The presence of HCV RNA in serum indicates an active infection. Testing for HCV RNA is also helpful in patients in whom EIA tests for anti-HCV are unreliable. Likewise, patients with acute hepatitis may test negative for anti-HCV when the physician first tests. In these situations, HCV RNA is usually present and confirms the diagnosis. Recombinant Immunoblot Assay Immunoblot assays are used to confirm anti-HCV reactivity, too.
Color changes indicate that antibodies are adhering to the proteins.
An immunoblot is considered positive if two or more proteins react and is considered indeterminate if only one positive band is detected. If the immunoblot test for anti-HCV is positive, the patient has most likely recovered from hepatitis C and has persistent antibody without virus. If the immunoblot test is negative, the EIA result was probably a false positive. Immunoblot assays are highly specific and valuable in verifying anti-HCV reactivity. PCR Amplification PCR amplification can detect low levels of HCV RNA in serum.