Tuesday, November 8, 2011

How has Magic survived HIV

Note: This article was updated at 12:00 p.m. on Tuesday, Nov. 8.

On Nov. 7, 1991, Los Angeles Lakers point guard Earvin "Magic" Johnson shocked the world when he announced that he had contracted HIV, the virus that causes AIDS. After the press conference, the perception was that Johnson had just pronounced his own death sentence.

Yet, 20 years later, the now-52-year-old Johnson is going as strong as ever in his roles as a sports analyst, businessman and HIV activist. In 1991, when most of what people knew about HIV/AIDS was that it lead to death at a young age, this outcome might have seemed impossible.

So why is Johnson still alive?

The answer to Johnson's survival is far from "magic." According to reports, he takes the same kinds of drugs that are available to other HIV patients in the developed world, and increasingly in impoverished nations in Africa and Asia, where the disease still runs rampant. Many people have lived with HIV even longer than Johnson.

"There is nothing unique about Magic," said Spencer Lieb, senior epidemiologist and HIV/AIDS research coordinator for the Florida Consortium for HIV/AIDS Research. "There are still people alive and kicking and doing very well 20 and 30 years after infection." [Does Circumcision Prevent HIV?]

Lieb said that in the state of Florida alone, hundreds of patients have hung on since becoming infected with HIV in the early 1980s, when the first confirmed AIDS cases turned up in the United States. But Johnson and these people are still in the minority: According to research and estimates by Centers for Disease Control and Prevention, about 1.2 million Americans have HIV, and 20 percent of them are undiagnosed. Approximately 50,000 people become infected each year, and more than 18,000 die annually.

Stopping HIV in the back court

The key with Johnson and others has been preventing their incurable disease from progressing into full-blown AIDS.

Upon infection with human immunodeficiency virus (HIV), a person's immune system kills off nearly all of the virus and infected cells. But some small number remain, and over time, those HIV cells replicate, and replicate, and replicate. Then, usually 10 years after the initial infection, the viral load reaches a critical count, and the virus begins killing off the vital immune cells that protect us against infections.

At that critical count, a person is considered to have acquired immunodeficiency syndrome (AIDS); with the body’s immunological defenses destroyed, it's usually only a matter of months before a range of opportunistic infections and cancers complete their lethal work.

Researchers have developed a number of powerful drugs to help people like Johnson avoid this fate. The key weapon has been a regimen of three or four antiretroviral drugs, collectively known as highly active antiretroviral therapy, or HAART.

According to a Newsweek story from last spring, one of Johnson's doctors who helped pioneer the treatment placed him on the then-experimental drug cocktail in 1994, about a year and a half before it came into widespread use in 1996. [Top 10 Stigmatized Health Disorders]

"Magic got a jumpstart on experimental drugs before they were released to the general public," Lieb told Life's Little Mysteries, "but there were many people in clinical trials benefitting at the same time."

The meds that slam dunk HIV

HIV spreads by hijacking a subset of white blood cells called T cells, which are the body's first line of defense against foreign invaders, and using the cells' DNA to make copies of itself or replicate; in this process, these T cells get destroyed. The most common drugs in the HAART regimen target two of the enzymes that HIV uses to replicate itself.

The first enzyme, called reverse transcriptase, turns the virus' genetic instructions encoded in a single RNA strand into double-stranded DNA. (In scientific terms, this mode of replication classifies HIV as a retrovirus, hence "antiretroviral" drugs.)

The second enzyme, known as protease, creates new, functional HIV virus particles by cutting up the proteins cranked out by our hijacked cellular machinery.

Medication can disrupt these processes, and to that end, Johnson is currently taking reverse transcriptase inhibitor and protease inhibitor drugs, which are contained in the pharmaceuticals Trizivir and Kaletra, respectively, as reported by Newsweek.

Although these and other HIV-fighting drugs are "hideously expensive," Lieb noted, so are a substantial number of prescription drugs for much more everyday diseases.

Public and private medical insurance, as well as various assistance programs, make the medicines affordable and available to the vast majority of patients in the United States and other parts of the world. It is a "myth," said Lieb, that Johnson, who is wealthy, is buying himself special treatments.

Staying in the game

By taking the right regimen every day, most HIV patients can see the number of virus particles in a sample of their blood, or viral load, become undetectably low.

Not only does a low viral count stave off symptoms of HIV and AIDS, but it also slashes the odds of a randomly mutated copy of the virus emerging that can prove resistant to the therapy. Furthermore, a low viral load severely reduces the risk of transmitting the virus to others.

Yet even without modern drugs, in rare instances an HIV-positive person can manage on their own to keep AIDS at bay. These "long-term nonprogressors" or "elite controllers," estimated at as few as one in 500, have lived for decades with HIV, despite not being on antiretroviral therapy.

It is not known if Johnson is among this "scarce breed," as Lieb called them, but more than likely "without medications, he'd be progressing."

Researchers continue to study long-term nonprogressors for get insights on HIV resistance that could help the 33 million people battling the virus.

As Johnson has prominently shown, however, those with HIV can still live productive lives. Lieb has seen many such promising cases in person. "We have very buff-looking, healthy-looking HIV patients who have been infected for ages," Lieb said. "You can't tell the difference between them and you and me."

See the article here


Dr. Joshua Brooks
Chiropractor, Fairfax VA 22031

No comments:

Post a Comment