HCV RNA Quantitative RTPCR and HCV Genotyping combo
HCV RNA Quantitative RTPCR and HCV Genotyping combo
Hepatitis C virus (HCV) is an RNA virus that causes liver inflammation to interrupt the organ's ability to carry out its vital functions. Based on nucleotide sequence variations, HCV has at least seven distinct genotypes (1-7) and over 67 subtypes, labeled as genotypes 1a, 1b, 2a, etc. In India, genotype 3 (63.85%) and genotype 1 (25.72%) are the most prevalent, with other genotypes also present in various regions of the country.
Most people with HCV have one principal genotype that remains the same throughout the course of hepatitis C infection. While all genotypes of HCV can cause liver damage, the risk of leading to liver cirrhosis or cancer is higher in some than others. Therefore, identifying the specific HCV genotype and subtype is crucial for both patients and doctors when selecting treatment and monitoring response.
If you've been diagnosed with HCV, your doctor will perform a combined HCV RNA Quantitative RT-PCR and Genotyping Combo test to confirm the presence of HCV infection before starting treatment. They will also determine the specific HCV genotype causing your illness, enabling them to choose the most appropriate antiviral therapy to increase your chance of achieving a complete cure.
HCV RNA Quantitative RT-PCR and Genotyping Combo test can detect and distinguish HCV genotypes 1a,1b, 2 a/c, 2 b, 3, 4, 5, and 6
What is HCV RNA Quantitative RT-PCR and Genotyping Combo Used For?
HCV RNA Quantitative RT-PCR and Genotyping Combo is beneficial for:
To confirm the diagnosis of HCV infection in patients positive for HCV antibody
Measuring the patient’s HCV RNA viral load before initiating antiviral therapy
Determining the causative HCV genotype to select appropriate antiviral therapy
Assessing the sustained virologic response (SVR) during HCV treatment
Monitoring patient’s response to therapy
Which tests are included in HCV RNA Quantitative RT-PCR and Genotyping Combo?
This assay comprises two tests:
HCV RNA PCR Quantitative, Real-Time PCR
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This test uses polymerase chain reaction to measure the amount of HCV RNA in the blood in real-time during treatment. This helps clinicians assess the effectiveness of treatment and determine if any adjustments are necessary to enhance the patient's health outcome
HCV Genotyping
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This method differentiates HCV genotypes and the most common subtypes by looking at specific portions of the viral genetic material, like the 5' untranslated region (5' UTR), 3' core, NS5b, and 5' non-coding region
Symptoms of Hepatitis C
Most people with HCV lack symptoms. Yet, a small percentage may experience mild symptoms such as
Jaundice (yellow discoloration of the eye and skin)
Tiredness
Nausea and Vomiting
Fever
Pain in the upper right part of the belly
Joint pain
Dark-colored urine and stool
Preparation for Test
This test does not require any special preparation. Nevertheless, let your doctor know your medical history and the medications and supplements you take to avoid any interference in the accuracy of results
Interpretation of Test Results
The HCV RNA quantitative assay yields results that range from 15 to 100,000,000 IU/mL (1.18 to 8.00 log IU/mL). Specimens with HCV RNA levels greater than or equal to 500 IU/mL (2.70 log IU/mL) will be tested for the HCV genotype.
Specimens in which HCV RNA is undetectable or detectable but not measurable will not be considered for genotype evaluation.
|
HCV Genotype Results |
Interpretation |
|
1a |
Definitive genotype 1a |
|
1b |
Definitive genotype 1b |
|
2 |
Definitive genotype 2 |
|
3 |
Definitive genotype 3 |
|
4 |
Definitive genotype 4 |
|
5 |
Definitive genotype 5 |
|
6 |
Definitive genotype 6 |
|
1 |
Definitive genotypes could not be assigned. Sample may have subtype 1a, 1b |
|
Indeterminate |
HCV RNA detected(i.e., less than 500 IU/mL), but genotype can't be assigned |
|
Indeterminate (Mix genotype) |
Results may be due to low HCV RNA levels or probe reactivity to multiple genotypes(genotypes 1 and 2; genotypes 1 and 3; genotypes 1 and 4; genotype 1 and 6) or mixed genotype infeection |
|
Undetected |
Assay failed to detect HCV RNA Does not rule out active HCV infection |
Only samples with genotype 1 or a mixed genotype containing Type 1 or Type 6 are evaluated further with reflex hepatitis C high resolution genotyping
FAQs
Should I repeat the HCV genotype testing if I am already on antiviral treatment?
Repeating a genotype test may be warranted if your doctor suspects you may have been reinfected with a different HCV genotype after achieving a sustained virological response. However, it's a rare circumstance that occurs in less than 1% of patients who complete treatment
What is sustained virological response(SVR)?
SVR is defined as the disappearance of PCR-detectable HCV RNA in the blood for at least 12 weeks or more after treatment
Do HCV genotypes change over time?
The HCV genotype usually stays the same throughout the illness. Nonetheless, there are exceptions. For example, if you travel, you may become infected with HCV genotypes common in different places. Furthermore, missing treatment doses may cause changes in the viral genome, resulting in genotype change and acquired resistance to the antiviral drugs
Why does the HCV genotype matter?
Knowing the various HCV genotypes is not beneficial by itself, but when combined with additional markers such as quantitative HCV RNA evaluation, it becomes valuable in managing chronic hepatitis C patients. This information aid clinicians in determining the duration of treatment. For instance, individuals with HCV genotype 1 typically achieve sustained virologic response (SVR) rates of 40% to 50% after 48 weeks of standard combination therapy (ribavirin plus pegylated interferon alpha-2a or alpha-2b).
On the other hand, a 24-week regimen of combination therapy is optimal for chronic HCV genotype 2 and 3 infections in patients who demonstrate early viral clearance
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