Removal of maternal antibodies from a woman with repeated fetal loss due to P blood group incompatibility.

BACKGROUND: Plasmapheresis is intended to lower plasma antibody levels in women with blood group incompatible pregnancies. CASE REPORT: Therapeutic specific antibody removal by using antigen-positive red cells was applied to a blood group p pregnant women who had a high titer (128) of IgG anti-PP1Pk and had lost all six previous fetuses in blood group P-incompatible pregnancies. Plasma was taken from the patient with an intermittent-flow cell separator, mixed with a volume of washed and packed P-positive red cells equivalent to one-fifth of the volume of plasma, and incubated for 10 minutes in an ice water bath. The PP1Pk antibodies were removed, and the autologous plasma was transfused. Treatment by specific antibody removal was started in the seventh week of gestation, and performed one to three times a week for a total of 56 times up to the 34th week. The volume of plasma treated was 2.4 L per procedure on average and totaled 135 L. After each treatment, the antibody titer in the patient's plasma usually decreased by 1 log2, and no deleterious effect on the women was noted. The titers of IgG anti-P and anti-Pk were kept between 4 and 16 after the ninth week of gestation. At the end of the 34th week of gestation, a male infant was delivered by cesarean section. The infant did not require an exchange transfusion and is now a healthy 2-year-old boy.
CONCLUSION: This therapeutic method is very useful in the management of fetomaternal P-incompatibility.