What laboratory tests are recommended for the diagnosis and management of cirrhosis?

Laboratory Tests for Cirrhosis

For diagnosis and management of cirrhosis, obtain a comprehensive hepatic function panel including bilirubin, AST, ALT, alkaline phosphatase, albumin, PT/INR, and platelet count, along with a complete blood count and renal function tests (creatinine, BUN). 1

Initial Diagnostic Laboratory Panel

When cirrhosis is suspected, the following tests should be ordered immediately:

Core Liver Function Tests

• Bilirubin (total and direct/conjugated) - elevated conjugated bilirubin indicates advanced disease or biliary obstruction 1
• AST and ALT - typically elevated in active liver injury, with AST/ALT ratio often >1 in cirrhosis 1
• Alkaline phosphatase - may be elevated, particularly in cholestatic liver disease 1
• GGT (gamma-glutamyl transferase) - useful for detecting hepatobiliary involvement and calculating fibrosis indices 1
• Albumin - decreased levels indicate impaired synthetic function and are part of prognostic scoring 1
• PT/INR - prolonged values reflect impaired hepatic synthetic function and are critical for Child-Pugh and MELD scoring 1

Hematologic Parameters

• Complete blood count with platelet count - thrombocytopenia (platelets <150,000/mm³) suggests portal hypertension and is a surrogate marker for advanced disease 1
• Platelet count is specifically important for calculating fibrosis indices like APRI and FIB-4 1

Renal Function

• Creatinine and BUN - essential for MELD score calculation and detecting hepatorenal syndrome 1
• Creatinine is an established prognostic marker in liver disease 1

Etiologic Workup

Once cirrhosis is suspected, determine the underlying cause with these additional tests:

Viral Hepatitis Screening

• Hepatitis B panel: HBsAg, hepatitis B surface antibody, hepatitis B core antibody (HBcAb total and IgM if acute hepatitis suspected) 1
• Hepatitis C antibody with reflex to viral load if positive 1
• Confirm viral load in all positive cases to guide antiviral therapy 1

Metabolic and Autoimmune Causes

• Ferritin and transferrin saturation - screen for hemochromatosis 1, 2
• Autoimmune markers - consider if etiology unclear 1
• Alpha-1 antitrypsin level - screen for alpha-1 antitrypsin deficiency 1
• Ceruloplasmin - consider for Wilson disease, particularly in younger patients 1

Additional Markers

• Mean corpuscular volume (MCV) - elevated in alcohol-related liver disease and useful for the ALD/NAFLD index 1

Monitoring and Prognostic Laboratory Tests

For patients with established cirrhosis, perform these tests every 6 months:

Prognostic Scoring Components

• Child-Pugh score components: albumin, bilirubin, PT/INR (combined with clinical assessment of ascites and encephalopathy) 1
• MELD score components: bilirubin, creatinine, INR - provides numerical scale from 6-40 for transplant prioritization 1
• Albumin-bilirubin (ALBI) grade - useful for predicting survival in decompensated cirrhosis 1

Fibrosis Assessment Indices

Calculate these non-invasive markers using routine labs:

• APRI (AST to Platelet Ratio Index): [(AST/ULN AST)/platelet count] × 100, with threshold ≥0.545 suggesting advanced fibrosis 1
• GPR (GGT to Platelet Ratio): [(GGT/ULN GGT)/platelet count] × 100, with threshold ≥0.32 suggesting F3-F4 fibrosis 1
• FIB-4: (Age × AST)/(platelet count × √ALT) - values >1.5 suggest fibrosis 1

Ascites-Specific Testing

When ascites is present or develops:

Diagnostic Paracentesis

• Ascitic fluid cell count with differential - neutrophil count >250/mm³ diagnoses spontaneous bacterial peritonitis 1
• Ascitic fluid total protein - helps classify ascites type 1
• Serum-ascites albumin gradient (SAAG) - requires simultaneous serum albumin; SAAG ≥1.1 g/dL indicates portal hypertension 1
• Ascitic fluid culture - inoculate blood culture bottles at bedside when SBP suspected 1

Additional Ascitic Fluid Tests (Based on Clinical Context)

• Cytology, amylase, BNP, adenosine deaminase - order based on pre-test probability of specific diagnoses 1

Critical Clinical Pitfalls

Avoid using high thresholds for liver enzyme abnormalities - use age and sex-normative values, as delayed diagnosis can occur when waiting for values >1.5-2× upper limit of normal 1. Persistent abnormalities over 3-6 months warrant further evaluation even if mildly elevated 1.

Do not rely solely on laboratory tests to exclude cirrhosis - many patients with histological cirrhosis have normal liver enzymes, particularly in compensated disease 1, 2. Combine laboratory findings with imaging and elastography for accurate assessment 2, 3.

Recognize transient elevations - liver enzymes may be temporarily elevated during systemic inflammation or antibiotic treatment; perform screening during clinical stability 1.

In patients with ascites on hospital admission, perform diagnostic paracentesis immediately without delay to rule out SBP, even if asymptomatic 1. Also perform paracentesis urgently in patients with GI bleeding, shock, fever, encephalopathy, or worsening liver/renal function 1.