What Does a Hepatitis C Antibody (Hep C Ab) Reactive Result Mean?
A reactive hepatitis C antibody test means that antibodies to HCV have been detected in your blood, but this does NOT automatically mean you have active hepatitis C infection—it requires follow-up HCV RNA testing to determine if you have current infection, past resolved infection, or a false-positive result. 1
Three Possible Interpretations of a Reactive HCV Antibody
A reactive HCV antibody result indicates one of three scenarios 1:
- Current active HCV infection (requires treatment)
- Past HCV infection that has resolved (either spontaneously or through successful treatment)
- False-positive result (no infection ever occurred)
Critical Next Step: HCV RNA Testing Required
You must proceed immediately to HCV RNA testing (nucleic acid test) to distinguish between these three possibilities. 1
Interpretation Based on HCV RNA Results:
If HCV RNA is detected: This confirms current active HCV infection requiring medical evaluation and treatment 1, 2
If HCV RNA is NOT detected: This indicates either:
Understanding False-Positive Results
The likelihood of false-positive results varies significantly by population 1:
- Low-risk populations (general population, healthcare workers, blood donors): Approximately 35% of reactive results are false-positives (range 15-60%) 1
- Immunocompromised populations (hemodialysis patients): Approximately 15% are false-positives 1
This high false-positive rate is why you cannot rely on antibody testing alone—confirmatory testing is essential. 1
Clinical Management Algorithm
If HCV Antibody Reactive + HCV RNA Detected:
- Patient has current HCV infection 1, 2
- Requires counseling, medical evaluation, and consideration for antiviral treatment 1
- Patient is infectious and can transmit HCV to others 2
If HCV Antibody Reactive + HCV RNA NOT Detected:
- No current HCV infection 2
- No treatment required 2
- Patient is NOT infectious 2
- No further action needed in most cases 2
Exceptions Requiring Repeat HCV RNA Testing:
- Suspected HCV exposure within the past 6 months (window period) 1, 2
- Clinical evidence of active liver disease 1, 2
- Immunocompromised patients 1, 2
- Concerns about specimen handling or storage 1
Important Clinical Caveats
Window Period Considerations: False-negative antibody results can occur during the first weeks after infection before antibody develops, though HCV RNA can be detected as early as 1-2 weeks after exposure 1
Immunocompromised Patients: Occasionally, persons with chronic HCV infection who are immunocompromised may be persistently antibody-negative, and HCV RNA detection might be the only evidence of infection 1
Reinfection Risk: If the reactive antibody represents past resolved infection, the patient can be reinfected if exposed again—HCV antibodies do NOT provide protective immunity 2
Patient Counseling Points
When HCV antibody is reactive but RNA is negative 2:
- You do not have active hepatitis C infection
- You are not infectious to others
- No treatment is needed
- If this represents past infection, you can be reinfected with future exposure