Children born with severe combined immunodeficiency (SCID)
are usually diagnosed within the first 6 months of life and are often kept in
isolation as a result. More specifically, adenosine deaminase (ADA)-deficient
SCID causes cells not to create the enzyme ADA, which is important in the
production of healthy white blood cells and is necessary for a properly
functioning immune system.
Dr. Donald Kohn dedicated 3 decades to researching how to
use a patient’s own stem cells to restore his/her immune system, focusing on
ADA-deficient SCID. Patients’ stem cells were removed from their bone marrow
and genetically modified to correct the deficiency. Dr. Kohn used a virus
delivery system to insert the corrected gene that would produce the missing enzyme.
The cells are transplanted back into the patient where the enzyme will
continually be produced, and the patient will then have a fully functioning
immune system.
Clinical trials began in 2009. Prior to this therapy, only two treatment options were available. Patients could get the enzyme injected twice a week for the rest of their lives. They could also receive bone marrow transplants, but matches can be rare and rejection of the cells can be detrimental to the recipient. 18 kids participated in the clinical trials. All 18 kids were cured of the disease. This new therapy has so far shown to give much more desirable outcomes. FDA approval is the next step for the treatment so other children across the
U.S. will have access to the treatment. Also, this gene therapy is now going to
be used as treatment for sickle cell disease.
People have different perceptions when they hear about stem
cells. As more research is being done on gene therapy, should stem cells
continue to be researched as a gene therapy? What are the advantages and
disadvantages of this therapy and should stem cells be used as a gene therapy
for more diseases?
For more information:
https://www.stemcell.ucla.edu/news/stem-cell-breakthrough-ucla-researcher-pioneers-gene-therapy-cure-children-“bubble-baby”-diseas
This is a very interesting approach to treating SCID. I was interested in how stem cells can be used to treat sickle cell anemia after you mentioned it in your post. I did some searching and I came across this article http://www.pnas.org/content/106/24/9826.short which discusses how induced pluripotent stem cells (iPS cells) could be used as a new approach to gene therapy for diseases such as thalassemia and sickle cell anemia. Although, we are far away from using this process on fetuses, it does provide a foundation for a new path for gene therapy. Thus, although there are controversies surrounding the use of stem cells, medicine and research are headed in the direction of stem cell gene therapy. When it comes to using stem cells, it would be difficult to stop using them completely, but exploring different ways of obtaining stem cells, such as iPS cells, may lessen the conflict clouding around stem cells.
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ReplyDeleteThis is a very interesting article! There has been so much work and hype around stem cells and their application in diseases, whether it be from immune disorders, breast cancer, or neurodegenerative disorders. I first became interested about stem cell therapies as they relate to neurodegenerative diseases such as ALS. I recently read an article about induced pluripotent stem cells as a way of disease modeling in neurodegenerative disorders like ALS that I found extremely interesting, very similar to your article you found!
ReplyDeletehttp://www.ncbi.nlm.nih.gov/pubmed/?term=Reverse+engineering+human+neurodegenerative+disease+using+pluripotent+stem+cell+technology.+Liu+Y1%2C+Deng+W2.
Successful application of a patient's own hemotopoietic stem cells for curing a debilitating enzyme deficiency is extremely valuable for better patient outcomes. I am interested to see the results of the clinical trial.
Using gene therapy like this is great, these new approaches in gene therapy such as gene correction in autologous hemotopoietic stem cells seems very promising. And although there is controversy around stem cells, they seem to be the direction many areas of research are heading to solve many problems. My question is if there are any off target effects of such gene therapy? Other papers I have read about stem cells seem to discuss more problems with off target effects as well as implantation issues.