What are the next steps for a patient with a reactive Hepatitis C Antibody (HCV Ab) test result?

Next Steps for a Patient with Reactive Hepatitis C Antibody Test

The next step for a patient with a reactive Hepatitis C Antibody (HCV Ab) test is to immediately proceed with HCV RNA testing via nucleic acid test (NAT) to confirm current infection status. 1 This is essential to distinguish between active infection and resolved or false positive results.

Understanding the Reactive HCV Antibody Result

A reactive HCV antibody test indicates one of three possibilities:

1. Current HCV infection
2. Past HCV infection that has resolved
3. False positive result

The presence of antibodies alone cannot distinguish between these scenarios, which is why confirmatory testing is critical.

Testing Algorithm

1. HCV RNA Testing (NAT)

   • Should be performed as soon as possible after the reactive antibody result
   • This is the definitive test to determine if active infection is present
   • Can be performed as a reflex test from the same blood sample or through a subsequent blood draw

2. Interpretation of HCV RNA Results:

   • If HCV RNA is detected: Confirms current HCV infection requiring linkage to care and treatment
   • If HCV RNA is not detected: Indicates either past resolved infection or false positive antibody result

Clinical Management Based on Results

If HCV RNA is Positive (Active Infection):

1. Comprehensive Evaluation:

   • Complete blood count
   • Liver function tests (AST/ALT, alkaline phosphatase, GGT, bilirubin, albumin)
   • Prothrombin time/INR
   • Assessment for liver fibrosis (non-invasive or biopsy)
   • HCV genotype testing (for treatment planning)

2. Referral to Specialist Care:

   • Prompt referral to hepatology, gastroenterology, or infectious disease specialist
   • Evaluation for antiviral therapy with direct-acting antivirals (DAAs)

3. HBV Screening:

   • Test for evidence of current or prior HBV infection (HBsAg and anti-HBc)
   • This is critical as HBV reactivation can occur during HCV treatment 2, 3

4. Patient Education:

   • Counseling on preventing transmission to others
   • Importance of avoiding alcohol
   • Vaccination against hepatitis A and B if susceptible

If HCV RNA is Negative (No Active Infection):

1. Patient Education:

   • Explain that this indicates either past resolved infection or false positive antibody test
   • Reassure that the patient is not currently infected and not infectious to others

2. Consider Additional Testing:

   • If recent exposure is suspected (within past 6 months), repeat HCV RNA testing may be warranted
   • For immunocompromised patients, additional testing should be considered 1

Important Considerations

• Reflex Testing Benefits: Studies show that reflex viral load testing significantly increases the likelihood of completing the diagnostic process (RR: 1.35; 95% CI: 1.16-1.58) and may improve linkage to care 4

• Timing: HCV RNA testing should ideally be performed within 48 hours of receiving the reactive antibody result 5

• Risk of HBV Reactivation: All patients with HCV should be tested for HBV before initiating treatment, as HBV reactivation during HCV treatment can lead to fulminant hepatitis, liver failure, and death 2, 3

• Treatment Efficacy: Modern direct-acting antiviral treatments have high cure rates (>95%) and are well-tolerated, making early diagnosis and treatment crucial for preventing complications like cirrhosis and hepatocellular carcinoma 1

Common Pitfalls to Avoid

1. Failing to order HCV RNA testing after a reactive antibody test - this leaves the diagnosis incomplete

2. Misinterpreting antibody positivity as current infection without RNA confirmation

3. Neglecting HBV screening before initiating HCV treatment

4. Delaying referral to specialist care for patients with confirmed active infection

5. Inadequate patient education about transmission risk and lifestyle modifications

By following this systematic approach to HCV diagnosis and management, you can ensure appropriate care for patients with reactive HCV antibody tests and optimize outcomes by identifying those who need treatment while reassuring those who do not have active infection.