HCV IgM

Function

The HCV IgM test detects Immunoglobulin M antibodies against the Hepatitis C virus. IgM is the first antibody the immune system produces when it encounters a new infection. While HCV RNA (PCR) and HCV Total Ab (IgG) are more common, the IgM assay specifically helps in identifying recent exposure.

Why it is Ordered

This test is ordered when a physician suspects an acute (recent) Hepatitis C infection. Most cases of HCV are asymptomatic in the early stages, but some patients present with jaundice, dark urine, and extreme fatigue. Distinguishing between a new, acute infection and the exacerbation of a long-standing chronic infection is the primary clinical goal.

Associated Conditions

• Acute Hepatitis C: The primary condition where HCV IgM would be elevated.
• Liver Enzyme Elevation: Often ordered alongside ALT and AST tests to investigate the cause of liver inflammation.
• Chronic Hepatitis Flare: In some cases, patients with chronic HCV may show transient IgM positivity during a viral flare-up, though this is less common than in Hepatitis B.
• Recent Needle Stick/Exposure: Part of a post-exposure protocol for healthcare workers or individuals with high-risk exposure.