[High titer cold agglutinins with anti-pr specificity after rubella infection (author's transl)].

High titer cold agglutinins (CA) after rubella infection are reported. When the rubella exanthema disappeared the clinical aspect of a cold agglutinin disease was observed. Three weeks after the appearance of the cutaneous eruption the CA titer reached a maximum of 1/8000, to then continuously fall off to normal values within 20 weeks. Double diffusion tests showed that the isolated CA were IgM proteins that possess only chi-type light chains. In spite of normal protein- and immunoelectrophoresis patterns obtained with whole serum samples, the isolated CA showed restricted electrophoretic mobility and a deformation of the precipitate typical for monoclonal immunoglobulins. In contrast to the common anti-I specificity of IgM CA, the IgM CA described showed anti-Pr specificity. Possible interrelations between CA specificities and types of germs inducing reactive cold agglutination are discussed.