When I was a kid, school always began the day after Labor Day. Although it has been many years since I’ve attended school, every September I get a deep yearning to learn something new. Today’s blog is a back-to-school primer on hepatitis C.
What is hepatitis C?
Hepatitis C virus (HCV) is a small RNA-virus, approximately 50 nm in size. It is the lone member of the hepacivirus genus in the family Flaviviridae. Yellow Fever is in the same family (but not the same genus). Flavus is yellow in Latin, a color that some people turn if they have Yellow Fever or hepatitis C. (Here is a little more trivia about yellow: the medical term for the yellowish color is jaundice, which indicates liver damage. The word jaundice comes from the French for yellow.)
When hepatitis C enters the body, it relies on liver cells to sustain it so it can multiply. This multiplication is called viral replication and HCV may do this up to a trillion times daily.
Once hepatitis C infects the liver cell it uses RNA in order to replicate. HCV does not kill the liver cell directly. It acts more like a hostage-taker than a murderer. Sensing danger, the body’s immune system tries to destroy the unwanted virus, but HCV usually wins. The body keeps trying to clear the virus, a process that slowly destroys the liver. Sometimes in the first six months after exposure, the immune system triumphs over hepatitis C. When this happens, people are left with the HCV-antibody but not the actual virus.
Since an HCV-antibody doesn’t tell you if you were exposed to hep C, had hep C, or have hep C, a viral load test (HCV RNA) is necessary. If the hepatitis C-antibody test is positive, and your viral load is undetectable, then you don’t have hepatitis C. The Centers for Disease Control and Prevention (CDC) estimates that 15 to 25 percent of people who are infected with hepatitis C are able to clear the virus on their own.
This concept can be a little tricky, and here is how I explain it: If a mugger was about to attack you and someone happened to photograph the event, you would have a picture of the attack. Someone looking at the photo would not know if you got attacked or if the attack was fought off.
Imagine that the hepatitis C virus is the mugger and the hepatitis C antibody is the photograph of the mugger. If you were attacked by hepatitis C, your body would produce antibodies—much like photographs of the attack. As long as you carried the hepatitis C virus, your viral load and your antibody tests will be positive. However, if your body cleared hepatitis C on its own, the viral load would be negative, but the hepatitis C-antibody test would be positive. The virus is gone, but you have its photograph—proof that you once had hepatitis C. The hepatitis C antibody can’t hurt you any more than the mugger in the photo can hurt you.
The bottom line is to never assume that a positive hepatitis C-antibody test means you have the virus—get further testing.
Next week’s blog is a hepatitis C history lesson.