THE virus which causes Aids has helped scientists develop a cure for two severe hereditary diseases.
Using knowledge gathered from the HIV virus, the researchers were able to successfully treat the conditions metachromatic leukodystrophy and Wiskott-Aldrich syndrome.
Scientists found, at the origin of both diseases, a genetic defect that results in the deficiency of a protein essential in the early years of life. In the case of metachromatic leukodystrophy, previously incurable, the nervous system is affected.
Babies with the disease are apparently healthy at birth, but at some point they begin to gradually lose the cognitive and motor skills they have acquired, with no possibility of stopping the neuro-degenerative process.
Children with Wiskott-Aldrich syndrome, on the other hand, have a faulty immune system that makes them vulnerable to the development of infections, auto-immune diseases and cancer. They also have a defect in blood platelets which causes frequent haemorrhaging.
Researchers tried to correct the genetic defect that causes these diseases with gene therapy as part of a £16 million study.
The technique involves withdrawing stem cells from the bone marrow of the patient and introducing a corrected copy of the defective gene using “viral vectors” – a method used to deliver genetic material into cells – derived from the HIV virus. Once re-injected into the body, the treated cells are able to restore the missing protein to key organs.
The breakthrough came after gene therapy was carried out on six children over three years.
Luigi Naldini, director of the San Raffaele Telethon Institute for Gene Therapy in Milan, said: “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.”
Fellow scientist Alessandro Aiuti, who ran one study, added: “After 15 years of effort and our successes in the laboratory, but frustration as well, it’s exciting to be able to give a concrete solution to the first patients. Thanks to gene therapy, the children no longer have to face severe bleeding and infection. They can run, play, go to school.”
Alessandra Biffi who ran another study, said: “Until now, we have never seen a way to engineer stem cells using gene therapy that is as effective and safe as this one. These results pave the way for new therapies for other more common diseases.”
Both trials called for the participation of 16 patients in total – six suffering from Wiskott-Aldrich syndrome and ten from metachromatic leukodystrophy.
The results, published in the journal Science, refer only to the first six patients – consisting of three from each study for whom sufficient time had passed to let scientists draw the first significant conclusions regarding the treatment’s safety and efficiency.