title: In a diagnostic test study the validity of three serodiagnostic test was compared in patients with liver echinococcosis.
abstract: OBJECTIVE
  To determine the efficacy of immunoprecipitation (DD5), enzyme immunoanalysis (ELISA-IgG), and immunoelectrotransference or Western blot (WB) in patients with liver echinococcosis (LE) used separately, in parallel and in series.
  
  
  METHODS
  Diagnostic test study. DD5, ELISA-IgG, and WB were applied in 75 patients with LE and 75 with cholelithiasis. Surgery was considered a reference standard. The sample size was calculated assuming a 99% confidence interval (99% CI), expected sensitivity (S) of 90% and a worst result of 80%; expected specificity (SP) of 95% and a worst result of 85%. S, SP, and predictive values (PPV and NPV) were calculated.
  
  
  RESULTS
  The best S was verified with ELISA-IgG and WB (82.7%) and the best SP with DD5 (94.7%). DD5 presented a better PPV (92.9%) and WB a better NPV (83.5%). When applying the tests in parallel, the best S was obtained from the combination of DD5 and WB (82.7%); and the best SP, PPV and NPV with ELISA-IgG and WB (88.0%, 87.3%, and 83.5%, respectively).
  
  
  CONCLUSIONS
  DD5 appears as the most specific test and as having greater PPV; ELISA-IgG and WB are more sensitive. The combined use of these tests does not improve diagnosis validity.
authors.affiliation: Department of Surgery, Hospital Regional de Temuco, Faculty of Medicine, Universidad de La Frontera, Casilla 54-D, Temuco, Chile. cmantero@ufro.cl
authors.forename: Carlos
authors.initials: C
authors.lastname: Manterola
authors.forename: Alvaro
authors.initials: A
authors.lastname: Cuadra
authors.forename: Sergio
authors.initials: S
authors.lastname: Muñoz
authors.forename: Antonio
authors.initials: A
authors.lastname: Sanhueza
authors.forename: Luis
authors.initials: L
authors.lastname: Bustos
authors.forename: Manuel
authors.initials: M
authors.lastname: Vial
authors.forename: Flery
authors.initials: F
authors.lastname: Fonseca
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001652:Bile Ducts / Q000473:pathology; D015153:Blotting, Western / Q000379:methods; D004444:Echinococcosis, Hepatic / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D047468:Immunoprecipitation / Q000379:methods; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D012698:Serologic Tests
chemical_list: D007074:Immunoglobulin G