What is the most likely cause of ascites in a patient with chronic viral hepatitis and a high serum-ascites albumin gradient (SAAG) (>1.1)?

Answer: Liver Cirrhosis (Option C)

In a patient with chronic viral hepatitis presenting with ascites and a SAAG >1.1 g/dL, liver cirrhosis is the most likely diagnosis, as a high SAAG indicates portal hypertension with 97% accuracy, and cirrhosis accounts for approximately 85% of all ascites cases. 1, 2

Understanding SAAG in This Clinical Context

The SAAG value is the definitive diagnostic tool here:

• A SAAG ≥1.1 g/dL confirms portal hypertension as the underlying mechanism with 97% accuracy 1, 2, 3
• This patient has chronic viral hepatitis, which is a well-established cause of cirrhosis and subsequent portal hypertension 1
• The progression from chronic viral hepatitis → cirrhosis → portal hypertension → ascites is the classic pathophysiologic sequence 1

Why the Other Options Are Incorrect

Pancreatitis (Option A):

• Pancreatic ascites produces a low SAAG (<1.1 g/dL), not high 3
• This is a non-portal hypertension cause of ascites 2

Tuberculosis (Option B):

• Tuberculous peritonitis causes low SAAG (<1.1 g/dL) ascites 1, 2, 3
• While TB can coexist with cirrhosis in "mixed ascites" (5% of cases), the primary driver would still be the cirrhosis, and the SAAG would remain ≥1.1 g/dL 1

Nephrotic Syndrome (Option D):

• Nephrotic syndrome produces low SAAG (<1.1 g/dL) ascites 1, 2, 3
• It is explicitly listed as a non-portal hypertension cause 1
• The exception is that nephrotic syndrome patients may respond to diuretics despite low SAAG, but this doesn't change the SAAG value itself 1

Clinical Epidemiology Supporting This Answer

Cirrhosis dominates the differential:

• Cirrhosis accounts for 68-85% of all ascites cases 4, 5
• Among high SAAG cases specifically, cirrhosis represents 81-95% of patients 4
• In patients with known chronic liver disease (like this patient with viral hepatitis), the pretest probability of cirrhotic ascites is extremely high 6

Key Diagnostic Principle

The SAAG categorizes ascites into two fundamental groups:

• High SAAG (≥1.1 g/dL): Portal hypertension causes - primarily cirrhosis, but also cardiac ascites, Budd-Chiari syndrome, and sinusoidal obstruction syndrome 2, 3
• Low SAAG (<1.1 g/dL): Non-portal hypertension causes - malignancy, tuberculosis, nephrotic syndrome, pancreatic ascites 2, 3

Given this patient's chronic viral hepatitis and high SAAG, liver cirrhosis is the overwhelmingly most likely diagnosis 1, 5.