Intermittent Viremia in Acute Hepatitis C
Fluctuating ALT levels with intermittent viremia patterns are the most characteristic feature of acute hepatitis C, though the term "intermittent vitality" appears to be a misinterpretation—the clinical phenomenon is intermittent viremia and fluctuating biochemical markers, not vitality. 1
Key Clinical Pattern
The course of acute hepatitis C is inherently variable, with elevations in serum ALT levels occurring in a fluctuating pattern as its most characteristic feature 1. This fluctuation represents the hallmark of acute HCV infection rather than a stable, predictable course.
Specific Fluctuation Patterns
- Normalization of ALT levels may occur and initially suggests full recovery, but this is frequently followed by ALT elevations that indicate progression to chronic disease 1
- This fluctuating pattern makes single ALT determinations unreliable for excluding ongoing hepatic injury 1
- Patients may have prolonged periods (≥12 months) of normal ALT activity despite histologically confirmed chronic hepatitis 1
Viremia Patterns During Acute Phase
- HCV RNA appears in serum early during the incubation period, increases in titer, peaks at symptom onset, then disappears only in resolving disease 2
- In the 85% who progress to chronic infection, HCV RNA remains persistently present 2, 3
- The fluctuating nature of viremia during acute infection makes timing of testing critical for accurate diagnosis 4, 5
Clinical Implications
Diagnostic Challenges
- The fluctuating pattern of both ALT and viremia means that long-term follow-up is required to determine clinical outcome or prognosis 1
- A single negative HCV RNA test during the acute phase may be misleading if obtained during a transient dip in viremia 4
- Anti-HCV antibodies can be delayed in up to 30% of patients at symptom onset, making qualitative HCV RNA detection the most reliable diagnostic method 4
Monitoring Strategy
- Patients should be monitored with HCV RNA quantification every 4 weeks, with treatment considered for those still positive at 12 weeks after initial presentation 1
- This approach accounts for the fluctuating nature of acute infection while allowing time for spontaneous clearance 1, 6
Common Pitfall
The major pitfall is assuming viral clearance based on a single normal ALT or negative HCV RNA test during the acute phase, when the fluctuating pattern may simply represent a temporary dip before progression to chronicity 1. Sequential testing over months is essential to distinguish true spontaneous clearance from intermittent fluctuation 1, 4.