title: Relevance of adjusted cut-off values in commercial serological immunoassays for Helicobacter pylori infection in children.
abstract: We assessed the sensitivity and specificity of H. pylori IgG and IgA with a commercial immunoassay performed in Chile and a second non-commercial immunoassay performed in a reference laboratory in the United States, in serum of 80 children and adults referred for gastrointestinal endoscopies in a developing country. Overall, 56% of the patients were infected with H. pylori based on rapid urease test and staining techniques on gastric biopsies. When Receiver Operator Curves (ROC) were developed, the sensitivity and specificity were similar for IgG and IgA. Both immunoassays exhibited better specificity, positive and negative predictive value (NPV) in children than in adults when cut-off values were corrected according to the local population than when they were assessed using the cut-off values pre-defined in other populations. These results underline the need to establish more precise cut-off values corrected in the local populations where assessments of antibodies as diagnostic markers of H. pylori infection are planning.
authors.affiliation: Department of Pediatrics, Pontificia Universidad Catolica de Chile, School of Medicine, Santiago, Chile.
authors.forename: Paul
authors.initials: P
authors.lastname: Harris
authors.forename: Guillermo
authors.initials: G
authors.lastname: Perez-Perez
authors.forename: Alejandro
authors.initials: A
authors.lastname: Zylberberg
authors.forename: Antonio
authors.initials: A
authors.lastname: Rollán
authors.forename: Carolina
authors.initials: C
authors.lastname: Serrano
authors.forename: Francisca
authors.initials: F
authors.lastname: Riera
authors.forename: Helly
authors.initials: H
authors.lastname: Einisman
authors.forename: Daniela
authors.initials: D
authors.lastname: García
authors.forename: Paola
authors.initials: P
authors.lastname: Viviani
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood; D002648:Child; D002675:Child, Preschool; D002677:Chile; D003906:Developing Countries; D005260:Female; D016481:Helicobacter Infections / Q000097:blood / Q000175:diagnosis* / Q000276:immunology*; D016480:Helicobacter pylori / Q000276:immunology* / Q000302:isolation & purification*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity
chemical_list: D000907:Antibodies, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G