Investigations and Diagnosis of Hepatitis C
The clinical symptoms alone cannot determine the diagnosis of Hepatitis C. The diagnostic test for Hepatitis C involves a study of certain Liver enzymes and Hepatitis C specific antibodies in the blood. Anti Hepatitis C (Anti HCV) virus antibodies can be detected in the blood after 3 to 6 weeks. It may be noted that Anti HCV may not be detected adequately during the acute phase of Hepatitis C. ELISA test for HCV antibody is an important diagnostic test to detect the HCV antibodies, which indicates exposure to the infection.
A. The Qualitative test: (To find our Antibodies to Hepatitis C virus):
- Enzyme immunoassay test (EIA): This test has to be carried out in the initial stage.
- Recombinant Immunoblot Assay (RIBA): This an additional test to support and confirm the diagnosis if the EIA is positive.
The above tests will give a clue if one has an exposure to the infection. However, they cannot indicate the quantum or extent of infection. There are some quantitative tests to determine the amount of virus titer, which is HCV RNA.
B. The Quantitative test:
- The quantitative tests to detect amount (titer) of virus (HCV RNA) are:
- Amplicor HCV Monitor™
- Quantiplex HCV RNA (bDNA)
It is important to note that the laboratory test as above may be a false positive or false negative.
C. Genotype study:
The Hep C virus can have several variants, largely six of them, namely Genotype 1, Genotype 2, Genotype 3, Genotype 4, Genotype 5, and Genotype 6. There are also some subtypes such as 1a, 1b, etc. Patients from different countries have shown different types, which can be briefed as under:
Genotype distribution
|
No
|
Type
|
Genotype
|
|
1
|
North America, South America, Europe
|
1
|
|
2
|
North America, South America
|
2
|
|
3
|
India, Nepal, Bangladesh, Pakistan, Egypt
|
3
|
|
4
|
Egypt
|
4
|
|
5
|
Central and South America
|
5
|
|
6
|
South-east Asia, Japan, China
|
6
|
What is Genotyping?
The patents often have this question. Genotyping is nothing but a specific arrangement of the genetic material of RNA in the virus, which has different possibilities, based on which the typing has been done.
D. Other blood tests:
A complete blood profile is which also consist of the white, red cell and platelet count, hemoglobin count is done. Also, the blood levels of certain liver enzymes such as Alanine Aminotransferase (ALT) and SGOT has to be carried out routinely.
E. Liver biopsy:
The biopsy of liver tissues is not done routinely. It is required to be done to evaluate the scarring (cirrhosis) and cancer of the liver. A liver biopsy gives an idea of the extent and severity of fibrosis and cirrhosis.