Breakthrough in HIV/AIDS research gives hope for improved drug therapy

May 16, 2014

The first direct proof of a long-suspected cause of multiple HIV-related health complications was recently obtained by a team led by the University of Pittsburgh Center for Vaccine Research (CVR). The finding supports complementary therapies to antiretroviral drugs to significantly slow HIV progression.

The study, which will be published in the June issue of the Journal of Clinical Investigation and is available online, found that a drug commonly given to patients receiving kidney dialysis significantly diminishes the levels of bacteria that escape from the gut and reduces health complications in non-human primates infected with the simian form of HIV. The study was funded by the National Institutes of Health (NIH).

"We now have direct evidence of a major culprit in poor outcomes for some HIV-infected people, which is an important breakthrough in the fight against AIDS," said Ivona Pandrea, M.D., Ph.D., professor of pathology at Pitt's CVR. "Researchers and doctors can now better test potential therapies to slow or stop a key cause of death and heart disease in people with HIV."

Chronic activation of the and inflammation are major determinants of progression of HIV infection to AIDS, and also play an important role in inducing excessive blood clotting and heart disease in HIV patients. Doctors believed this was due to microbial translocation, which occurs when bacteria in the gut gets out into the body through intestinal lining damaged by HIV. However, no direct proof of this mechanism existed.

Dr. Pandrea and her colleagues showed blocking the bacteria from leaving the intestine reduces the chronic immune activation and inflammation. They did this by giving the drug Sevelamer, also known by the brand names Renvela and Renagel, to monkeys newly infected with simian immunodeficiency virus, or SIV, the primate-form of HIV.

Sevelamer is an oral drug approved by the U.S. Food and Drug Administration to treat elevated levels of phosphate in the blood of patients with chronic kidney disease.

The bind to Sevelamer, making it much more difficult for the bacteria to escape into the body and cause serious problems, such as , while further weakening the immune system and allowing HIV to progress to full-blown AIDS.

In SIV-infected monkeys treated with Sevelamer, levels of a protein that indicates microbial translocation remained low. However, in the untreated monkeys the levels increased nearly four-fold a week after SIV infection.

The treated monkeys with the lower rates of microbial translocation also had lower levels of a biomarker associated with excessive blood clotting, showing that heart attacks and stroke in HIV patients are more likely associated with chronic immune system activation and inflammation, rather than HIV drugs.

"These findings clearly demonstrate that stopping bacteria from leaving the gut reduces the rates of many HIV comorbidities," said Dr. Pandrea.

Because most interventions in people infected with HIV begin after the person has reached chronic stages of infection when the gut is already severely damaged, Dr. Pandrea notes, "These treatments may not be as effective later in the infection. Clinical trials in HIV-infected patients were not yet successful in reducing microbial translocation in chronically infected patients. Our study points to the importance of early and sustained drug treatment in people infected with HIV."

Other approaches, such as coupling Sevelamer with antibiotics, anti-inflammatory drugs, probiotics or supplementation of existing HIV/AIDS drugs could further reduce the likelihood of microbial translocation. Clinical trials are underway to assess these strategies.

Explore further: Can marijuana protect the immune system against HIV and slow disease progression?

Related Stories

Can marijuana protect the immune system against HIV and slow disease progression?

February 18, 2014
New evidence that chronic intake of THC, the primary psychoactive ingredient in marijuana, can protect critical immune tissue in the gut from the damaging effects of HIV infection is reported in AIDS Research and Human Retroviruses.

Could probiotics help HIV patients?

January 16, 2013
Antiretroviral (ARV) drugs are the first line therapy for patients with HIV; however, ARV-treated, HIV-infected individuals still have a higher mortality rate than uninfected individuals. During the course of infection, HIV ...

Transplant drugs may help wipe out persistent HIV infections

April 3, 2014
New research suggests that drugs commonly used to prevent organ rejection after transplantation may also be helpful for combating HIV. The findings, which are published in the American Journal of Transplantation, suggest ...

Low cholesterol in immune cells tied to slow progression of HIV

April 29, 2014
People infected with HIV whose immune cells have low cholesterol levels experience much slower disease progression, even without medication, according to University of Pittsburgh Graduate School of Public Health research ...

Hemophilia and long-term HIV infection—is there a protective link?

December 11, 2013
People with the genetic blood clotting disorder hemophilia who have been infected with HIV for decades have an increased proportion of immune cells in their blood that specifically target HIV. This protective immune response ...

Recommended for you

Scientists divulge latest in HIV prevention

July 25, 2017
A far cry from the 1990s "ABC" campaign promoting abstinence and monogamy as HIV protection, scientists reported on new approaches Tuesday allowing people to have all the safe sex they want.

Girl's HIV infection seems under control without AIDS drugs

July 24, 2017
A South African girl born with the AIDS virus has kept her infection suppressed for more than eight years after stopping anti-HIV medicines—more evidence that early treatment can occasionally cause a long remission that, ...

Meds by monthly injection might revolutionize HIV care (Update)

July 24, 2017
Getting a shot of medication to control HIV every month or two instead of having to take pills every day could transform the way the virus is kept at bay.

Candidate AIDS vaccine passes early test

July 24, 2017
The three-decade-old quest for an AIDS vaccine received a shot of hope Monday when developers announced that a prototype triggered the immune system in an early phase of human trials.

Paris spotlight on latest in AIDS science

July 21, 2017
Some 6,000 HIV experts gather in Paris from Sunday to report advances in AIDS science as fading hopes of finding a cure push research into new fields.

Scientists elicit broadly neutralizing antibodies to HIV in calves

July 20, 2017
Scientists supported by the National Institutes of Health have achieved a significant step forward, eliciting broadly neutralizing antibodies (bNAbs) to HIV by immunizing calves. The findings offer insights for HIV vaccine ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.