What are the consequences of exposure to low-dose ionizing radiation, such as that experienced during medical examinations using X-rays? Previous epidemiological studies have associated exposures to low-dose irradiation (<0.1 Gy) with an increase in the frequency of onset of hematological diseases. Until recently, a biological link had been identified between exposure to low-dose irradiation and hematopoietic cell abnormalities. Now the results obtained by researchers from the François-Jacob Institute at CEA, INSERM, Universities Paris Sud and Paris Diderot show that low-dose radiation of hematopoietic stem cells (HSCs)—responsible for the formation of all blood cells—leads to a decrease in the number of HSCs and in their functionality.

This seemingly harmful property can actually prove useful in a medical context: low-dose irradiations are two-faceted—they have their own Yin and Yang. The researchers took advantage of this property to test a new protocol allowing a bone marrow transplant without myeloablation. The protocol currently used in autologous bone marrow transplant consists in the drug-induced destruction of the patient's bone marrow before transplant (myeloablation)—a process which unfortunately comes with numerous undesirable side effects. Scientists have shown that low-dose irradiation (a dose used in medical imaging) preceded by a currently used clinical treatment causes the release of CSH from the bone marrow, which would allow a bone marrow transplant without myeloablation.

This result was the subject of a press release.