There are thought to be around 2.6 million children around the world living with HIV, with roughly only one-third of these receiving any treatment for the disease. But researchers working in South Africa have found something astonishing: Around one in 10 children tested seemingly has an immune system that prevents the HIV from progressing to AIDS.
When a person is infected with HIV, the body’s usual response is for the immune system to mount a massive attack to try and quash the virus. Unfortunately for the body, this is effectively the wrong tactic, as the virus infects the immune cells, and eventually the immune system is destroyed. When this happens the patient develops acquired human immunodeficiency syndrome (AIDS), and other opportunistic infections such as pneumonia can then take hold, eventually proving fatal.
Yet the researchers of a new study, published in Science Translational Medicine, found that out of 170 children they looked at in South Africa, around 10 percent of them did something differently. Rather than their immune systems being pushed into overdrive, it instead remained calm, and failed to mount an attack on the virus. Paradoxically, this seems to have a protective effect, preventing the children from going on to develop AIDS. Whether or not this protection continues to adulthood is not known, but the researchers think this is unlikely.
Interestingly, this method of dealing with HIV by the body has been seen before, but only in non-human primates. A substantial proportion of monkeys in Africa are infected with their own equivalent of the virus, simian immunodeficiency virus (SIV), and it is thought that they have been evolving alongside it for hundreds of thousands of years, and when infected the primates’ bodies do a similar thing, reducing their immune response. “Natural selection has worked in these cases, and the mechanism is very similar to the one in these kids that don't progress,” Professor Philip Goulder
“Natural selection has worked in these cases, and the mechanism is very similar to the one in these kids that don't progress,” Professor Philip Goulder, one of the authors of the paper from the University of Oxford, told BBC News.
While a small proportion of adults have been found to be resistant to the progression of AIDS, they are found at a much lower number than the children have been, with only 0.3 percent having natural protection. But research has also found that the mechanism behind the adult’s protection is seemingly different to that seen in the children, meaning that some of the focus in research should be shifted.
“Research has often concentrated on certain HLA class I molecules for HIV protection, as these are found in the rare adults who do not experience disease progression,” explained Professor Goulder. “In children, protection is not dependent on HLA, and lack of HIV disease here seems to result from avoiding making strong immune responses against HIV.”
The study conducted was small, and is only in its early days, meaning that the scientists want to expand it further, and continue investigating these protected children, something which could take years.
