Frequência de alelos HLA-DQ2 e HLA-DQ8 em celíacos e seus parentes de primeiro grau.

Abstract

Celiac disease (CD) is characterized by being an autoimmune disorder triggered by the ingestion of gluten, with intestinal disorders as its main manifestation. This disorder would be linked to genetic factors, mainly those found in the Human Leukocyte System (HLA), class II (HLADQ), namely the HLA-DQ2 (DQA1*0501 and DQB1*0201) and HLA-DQ8 (DRB1*04) alleles. , responsible for encoding the DQ2 and DQ8 proteins. It is known that these alleles are present between 25 to 30% of the population, reaching up to 95%, and the other 5% of celiacs would have triggered the disease due to other genetic factors, therefore, HLA-DQ screening was included among the stages of CD diagnosis, being used mainly for asymptomatic patients and also for screening risk groups for CD. Therefore, the aim of this study is to analyze the frequency and prevalence of DQ2 and DQ8 alleles in celiac patients, first-degree relatives and people under investigation. In the total of samples collected, n = 78, n=67 analyzes and analyzed questionnaires were obtained, giving a total of 85.9% of the total, of which 37 samples (55.2%) were diagnosed with CD, 13 samples from relatives of celiac patients (19.4%) and 17 samples under investigation for CD (25.4%), and 9 lost samples that we could not return from the participants (14,1 %). As for the genotypes DQ2 A, DQ2 B, DQ A+B, DQ8 and DQ2 A + B + DQ8 A of the celiac patients evaluated (n=37), 23 (62%) had at least 1 allele, being DQ2 A (n=3) 13.1%, DQ2 B (n=8) 34.8%, DQ2 AB (n=12) 52.1%, while for the DQ8 allele (n=7) 30.4% were positive, and ( n=11) 37.8% did not present any allele. As for the genotypes DQ2 A, DQ2 B, DQ A+B, DQ8 and DQ2 A + B + DQ8 A of the celiac patients evaluated (n=37), 23 (62%) had at least 1 allele, being DQ2 A (n=3) 13.1%, DQ2 B (n=8) 34.8%, DQ2 AB (n=12) 52.1%, while for the DQ8 allele (n=7) 30.4% were positive, and ( n=11) 37.8% did not present any allele. Regarding genetic testing, most people in all three groups had at least one of the alleles, however, the group of people under investigation had a higher percentage of alleles, with a lower percentage of not having the alleles studied between the groups. The DQ2 AB genotype was the most found in all groups. Celiac patients had a greater number of symptoms, pathologies and biopsy and serological tests to search for a correct diagnosis between the groups, however, CD should be investigated in the groups of relatives of celiacs and people under investigation of the disease, since most had celiac relatives and reported symptoms and diseases related to CD, being classified as a risk group. Even if these individuals do not have classic symptoms of CD, a biopsy is necessary because it can treat asymptomatic individuals, thus avoiding further complications related to this pathology in the future.