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

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

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

Usefulness of the organ culture system in the in vitro diagnosis of coeliac disease: A multicentre study

Objective. Diagnosis of coeliac disease is based on the presence of villous atrophy which recovers following a gluten-free diet. The presence of circulating antiendomysial antibodies as well as their disappearance after a gluten-free diet supports the diagnosis. It has also been demonstrated that antiendomysial antibodies are detectable in supernatants of cultured intestinal biopsies from patients with coeliac disease. The objective of this study was to compare the histology and antiendomysial antibodies in culture supernatants of intestinal biopsies to validate the in vitro organ culture system as a future diagnostic tool for coeliac disease. Material and methods. Seventy-five antiendomysial serum-positive patients on a gluten-containing diet were evaluated. Patients underwent endoscopy with 5 biopsy fragments: 3 for histology, 1 cultured with and the other without gliadin-peptide activator. Antiendomysial antibodies were evaluated in all culture supernatants. Results. Sixty-eight patients had evidence of villous atrophy, while 73 out of 75 were positive to the organ culture system. The agreement rate between organ culture and histology results was 94%. Conclusions. As all the centres participating in the study obtained good agreement between organ culture and histology results, the new system could be considered a reliable tool for the diagnosis of coeliac disease. Nevertheless, it is possible to highlight cases with an organ culture-positive and -negative histology. This feature could be of considerable interest because, as the sensitivity of organ culture seems to be greater than the initial histology, the new system might be useful in uncertain cases where the risk of missing the diagnosis of coeliac disease is high

Spanish Pediatric Inflammatory Bowel Disease Diagnostic Delay Registry: SPIDER Study From Sociedad Española de Gastroenterología, Hepatología y Nutrición Pediátrica.

Background and Aims: Diagnostic delay (DD) is especially relevant in children with inflammatory bowel disease, leading to potential complications. We examined the intervals and factors for DD in the pediatric population of Spain. Methods: We conducted a multicentric prospective study, including 149 pediatric inflammatory bowel disease patients, obtaining clinical, anthropometric, and biochemical data. Time to diagnosis (TD) was divided into several intervals to identify those where the DD was longer and find the variables that prolonged those intervals. Missed opportunities for diagnosis (MODs) were also identified. Results: Overall TD was 4.4 months (interquartile range [IQR] 2.6-10.4), being significantly higher in Crohn's disease (CD) than in ulcerative colitis (UC) (6.3 [IQR 3.3-12.3] vs. 3 [IQR 1.6-5.6] months, p = 0.0001). Time from the visit to the first physician until referral to a pediatric gastroenterologist was the main contributor to TD (2.4 months [IQR 1.03-7.17] in CD vs. 0.83 months [IQR 0.30-2.50] in UC, p = 0.0001). One hundred and ten patients (78.3%) visited more than one physician (29.9% to 4 or more), and 16.3% visited the same physician more than six times before being assessed by the pediatric gastroenterologist. The number of MODs was significantly higher in CD than that in UC patients: 4 MODs (IQR 2-7) vs. 2 MODs ([IQR 1-5], p = 0.003). Referral by pediatricians from hospital care allowed earlier IBD diagnosis (odds ratio 3.2 [95% confidence interval 1.1-8.9], p = 0.025). Conclusions: TD and DD were significantly higher in CD than those in UC. IBD patients (especially those with CD) undergo a large number of medical visits until the final diagnosis