[Viruses and cell therapy. Evaluation of cell therapy from the virologic viewpoint]

The risks of cell therapy as seen by the microbiologist and virologist, are not calculable. Numerous viruses with longterm persistence in the host cells, cannot be detected on the basis of an acute disease in the host. This applies, for example to herpesviruses, lentiviruses, retroviruses, hepatitis C virus, Borna disease virus and the so-called unconventional viruses. There are two reasons why testing of the donor animal ist not possible, the first being the great number of potential pathogens, the second being the fact that for some of these agents there are no signs of a diagnostic approach involving isolation or antibody detection. e.g. scrapie (BSE). Further, so far unknown viruses must be expected.