IgG subclasses in rhesus-D immunization. Effects of weekly small volume plasmapheresis.

The IgG subclass composition was determined of the anti-D antibodies present in the serum of 22 women who had a history of severe rhesus-D immunization and who weekly underwent small volume plasmapheresis during their current pregnancy. There was no correlation between the subclass patterns of IgG anti-D antibodies and the degree of illness of the child; the good clinical results obtained with the small volume plasmapheresis could not be explained by a consistent change in the anti-D IgG subclass composition.