Avaliação de antígeno leucocitário humano classe I e II em pacientes pediátricos com gastrite e úlcera duodenal ativas e Helicobacter pylori positivo / Evaluation of human leukocyte antigen class i and ii antigens in helicobacter pylori-positive pediatric patients with active gastritis and duodenal ulcer

ABSTRACT BACKGROUND: As being the first bacteria determined to be carcinogenic, Helicobacter pylori (H. pylori) is a pathogen localized in the stomach in more than half of the world population. Some earlier studies have found a relation between tissue histocompatibility antigens and gastric cancers depending on the regions. OBJECTIVE: The present study aimed to determine the distribution of human leukocyte antigen (HLA) class I and class II antigens in H. pylori-positive pediatric patients with active gastritis and duodenal ulcer, excluding cancer cases, in our center. METHODS: The study included 40 patients diagnosed with H. pylori-positive active gastritis and duodenal ulcer and 100 controls consisting of healthy donor candidates. The HLA class I and class II antigens were studied in the isolated DNA samples using the polymerase chain reaction sequence-specific oligonucleotide probes. RESULTS: The frequency of HLA-B*51 antigen was significantly higher in the patient group than in the control group (40% vs 17%; P=0.003). There was no difference between the two groups in terms of the frequencies of HLA-A, HLA-C, HLA-DR, and HLA-DQ antigens. CONCLUSION: It was determined that HLA-B*51 plays a critical role in H. pylori infection.

RESUMO CONTEXTO: Determinada como sendo a primeira bactéria cancerígena, o Helicobacter pylori (H. pylori) é um patógeno localizado no estômago em mais da metade da população mundial. Alguns estudos anteriores têm encontrado uma relação entre câncer gástrico e antígenos de histocompatibilidade de tecido dependendo das regiões. OBJETIVO: O presente estudo teve como objetivo determinar a distribuição em nosso centro do antígeno leucocitário humano (HLA) de classe I e antígenos classe II em pacientes pediátricos H. pylori-positivos com gastrite e úlcera duodenal ativas, excluindo casos de câncer. MÉTODOS: O estudo incluiu 40 pacientes H. pylori-positivos diagnosticados com gastrite e úlcera duodenal ativas e 100 controles consistindo de candidatos doadores saudáveis. Foram estudadas nas amostras de DNA isoladas o antígeno leucocitário humano classe I e antígenos classe II, utilizando-se as cadeias de sequência específica de polimerase do oligonucleotideo. RESULTADOS: A frequência do antígeno HLA - B * 51 foi significativamente maior no grupo de pacientes do que no grupo controle (40% vs 17%; P=0,003). Não houve diferença entre os dois grupos em termos das frequências dos antígenos HLA-A, HLA-DR, HLA-DQ e HLA-C. CONCLUSÃO: Determinou-se que o HLA - B * 51 desempenha um papel crítico na infecção pelo H. pylori.

EVALUATION OF HUMAN LEUKOCYTE ANTIGEN CLASS I AND II ANTIGENS IN HELICOBACTER PYLORI-POSITIVE PEDIATRIC PATIENTS WITH ACTIVE GASTRITIS AND DUODENAL ULCER.

BACKGROUND: As being the first bacteria determined to be carcinogenic, Helicobacter pylori (H. pylori) is a pathogen localized in the stomach in more than half of the world population. Some earlier studies have found a relation between tissue histocompatibility antigens and gastric cancers depending on the regions. OBJECTIVE: The present study aimed to determine the distribution of human leukocyte antigen (HLA) class I and class II antigens in H. pylori-positive pediatric patients with active gastritis and duodenal ulcer, excluding cancer cases, in our center. METHODS: The study included 40 patients diagnosed with H. pylori-positive active gastritis and duodenal ulcer and 100 controls consisting of healthy donor candidates. The HLA class I and class II antigens were studied in the isolated DNA samples using the polymerase chain reaction sequence-specific oligonucleotide probes. RESULTS: The frequency of HLA-B*51 antigen was significantly higher in the patient group than in the control group (40% vs 17%; P=0.003). There was no difference between the two groups in terms of the frequencies of HLA-A, HLA-C, HLA-DR, and HLA-DQ antigens. CONCLUSION: It was determined that HLA-B*51 plays a critical role in H. pylori infection.