The anti-HCV test is used to diagnosis hepatitis C. The test is ordered for patients that have symptoms of liver disease or have used needles to inject illegal drugs. The blood test works by detecting the presence of antibodies produced by the immune system in response to the hepatitis C virus.
Hepatitis C is a disease that affects the liver. It is caused by HCV. This is one type of virus which damages the liver. Additional viruses include the hepatitis A and B viruses. HCV is part of the Flaviviridae virus family, which consists of viruses that feature an outer envelop embedded with proteins and RNA genetic material. HCV is capable of reproducing within the cells of the liver.
The immune system responds to the virus, causing inflammation of the liver. Initially, the symptoms aren’t specific and can include fatigue, loss of appetite, muscle aches and fever. Eventually, the liver becomes scarred (cirrhosis) and loses its ability to function normally. Symptoms at this stage include weakness, weight loss, rash formation on palms, yellow skin or eyes and confusion.
The Anti-HCV Test
The anti-HCV blood test is used by doctors to determine if a patient has contracted hepatitis C. The test specifically looks for the antibodies produced by the immune system in response to the hepatitis C virus (HCV).
A specific biochemical technique known as enzyme-linked immunosorbent assay (ELISA) is used to detect the presence of HCV antibodies in the blood. ELISA takes advantage of the antigen-antibody binding relationship to screen the blood for specific HCV antibodies.
In this test, a patient’s blood sample is incubated on a testing plate along with anti-HCV antibodies. To determine if viral antigen-antibody complexes have formed on the testing plate, a predetermined enzyme is used as an indicator. When the enzyme is activated, a color change is detected, indicating the presence of HCV antibodies.
Test Results: Positive or Negative
The anti-HCV test produces a positive or negative result. A negative result means that there aren’t any antibodies for HCV in the blood. It could also mean that the infection occurred recently and there aren’t adequate levels of antibodies to be detected.
If the test is positive, there are antibodies for HCV in the blood. This can indicate two things: The hepatitis C infection is ongoing and present, or the hepatitis C infection is no longer active. A positive anti-HCV test will require further testing to determine the exact nature of the infection.
When Should You Take the Anti-HCV Test?
You should be screened for hepatitis C if you have symptoms of hepatitis, have been exposed to contaminated needles, have received long term dialysis or have received blood transfusions before 1992. Additionally, children born to HCV positive mothers should be screened for hepatitis C.
After a positive anti-HCV test, a HCV RNA qualitative test is ordered to determine the nature of the infection. If the test is positive, there are HCV RNA in the blood, indicating a current ongoing infection. If it is negative, viral RNA is not present, indicating a past infection that is inactive.
References
1. “Hepatitis C: The Test.” Lab Tests Online . American Association for Clinical Chemistry. 15 March 2010. Web. 11 June 2010.
2. Kimball, John W. “ELISA.” Kimball’s Biology Pages . 20 August 2004. Web. 11 June 2010.
3. “Hepatitis C Symptoms, Screening Tests.” MedicineNet, Inc. 2010. Web. 11 June 2010.
