Comparison of cell-fusing activity of brain suspensions from patients with Creutzfeldt-Jakob disease and other degenerative neurological diseases.

In vitro cell-fusing activity of brain suspensions from 33 patients with transmissible cases of Creutzfeldt-Jakob disease (CJD) was compared to activity of brains from 26 patients with a variety of other degenerative neurological diseases, and with activity of brains from 25 patients without neurological disease. A significantly higher proportion of CJD brains (61%) was positive than other neurologically diseased brains (31-35%) or the brains without neurological disease (0-4%). Although not yet sufficiently specific to be useful as a diagnostic test for human CJD, the assay nevertheless opens a line of investigation into the pathophysiology of degenerative neurological diseases and could prove immediately useful in rapidly locating material of maximum interest in purification procedures for experimental spongiform encephalopathy virus.