title: Serological assessment of the early response to eradication therapy using an immunodominant outer membrane protein of Helicobacter pylori.
abstract: Eradication of Helicobacter pylori infection cures gastritis and prevents recurrence of peptic ulcers. Endoscopy is usually used to evaluate the effectiveness of eradication therapy. We designed a new noninvasive assay system for the early evaluation of eradication of H. pylori infection in which a crude H. pylori outer membrane protein preparation (HPOmp) is used as an antigen, and we determined the sensitivity and specificity of the serological assay system. Immunoblot analysis showed that anti-HPOmp antibodies reacted to a protein with a molecular mass of approximately 29 kDa. In those patients who responded to therapy, the anti-HPOmp immunoglobulin G (IgG) titers measured by enzyme-linked immunosorbent assay (ELISA) at 1 month after the end of therapy were significantly lower than those before treatment (34.8% reduction; P < 0.001), and the posttreatment reduction in the antibody titer was significantly greater than that of the titer measured with a commercially available anti-H. pylori IgG ELISA (34.8% versus 16.1%; P < 0.001). When a 25% reduction of anti-HPOmp IgG titer at 1 month after the end of treatment was taken as the cutoff value for H. pylori eradication, the sensitivity and specificity of our new assay were 75% (51 of 68 treatment responders) and 96% (22 of 23 nonresponders), respectively. Our results indicate that the novel serological test with HPOmp might be a clinically useful tool for assessment of eradication of H. pylori.
authors.affiliation: Department of Infectious Diseases Control, Oita Medical University, Oita, Japan. a24zono@oita-med.ac.jp
authors.forename: A
authors.initials: A
authors.lastname: Nishizono
authors.forename: T
authors.initials: T
authors.lastname: Gotoh
authors.forename: T
authors.initials: T
authors.lastname: Fujioka
authors.forename: K
authors.initials: K
authors.lastname: Murakami
authors.forename: T
authors.initials: T
authors.lastname: Kubota
authors.forename: M
authors.initials: M
authors.lastname: Nasu
authors.forename: M
authors.initials: M
authors.lastname: Watanabe
authors.forename: K
authors.initials: K
authors.lastname: Mifune
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005069:Evaluation Studies as Topic; D005260:Female; D016481:Helicobacter Infections / Q000188:drug therapy* / Q000276:immunology / Q000382:microbiology; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D015151:Immunoblotting; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins