Comparison of different methods for the detection of rubella-specific IgM antibodies.

The rubella specific IgM titer in the serum specimens originating from healthy persons and from patients with clinical signs of rubella infection was determined by hemagglutination inhibition or hemagglutination reduction after IgM separation with the following methods: (a) density gradient centrifugation; (b) polyacrylamide agarose gel chromatography; (c) ion exchange chromatography with diethylaminoethyl cellulose columns; (d) solid-phase immunosorbent technique using microplates; (e) solid-phase immunosorbent technique using polyacrylamide microimmunobeads. Alternatively, we removed IgG and IgA by the use of protein A, anti-IgG, and anti-IgA, covalently coupled to controlled-pore glass (f). The titers obtained by the different methods showed qualitatively good correlations when combined with mercaptoethanol reduction. The quantitative measurement of specific IgM titers, however, revealed a lower sensitivity of column chromatography and methods of removal of IgG/IgA.