IgG1 subclass restriction of oligoclonal measles virus-specific IgG antibodies in patients with subacute sclerosing panencephalitis and in a patient with multiple sclerosis.

A restriction to the IgG1 subclass was demonstrated for measles virus-specific IgG antibodies isolated from the sera of five patients with subacute sclerosing panencephalitis, from the cerebrospinal fluid of one of the patients, and from brain extract from a sixth patient. A predominance of IgG1 was also observed in measles antibodies isolated from the serum and brain extract of a patient with multiple sclerosis. Evidence is presented that the IgG1 restriction is associated with the occurrence of oligoclonal measles antibodies in these patients. A similar restriction to the IgG1 subclass was not observed in measles antibodies isolated from the serum of a measles-convalescent child or from pooled normal serum and IgG.