Search for a retrovirus in multiple sclerosis by enzymatic amplification of DNA from brain capillaries, brain tissue and mononuclear cells from peripheral blood.

Attempts were made to trace a possible retrovirus in multiple sclerosis (MS) by means of polymerase chain reaction. The primers derived from conserved sequences in the genome of human T cell leukemia/lymphoma virus type I (HTLV-I) and the amplifications were carried out at varying stringency conditions (i.a. annealing at low stringency to enhance the cross-reactivity of the primers). Included in the study were samples of DNA from brain capillaries (five MS patients), brain tissue (three MS patients) and peripheral blood mononuclear cells (three MS patients). Using an HTLV-I derived probe at relaxed conditions of stringency, hybridization signals were not recorded with amplified material from any of these samples. Aspects of infections with neurotropic retroviruses that could be relevant to the search for a retrovirus in MS are reviewed.