Actual aspects of cold agglutination.

Cold agglutinins (CA) can be directed against antigens of the I/i system and the Pr complex. In addition, anti-Gd CA have been recently described. The CA immunoglobulins, serological specificities and the antigen immunochemistry are reviewed. CA permitted studies on interrelations between antibody structures and specificities. The significance of subgroup preferences and cross-idiotypic specificities is discussed. Interrelations between CA specificities and certain virus infections are pointed out, and recent results obtained from studies using CA as indicators for membrane alterations of other than red cells are reviewed.