What is the recommended initial blood work for patients with chronic hepatitis C (HCV) who have elevated aspartate aminotransferase (AST) and alanine aminotransferase (ALT)?

Recommended Blood Work for Chronic Hepatitis C Patients with Elevated AST and ALT

For patients with chronic hepatitis C and elevated transaminases, obtain a complete blood count, international normalized ratio, comprehensive hepatic function panel (albumin, total and direct bilirubin, ALT, AST, alkaline phosphatase), calculated GFR, HCV genotype and subtype, and quantitative HCV viral load within 12 weeks prior to initiating antiviral therapy. 1

Essential Pre-Treatment Laboratory Panel

The AASLD-IDSA guidelines provide a clear framework for initial assessment 1:

Core Laboratory Tests (within 12 weeks of treatment initiation)

• Complete blood count - Essential for assessing baseline hematologic status and detecting thrombocytopenia, which may indicate advanced fibrosis 1
• International normalized ratio (INR) - Critical marker of hepatic synthetic function 1
• Comprehensive hepatic function panel including:
  • Albumin
  • Total and direct bilirubin
  • ALT and AST (already elevated in your patient)
  • Alkaline phosphatase 1
• Calculated glomerular filtration rate (GFR) - Required for medication dosing and monitoring renal function 1

Virologic Assessment

• HCV genotype and subtype - Determines treatment regimen selection 1
• Quantitative HCV viral load - Establishes baseline viremia, though this may be deferred if it won't influence treatment duration 1

Additional Monitoring for Patients Not Achieving SVR

If your patient has not yet been treated or failed previous treatment, the following monitoring is recommended every 6-12 months 1:

• Hepatic function panel - Monitor disease progression 1
• Complete blood count - Assess for cytopenias suggesting portal hypertension 1
• International normalized ratio - Track synthetic function 1

Fibrosis Assessment Considerations

While not explicitly required in the initial blood work, noninvasive fibrosis assessment should be considered 1:

• Platelet count <140,000/mm³ has 83% sensitivity and 85% specificity for detecting cirrhosis in HCV patients 2
• AST/ALT ratio ≥1 suggests advanced fibrosis or cirrhosis, with 39% sensitivity but 92% specificity 2
• Combined platelet count ≤140,000/mm³ and globulin/albumin ratio ≥1 achieves 100% specificity for cirrhosis 2

Important Clinical Pitfalls to Avoid

Do not rely solely on transaminase levels to assess disease severity. Both AST and ALT can be normal or minimally elevated even in patients with active disease and advanced fibrosis 3. In fact, AST may remain elevated in patients whose ALT has normalized, suggesting that measuring both enzymes provides complementary information 3.

The AST/ALT ratio increases with histological progression. A ratio ≥1 is highly suggestive of cirrhosis in HCV patients 3, 4. This ratio correlates significantly with both histologic stage and liver functional impairment (r=-0.621, P<0.001 with MEGX testing) 4.

Elderly patients with elevated transaminases require closer monitoring. In patients ≥65 years with chronic HCV, cirrhosis and HCC develop more frequently in those with AST/ALT >40 IU/L compared to those with normal levels (p<0.001) 5.

Surveillance for Advanced Disease

If advanced fibrosis (Metavir F3-F4) is present or suspected based on the above parameters 1:

• Ultrasound surveillance for HCC every 6 months 1
• Endoscopic surveillance for esophageal varices if cirrhosis is confirmed 1

Thyroid Function Monitoring

• Thyroid-stimulating hormone is only required if interferon-based therapy is planned (every 12 weeks during treatment) 1

This systematic approach ensures comprehensive baseline assessment while identifying patients who require more intensive monitoring or immediate treatment consideration based on disease severity markers.