If you haven’t seen this story, it’s an amazing triumph for adult stem cell therapy and HIV. However, one man’s gain is another man’s loss. What should be read between the lines is that the genes of the donor stem cells (the ones that were able to take out HIV by crippling the CCR5 receptor) still functioned in the host. Why is this important? It means that stem cells transplanted from person A to B can carry with them genes and their gene functions. This comes on the heels of another study which showed that mice bred to have osteoporosis were able to transmit that disease to normal mice without known bone problems.
Who cares? Well, companies pursuing allogeneic stem cell products should be very concerned by this finding. It means that off the shelf stem cells likely carry with them all of the good and bad genes from the donor into the host. This means that until we know everything there is know about the upside and downside of every gene, inserting new genes into people is a huge risk. It means allogeneic stem cells plays (embryonic, cord blood, and adult donor cells) are really gene therapy plays. While this may prove revolutionary for curing the most deadly diseases (like HIV or GVHD), where the benefits outweigh the unknown risks, for everyday diseases, the potential risks likely outweigh the benefits.
To learn more about some of these issues, see below: