Author: Garrett Wachoski-Dark
Approximately 35 million people are currently infected with human immunodeficiency virus (HIV) – nearly the entire population of Canada! If left untreated most infected individuals would die to acquired immune deficiency syndrome (AIDS) related illnesses. To date more than 20 million lives have been claimed by the HIV/AIDS pandemic. These statistics are menacing but how did they become so? After all, did Margaret Heckler, US Health and Human Services Secretary in the 1980’s, not promise a cure within only 2 years? The problem is that HIV is quite different from most viruses we are used to.
HIV Infections Target the Immune System
Most viruses are selective with the type of cell they infect, and HIV is no different. The headache with HIV is that it targets white blood cells. The body is reliant on those cells to fight off viral and bacterial infections, and is very efficient at eliminating threats. However, HIV goes largely undetected because it hides right under the nose of the immune system, that is, within the immune system.
In what is called a productive infection, HIV multiplies itself within the white blood cells and then disrupts the cell membrane, killing the cell. This action releases amplified numbers of HIV into the blood stream where the virus quickly finds other cells to infect. This process repeats itself and eventually decreases the amount of white blood cells in the body to such a level that the patient develops AIDS.
AIDS Will Not Kill You, But Leaves You Vulnerable to Disease that Will
Death due to AIDS is technically a misnomer. AIDS itself is the syndrome associated with a significant decrease in certain subpopulations of white blood cells. The result is a weakened immune system that is unable to fight off diseases such as cancer or tuberculosis. AIDS patients are therefore more likely to die to such illnesses than individuals with a fully functioning immune system.
Can HIV/AIDS Be Treated?
Unfortunately, there is no cure for HIV/AIDS, but it can be treated. The lack of a cure stems largely from HIV having a latent phase in its life cycle in addition to its productive phase. In the latent phase, HIV does not reproduce, and because it does not produce any machinery, the body remains unable to detect its presence. The good news is that if HIV does not reproduce, then it does not kill white blood cells and subsequently AIDS does not develop. This idea is where HIV therapy comes into play.
Currently there are 6 main classes of anti-HIV drugs, all of which attempt to prevent HIV from replicating. In some cases, patients may need to take combinations of drugs to fully disrupt the HIV lifecycle. Patients taking anti-HIV drugs do not develop AIDS and live a normal life. Sadly, even though HIV does not develop into AIDS and patients are rarely infectious, HIV continues to persist latently. This means that anti-HIV drugs must be taken for the entire life of the patient.
Figure 2. Left, HIV budding in green
Will There Ever Be a Cure?
The answer is uncertain, but hope does exist. Around 1% of the population is partially or fully immune to HIV. Such people have a mutated marker on the surface of their white blood cells that the HIV must attach to to get inside the cell. If the cell surface is the door, then this mutated marker acts like a missing door handle. Moreover, there has been a single case where a man, Timothy Ray Brown, was fully cured of his HIV infection by a full bone marrow transplant. Nobody else has ever been fully cured of HIV/AIDS, however there have been cases where individuals were functionally cured, meaning they no longer needed to take medication to prevent their infection from developing into AIDS. It seems likely that in the future a true cure will be found, though the complex nature of HIV leaves an exact date undetermined.