High frequency of human herpesvirus 6 DNA in multiple sclerosis plaques isolated by laser microdissection.

The frequency of human herpesvirus 6 (HHV-6) DNA was assessed in autopsy material from multiple sclerosis (MS) plaques and normal-appearing white matter (NAWM) from brains of persons with MS, healthy brains, and brains of persons with other neurologic diseases. Specific areas from formalin-fixed, paraffin-embedded brain tissue samples were isolated by laser microscope. DNA was extracted from laser microdissected brain material, and HHV-6 genomic sequences were amplified by nested polymerase chain reaction.