Immunological response of subacute sclerosing panencephalitis patients to measles virus

The immunological responses of patients with clinical signs of SSPE were examined by the direct migration inhibition, complement-mediated antibody cytoxicity and the lymphocyte-mediated cytotoxicity assay techniques. Peripheral lymphocytes migrated similarly to controls when exposed to measles antigen. Lymphocytes from SSPE patients responded to a SSPE strain of measles infected cells in a manner similar to lymphocytes from controls. A factor which interfered with the expected activity of sensitized lymphocytes to measles virus was detected in some cerebral spinal fluid obtained from SSPE patients. The blocking activity varied from 100% in 4 of 20 patients with SSPE to no blocking in 2 of the SSPE patients. The occurrence of blocking factor in SSPE patients could not be related to sex or age of the patient, serum of CSF antibody levels, and duration of disease or outcome.