Answer
E. Patients with a positive antibody to hepatitis C virus (HCV) but negative HCV RNA do not have HCV infection, and no further testing is required.
Patients who are hepatitis C virus (HCV) antibody positive but HCV RNA negative do not have HCV infection. Therefore they do not need further testing. Consider repeating the HCV RNA test if there are risk factors for recent HCV infection or if there is other clinical evidence of liver disease, but neither of these is present in this patient. The 2013 guideline from the U.S. Preventive Services Task Force recommended screening for hepatitis C once in all persons born between 1945 and 1965, as well as targeted screening of persons with risk factors such as illicit drug use, receipt of blood products, hemodialysis, and multiple sex partners. Screening is accomplished by testing for antibody to HCV (anti-HCV). If antibody testing is positive, the next step is to perform HCV RNA testing, which is often done by “reflex” testing in many laboratories. The test results are interpreted in the following ways: Positive anti-HCV with negative HCV RNA indicates either false-positive anti-HCV or cleared infection, and positive anti-HCV with positive HCV RNA indicates active infection. Rarely, in instances of acute HCV infection or in an immunosuppressed patient, HCV RNA may be positive despite a negative anti-HCV.
Liver ultrasound and serial alanine aminotransferase monitoring are not necessary in the absence of clinical evidence of liver disease.
Reference
Centers for Disease Control and Prevention (CDC). Testing for HCV infection: an update of guidance for clinicians and laboratorians. MMWR Morb Mortal Wkly Rep. 2013 May 10;62(18):362-5. PMID: 23657112