An antibiotic and a protein can work together to fight radiation-induced infections better than either can manage alone. Doctors already use antibiotics to treat radiation sickness. But the addition of a protein from the immune system — bactericidal/permeability-increasing protein (BPI), which acts against poisons called endotoxins — improves the survival rate of irradiated mice, according to a study published today in Science Translational Medicine.
The combination of BPI with the antibiotic fluoroquinolone helped mice that were treated up to a day after exposure to radiation. This is important, because most existing treatments for radiation sickness — including those stockpiled by the US government, such as potassium iodide and the protein granulocyte colony-stimulating factor — must be taken before or within hours of exposure, which is not always possible. In the event of a nuclear crisis that exposes hundreds or thousands of people to radiation, the ensuing chaos could delay treatment.
“The most important thing about the BPI and fluoroquinolone combination is that it is effective at 24 hours after exposure,” says Eva Guinan, a haematologist at Harvard Medical School in Boston, Massachusetts, who led the study.