Observations on the effect of irradiation in chronic acquired hemolytic anemia exhibiting hemolytic activity for transfused erythrocytes.

By ROBERT S. EVANS, M.D., AND ROSE T. DUANE, A.B. E VIDENCE is accumulating that transfused cells are destroyed at an accelerated rate in one type of acquired hemolytic anemia. ‘ Since normal cells as well as the patient’s are involved it is evident that a hemolysin is present which is active against all erythrocytes. In the few instances in which a hemolysin has been demonstrated in vitro it has exhibited the characteristics of an immune body requiring complement for activity. 7 If an antigen, antibody reaction is the basis of hemolysis in the hemolytic anemias showing accelerated destruction of transfused cells it is not surprising that the agent has seldom been demonstrated in serum or plasma, since it is active at body temperature and would therefore be expected to become attached to the red cells as it is released. Recent investigations on the formation of antibodies have re-emphasized the importance of lymphatic tissue and lymphocytes in antibody production.8’9 Previous observations by Hektoen 10 and by Murphy and Sturm “demonstrated that sufficient irradiation of lymphatic tissue will inhibit antibody formation in animals. It seemed worth while, therefore, to observe the effect of irradiation on the hemolytic anemia in a patient in whom it had been demonstrated that normal red cells as well as her own were destroyed in vivo at an accelerated rate. Because irradiation and transfusion were followed by a remission in the severity of the disease a second patient with chronic hemolytic anemia exhibiting similar features was also exposed to irradiation. The results of these observations are reported.