Immunohematological Studies on the Effect of Prednisolone on experimental Hemolytic Anemia

Abstract

A report was made of the effect of prednisolone on hemolytic anemia produced in rabbits following repeated intravenous injection of egg-albumin. In a group of 15 anemic rabbits subjected to a 3-day administration of prednisolone, 11 rabbits showed a prompt but temporaty improvement of anemia, 5 rabbits became temporarily direct and indirect antiglobulin test negative. Following administration of prednisolone at a gradually decreased daily dosage from 3 mg to 0.5 mg per kg of body weight for 30 days, 12 in a group of 18 anemic rabbits had their anemia markedly improved and their Cr^<51>-labeled red cells longer survived, 8 of the 12 rabbits became direct and indirect antiglobulin test negative, the absence of the disappearance of complete antibody against egg-albumin. IgM and c' component of incomplete antibody against erythrocytes disappeared earlier than IgG component following administration of prednisolone. In nonresponsive rabbits, the disappearance of IgG and IgM was temporary. The development of hemolytic anemia in rabbits following administration of an eluate from incomplete antibody coated red cells was inhibited in 3 groups, each group consisting of 4 rabbits and 2 or 1 control, following treatment with prednisolone. The present experimental results revealed that in many instances direct antiglobulin test proved to be negative although indirect antiglobulin test was positive. It seems that administration of prednisolone prevented the injected incomplete antibody from being attached to the red cell in these rabbits without mechanism of incomplete antibody formation. It is concluded that the main effect of prednisolone on autoimmune hemolytic anemia is likely to consist of suppression of an incomplete autoantibody formation and prevention of incompleet autoantibody from being attached to the red cell. It is to be noted that mechanism of prevention of such attachment can not be ignored as a responsible factor of prednisolone for a prompt response in autoimmune hemolytic anemia.