HBV & HIV
I sometimes like to think of HIV as a party virus. It likes to hang out with other viruses and microorganisms and people are often infected with many of HIV’s “friends”. Some of HIV’s party buddies include herpes simplex virus, gonorrhea, Chlamydia, syphilis, human papilloma virus, cytomegalovirus, and the hepatitis viruses (hepatitis B, C and some other types). The next couple articles will focus on the hepatitis viruses, starting with hepatitis B.
Hepatitis viruses are NOT related to each other. Hepatitis A, B and C are totally different viruses. They have different structures and the replicate differently. The only thing they have in common is that they attack the liver. But they even have different ways of damaging the liver. Hepatitis B virus (HBV) doesn’t actually destroy liver cells itself, but as the immune system attacks the infected cell, liver damage occurs. HBV infection is common with HIV infection because they are spread by similar means. Like HIV, HBV can be transmitted by sharing needles, sexual intercourse and from mother-to-child during pregnancy. Of the individuals in the US with HIV disease, 6-14% also have HBV infection, and worldwide, up to 4 million individuals may have HIV and HBV infection.
Most healthy adults (about 90%) and children (about 75%) are able to control and eliminate hepatitis B infection without medication. But if the person also has HIV infection, there is impaired immune function such that the percentage of individuals who can clear HBV infection is much smaller, so the infection becomes chronic, meaning it lingers around and continues to slowly cause liver damage.
The signs and symptoms in new infections (acute infection) include nausea and vomiting, fatigue, fever, pain in the area of the liver, and yellowing of the skin and/or eyes. But with persistent infection (chronic infection), there may not be any symptoms. Laboratory tests performed by your medical provider are needed to diagnose HBV.
Untreated HBV infection can cause liver cirrhosis, which may progress o liver cancer. However, HBV may be able to produce liver cancer even in patients who have not developed cirrhosis. What is cirrhosis? The liver is the body’s largest organ and it performs many critical functions related to the body’s metabolism, managing nutrients and clearing toxic compounds. It is a fleshy, pulpy organ that receives a lot of blood flow and is sort of spongy in texture. Think of the liver as a juicy ripe navel orange (yummy!). Now, take that orange and let it sit out on the counter for a couple weeks. Your juicy orange now becomes a hard, shrunken, dried-up husk that you would never want to eat. This is the liver with cirrhosis. The pulpy tissue has been transformed into a fibrous tissue with much less active tissue able to carry on the liver’s vital work. This means the liver’s important functions cannot be done and the patient’s health deteriorates. Further, the change in texture in the liver tissue changes the dynamics of blood flow through the organ and can damage. A liver biopsy is one of the best ways to determine how severely the liver is damaged. For this test, a tiny piece of tissue is collected from the liver through a minor surgical procedure, but there are other tests as well. If the patient happens to have HIV in addition to HBV (or hepatitis C), the liver progresses to cirrhosis much more quickly and there are higher rates of liver cancer. Suppressing HIV with medication is important in slowing down HBV.
Probably the best news for HIV patients and individuals at high risk for contracting HBV is that an effective vaccine has been available for about 25 years. Well, if this vaccine is so good, why not give it to everyone? Remember as we mentioned above, most healthy individuals are likely to effectively eliminate HBV infection if they contract it, so they don’t need a vaccine. For these individuals, there are antibodies generated against HBV that can be detected in the blood. So before vaccinating anyone, we must first check to see if they have antibodies, and if so, they are already protected against HBV and don’t need a vaccine. For individuals who don’t have antibodies, three vaccinations spaced over weeks and then months are required. You must have all three to have the most protection. People with HIV disease may need higher doses of vaccine to get adequate protection, especially if they have more advanced HIV disease. For these patients, it may be better to treat HIV for a while to strengthen the immune system before giving the vaccine so that it can produce enough HBV antibodies.
There are several good drugs that are effective in treating HBV. These drugs can suppress the virus to undetectable levels just as the HIV drugs do. Three of the drugs active against HBV are also good HIV drugs. This is very convenient for individuals with both HIV and HBV. These three drugs are lamivudine/3TC (Epivir), tenofovir (Viread) and emtricitibine/FTC (Emtriva). A combination product of tenofovir and emtricitibine called Truvada is approved for HIV disease and is also a great combo for HBV. Adefovir (Hepsera) has modest activity against HBV. Two other drugs, entecavir (Baraclude) and telbivudine (Tyzeka) have potent activity against HBV. Another product, alpha-interferon, also has activity against HBV. This drug with be discussed in more detail in the next article on hepatitis C. Some patients may be cured by the treatment by one or a combination of these drugs.
1) If you have HIV infection, talk to your medical provider about getting tested for HBV and then vaccination. If you do not have HIV but are at high risk for HBV infection (intravenous drug user, gay men, commercial sex workers), you may also want to consider getting vaccinated.
2) If you need the vaccine, be sure to get all three vaccinations
3) If you have HIV and HBV, make sure to treat your HIV and your HBV as well
4) Practice safe sex!!! If you inject drugs, use clean needles or learn to use bleach to clean your works. Seek medical treatment for substance abuse.
The next article will discuss hepatitis C infection with HIV disease.
By Dr. Keith Crawford, BDO HIV Expert
Dr. Crawford received a B.S degree in Biology from Cornell University and a B.S. in Pharmacy from Temple University. He completed a residency in clinical pharmacy at the National Institutes of Health. He earned a doctorate in Pharmacology from the Uniformed Services University of the Health Sciences in Bethesda, Maryland. He completed a post-doctoral fellowship at the National Institutes of Health, studying microbial biochemistry and genetics.
He is currently in the Department of Clinical Pharmacology at the Johns Hopkins University School of Medicine where he develops clinical research studies to improve treatment of HIV infection. He is also on faculty at Howard University College of Medicine, in the Department of Pharmacology.