Antigenic Phenotyping of Lymphoid Cells and B Cell Gene Rearrangement in Type B Gastritis and in Gastritis Not Associated with <i>Helicobacter pylori</i> Colonization

Abstract

Marginal-zone B cells of the mucosa-associated lymphoid tissue (MALT) are the normal counterpart of the neoplastic cells in MALT lymphoma. In both cases these lymphocytes express surface immunoglobulins, but are negative when stained for B cell associated antigens like CD10 and CD23. Furthermore, the B cell gene rearrangement has been found in Helicobacter pylori associated chronic gastritis and in extranodal type of marginal-zone lymphoma. The aim of this study was to quantify the number of IgM-, CD10-, and CD23-positive lymphocytes in patients with type B gastritis and to compare the results with the antigen profile of mononuclear cells in patients with gastritis not associated with H. pylori. Additionally, the immunoglobulin heavy-chain (IgH) gene rearrangement in H. pylori positive and H. pylori negative gastritis was studied. From 23 patients with a positive urease test and/or histologically proven H. pylori infection and chronic gastritis and from 22 patients with H. pylori negative chronic gastritis mucosa biopsy specimens were taken. Single-cell suspensions were obtained following enzymatic digestion. For immunocytochemistry, an alkaline phosphatase-antialkaline phosphatase method was applied. IgH gene rearrangement in formalin-fixed, paraffin-embedded specimens was determined by polymerase chain reaction in 11 patients with chronic gastritis. An increase in mu-positive plasma cells and B lymphocytes was detected in patients with H. pylori positive gastritis as compared with patients with H. pylori negative gastritis (10.0 vs. 3.9%, p < 0.001, and 4.3 vs. 1.6%, p < 0.01, respectively). In both groups, the proportion of CD10- and CD23-positive lymphocytes was <1%. IgH gene rearrangement was not restricted to type B gastritis; single bands were also present in 3 of 7 patients with H. pylori negative chronic gastritis. Our finding of IgH gene rearrangement in some of the patients with H. pylori negative chronic gastritis indicates that additional factors may be critical for these genotypical changes and for the pathogenesis of gastric MALT lymphoma.

Pediatric Helicobacter pylori Infection and Circulating T-Lymphocyte Activation and Differentiation

“…Another difference observed in H. pylori-infected children was the increase in the percentage of CD19 + B cells with low expression of the CD19 receptor. Similar changes have been observed in other studies that evaluated the number of CD19 + cells in peripheral blood and gastric mucosa in children and adults [1,12,[30][31][32][33][34][35][36][37][38] showing a higher number of these cells in the former group. Thus, these results indicate that H. pylori infection also induces a systemic humoral immune response.…”

“…Helicobacter ISSN 1523-5378 ª 2011 Blackwell Publishing Ltd, Helicobacter 16: [27][28][29][30][31][32][33][34][35] low titers of anti-H. pylori antibodies [1], a low degree and activity of gastritis [5,6], mild gastric inflammatory changes induced even by more virulent H. pylori strains [7], and low levels of Th1 cytokines in the gastric mucosa [8]. A high local Treg cell response accompanies such findings [9].…”