ABSTRACT
We compared a noninvasive serological test using a commercial immunoblot assay (Helicoblot 2.0) to tissue-based methods [rapid urease test (CLO test), histology and culture] in eighty Thai patients undergoing upper endoscopy. A true positive test was defined as at least two of the biopsy-related tests being positive. The CLO test was the most accurate test with sensitivity and specificity as high as 100%, whereas histology and culture had sensitivity of 100% and 72.2%, respectively, and the specificity of 72.7% and 96%, respectively. The serological test had a high sensitivity (97.2%) but exhibited an unsatisfactory specificity (40.9%). We concluded that the rapid urease test using multiple gastric biopsies was the most appropriate method for diagnosing H. pylori status. The role of immunoblot assay as a serological screening test in our population remains doubtful, but it may identify patients who have been infected with certain strains of H. pylori.
Subject(s)
Helicobacter Infections/diagnosis , Helicobacter Infections/immunology , Helicobacter pylori , Immunoblotting/methods , Adult , Aged , Aged, 80 and over , Antibodies, Bacterial/blood , Biopsy , Female , Helicobacter Infections/complications , Helicobacter Infections/enzymology , Helicobacter pylori/immunology , Helicobacter pylori/isolation & purification , Humans , Immunoblotting/statistics & numerical data , Male , Middle Aged , Sensitivity and Specificity , Serologic Tests , Stomach Ulcer/complications , Urease/analysisABSTRACT
Two hybridoma cell lines producing monoclonal antibodies (MAbs) against a hemagglutinin/protease (HA/P) from Vibrio cholerae non-01 were produced and characterized. The two MAbs contained the kappa light chain and were IgG1 type. They similarly neutralized HA/P protease activity derived from both V. cholerae non-01 and V. cholerae 01, whereas they were unable to neutralize the hemagglutinating activity of HA/P, suggesting that the epitopes for protease and hemagglutination activities are different. Western blotting analysis and the cross-neutralization test with the two MAbs confirmed the identity of HA/P produced by V. cholerae non-01 and 01. This study also suggests that HA/P of V. cholerae and a protease of V. parahaemolyticus are immunologically unrelated.
Subject(s)
Antibodies, Bacterial/immunology , Antibodies, Monoclonal/immunology , Metalloendopeptidases/immunology , Vibrio cholerae/immunology , Animals , Blotting, Western , Cell Line , Enzyme-Linked Immunosorbent Assay , Hemagglutination , Hybridomas , Mice , Neutralization Tests , Vibrio cholerae/enzymologyABSTRACT
A protease produced by a clinical isolate of Vibrio cholerae non-O1 was purified to apparent homogeneity by ammonium sulfate fractionation and successive column chromatography on DEAE-Sephadex A25, Sephadex G100, Mono Q, and Phenyl Superose. Like the hemagglutinin-protease of V. cholerae O1, the purified protease had both hemagglutinating and proteolytic activities. The protease was heat labile, and in contrast to crude preparations, no Arrhenius effect was observed with the purified protein. Immunological analyses indicated that the proteases (or hemagglutinins) derived from V. cholerae O1 and non-O1 are identical.
