Antibodies against measles virus polypeptides in different disease conditions.

The occurrence of antibodies to the nucleoprotein and matrix (M) antigens of measles virus was determined in early and late measles convalescent sera and in sera from patients with multiple sclerosis, subacute sclerosing panencephalitis, chronic active hepatitis, and atypical measles. Antibodies to the two components were identified separately in serially diluted samples both by radioimmune precipitation assays and by complement fixation tests employing purified nucleoprotein and M components as antigens. The antibody response to M antigen in connection with acute infections was weak, and with time titers of antibodies to M antigen were reduced below detectable levels in most cases. A different situation was seen in patients with atypical measles. A pronounced antibody response to M antigen was shown to be a part of the generally accentuated immune response in these patients. Confirming results of others, it was shown that in spite of the increased antibody titers against most measles components in sera from patients with subacute sclerosing panencephalitis, no or only low titers of antibodies to M antigen were present. However, a similar representation of antibodies to measles virus components was also seen in sera from patients with active chronic hepatitis. The significance of this finding for the interpretation of a weak antibody response to M antigen in the presence of a pronounced antibody response to other components is discussed.