AIDSmeds.com - Hepatitis C : What happens when someone is infected?

Being infected with HCV does not necessarily mean that liver disease will occur. What's more, it can take several years—decades, in many cases—for HCV to cause life-threatening liver disease.

The Acute Phase

The first six months after HCV infection are known as the acute phase. Soon after HCV enters the body, it infects cells in the liver called hepatocytes. During the acute phase, only a small number of people (about 25 percent) actually experience symptoms of infection, such as fatigue, decreased appetite, nausea or jaundice (yellowing of the skin and eyes). Almost everyone with acute HCV will experience an increase in their liver enzymes, especially one called alanine aminotransferase (ALT), because some liver cells are being damaged. Sometimes ALT will skyrocket to 10 times the normal level. Since people who are taking HIV meds have their liver enzymes checked every three to six months, doctors have been able to identify cases of acute HCV in HIV-positive people who have no other symptoms of infection.

About 15 percent of HIV-positive people who are infected with HCV are able to clear the virus from their bodies without treatment. In medical speak, this is called “spontaneous viral clearance.” This usually happens during the acute phase—or first six months—after becoming infected.

Some things can predict the likelihood of spontaneous viral clearance, regardless of HIV status. People who have a 2 log—or 99 percent—drop in their hepatitis C viral load after four weeks are more likely to spontaneously clear hepatitis C, as are people with the IL-28B CC genotype (see “How is it diagnosed, and what tests are used?”).

The Chronic Phase

The majority of people (85 percent) living with HIV who become infected with HCV have chronic hepatitis C—an infection that will stay with them for life unless they are successfully treated. In other words, if 100 HIV-positive people are infected with HCV tomorrow, 15 of them will clear the virus from their bodies within six months, whereas 85 of them will remain infected with the virus unless they are successfully treated.

Some people live with hepatitis C for many years without developing liver damage or experiencing symptoms. Many people will have some signs and symptoms of liver disease, such as fatigue, nausea, muscle aches and abdominal pain.

Hepatitis C can cause mild-to-moderate liver scarring (fibrosis) or serious liver scarring (cirrhosis). It can also lead to a buildup of fat in the liver (steatosis), which worsens liver scarring. Here are some pictures of a healthy liver, then fibrosis, then cirrhosis:

Cirrhosis affects the way the liver works, and it increases the risk for liver failure and liver cancer. Between 1 percent and 5 percent of people with cirrhosis will die from these complications of chronic HCV infection each year, notably liver cancer or liver failure.

The Affects of HIV

HIV increases the risk for—and can speed up the development of—liver damage from hepatitis C. Other factors, such as alcohol intake, duration of hepatitis C infection, hepatitis B coinfection, being older than 40 and using certain ARVs (such as Videx or Zerit), may also worsen liver damage. People with fewer than 200 CD4 cells are more likely to have liver damage from HCV.

ARV therapy may delay hepatitis C progression by keeping the immune system strong, but HIV drugs should be chosen carefully to avoid liver toxicity. People taking ARVs should have their liver enzymes monitored regularly.

Coinfected people usually have higher HCV viral loads than people with HCV alone, but—unlike HIV—the hepatitis C viral load is not linked to disease progression or liver damage. Liver enzymes are not a reliable indicator of disease progression, because some people have liver damage despite persistently normal liver enzyme levels.

Even though it happens more rapidly in HIV-positive people, hepatitis C progression varies widely among individuals. Researchers have found that about 25 percent of people coinfected with HIV/HCV have rapid fibrosis progression (meaning two stages over three to four years). Some researchers have reported moderate liver damage in HIV/HCV-coinfected people within a few years of HCV infection, but this is unusual.

Now that people with HIV are living longer, many coinfected people are developing cirrhosis. In general, HIV is known to double the rate of cirrhosis. Experts estimate that, without HCV treatment, at least 20 percent of coinfected people will develop cirrhosis 20 years after HCV infection and 40 percent to 59 percent of people will develop cirrhosis 30 years later.

Discontinuing HIV treatment can worsen cirrhosis in coinfected people. Although the three-year survival rate among HIV/HCV-confected people with cirrhosis is 87 percent, once liver failure (also called decompensated cirrhosis) occurs, the survival rate drops to 50 percent at two years.

In fact, end-stage liver disease from untreated, or unsuccessfully treated, hepatitis C has become a leading cause of death among people with HIV in the United States and Western Europe, where there is widespread access to antiretroviral therapy. Compared with people who have only hepatitis C, those with both HIV and HCV are more likely to experience liver failure—which is often fatal unless a transplant is performed. In one study, people infected with both viruses were 21 times more likely to die of liver failure than those only infected with HCV.

Hepatitis C is treatable, and it can be cured (although this is less likely for coinfected people than those with HCV alone). Many new HCV drugs are currently in development (see, “Are there experimental therapies?”). These are already proving to be much more effective in people with HCV alone. Some are already being studied in HIV/HCV-coinfected people.