title: Diagnostic value of anti-smooth muscle antibodies and liver enzymes in differentiation of extrahepatic biliary atresia and idiopathic neonatal hepatitis.
abstract: BACKGROUND
  We aimed to evaluate the diagnostic value of anti-smooth muscle antibodies (ASMA) and two liver markers (gamma-glutamyl transpeptidase [GGT] and alkaline phosphatase [ALP]) for differentiating between patients with extrahepatic biliary atresia (EHBA) and idiopathic neonatal hepatitis (INH).
  
  
  METHODS
  During April 2010-2011, all infants at 2 weeks of age who were diagnosed with cholestasis and admitted to Children's Hospital of Tabriz were enrolled. Based on the results of physical examination, laboratory, imaging and pathological studies, neonates were divided into two groups (EHBA and INH). Receiver operating characteristics analysis was used to define sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for ASMA, GGT and ALP.
  
  
  RESULTS
  Thirty neonates with cholestasis (18 with EHBA and 12 with INH) and mean age of 54.66 ΁ 25.86 days were enrolled. Total and direct bilirubin, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase and ASMA titres were highly not significant (P > 0.05) in patients with INH. GGT (P = 0.008) and ALP (P = 0.01) had statistically significant differences that were higher in patients with EHBA. The sensitivity, specificity, PPV and NPV, accuracy, LR+ and LR- of SMA in differentiating cases with BA were 66.7%, 75%, 80% 60%, 70%, 2.68 and 0.44, respectively. For GGT, the values were 88.9%, 66.7%, 80%, 80%, 79.1%, 3.08 and 0.31, respectively. Finally, for ALP, the values were 77.8%, 75%, 82.4%, 69.2%, 80%, 2.66 and 0.24, respectively.
  
  
  CONCLUSIONS
  Our study showed that ASMA may be a useful biomarker for differentiation of EHBA from INH. Further studies with larger samples are recommended for confirming the results of this study.
authors.affiliation: Liver and Gastrointestinal Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Mandana
authors.initials: M
authors.lastname: Rafeey
authors.affiliation: Department of Pediatrics, Pediatric Health Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Lida
authors.initials: L
authors.lastname: Saboktakin
authors.affiliation: Liver and Gastrointestinal Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Jamshid Shoa
authors.initials: JS
authors.lastname: Hasani
authors.affiliation: Liver and Gastrointestinal Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Shahnaz
authors.initials: S
authors.lastname: Naghashi
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism*; D000906:Antibodies / Q000097:blood*; D001656:Biliary Atresia / Q000097:blood / Q000175:diagnosis* / Q000201:enzymology; D015415:Biomarkers / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D006505:Hepatitis / Q000097:blood / Q000175:diagnosis* / Q000201:enzymology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009130:Muscle, Smooth / Q000276:immunology*; D011237:Predictive Value of Tests; D012372:ROC Curve; D005723:gamma-Glutamyltransferase / Q000378:metabolism*
chemical_list: D000906:Antibodies; D015415:Biomarkers; D005723:gamma-Glutamyltransferase; D000469:Alkaline Phosphatase