What are the implications and next steps for a patient with a reactive Hepatitis C (HCV) antibody test and an undetectable Hepatitis C virus (HCV) RNA level?

Interpretation of Reactive HCV Antibody with Undetectable HCV RNA

A reactive Hepatitis C antibody with undetectable HCV RNA (<15 IU/mL) indicates past, resolved HCV infection rather than current infection, and no specific hepatitis C treatment is required. 1

Understanding the Test Results

The laboratory results show:

• Hepatitis C Antibody: Reactive (abnormal)
• HCV RNA (LOG-10): <1.18 log-10 (within reference range)
• HCV RNA (IU): <15 ND (Not Detected) IU/mL

This pattern represents a classic case of resolved hepatitis C infection, where the patient:

• Has been exposed to HCV in the past (positive antibody)
• Has successfully cleared the virus (undetectable viral RNA)

Clinical Implications

What This Means

• The patient does not have active hepatitis C infection
• The patient is not infectious to others
• No HCV-specific treatment is needed
• The patient has likely developed some immunity to the specific HCV strain they were exposed to, though reinfection with different strains remains possible

Potential Scenarios Explaining These Results

1. Spontaneous viral clearance: Approximately 15-25% of people infected with HCV spontaneously clear the virus without treatment 1
2. Previously successful treatment: The patient may have received antiviral therapy in the past
3. False positive antibody test: Much less likely, but possible in low-risk populations 1

Recommended Next Steps

1. Patient education:

   • Explain that the patient had HCV exposure in the past but is not currently infected
   • Clarify that they are not infectious to others
   • Discuss that they do not need HCV treatment

2. Risk assessment:

   • Evaluate for ongoing risk factors for HCV reinfection
   • Provide counseling on prevention if risk factors exist

3. Consider additional testing only if:

   • Recent exposure (within past 6 months) is suspected 1
   • Patient is immunocompromised 1
   • There are concerns about specimen handling or storage 1

4. If uncertainty exists about false positivity:

   • Consider testing with a second, different HCV antibody assay to confirm true antibody positivity 1

Special Considerations

When to Repeat Testing

• Repeat HCV RNA testing is generally NOT needed unless:
  • The patient has had recent high-risk exposure (within 6 months)
  • The patient shows clinical evidence of liver disease despite negative RNA
  • The patient is severely immunocompromised 1

Common Pitfalls to Avoid

1. Misinterpreting as active infection: Some providers incorrectly assume any positive antibody means current infection
2. Unnecessary referrals: Referring to hepatology when no active infection exists
3. Failure to report: Remember that "hepatitis C (past or present)" is a reportable condition in most jurisdictions 1
4. Overlooking recent exposure: In cases of very recent infection (within 2-3 weeks), RNA may be positive before antibodies develop 2

By following this evidence-based approach, you can provide appropriate care and avoid unnecessary interventions for patients with resolved HCV infection.