Serum Ascites Albumin Gradient (SAAG) Interpretation

The serum ascites albumin gradient (SAAG) is a formula used to assist in determining the etiology of ascites. Also see Medscape’s Ascites Albumin Gradient Calculator.

The formula is below.

SAAG = serum albumin – ascites albumin

A high gradient (SAAG >1.1 g/dL) indicates portal hypertension and suggests a nonperitoneal cause of ascites. Such conditions may include the following:[1, 2]

• Cirrhosis

• Fulminant hepatic failure

• Veno-occlusive disease

• Hepatic vein obstruction (ie, Budd-Chiari syndrome)

• Congestive heart failure

• Nephrotic syndrome

• Protein-losing enteropathy

• Malnutrition

• Myxedema

• Ovarian tumors

• Pancreatic ascites

• Biliary ascites

• Malignancy

• Trauma

• Portal hypertension

A low gradient (SAAG < 1.1 g/dL) indicates nonportal hypertension and suggests a peritoneal cause of ascites. Such conditions may include the following:[1, 2]

• Primary peritoneal mesothelioma

• Secondary peritoneal carcinomatosis

• Tuberculous peritonitis

• Fungal and parasitic infections (eg, Candida, Histoplasma, Cryptococcus, Schistosoma mansoni, Strongyloides, Entamoeba histolytica)

• Sarcoidosis

• Foreign bodies (ie, talc, cotton and wood fibers, starch, barium)

• Systemic lupus erythematosus

• Henoch-Schönlein purpura

• Eosinophilic gastroenteritis

• Whipple disease

• Endometriosis