A HCV blood test is one of the methods for diagnosing hepatitis C virus. This test is prescribed in the presence of hepatitis C symptoms, an increase in hepatic transaminases, as well as examinations of people at risk for infection with viral hepatitis.
In the latter case, together with a blood test for HCV, a HBs Ag blood test is performed.
HCV (hepatitis C virus hepatitis C virus) belongs to the family of flaviviruses. It was first discovered in 1988 by a group of researchers from the American biotechnological company Chiron. The HCV genome is represented by an RNA molecule, so the virus mutation rate is very high. In people with hepatitis C virus, viral particles are detected whose genomes differ by 1-2%. This feature of the virus population allows it to multiply successfully in spite of the protective reactions of human immunity. Differences in the genomes of the virus can affect the course of infection and treatment outcomes.
According to the World Health Organization, to date, about 150 million people are infected with HCV, each year hepatitis C virus causes the death of more than 350,000 patients.
Hepatitis C transmission methods
Hepatitis C virus is transmitted with infected blood, for example, to a recipient from a blood donor or organs, to an infant from an infected mother, through sexual contact, using non-sterile syringes in medical institutions, and tattoo and piercing instruments in salons.
The disease can occur in acute form, lasting several weeks and in chronic, which can result in cancer or cirrhosis of the liver.
HCV blood test: what does this mean in terms of immunology?
A blood test for HCV is based on the detection of specific immunoglobulins of the IgG and IgM classes, therefore this type of study is sometimes called an anti-HCV blood test. Immunoglobulins are specific proteins of the immune system, they are produced by B-lymphocytes in response to the detection of foreign proteins in the body. When infected with hepatitis C virus, immunoglobulins are produced against the envelope proteins of the virus, the nucleocapsid core protein and non-structural NS proteins. The appearance of the first antibodies to the virus occurs no earlier than 1-3 months after infection. Based on the antibodies detected, the doctor can determine the phase of the infection (acute, latent or reactivation). Specific antibodies to hepatitis C can be detected even after 10 years after the disease, but their concentration is low, and they are not able to protect against re-infection with the virus.
Interpretation of analysis results
- Positive HCV blood test. What does it mean? This result indicates hepatitis C in acute or chronic form, or a previous illness.
- Negative HCV blood test. What does it mean? There is no hepatitis C virus in the blood or infection has occurred recently, so there are no antibodies to it yet. In some patients, antibodies to this virus are not produced at all. This scenario of the development of the disease is called seronegative, it occurs in 5% of cases.
- PCR for HCV RNA showed the absence of the virus, previously received a positive HCV blood test. What does it mean? The result of a blood test for HCV was false positive, the cause of this may be some infections, neoplasms, autoimmune diseases.