​Within the scope of evaluating the transfusion risk related to Creutzfeldt-Jakob disease (vCJD), researchers from the CEA, the La Pitié-Salpêtrière university hospital, the AP-HP, the CNRS, Inserm, INRA, ENVT, the Institut Pasteur and MacoPharma exposed mice and macaques to blood products from donors infected with vCJD.

Scientists found few cases of vCJD transmission in its classical form (less than 3% of the exposed animals). On the other hand, CEA researcher and lead author Emmanuel Comoy explains that "in a much larger proportion (nearly 10% of the animals exposed), recipient animals developed fatal neurological syndromes different from vCJD". These syndromes do not display all of the classic characteristics of prion diseases, and they are referred to as myelopathy in affected primates since they mainly concern the spinal cord.

The myelopathic form of the disease was observed in animals transfused with blood from apparently healthy carriers, i.e. prion-exposed donors with no identifiable pathology, as well as blood obtained from patients with clinical signs of vCJD.

The study thus reveals a diversity of symptoms, from healthy carriers to the typical vCJD form, showing that multiple prion variants could coexist and emerge under different clinical forms depending on the transmission conditions.

This result was the subject of a press release.