Experimental gene treatments are being used to treat neurodegenerative rare diseases. I’ve posted before about how viruses are being used to encode new, “corrected” genetic strands in patients with diseases of the brain. Now, scientists are using these viruses to treat the patient’s own hematopoietic stem cells, which are then tranfused back into the body.
Three seperate diseases have now been treated with some success.
In 2009, Aubourg and colleagues published results from a pioneering trial in which they used lentiviral-based gene therapy on HSCs for the first time to treat X-linked adrenoleukodystrophy (ALD), a neurodegenerative disease that affects young males. Roughly 2 years after the treatment, many of the patients’ immune cells carried the corrected the gene, and disease progression had stopped entirely.
[…] a team led by TIGET’s Allesandra Biffi treated three children with a rare lyosomal storage disorder called metachromatic leukodystrophy (MLD)—a neurodegenerative disease caused by mutations in the gene that produces the enzyme arylsulfatase A (ARSA). There is currently no successful treatment for MLD and patients usually die within a few years.
The researchers transferred a functional ARSA gene into HSCs taken from nine pre-symptomatic MLD patients. Analyses performed 2 years after treatment with the modified HSCs in one patient, and after 18 months in another two patients, revealed that 45–80 percent of the blood cells carried the functional gene. The enzyme was present at normal, healthy levels in these cells and in the cerebro-spinal fluid, where it was completely lacking before. What’s more, long after the symptoms would usually have manifested, the progression of the disease had been stopped in its tracks.
In a separate study, a group led by TIGET’s Allesandro Aiuti used the same approach to treat three children with Wiskott-Aldrich Syndrome (WAS), a rare immunodeficiency disorder caused by mutations in the gene encoding a protein called WASP. Analyses carried out 20–32 months after the treatment showed that 20–25 percent of targeted blood cells were genetically corrected; the immune system had largely been restored in all three patients; and symptoms, such as recurring infections of eczema, were reduced or had disappeared altogether.
There is the full, easy-to-read article here. I wonder what this might mean for GM1 and other related disease patients in the near future.