Immunosuppressive therapy in Rh-incompatible transfusion.

Postpartum injections of 250 ,tg of anti-D gammaglobulin prevent Rh-immunization of Rh-negative women, with an im-munosuppression success rate of approximately 95% (Eklund and Nevanlinna, 1971). The average fetomaternal transfusion, however, is less than 1-5 ml in 98% of cases (Clarke et al., 1966), and so far there are few observations on trying to suppress primary Rh-immunization due to massive inadvertent transfusion of Rh-positive blood (Hughes-Jones and Mollison, 1968; Keith et al., 1970). We report here three cases in which Rh-negative women received in error a Rh-transfusion and in which large doses of anti-D gammaglobulin appeared to have suppressed primary immunization when they were tested for immune anti-D formation 12 months or later after the accident. Case Reports Case 1.-A 22-year-old primigravida was delivered of a child by caesarean section on 8 March 1968. She was group A Rh-negative and the infant's group was A Rh-positive. A transfusion of 400 ml of A Rh-positive blood was given on 12 March. Five hours later an infusion of anti-D plasma was started intravenously and given in the course of 31 hours. After the infusion of 180 ml over two hours the patient's temperature rose to 38-6'C and she had an attack of shivering. The treatment was stopped for 14 hours and started again at a rate of 30 ml/hour without further reactions. A total of 630 ml of plasma was administered, containing 8,200 utg of anti-D (see Table), as estimated by Dr. N. C. Hughes-Jones. The plasma haemoglobin reached a peak concentration of 150 mg/100 ml. The urinary output was normal throughout. The number of surviving Rh-positive cells was determined by the Ashby differential agglutination technique; the results are shown in the Chart. Samples of blood obtained up to 22 months after the transfusion showed no antibody. At the time of writing the patient had not had a subsequent Rh-postive pregnancy. Case 2.-An 18-year-old woman aborted at 16 weeks' gestation on 21 May 1969. She had not been pregnant before and had never received blood transfusions. Because of severe bleeding she was given 800 ml of A Rh-positive blood. She was group A Rh-negative. Nine hours after the beginning of the blood transfusion she was given 2,500 ,ug of anti-D gammaglobulin, and 24 hours later she received an additional dose of 2,500 ,ug (see Table). Approximate estimates of the survival of transfused red cells were made by an Ashby count; the results are …