杏吧原创

Researchers have acknowledged that we still have far to go in the quest to eliminate HIV infection, and that this goal may be unattainable.

In 2012, the International AIDS Society launched a programme called Towards an HIV Cure, but a series of setbacks have dampened optimism. 鈥淎 cure is a long way off, and I don鈥檛 know if it will ever be achieved,鈥� says Sharon Lewin of the University of Melbourne, Australia.

People with HIV must take antiretroviral drugs for the rest of their lives to keep the virus in check. If they stop their medication, viruses lying dormant in their cells can re-emerge and restart active infection.

Completely eradicating the virus from the body would do away with the need for a constant regime of expensive antiretrovirals. But so far efforts to do this have foundered. One strategy has been to use drugs to flush latent viruses out of their hiding places, but this hasn鈥檛 been successful.

There was excitement when some patients who received the drugs soon after infection appeared to be cured. It seemed as if prompt medication had prevented HIV from establishing itself within the body, but in all cases, the virus returned. 鈥淲e have big challenges predicting when and if the virus will rebound,鈥� says Lewin.

Improving remission

Following these setbacks, the International AIDS Society has now released a new road map, outlining more realistic plans for fighting HIV. Before there can be hope of a cure, researchers need to tackle important gaps in knowledge, including where and how the virus hides, and how to detect the dormant virus. 鈥淭he challenges remain substantial,鈥� it concludes.

But while a cure remains a long way off, Lewin says there are better prospects for achieving long periods of remission. Early experiments suggest we could develop treatments that keep the virus below detectable levels for long periods without the need for the usual antiretroviral drugs.

鈥淩emission is an important step, and looking forward, we will have different ways to achieve remission, allowing people to come off their usual treatment,鈥� says Lewin.

One way to do this might be through gene editing and gene therapy. These techniques could allow patients鈥� blood cells to be genetically engineered outside the body to combat the virus, then placed back into the body to keep the virus in check without help from drugs. 鈥淲e now have a bigger emphasis on long-term immunity, and more confidence about gene therapy,鈥� says Lewin.

To date, only one person has ever been cured: Timothy Brown. He had blood cancer and HIV, and received a bone marrow transplant containing a rare combination of mutated genes that stop the virus from infecting cells. After the transplant, his blood was completely replaced with the HIV-resistant cells, getting rid of the virus for good.

鈥淚t鈥檚 still only one person, Timothy Brown, so [a true cure] is looking pretty rare,鈥� says Lewin. 鈥淏ut a cure remains an important and aspirational goal.鈥�