Transmissive spongiform encephalopathies (TSE) diagnostic methods

Abstract

TSE represents a group of neurodegenerative diseases in animals and humans characterized by progressive tendency, long incubation period and fatal ending. Animal diseases are scrapie in sheep, transmissive mink encephalopathy (TME), chronic wasting disease of deer (CWD), bovine spongiform encephalopathy (BSE), feline spongiform encephalopathy (FSE) and spongiform encephalopathy's in some zoo animals. In humans, five diseases are known: Creucfeldt-Jakob disease (CJD), Gerstmann-Straussler-Scheinker syndrome (GSS), kuru, fatal family insomnia, and new variant of CJD (vCJD). Basic pathogenic component is specific form of PrPsc fibrilar protein. There are no commercial diagnostic tests for PrPsc detection in live animals available at the moment, so the pathogen has to be confirmed by pathohystological, immunohystochemical and electron-microscopy examinations on tissue samples of the nervous, rarely lymphatic, system. In the recent years, in the field of routine confirmatory diagnostic, immunoblotting method - Priantes takes the first place. A routine, fast diagnostic test ELISA, has also been used (Biorad and Enfer). All the three methods mentioned above have been validated as 100% specific and are accepted by the European Community for diagnostic and control of transmissive encephalopathies.

Transmisivne spongiformne encefalopatije predstavljaju grupu neurodegenerativnih oboljenja životinja i ljudi sa dugom inkubacijom progresivnim tokom i fatalnim ishodom. Ovde spadaju oboljenja životinja kao što je skrepi kod ovaca, prenosiva encefalopatija nerčeva, bolest kroničnog slabljenja jelena, spongiformna encefalopatija goveda, spongiformna encefalopatija mačaka i spongiformne encefalopatije kod nekih životinja u zoološkim vrtovima. Kod ljudi je poznato pet različitih oboljenja kao što su Creutzfeldt-Jakobova bolest, Gerstmann-Straussler-Scheinkerov sindrom, kuru fatalna familijarna insomnia, i nova varijanta CJD. Osnovna komponenta uzročnika svih navedenih bolesti je specifična forma PrPK flbrilarnog proteina. Danas još uvek nema dostupnih komercijalnih dijagnostičkih testova za detekciju PrPsc na živim životinjama, pa se agens dokazuje patohistološkim, imunohistohemijskim i elektronmikroskopskim ispitivanjima na uzorcima tkiva nervnog, a rede limfatičnog sistema. Poslednjih godina u rutinskoj i konfirmativnoj dijagnostici neprikosnovena je imunobloting metoda - Priantes. Od brzih testova u rutinskoj dijagnostici koriste se još ELISA (Biorad i Enfer). Sve tri navedene metode su vrednovane kao 100% specifične i prihvaćene su od strane Evropske zajednice za dijagnostiku i kontrolu transmisivnih encefalopatija.