Plasma exchange for a hemolytic crisis due to autoimmune hemolytic anemia of the IgG warm type.

A patient with a hyperacute hemolytic crisis due to AIHA of the IgG type was treated by combined plasmapheresis and exchange transfusion. A discontinuous flow centrifuge was used. Immediately after the exchange the hemoglobin level rose from 2.6 to 9.8 g/dl. The D. A. T. became weakly positive and the hemolytic crisis subsided. During the days following the exchange the autoantibodies responsible for the hemolytic crisis, switched from IgG1 and IgG3 to IgG2 and IgG4. The clinical and laboratory picture stabilized thereafter.