Immunological studies of subacute measles encephalitis in ferrets: similarities to human subacute sclerosing panencephalitis.

Ferrets inoculated with subacute sclerosing panencephalitis virus strains D.R. and Biken developed a subacute encephalitis. Brain extracts, at neutral pH, from these ferrets showed high measles antibody titers, increased concentrations of immunoglobulin G (IgG), and higher IgG/albumin ratios than those of controls. Although the brain extracts of subacute encephalitic animals showed significant synthesis of measles-specific IgG (20 to 60% of the total IgG) within the central nervous system, the electrophoretic patterns of these extracts did not show oligoclonal bands in the gamma-globulin region. Brain residues from most ferrets with subacute encephalitis, when eluted at low pH, demonstrated the presence of bound measles-specific antibodies. Excluding the electrophoresis data, other results are identical to those seen in human subacute sclerosing panencephalitis, indicating that the subacute encephalitis in ferrets may serve as a model for human subacute sclerosing panencephalitis.