Aetiology and diagnostic utility of serum ascites albumin gradient in children with ascites

Abstract

BackgroundAscites in children is multifactorial and serum ascites albumin gradient (SAAG) ≥1.1 helps differentiate portal hypertension (PHTN) related from non-PHTN ascites. AimsWe evaluated the aetiology and diagnostic accuracy of SAAG in children with ascites. MethodsChildren with ascites were retrospectively evaluated. Etiological diagnosis was based on clinical presentation and investigations. All cases with ascitic fluid analysis and a definite diagnosis were included for calculating the utility of SAAG. ResultsWe enrolled 878 children (568[64.7%] boys). Majority were PHTN related (638[72.7%]) and secondary to acute viral hepatitis (98,15.4%), acute liver failure (185,29%), chronic liver disease (276,43.3%) and Budd-Chiari syndrome (79,12.4%). Other causes included tubercular (46,5.2%), pancreatic (32,3.6%), chylous (20,2.3%), biliary (12,1.4%), pseudoascites (16,1.8%), infections (46,5.2%), nephrotic (26,2.9%), malignancy (23,2.6%), cardiac (9,1.0%) and others (10,1%). SAAG (n = 305) correctly differentiated PHTN and non-PHTN ascites in 272 (89.2%) cases, with a high sensitivity (97%), specificity (93%) and diagnostic accuracy (95.8%). Reasons for inaccurate SAAG included mixed ascites (n = 9), different day serum and ascitic fluid albumin estimation (n = 5), serum albumin ≤1.1 g/dL (n = 2), chylous ascites (n = 3), hypergammaglobulinemia (n = 1), albumin infusions (n = 1) and unexplained (n = 12). ConclusionsNearly 27% children had non-PHTN related ascites. SAAG differentiates PHTN from non-PHTN ascites with a diagnostic accuracy of 95%.