title: Immunoblotting and serology for diagnosis of Helicobacter pylori infection in children.
abstract: BACKGROUND
  The easiest way to identify the presence of current or past Helicobacter pylori infection is to test for antibodies. The aim of this study was to compare an enzyme-linked immunosorbent assay (ELISA) technique based on the detection of IgG antibodies directed against a global antigenic preparation with immunoblotting based on the analysis of IgG antibody reactivity to separate proteins.
  
  
  METHODS
  Sera were collected from 80 children (mean age, 9.9 +/- 4.3 years). The reference tests were microbiologic and histologic examination of gastric biopsies obtained at upper endoscopy.
  
  
  RESULTS
  The immunoblotting was more sensitive (100%) and specific (88%) than ELISA (96 and 79%, respectively) in the evaluation of H. pylori infection in children. Its positive predictive value was 92%, and its negative predictive value was 100%. The best performance index of immunoreactive bands to detect antibodies was obtained with the 26-kDa (88.7%), 30-kDa (77.5%) and 19.5-kDa (70%) antigens. Antibodies by immunoblot technique against the CagA antigen were present in 43.1% of children.
  
  
  CONCLUSIONS
  Immunoblotting is highly sensitive and more specific than ELISA in children and provides additional information about the full serologic profile. Immunoblotting may therefore be a useful complement to serology, particularly in cases with doubtful ELISA results.
authors.affiliation: Microbiology Service, Hôpital St. Vincent de Paul, Paris, France. j.raymond@svp.ap-hop-paris.fr
authors.forename: J
authors.initials: J
authors.lastname: Raymond
authors.forename: C
authors.initials: C
authors.lastname: Sauvestre
authors.forename: N
authors.initials: N
authors.lastname: Kalach
authors.forename: M
authors.initials: M
authors.lastname: Bergeret
authors.forename: C
authors.initials: C
authors.lastname: Dupont
mesh_terms: D000293:Adolescent; D000907:Antibodies, Bacterial / Q000097:blood*; D002648:Child; D004797:Enzyme-Linked Immunosorbent Assay; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000382:microbiology; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D015151:Immunoblotting; D007074:Immunoglobulin G / Q000097:blood*; D011237:Predictive Value of Tests; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D012698:Serologic Tests
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D011933:Reagent Kits, Diagnostic