ABSTRACT
This chapter addresses human transmissible spongiform encephalopathies (TSEs) and the theoretical possibility of transmission of these diseases by the transfusion of blood and blood products. TSEs are rapidly progressing, fatal diseases, characterized by mental deterioration, cerebellar dysfunctions, involuntary movements, and psychiatric alterations. The brains of these patients show spongiform degeneration and deposition of an amyloid protein called prion protein (PrPres). This protein is the protease-resistant form of a cellular protein called PrPc, which is enclosed by a gene designated PRNP. PrPres is pathognomonic for this group of illnesses. The diagnosis of human TSE can be strongly suspected on clinical grounds (e.g., by a characteristic electroencephalogram in a number of cases), but it can be only confirmed by histological or biochemical investigations of brain material after biopsy or autopsy. Over 85% of the cases of human TSEs are sporadic, appearing in individuals without family history. About 10% of the cases are familial. More than 80 cases of iatrogenic transmission of human TSEs have been reported. A new form of Creutzfeldt-Jakob disease (CJD) named new variant CJD (nvCJD) was described in 1996, and there is evidence indicating that it is
related to bovine spongiform encephalopathy (BSE). These issues have been reviewed (1-3).
