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

Background: Ascites in children is multifactorial and serum ascites albumin gradient (SAAG) ≥1.1 helps differentiate portal hypertension (PHTN) related from non-PHTN ascites.

Aims: We evaluated the aetiology and diagnostic accuracy of SAAG in children with ascites.

Methods: Children 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.

Results: We 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).

Conclusions: Nearly 27% children had non-PHTN related ascites. SAAG differentiates PHTN from non-PHTN ascites with a diagnostic accuracy of 95%.