Relationship between measles HI titers and an MS susceptibility gene.

Recently published studies of formal linkage analyses strongly suggest that a multiple sclerosis susceptibility (MSS) gene is linked to the HLA region of the sixth chromosome. The objective of this analysis was to investigate whether or not the gene has any demonstrable relationship to the immune status with regard to measles within members of multiple-case MS families. Family members were HLA-typed, and levels of antibodies to measles were determined using the hemagglutination inhibition assay. Since a specific, HLA-defined haplotype within each family is presumably a marker for the MSS gene, family members were characterized as either carrying [(+) controls] or not carrying [(-) controls] the MSS gene by the presence of this specific haplotype. Twenty families were entered into the analyses. Results revealed that the mean titer to measles was not different between (+) and (-) controls, and that MS cases had significantly higher titers than both control groups combined.