Hepatitis C

Question 1

What are the diagnostic tests in HCV?

Answer 1

HCV Ab

• Screening test
• Low false positive rate if risk factor/raised ALT
• False negs if immunosuppressed or window period (6 weeks)
• Does not distinguish between active and resolved disease

HCV RNA

• Uses PCR
• Most specific for active infection
• Usually positive at 1-2 weeks

Question 2

How are qualitative and quantitative HCV RNA tests used?

Answer 2

Qualitative
- Used to diagnose infection or test for cure

Quantitative

• Reflective of viral burden
• Predictor of response to IFN