Friday , May 7 2021

8 baby bubbles were saved by the AIDS virus

First world. In the United States, eight babies with "baby bubble syndrome", a rare genetic disease that affects only one in 200,000 births, were saved by a new treatment, the latest of which combines chemotherapy and genetics with the AIDS virus, New England Journal of Medicine.

To treat children born without immune protection and sentenced to spend their lives in a cut-off bubble of the world and its bacteria, the doctors of St. George's Hospitals and Memphis and the children at the University of California, New York, had the idea of ​​adding chemotherapy to traditional genetic therapy that included taking stem cells from the injection patient The missing gene for the lab.

Cancer chemotherapy is usually used, and chemotherapy was here to remove all the cells in the patient's bone marrow. "Until now we did not do it because they thought it was to make him take another risk," says Ann Gally, director of research at Inserm / Genethon in Figaro. "If you remove the bone marrow and then the implant will not take, it permanently loses its immune system." Realizing that chemotherapy is the only way to transplant the entire immune system in a sustainable manner, researchers took the risk.

HIV is synthesized in the laboratory

In addition, they used the human immunodeficiency virus, better known as HIV, to transfer the gene to the heart of the cells. "The advantage of HIV is that it makes it very easy to insert a copy of the normal gene into the DNA of the cells," explains Ann Gally. This type of virus "is synthesized in the laboratory, like drugs, but not contagious. We only keep the properties we are interested in. It's a bit like a shell," says the researcher. This technique has been used for long gene therapy.

And it worked perfectly. A month after receiving the treatment, only one baby had to receive a second dose. A year later, eight children are out of the woods. "These patients … react to vaccines and have an immune system that allows them to produce all the immune cells they need to protect themselves against infections," says Dr. Evelina Marquez, co-author of the study and a doctor at the clinic. St. George's Children Memphis.

"Although longer follow-up is needed to assess the later effects of treatment, these results show that most patients with this gene therapy will develop a continuous and complete immune response without side effects." Mort Quan, a pediatrician at Benioff Children's Hospital, University of California, San Francisco.

Therefore, the researchers hope that this treatment, which includes several innovations, will serve as a basis for the development of genetic therapies for the treatment of other devastating blood diseases. Today, these treatments occur only in clinical trials and some patients treated in this way have subsequently developed leukemia or seen the effects of treatment being exhausted after 15 to 20 years. A few years ago, however, the Franco-American trial was already successful, healing seven baby bubbles.

Life expectancy is very limited

In the first patient with the disease in 1971, David Water, who was forced to spend his short life in a bubble to protect himself against potential infections. . This disease is due to lack of structure on the cells of the immune system, otherwise cells are like blind: they can not move, do not reproduce, they do not activate, explains Ann Gally.

Deficit caused by an error in the genetic code. Babies born with this syndrome have an immune system, but it is as if they were switched off. And if, at birth, the baby looks healthy, very quickly, it begins to catch all kinds of infections (pneumonia, Meningitis, septicemia …) Which put his life in danger. If she does not take any action, her life expectancy is very limited. Thus, David Water died at the age of twelve despite a bone marrow transplant, the treatment most used to treat baby bubbles.

Unfortunately, in addition to being very restrictive (taking immunosuppressants for life, developing cancer), this solution is not universal. In fact, children who do not have matching donors around them have all the risks of rejection. That's why today's power paves the way for new and exciting customers.

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