EPO, or erythropoietin, is well known for its misuse by athletes in search of performance.
But before being a doping product, this hormone allowed a therapeutic revolution to fight against anemia.
It is this ambivalence that the nephrologist Gilbert Deray details in "Sans Rendez-Vous".
Everyone knows EPO as a doping product, brought to the fore because of sad sports stories.
In fact, this hormone increases the number of red blood cells and therefore the oxygen available.
Some athletes therefore saw it as a way to improve their performance.
But before being diverted from its use, erythropoietin, a hormone naturally produced by our kidneys, has been recreated in the laboratory since 1977 to simplify the lives of many anemic patients.
"A therapeutic revolution"
This hormone is "produced by the kidneys as soon as there is a lack of red blood cells, therefore oxygen. If you climb to the top of a mountain, you will produce EPO", explains Prof. Gilbert Deray, head of the department. of nephrology at the Pitié-Salpêtrière hospital in Paris.
More than useful, this hormone is essential because "when one lacks erythropoietin, one is in anemia", specifies the specialist.
Patients with too low an EPO level therefore suffer from renal failure and their oxygen supply is deficient.
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"The creation of EPO is therefore a therapeutic revolution. Before, it was necessary to transfuse" people with anemia.
“Now it's a monthly injection,” explains Gilbert Deray.
According to the doctor, who lived through this medical revolution, anemia required a transfusion every two to four weeks.
This led to fatigue as well as "aluminum encephalopathy", due to the presence of this metal in the transfusions.
All this has almost disappeared thanks to the EPO, which replaced this heavy device by "a painless skin prick", says the nephrologist.
The hormone is also used in oncology or before certain surgeries.
Risk of stroke in case of doping use
The flip side has been the development of illegal and non-medical use of this hormone.
Because as the nephrologist explains, "by increasing the number of red blood cells, we increase the available oxygen and therefore performance".
The process, normally naturally regulated, is forced into action.
But the consequences can be serious.
Because as Gilbert Deray points out, "you also increase the risk of having a stroke. If you increase the number of red blood cells, they can come together and make a small clot."
There is also an increased risk of high blood pressure and thrombosis.
Finally, excess EPO is suspected of promoting certain cancers.
Outside the medical framework, EPO is therefore to be absolutely avoided.