We investigated the expression of CD99 in 35 hyperplastic perigastric lymph nodes, which were resected for gastric carcinoma or chronic peptic ulcer. Essentially, all lymphocytes in lymph nodes expressed CD99, but there were two populations with respect to the intensity of CD99 expression--CD99high and CD99low cells. We showed CD99high cells were distributed in paracortical and medullary cords by immunohistochemical study while germinal center cells were CD99low. Using three-color flow cytometric analysis with CD3, CD4, CD8, CD19, CD23, CD45RA, CD45RO, CD69, CD138, IgM, IgD, and IgG, most of CD99high cells were shown to be activated/memory T cells. CD4+CD45RO+ T cells were the subset revealing the highest intensity of CD99 expression while CD4+CD45RA+ T cells were CD99low. Among B cells, IgG+ B cells revealed a higher level of CD99 molecules than IgM+ B cells. These results suggest that CD99 is one of activation-related molecules which are upregulated in recently activated lymphocytes.
Adult ; Aged ; Antigens, CD/analysis* ; B-Lymphocytes/immunology* ; Cell Adhesion Molecules/analysis* ; Flow Cytometry ; Germinal Center/immunology ; Human ; Immunohistochemistry ; Immunologic Memory/immunology* ; Lymph Nodes/immunology* ; Middle Age ; Peptic Ulcer/immunology* ; Stomach Neoplasms/immunology* ; T-Lymphocytes/immunology*

OBJECTIVETo construct a prokaryotic expression system of a fragment from Helicobacter pylori cagA gene and to detect the CagA positive Helicobacter pylori (CagA(+) H. pylori) and its antibody with the recombinant protein cagA 1.

METHODSH.pylori isolates were obtained from biopsy specimens of 156 patients with gastric diseases. PCR method was used to detect frequency of cagA gene in 109 H. pylori isolates and to amplify a 2 148 bp fragment (cagA1) of cagA gene from a clinical strain Y06. A prokaryotic expression system of cagA1 was constructed. Expression of the target recombinant protein (rCagA1) was examined by SDS-PAGE. Western blot and immunodiffusion assay were applied to determine immunoreactivity and antigenicity of rCagA1. Two ELISA protocols were established to detect CagA expression in 109 H. pylori isolates and CagA antibody in serum of patients with gastric diseases. Correlations between infection of CagA(+) H. pylori and gastric diseases were analyzed.

RESULTSH. pylori strains were isolated from 80.8% of the biopsy specimens (126/156) and 97.2% of the isolates (106/109) were cagA gene positive. In comparison with the reported data, homologies of nucleotide and putative amino acid sequences of the cloned cagA1 fragment were 94.83% and 93.30%, respectively. The output of rCagA1 was approximate 30.0% of the total bacterial proteins. rCagA1 was able to combine with the commercial antibody against whole cell of H. pylori and to induce the immunized rabbits to produce antibody with an immunodiffusion titer of 1:4. 92.6% of the H. pylori isolates (101/109) expressed CagA and 88.1% of serum samples (96/109) were CagA antibody positive. The percentage of CagA(+) H. pylori strains (97.9%) of peptic ulcer trended to be higher than that of gastritis (88.5%), but there was no statistically significant difference between two groups (chi(2)=3.48, P>0.05).

CONCLUSIONThe recombinant rCagA1 can be used to detect CagA of H. pylori and its antibody. No association is found between CagA expression of H. pylori strains and types of gastric diseases in this study.

Adolescent ; Adult ; Aged ; Amino Acid Sequence ; Antibodies, Bacterial ; blood ; Antigens, Bacterial ; biosynthesis ; genetics ; immunology ; Bacterial Proteins ; biosynthesis ; genetics ; immunology ; Base Sequence ; Female ; Gastritis ; microbiology ; Genes, Bacterial ; genetics ; Helicobacter Infections ; immunology ; metabolism ; Helicobacter pylori ; genetics ; immunology ; Humans ; Male ; Middle Aged ; Molecular Sequence Data ; Peptic Ulcer ; microbiology ; Prokaryotic Cells ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; Sequence Homology

BACKGROUND/AIMS: The aims of this study were to evaluate whether doctors and nurses in a single hospital were at an increased risk of acquiring Helicobacter pylori infection in 2011 and to identify risk factors for H. pylori seroprevalence. METHODS: Nurses (n=362), doctors (n=110), health personnel without patient contact (medical control, n=179), and nonhospital controls (n=359) responded to a questionnaire during a health check-up, which included questions on socioeconomic status, education level, working years, and occupation in 2011. The prevalence of H. pylori was measured by serology. RESULTS: The seroprevalence rate was 29.8% (nurses), 34.5% (doctors), 30.7% (medical control), and 52.9% (nonhospital control). Among younger subjects (<40 years of age), the nonhospital control had a higher seropositivity rate (48.1%) than nurses (29.2%), doctors (29.8%), and the medical control (24.8%), which was not observable in subjects > or =40 years of age. The risk factors for H. pylori seroprevalence were not different for health and nonhealth personnel. A multivariate analysis indicated that seropositivity significantly increased with age, the province of residence, and a gastroscopic finding of a peptic ulcer. CONCLUSIONS: The medical occupation was not associated with H. pylori infection. The seroprevalence of H. pylori in one hospital in 2011 was found to be 38.7%, most likely due to the improvement in socioeconomic status and hospital hygiene policy in Korea.
Administrative Personnel ; Adult ; Age Factors ; Antibodies, Bacterial/*blood ; Cross-Sectional Studies ; Female ; Helicobacter Infections/blood/*epidemiology ; Helicobacter pylori/*immunology ; Humans ; Male ; Medical Staff, Hospital ; Middle Aged ; Nursing Staff, Hospital ; *Occupational Health ; Peptic Ulcer/epidemiology ; *Personnel, Hospital ; Pharmacists ; Prevalence ; Republic of Korea/epidemiology ; Residence Characteristics ; Risk Factors ; Seroepidemiologic Studies ; Time Factors ; Young Adult