Detection of measles virus antigen(s) in peripheral lymphocytes from patients with subacute sclerosing panencephalitis.

Peripheral blood lymphocytes from 5 patients with subacute sclerosing panencephalitis (SSPE) were stimulated with phytohemagglutinin (PHA) and analyzed for the presence of the measles virus antigen(s) by immunofluorescence (IF). For detection of viral antigen fluorescein-conjugated globulins from SSPE patients or from measles convalescents both with high anti-measles titer were used. Peripheral blood lymphocytes from 5 children with measles were used as a positive control. Measles virus antigen(s) were localized in PHA-transformed lymphocytes in all SSPE patients. The present results indicate that in SSPE measles-like virus infection may be found not only in the central nervous system, but also in the circulating lymphoid cells.