Deadly Genetic Diseases Successfully Treated With Modified AIDS Virus
The AIDS virus can be used to treat genetic diseases, according to Italian scientists.
After undergoing gene therapy vectors derived from HIV virus, children with hereditary diseases like metachromatic leukodystrophy and Wiskott-Aldrich syndrome showed significant health benefits.
"Three years after the start of the clinical trial, the results obtained from the first six patients are very encouraging: the therapy is not only safe, but also effective and able to change the clinical history of these severe diseases," lead researcher Luigi Naldini said in a news release.
Researchers explain that both metachromatic leukodystrophy and Wiskott-Aldrich syndrome are caused by a genetic defect that results in the deficiency of a protein essential for the organism in the early years of life.
Metachromatic leukodystrophy, which currently lacks any effective treatment, affects the nervous system. Babies with this disease are healthy at birth, but start to gradually lose the cognitive and motor skills they've acquired, with no possibility of stopping the neurodegenerative process.
Children with Wiskott-Aldrich syndrome have a faulty immune system that makes them much more vulnerable than normal to the development of infections, autoimmune diseases and cancer, as well as having a defect in the platelets which causes frequent bleeding.
Researchers in the study wanted to see if gene therapy could correct the genetic defect that causes these diseases.
They withdrew hematopoietic stem cells from the bone marrow of patients and introduced a corrected copy of the gene that is defective using viral vectors derived from HIV. After the cells were re-injected in the patients' bodies, they were able to restore the missing proteins to key organs and help improve disease symptoms.
The study began in 2010 and involved 16 patients. Six patients suffered from Wiskott-Aldrich syndrome and 10 from metachromatic leukodystrophy. However, the latest study, published in the journal Science, refers only to the first 6 patients (three from each study) or those for whom enough time has passed after therapy for scientists to draw the first significant conclusions regarding its safety and efficacy.
"In patients with Wiskott-Aldrich syndrome, blood cells are directly affected by the disease and the corrected stem cells replace the diseased cells creating a properly functioning immune system and normal platelets," Alessandro Aiuti, coordinator of the clinical study on these patients and Head of Research of the Pediatric Clinic at Telethon Institute for Gene Therapy said in a statement.
Thanks to gene therapy, the children no longer have to face severe bleeding and infection. They can run, play and go to school," Aiuti added.
"In the case of metachromatic leukodystrophy, however, the therapeutic mechanism is more sophisticated: the corrected hematopoietic cells reach the brain through the blood and release the correct protein that is 'gathered' there by the surrounding nerve cells. The winning card was to make engineered cells able to produce a quantity of protein much higher than normal, and thus effectively counteract the neurodegenerative process." Researcher Alessandra Biffi said in a news release.
Researchers said tat until now, there has never been a way to engineer stem cells using gene therapy that is as effective and safe as the one in the study. They say the results pave the way for new therapies for other more common diseases.