What are the consequences of exposure to low doses of ionizing radiation, for example during the medical use of x-rays? Earlier epidemiological studies have associated low-dose irradiation (<0.1 Gy) to an increased frequency of hematological diseases. However, no biological link had been demonstrated between low-dose irradiation and hematopoietic cell abnormalities. But information is arriving: A team of researchers from the CEA's François Jacob Institute, Paris Sud University and Paris Diderot University showed that low-dose irradiation of hematopoietic stem cells (HSCs), the differentiation of which gives rise to all types of blood cells, reduces both their number and function.

Although deleterious in principle, this property can prove useful in certain medical settings; there is thus a sort of yin and yang to low-dose irradiation. Case in point: The current protocol for autologous bone marrow transplants requires myeloablation, that is, the complete medical suppression of the patient's bone marrow activity, upstream of the transplant. However, myeloablation is associated with numerous adverse effects. Putting their observation to good use, the research team tested a new protocol for bone marrow transplants without myeloablation. They showed that by applying a very low-dose of radiation (that used in medical imaging) after the deployment of a current medical procedure to harvest HSCs, a bone marrow transplant can be successfully performed without myeloablation.  

This result has been shared through a press release.