Prevalence of celiac disease among blood donors in São Paulo: the most populated city in Brazil

OBJECTIVE: Celiac disease is a permanent enteropathy caused by the ingestion of gluten, which leads to an immunemediated inflammation of the small intestine mucosa. The prevalence of celiac disease varies among different nations and ethnic backgrounds, and its diversity is determined by genetic and environmental factors. São Paulo city is one of the largest cities in the world, with a vast population and an important history of internal migratory flow from other Brazilian regions, as well as immigration from other, primarily European, countries, resulting in significant miscegenation. The aim of the present study was to estimate the prevalence of adults with undiagnosed celiac disease among blood donors of São Paulo by collecting information on the ancestry of the population studied. METHODS: The prevalence of celiac disease was assessed by screening for positive IgA transglutaminase and IgA endomysium antibodies in 4,000 donors (volunteers) in the Fundação Pró-Sangue Blood Center of São Paulo, São Paulo, Brazil. The antibody-positive subjects were asked to undergo a small bowel biopsy. RESULTS: Of the 4,000 subjects, twenty-four had positive tests, although both antibody tests were not always concordant. For example, ten subjects were positive for IgA tissue transglutaminase only. In twenty-one positive patients, duodenal biopsies were performed, and the diagnosis of celiac disease was confirmed in fourteen patients (Marsh criteria modified by Oberhuber). In this group, 67% claimed to have European ancestry, mainly from Italy, Portugal and Spain. CONCLUSION: The prevalence of celiac disease is at least 1:286 among supposedly healthy blood bank volunteers in São Paulo, Brazil.

Alelos HLA-DQB1 y DRB1 asociados con la enfermedad celíaca en pacientes hospitalarios / Association between HLA-DQB1 and HLA-DRB1 alleles and coeliac disease in hospitalized patients

La enfermedad celíaca (EC) es una afección autoinmune que presenta asociación con determinados genes del sistema HLA. Se ha descrito que ciertas variantes (alelos) HLA de clase II DQ y DR están involucradas en la susceptibilidad primaria de esta enfermedad. La frecuencia de alelos HLA varía entre los diferentes grupos étnicos. La población actual de nuestro país presenta características étnicas particulares y, hasta el momento de realizado este trabajo, no se conocía la asociación de estos alelos con la enfermedad. Se presentan, por tanto, los datos obtenidos mediante determinación molecular de alelos HLA de clase II de cadena beta DQ y DR para una muestra total de 37 individuos (pacientes y controles). Se calculó el riesgo relativo (RR) y la fracción etiológica (FE) para cada alelo, genotipo y haplotipo DQB1-DRB1. Se determinó que los alelos DQB1*0201 y DRB1*03 están positivamente asociados a los pacientes (RR= 10,7, p<0,001 y RR=13, p<0,001 respectivamente). Cuando se analizaron los haplotipos, fue precisamente la combinación de estos alelos la que presentó una asociación positiva con la EC. Estos resultados permitieron establecer que, si bien existe mezcla étnica en nuestra población, los alelos involucrados en la susceptibilidad de la enfermedad celíaca son los mismos a los descritos en la literatura variando la frecuencia y, por lo tanto, el riesgo asociado a cada alelo