Analysis of a pregnancy-screening and neonatal-immunization program for hepatitis B in Hamilton, Ontario, Canada, 1977-1988.

During the 12 years from January, 1977, to December, 1988, the Hamilton Centre of the Canadian Red Cross Society (CRCS) Blood Transfusion Service screened 98,712 pregnant patients for hepatitis B surface antigen (HBsAg) and identified 120 positives (0.12%). The number of positives ranged from six to 16 per year. We were able to trace and enroll 65 mothers (54%) and 96 of their children in the follow-up study. The majority of the women were between 20 and 30 years of age (95.4%) and married (86%), and about one-half were employed outside the home. Sixty-five percent were white and 34% Asian, and 20 countries were listed as their places of origin. Hepatitis B immune globulin (HBIG) was available for neonatal immunization since 1977 and combined with vaccine since 1982. Of the 96 candidates for HBIG, 60 (63%) received HBIG within 24 hr, one after 3 months, four unknown, and 31 did not receive it. Of the 56 candidates for vaccination from 1982 to 1989, 26 (46%) received three doses, seven had two doses, eight had one dose, one was unknown, and 14 had none. HBsAg tests were performed on 69 children (71.8%) and anti-HBs on 61 (63.5%). Four of the children are HBsAg positive, 31 have anti-HBs, and 31 have no detectable antibodies. All four HBsAg positives had not received vaccine, and only one had received HBIG. Of the children positive for hepatitis B surface antibodies, five had received no immunization and therefore had been subclinically infected.(ABSTRACT TRUNCATED AT 250 WORDS)

Rhesus alloimmunization following intensive plasma exchange.

A 17-year-old woman was admitted to the hospital for the treatment of rapidly progressive systemic lupus erythematosus. She failed to improve when treatment with cyclophosphamide and prednisone and, therefore, was treated with intensive plasma exchange. A total of 24 liters of plasma was exchanged during six separate procedures over an 8-day period. The patient, who was blood group B Rh negative (Cde/cde), was found to have an IgG anti-D antibody reacting at a titer of 16 by the indirect antiglobulin technique 6 weeks after the first plasma exchange procedure. The titer of this antibody subsequently rose to 512. This patient, who had neither been pregnant nor received any blood products other than the plasma used during the plasma exchange, was presumably immunized by Rh positive red cells or stroma present in the transfused plasma. It is estimated that the patient received approximately 10(10) Rh positive cells, or approximately one ml of packed red cells--a quantity sufficient to cause Rhesus alloimmunization.