Differences in peripheral blood lymphocyte phenotypes between Helicobacter pylori-positive children and adults with duodenal ulcer.

Abstract

The immunological mechanisms involved in the development of duodenal ulcer, especially in childhood, are unclear. Helicobacter pylori-positive children and adults, with and without duodenal ulcer, were therefore compared with respect to CD4(+) T-cells, and CD8(+) T-cells, B-cells and B1a-cells, as well as cell activation (CD4(+)/HLA-DR(+) and CD8(+)/HLA-DR(+)) and co-stimulatory (CD4(+)/CD28(+) and CD8(+)/CD28(+)) markers, in peripheral blood. Children with and without duodenal ulcer differed significantly. In particular, there was a phenotypic change in CD8(+) T-cells from children with ulcer that involved a 200% increase in the number of CD8(+)/HLA-DR(+) cells/mm(3) and a decrease of 34.2% in the number of CD8(+)/CD28(+) cells/mm(3). This phenotype of chronically activated memory CD8(+) T-cells, which has also been observed in patients with AIDS and tuberculosis, is associated with disease severity and progression. A lower frequency of B1a-cells was also observed in the group of children with ulcer. Conversely, no difference between infected adults with and without ulcer was observed, but the percentage of CD4(+)/HLA-DR(+) cells was lower in adults with ulcer, suggesting that a down-regulated immune response may play a role in the development of duodenal ulcer in adults. Gastric inflammation correlated positively with CD4(+) and chronically activated CD4(+) T-cells in children and adults without duodenal ulcer, respectively. These results suggest that there are differences in the immunophenotyping profile between H. pylori-positive children and adults with duodenal ulcer, indicating the possibility of distinct immune mechanisms in the development of the disease according to age.

• Authors: T Figueiredo Soares, G Aguiar Rocha, A M Camargos Rocha, R Corrêa-Oliveira, O A Martins-Filho, A S Teles Carvalho, P F Souto Bittencourt, C Afonso Oliveira, A M M Ferreira Nogueira, M M D Alvares Cabral, A M Caetano Faria, D M M Queiroz
• Journal: Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases (Clin Microbiol Infect) Vol. 13 Issue 11 Pg. 1083-8 (Nov 2007) ISSN: 1198-743X [Print] England
• PMID: 17727687 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• HLA-DR Antigens

Topics

• Adolescent
• Adult
• Age Factors
• Aged
• B-Lymphocytes (immunology)
• CD4-Positive T-Lymphocytes (immunology)
• CD8-Positive T-Lymphocytes (immunology)
• Child
• Duodenal Ulcer (blood, immunology)
• Female
• HLA-DR Antigens (immunology)
• Helicobacter Infections (immunology, microbiology)
• Helicobacter pylori (immunology)
• Humans
• Immunophenotyping (methods)
• Male
• Middle Aged
• Prospective Studies
• T-Lymphocyte Subsets (immunology)