Hematopoietic or blood-forming stem cells have been used to treat blood diseases for many decades. Transplantation of donor cells helps to completely replace the patient's own blood cells (restore healthy hematopoiesis) and thus cope with the disease. This treatment helps with hereditary blood diseases and blood cancer. Today, there is data indicating that cancer develops in one in a thousand people after a HSC transplant, so scientists decided to find out whether the treatment can actually contribute to the development of cancer in the future. The findings are published on the Nature website.
The US team recruited 32 people to participate – 16 donor-recipient pairs. The participants had received donor cell transplants between 7 and 46 years ago for blood cancer. Using genome sequencing of the participants, it was found that mutations developed at a rate of 2% per year in donors, and at a rate of 2.6% in recipients.
"This is amazing. In fact, there were very few new mutations in the stem cells. So the recipients' cells are aging at the same rate as the donors' cells. For this reason, they do not have an increased risk of cancer," said co-author of the study, hematologist Spencer Champman.
Previously, the scientist conducted a similar clinical study involving 10 people and came to similar conclusions: recipients had only a slightly higher number of mutations compared to donors.
Other researchers noted that the stability of mutation risks over time indicates "a significant depth of regenerative capacity of the hematopoietic system."
Importantly, multiple cell mutations were more common in recipients, which explains the rare occurrence of cancer in people who received HSC transplants.
Scientists will continue to conduct such studies to gather more information about the risks and consequences of HSC transplantation for human health in the long term. Meanwhile, the data already available will become a significant part of the evidence base for the safety of such treatment for various diagnoses and methods of cell administration, including gene therapy.
Today, stem cell therapy is being studied in many areas. Research shows excellent prospects for therapy for HIV, osteoarthritis, Alzheimer's disease, diabetes, and other diagnoses.