What further laboratory tests are necessary for a patient with confirmed Hepatitis C (HCV) infection?

Laboratory Tests Required for Patients with Confirmed Hepatitis C Infection

For patients with confirmed Hepatitis C virus (HCV) infection, a comprehensive panel of laboratory tests should be performed to assess liver function, determine viral characteristics, screen for co-infections, and evaluate for potential treatment complications. 1

Initial Assessment Tests

• HCV RNA quantification - Essential to confirm active infection and establish baseline viral load before treatment 1
• HCV genotype and subtype determination - Critical for selecting appropriate direct-acting antiviral (DAA) therapy regimen 1
• Liver function tests - ALT, AST, alkaline phosphatase, total and direct bilirubin, albumin, and prothrombin time/INR to assess liver damage 1
• Complete blood count (CBC) - To evaluate for cytopenias that may be associated with advanced liver disease or could be affected by treatment 1
• Hepatitis B virus (HBV) testing - HBsAg and anti-HBc to screen for current or prior HBV infection that could reactivate during HCV treatment 2

Additional Required Testing

• Renal function tests - Serum creatinine and estimated glomerular filtration rate (eGFR) to guide medication selection and dosing 3
• HIV antibody testing - To identify HIV co-infection which may affect disease progression and treatment approach 1
• Pregnancy testing - For women of childbearing age, especially if ribavirin (which is teratogenic) might be used in the treatment regimen 2, 3
• Alpha-fetoprotein (AFP) - For screening of hepatocellular carcinoma in patients with cirrhosis 4

Assessment of Liver Disease Severity

• Fibrosis assessment - Either through non-invasive methods (FibroScan, FibroTest) or liver biopsy to determine the stage of liver fibrosis 1
• Imaging studies - Ultrasound, CT, or MRI to evaluate for signs of cirrhosis, portal hypertension, or hepatocellular carcinoma 1

Pre-Treatment Considerations

• Drug-drug interaction screening - Assessment of current medications that might interact with planned HCV treatment 2
• Resistance-associated substitution (RAS) testing - May be considered in specific situations where resistance might affect treatment outcomes 5

Monitoring During and After Treatment

• HCV RNA testing - To monitor viral response during and after treatment (typically at week 4, end of treatment, and 12 weeks post-treatment to confirm sustained virological response) 1
• Liver function tests - Regular monitoring of ALT/AST during treatment 1
• CBC - Particularly important if ribavirin is part of the treatment regimen 3
• Renal function - Particularly for regimens containing sofosbuvir in patients with renal impairment 3

Special Considerations

• For patients with cirrhosis - More frequent monitoring of liver function and regular screening for hepatocellular carcinoma and varices is recommended 4
• For patients with HBV co-infection - Regular monitoring of HBV DNA and liver enzymes during and after HCV treatment to detect potential HBV reactivation 2

Common Pitfalls to Avoid

• Failing to test for HBV co-infection - HBV reactivation can occur during or after HCV treatment, potentially leading to fulminant hepatitis, liver failure, and death 2
• Inadequate monitoring of drug interactions - Particularly with amiodarone, which can cause serious symptomatic bradycardia when co-administered with sofosbuvir-containing regimens 3, 2
• Relying solely on antibody testing - HCV RNA testing is essential to confirm active infection, as antibody testing alone cannot distinguish between resolved and current infection 1
• Overlooking the need for post-treatment monitoring - Sustained virological response should be confirmed 12 weeks after completion of treatment 1