Light-chain profiles in sera from patients with subacute sclerosing panencephalitis.

Sera from 2 subacute sclerosing panencephalitis (SSPE) patients were absorbed with a concentrated preparation of measles virus. Measles-specific IgG was eluted from the precipitates containing measles antigen-antibody complex. These IgGs, when subjected to immunofixation after isoelectric focusing showed a number of oligoclonal bands with one type of light-(L) chain. In urea polyacrylamide gel electrophoresis, the reduced and alkylated measles-specific IgG showed 1-3 homogeneous L-chain bands, whereas IgG isolated from unabsorbed sera and IgG isolated from supernatants of SSPE sera after absorption with measles virus showed a diffuse L-chain band. It can be concluded that in SSPE, measles virus is responsible for the synthesis of L-chain with restricted heterogeneity.