Celiac disease and HLA-DQ genotype: diagnosis of different genetic risk profiles related to the age in Badajoz, southwestern Spain.

BACKGROUND AND OBJECTIVES: celiac disease is associated with the HLA class II alleles: DQA1*05-DQB1*02 and DQB1*0302. The genetic risk for celiac disease may depend on the presence or absence of such alleles, their combination or number of copies. This study aimed to establish the differences in HLA genotypes between celiac patients diagnosed during childhood and adulthood, and between patients and healthy controls, and to determine the risk of disease in each genotypic category. METHODS: we classified 350 celiac patients at time of diagnosis and 218 controls into 14 categories according to their HLA genotype, based on the presence or absence of risk alleles. RESULTS: we found statistically significant differences between the genotype frequencies of celiac patients diagnosed as being children and adults. DQA1*05 (x 1 copy), DQB1*02 (x 1 copy), DQB1*0302 (x 0 copies) was the most frequent genotype in individuals diagnosed in childhood, whereas DQA1*05 (x 1 copy), DQB1*02 (x 2 copies), DQB1*0302 (x 0 copies) was the most frequent in adults. The risk for disease in each genotypic category in celiac children and adults turned out to be different. The presence of DQB1*0302 did not increase risk in children, but did in adults. CONCLUSION: in our celiac population, we found a different genetic pattern according to age of diagnosis. That could suggest that the pathogenic mechanism of the disease is not exactly the same in both age groups, which could somehow determine clinical presentation of the disease, its epidemiology, coexisting diseases, and complications.

Celiac disease and HLA-DQ genotype: diagnosis of different genetic risk profiles related to the age in Badajoz, southwestern Spain / Enfermedad celiaca y genotipo HLA-DQ: diagnóstico de diferentes perfiles de riesgo genético relacionados con la edad en Badajoz, suroeste de España

Background and objectives: celiac disease is associated with the HLA class II alleles: DQA1*05-DQB1*02 and DQB1*0302. The genetic risk for celiac disease may depend on the presence or absence of such alleles, their combination or number of copies. This study aimed to establish the differences in HLA genotypes between celiac patients diagnosed during childhood and adulthood, and between patients and healthy controls, and to determine the risk of disease in each genotypic category. Methods: we classified 350 celiac patients at time of diagnosis and 218 controls into 14 categories according to their HLA genotype, based on the presence or absence of risk alleles. Results: we found statistically significant differences between the genotype frequencies of celiac patients diagnosed as being children and adults. DQA1*05 (x 1 copy), DQB1*02 (x 1 copy), DQB1*0302 (x 0 copies) was the most frequent genotype in individuals diagnosed in childhood, whereas DQA1*05 (x 1 copy), DQB1*02 (x 2 copies), DQB1*0302 (x 0 copies) was the most frequent in adults. The risk for disease in each genotypic category in celiac children and adults turned out to be different. The presence of DQB1*0302 did not increase risk in children, but did in adults. Conclusion: in our celiac population, we found a different genetic pattern according to age of diagnosis. That could suggest that the pathogenic mechanism of the disease is not exactly the same in both age groups, which could somehow determine clinical presentation of the disease, its epidemiology, coexisting diseases, and complications (AU)

Utilidad del recuento e inmunofenotipaje de los linfocitos intraepiteliales de la mucosa intestinal en el diagnóstico de la enfermedad celiaca / Usefulness of intraepithelial lymphocytes immunophenotyping in intestinal mucosa for the diagnosis of coeliac disease

Introducción. Se han observado cambios característicos en las poblaciones de linfocitos intraepiteliales (LIE) de la mucosa intestinal en pacientes celiacos infantiles y adultos. Objetivos. Determinar el rango normal de las poblaciones de LIE por citometría de flujo y establecer su rentabilidad diagnóstica en la enfermedad celiaca (EC). Material y métodos. Estudio retrospectivo de 246 niños y 461 adultos con sospecha de EC a los que se había realizado estudio de poblaciones de LIE. El grupo de EC (221 niños y 98 adultos) lo forman individuos con serología celiaca positiva e histología con lesión grado Marsh 1 o mayor. El grupo control (25 niños y 363 adultos) lo constituyen individuos sin lesión intestinal y serología celiaca negativa a los que también se había realizado inmunofenotipo de LIE por citometría de flujo. Resultados. En el grupo de pacientes celiacos se observa un aumento significativo de LIE totales y LIE TCRγδ y un descenso significativo de LIE NK-like en comparación con los grupos control. En función de las curvas ROC, los puntos de corte en la población infantil fueron: %LIE > 14,2%, %LIE TCRγδ > 16,5% y %LIE NK-like < 10,1%. Los puntos de corte en la población adulta fueron: %LIE > 14,2%, %LIE TCRγδ > 16,1% y %LIE NK-like < 4,4%. En ambas poblaciones se obtienen una especificidad y VPP cercano o igual al 100%, con unos CP+ > 5 y CP− < 2 o próximos. Conclusiones. En el presente trabajo se han establecido los valores de corte para los tres parámetros analizados de los LIE. Estos parámetros permiten diagnosticar con una especificidad cercana al 100% la EC en el niño y en el adulto. Los valores de CP+ y CP− obtenidos muestran que estos parámetros son muy útiles en el diagnóstico de EC activa infantil y del adulto. Por lo tanto, el análisis de las poblaciones de LIE por medio de la citometría de flujo es una nueva herramienta diagnóstica de la EC que complementa el estudio anatomopatológico clásico aumentando su especificidad (AU)

Introduction: The intestinal mucosa of children and adult with coeliac disease shows characteristic changes in intraepithelial lymphocyte (IEL) populations. Objectives: Determination of the normal range of IEL populations by flow cytometry and its diagnostic usefulness in coeliac disease (CD). Methods: A retrospective study of 246 children and 461 adults with suspected CD with IEL immunophenotype results. The CD group (221 children and 98 adults) are individuals with positive coeliac serology and a histology lesion Marsh grade 1 or greater. The control group included 25 children and 363 adults without bowel lesion, negative serology and with IEL immunophenotype results. Results: The group of coeliac patients, adults and children, shows a significant increase in total IEL and TCRdeltagamma IEL, and a significant decrease in NK-like IEL compared with control groups. Based on ROC curves, the cut-off in coeliac children was: %IEL >14.2%, %TCRdeltagamma IEL>16.5% and %NK-like IEL<10.1%. The cut-off in the adult coeliac population was: %IEL >14.2%, %TCR IEL>16.1% and %NK-like IEL<4.4%. In both populations the specificity and PPV are close or equal to 100%, a CP+ >5 and a CP− <2 or near. Conclusions: The cut-off values of the LIE population analysed has been established in this study. The values of CP+ and CP− show that these parameters are very useful for the diagnosis of celiac disease in children and adults, with a specificity of approximately 100%. The immunophenotyping of LIE is a very useful technique in the diagnosis of CD, and complements the classical pathological study, thus increasing the specificity (AU)