Hepatitis C Virus: Hepatitis C is caused by infection with the Hepatitis C virus (HCV). The term ‘hepatitis’ simply means inflammation of the liver. HCV is found in highest concentrations in blood and in lower concentrations in other body fluids (e.g., semen, vaginal secretions, and wound exudates). HCV infection is a major cause of hepatic disease and the leading reason for liver transplantation. Acute HCV infection is often asymptomatic, or associated with non-specific symptoms, and usually goes undiagnosed. However, 60% to 85% of patients develop chronic infection, which is associated with increased risk of cirrhosis, end-stage liver disease, and hepatocellular carcinoma.HCV infection can be self-limited or chronic. Hepatitis C virus (HCV) infection in a pregnant woman poses a serious risk to her infant at birth. Hepatitis C is spread mainly by exposure to infected blood or body secretions. In infected individuals, the virus can be found in the blood, semen, vaginal discharge, breast milk, and saliva. Hepatitis C is not
Spread through food, water, or by casual contact. After treatment is initiated, measurement of HCV viral load at specified times helps predict the likelihood of SVR (sustained virologic response) (absence of detectable HCV RNA in serum 24 weeks after end of treatment) and guide treatment decisions. Detection and quantitation of HCV RNA is an important component of diagnosis and treatment monitoring.
Methodology: Taqman Real time PCR assay
- Assess viral response to treatment as measured by changes in the HCV RNA levels
- Predict and monitor response to therapy
- Confirm active hepatitis C virus (HCV) infection In patient
- assess rapid (RVR) and early (EVR) virology response
- Guide duration of antiviral therapy Confirm resolution of infection and sustained virology response (SVR)
- Identify HCV viral load quantitation for epidemiologic and prognostic purposes
- Viral loads are predictive of future risk of developing cirrhosis and HCC
- Monitor patients who were infected with HCV prior to liver transplantation
- Injection-drug abusers
- All pregnant women
- Men who have sex with men
- Persons who are sources for exposures (needle-stick, sexual assault)
- Persons with elevated ALT/AST of unknown etiology
- Persons needing immunosuppressive therapy (transplant, rheumatology and gastroenterology)
- HIV-positive persons
HCV RNA PCR quantitative test – monitor effectiveness of treatment and perform when treatment is complete
- Monthly until week 12 of treatment
- Negative result confirms treatment success
Specimen Required: Blood, serum, plasma, Collect in: Lavender (EDTA), pink (K2EDTA), or serum separator tube. Stability collection to initiation of testing On Cells: Ambient: 4 hours; after separation from cells: Refrigerated: 48 hours; Frozen at -20°C: 72 hours; Frozen at -70°C: 4 months. Do not thaw avoid repeated freezing and thawing
NOTE- Samples should be collected during the viraemic phase for the presence of viruses during the active infection.
Specimen Preparation: Separate serum or plasma from cells within 24 hours.
Storage/Transport Temperature: Frozen-20 0C. Refrigerate specimens at 2°C-4°C.
Unacceptable Conditions: Heparinized specimens, Hemolysis sample, Quantity not sufficient for analysis, specimen grossly contaminated, specimen too old, frozen whole blood specimen, specimen leaky or tube broken.
Interpretation: This test can quantitate/detect Hepatitis C Virus RNA over the linear range 30-107 IU/mL. However this does not mean that lower copies or higher copies cannot be detected. The lower copies can be detected in some cases. This is a limitation of the currently available extraction systems. The test is intended for use in conjunction with clinical presentation and other markers as an aid in assessing viral response to antiviral treatment as measured by change in HCV RNA levels. Early changes in plasma/ serum HCV RNA levels may predict long term response to Interferon therapy. A negative result does not preclude the presence of HCV infection because results depend on adequate/proper patient sample storage and transportation as RNA is fragile and thermo labile, absence of inhibitors and sufficient RNA to be detected.
Patients suffering from chronic HCV infection typically have intermittent viraemia. Samples collected during the non- viraemic phase may test negative despite the presence of active infection. Hence, in such case’s where HCV PCR is negative despite strong clinical suspicion, a repeat sample collected at an interval of two weeks from the initial sample is strongly recommended to rule out active disease.
The result of this test must always be correlated with clinical status and history of the patient and other relevant data and should not be used alone for the interpretation.
Note: The test is intended for use in conjunction with clinical presentation and other laboratory markers as an indicator of disease prognosis. This test is also used as an aid in assessing viral response to antiretroviral treatment as measured by changes in HCV RNA levels.