faeces of coeliac disease (CD) patients, untreated and treated with a gluten-free diet (GFD) and healthy controls.</p> <p>Results</p> <p>IgA-coated faecal bacterial levels were significantly lower in both untreated and treated CD patients than in healthy controls. IgG and IgM-coated bacterial levels were also significantly lower in treated CD patients than in untreated CD patients and controls. Gram-positive to Gram-negative bacteria ratio was significantly reduced in both CD patients compared to controls. <it>Bifidobacterium</it>, <it>Clostridium histolyticum</it>, <it>C. lituseburense </it>and <it>Faecalibacterium prausnitzii </it>group proportions were less abundant (<it>P </it>< 0.050) in untreated CD patients than in healthy controls. <it>Bacteroides-Prevotella </it>group proportions were more abundant (<it>P </it>< 0.050) in untreated CD patients than in controls. Levels of IgA coating the <it>Bacteroides-Prevotella </it>group were significantly reduced (<it>P </it>< 0.050) in both CD patients in comparison with healthy controls.</p> <p>Conclusions</p> <p>In CD patients, reduced IgA-coated bacteria is associated with intestinal dysbiosis, which altogether provide new insights into the possible relationships between the gut microbiota and the host defences in this disorder.</p

Aplicación racional de los nuevos criterios de la European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) 2020 para el diagnóstico de la enfermedad celíaca

Coeliac disease is a systemic immune-mediated disorder triggered by the ingestion of gluten, which is given in genetically predisposed subjects. It manifests with a wide variety of clinical symptoms, specific serological markers, HLA-DQ2/DQ8 haplotype, and enteropathy. The criteria followed for this have usually been those established by the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) since 1969. These criteria have advanced from the need of several intestinal biopsies to, thanks to the development of serological tests of high sensitivity and specificity, considering the enteropathy as one more element in this diagnosis and makes it possible to perform a diagnosis without the need of an intestinal biopsy in certain circumstances. The updated review of the 2012 criteria in 2019 provides new evidence on some aspects, such as the role of HLA, the diagnosis of asymptomatic patients, and the effectiveness of the serological markers. These aspects are reviewed in detail, with the aim of facilitating the rational application of the new 2020 criteria at all care levels. In this sense, Paediatric Primary Care is fundamental in the search for active cases and to perform a first serological study, being recommended that the diagnosis is always establishedby a Paediatric GastroenterologistLa enfermedad celíaca es un proceso sistémico de carácter inmunológico, desen-cadenado por el consumo de gluten, que se da en sujetos genéticamente predispuestos. Se expresa con una gran variedad de síntomas clínicos, marcadores serológicos específicos, hap-lotipo HLA-DQ2/DQ8 y enteropatía. El tratamiento consiste en eliminar de por vida el gluten de la dieta, por lo que es fundamental un diagnóstico adecuado. Los criterios seguidos para ello han sido habitualmente los establecidos por la European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) desde 1969. Estos criterios han ido evolucionando desde la necesidad de varias biopsias intestinales para el diagnóstico a, gracias al desarrollo de pruebas serológicas de alta sensibilidad y especificidad, considerar la enteropatía como un elemento más en este diagnóstico y posibilitar en determinadas circunstancias realizarlo sin necesidad de biopsia intestinal. La revisión actualizada en 2019 de los criterios 2012 aporta nueva evidencia sobre algunos aspectos, como el papel del HLA, el diagnóstico de los pacientes asintomáticos y la eficacia de los marcadores serológicos. Estos aspectos se revisan en detalle,con el objetivo de facilitar la aplicación de los nuevos criterios 2020 de una forma racional en todos los niveles asistenciales. En este sentido el pediatra de Atención Primaria es fundamental para la búsqueda activa de casos y realizar un primer estudio serológico, recomendándose que el diagnóstico sea siempre establecido por un pediatra gastroenterólog

The Use of Fecal Calprotectin Testing in Paediatric Disorders : A Position Paper of the European Society for Paediatric Gastroenterology and Nutrition Gastroenterology Committee

Objectives: The aim of the study was to review the evidence regarding the clinical use and value of fecal calprotectin (FC) measurements in different gastrointestinal disorders in children. Methods: A literature search was conducted in the PubMed, MEDLINE, EMBASE, and Cochrane databases until October 31, 2019. Subtopics were identified and each assigned to individual authors. Results: A total of 28 recommendations were voted on using the nominal voting technique. Recommendations are given related to sampling, measurement methods, and results interpretation. The 14 authors anonymously voted on each recommendation using a 9-point scale (1 strongly disagree to 9 fully agree). Consensus was considered achieved if at least 75% of the authors voted 6, 7, 8, or 9. Conclusions: Consensus was reached for all recommendations. Limitations for the use of FC in clinical practice include variability in extraction methodology, performance of test kits as well as the need to establish local reference ranges because of the influence of individual factors, such as age, diet, microbiota, and drugs. The main utility of FC measurement at present is in the diagnosis and monitoring of inflammatory bowel disease (IBD) as well as to differentiate it from functional gastrointestinal disorders (FAPDs). FC, however, has neither utility in the diagnosis of infantile colic nor to differentiate between functional and organic constipation. A rise in FC concentration, may alert to the risk of developing necrotizing enterocolitis and help identifying gastrointestinal involvement in children with Henoch-Schonlein purpura. FC measurement is of little value in Cow's Milk Protein Allergy, coeliac disease (CD), and cystic fibrosis. FC does neither help to distinguish bacterial from viral acute gastroenteritis (AGE), nor to diagnose Helicobacter Pylori infection, small intestinal bacterial overgrowth (SIBO), acute appendicitis (AA), or intestinal polyps.Peer reviewe

Reduced diversity and increased virulence-gene carriage in intestinal enterobacteria of coeliac children

<p>Abstract</p> <p>Background</p> <p>Coeliac disease is an immune-mediated enteropathology triggered by the ingestion of cereal gluten proteins. This disorder is associated with imbalances in the composition of the gut microbiota that could be involved in its pathogenesis. The aim of the present study was to determine whether intestinal <it>Enterobacteriaceae </it>populations of active and non-active coeliac patients and healthy children differ in diversity and virulence-gene carriage, so as to establish a possible link between the pathogenic potential of enterobacteria and the disease.</p> <p>Methods</p> <p><it>Enterobacteriaceae </it>clones were isolated on VRBD agar from faecal samples of 31 subjects (10 active coeliac patients, 10 symptom-free coeliac patients and 11 healthy controls) and identified at species level by the API 20E system. <it>Escherichia coli </it>clones were classified into four phylogenetic groups A, B1, B2 and D and the prevalence of eight virulence-associated genes (type-1 fimbriae [<it>fimA</it>], P fimbriae [<it>papC</it>], S fimbriae [<it>sfaD/E</it>], Dr haemagglutinin [<it>draA</it>], haemolysin [<it>hlyA</it>], capsule K1 [<it>neuB</it>], capsule K5 [<it>KfiC</it>] and aerobactin [<it>iutA</it>]) was determined by multiplex PCR.</p> <p>Results</p> <p>A total of 155 <it>Enterobacteriaceae </it>clones were isolated. Non-<it>E. coli </it>clones were more commonly isolated in healthy children than in coeliac patients. The four phylogenetic <it>E. coli </it>groups were equally distributed in healthy children, while in both coeliac patients most commensal isolates belonged to group A. Within the virulent groups, B2 was the most prevalent in active coeliac disease children, while D was the most prevalent in non-active coeliac patients. <it>E coli </it>clones of the virulent phylogenetic groups (B2+D) from active and non-active coeliac patients carried a higher number of virulence genes than those from healthy individuals. Prevalence of P fimbriae (<it>papC</it>), capsule K5 (<it>sfaD/E</it>) and haemolysin (<it>hlyA</it>) genes was higher in <it>E. coli </it>isolated from active and non-active coeliac children than in those from control subjects.</p> <p>Conclusion</p> <p>This study has demonstrated that virulence features of the enteric microbiota are linked to coeliac disease.</p

Increased prevalence of pathogenic bacteria in the gut microbiota of infants at risk of developing celiac disease: The PROFICEL study

8 páginas, 1 figura, 2 tablasCeliac disease (CD) is an immune-mediated enteropathy involving genetic and environmental factors, whose interaction influences disease risk. The intestinal microbiota, including viruses and bacteria, could play a role in the pathological process leading to gluten intolerance. In this study, we investigated the prevalence of pathogens in the intestinal microbiota of infants at familial risk of developing CD. We included 127 full-term newborns with at least one first-degree relative with CD. Infants were classified according to milk-feeding practice (breastfeeding or formula feeding) and HLA-DQ genotype (low, intermediate or high genetic risk). The prevalence of pathogenic bacteria and viruses was assessed in the faeces of the infants at 7 days, 1 month and 4 months of age. The prevalence of Clostridium perfringens was higher in formula-fed infants than in breast-fed over the study period, and that of C. difficile at 4 months. Among breastfed infants, a higher prevalence of enterotoxigenic E. coli (ETEC) was found in infants with the highest genetic risk compared either to those with a low or intermediate risk. Among formula-fed infants, a higher prevalence of ETEC was also found in infants with a high genetic risk compared to those of intermediate risk. Our results show that specific factors, such as formula feeding and the HLA-DQ2 genotype, previously linked to a higher risk of developing CD, influence the presence of pathogenic bacteria differently in the intestinal microbiota in early life. Further studies are warranted to establish whether these associations are related to CD onset later in life.This work was supported by grants AGL2011-25169, AGL2014-52101-P and AGL2007-66126-C03-03/ALI (YS and FP) from the Spanish Ministry of Economy and Competitiveness (MINECO). The scholarship to MO from CSIC (JAEpre) and the contract to ABP from the European Union's Seventh Framework Program under the grant agreement no 613979 (MyNewGut) are also fully acknowledged.Peer reviewe

Accuracy in Diagnosis of Celiac Disease Without Biopsies in Clinical Practice

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Predictors of Response to Exclusive Enteral Nutrition in Newly Diagnosed Crohn´s Disease in Children: PRESENCE Study from SEGHNP

Exclusive enteral nutrition (EEN) has been shown to be more effective than corticosteroids in achieving mucosal healing in children with Crohn´s disease (CD) without the adverse effects of these drugs. The aims of this study were to determine the efficacy of EEN in terms of inducing clinical remission in children newly diagnosed with CD, to describe the predictive factors of response to EEN and the need for treatment with biological agents during the first 12 months of the disease. We conducted an observational retrospective multicentre study that included paediatric patients newly diagnosed with CD between 2014–2016 who underwent EEN. Two hundred and twenty-two patients (140 males) from 35 paediatric centres were included, with a mean age at diagnosis of 11.6 ± 2.5 years. The median EEN duration was 8 weeks (IQR 6.6–8.5), and 184 of the patients (83%) achieved clinical remission (weighted paediatric Crohn’s Disease activity index [wPCDAI] 15 mg/L and ileal involvement tended to respond better to EEN. EEN administered for 6–8 weeks is effective for inducing clinical remission. Due to the high response rate in our series, EEN should be used as the first-line therapy in luminal paediatric Crohn’s disease regardless of the location of disease and disease activityS

Specific duodenal and faecal bacterial groups associated with paediatric coeliac disease

6 pages, 1 figure, 4 tables.-- Online version published 7 November 2008[Aims] To identify specific gut bacteria associated with coeliac disease (CD) at diagnosis and after treatment with a gluten-free diet (GFD) in a paediatric population.[Methods] 30 and 18 faecal samples from untreated and treated CD patients and 25 and 8 biopsy samples from untreated and treated CD patients, respectively, were analysed. In addition, 30 faecal and 8 biopsy samples from control children were evaluated for comparative purposes. Gut bacterial groups were quantified by real-time PCR.[Results] Bacteroides and Clostridium leptum groups were more abundant in faeces and biopsies of CD patients than in controls regardless of the stage of the disease. E coli and Staphylococcus counts were also higher in faeces and biopsies of non-treated CD patients than in those of controls, but their levels were normalised after treatment with a GFD. Bifidobacterium levels were lower in faeces of both groups of CD patients and in biopsies of untreated CD patients compared to controls. Similar bacterial groups were related to CD in biopsies and faeces, indicating that faecal microbiota partly reflects that of the small intestine in CD patients, and could constitute a convenient biological index of this disorder.[Conclusions] Duodenal and faecal microbiota is unbalanced in children with untreated CD and only partially restored after long-term treatment with a GFD, constituting a novel factor linked to this disorder.This work was supported by grants AGL-2005-05788-C02-01 and Consolider Fun-C-Food CSD2007-00063 from the Spanish Ministry of Science and Innovation. I3P-CSICPeer reviewe