An altered form of the AIDS-causing virus has been used to genetically modify a girl's immune system in order for it to be able to neutralize cancer cells, doctors at the Children's Hospital in Philadelphia announced.The experiment is the first of its kind to be performed on a child and one of the extremely rare, successful similar operations in the world, The New York Times reports.
7-year-old Emma Whitehead was diagnosed with acute lymphoblastic leukemia two years ago and was about to die last spring, after two chemotherapy sessions failed to improve her condition.
The experimental treatment, developed at the University of Pennsylvania and tried only by a few other centers such as the Memorial Sloan-Kettering cancer Center and the National Cancer Institute in New York, came as a desperate solution for her parents after doctors declared they had run out of options.
Although it almost killed her at the beginning, the procedure has proved successful in the end.
The operation consisted in removing millions of a type of white blood cells, called T-cells, from the patient's body and implant new genes that make the T-cells able to destroy the cancer cells.
An altered form of the H.I.V. virus was used to ensure the highest efficiency of the procedure, as it is one of the best carriers of genetic material into T-cells.
Afterwards, the T-cells were re-inserted into the girl's veins, starting to multiply and fight against the cancer cells.
Doctors declared that the subsequent worsening of the patient's condition was a sign that the treatment was working. The process is explained by the fact that the activation of the immune system, with chemical particles dripping out of the cells, causes a “shake and bake” reaction, consisting of a series of chills, fevers and a significant blood pressure decrease.
After an eleven-hour crisis, doctors figured a drug called tocilizumab could stabilize the level of interleukin-6 or IL-6 cytokine, which was worsening Emma's condition. Within hours after the drug had been administered, Emma began to recover.
“It’s time for her to be a kid again and get her childhood back,” Emma's father said.