Treatment with plasmapheresis and intravenous immunoglobulin in pregnancies complicated with anti-PP1Pk or anti-K immunization: a report of two patients.

BACKGROUND AND OBJECTIVES: In addition to anti-D alloantibody, other antibodies such as anti-K antibody and anti-PP1Pk antibody have been reported to cause severe haemolytic disease of the newborn (HDN). HDN caused by anti-K results not only from destruction of red cells but also from suppression of erythropoiesis. Anti-PP1Pk has been associated with abortion early in pregnancy. We report on two patients, one with anti-PP1Pk and the other with anti-K, who were treated with plasmapheresis and intravenous immunoglobulin (IVIG) during pregnancy in an attempt to reduce the plasma antibody levels. MATERIALS AND METHODS: The patient with anti-PP1Pk had lost all seven previous fetuses in the first trimester and therefore therapy in this patient was started at 8 weeks of gestation. The second patient had been sensitized to the K antigen through blood transfusion and had had two intrauterine fetal deaths at 26 weeks of gestation with signs of hydrops fetalis. Treatment in this patient was started during the 16th week of pregnancy. RESULTS: As a result of therapy, the antibody titre was reduced in both patients. In the first patient a healthy infant was delivered by Caesarean section at 37 weeks of gestation. The second patient gave birth at 36 weeks of gestation. Neither newborn required exchange transfusion. CONCLUSION: In our two patients, plasmapheresis combined with IVIG proved successful in the management of fetomaternal incompatibilities where the mechanism of fetal loss differs from the classical anti-D.

[Evaluation of the polyethyleneglycol antiglobulin test in the detection and identification of erythrocyte antibodies]. / Valoración de la prueba de antiglobulina con polietilenglicol en la detección e identificación de anticuerpos eritrocitarios.

PURPOSE: The polyethylene glycol antiglobulin test has been found to enhance the reactivity of most alloantibodies. MATERIAL AND METHODS: To investigate the utility of polyethylene glycol antiglobulin test for detection and identification of red blood cell antibodies, a comparison study of polyethylene glycol (PEG), a low-ionic-strength additive solution (LISS) and bovine serum albumin (BSA) was conducted. The sera of 47 different patients with positive antibody screening test by the LISS method, were tested in parallel with reagent antibody-detection cells using PEG, LISS and BSA. RESULTS: In the sera of 47 patients, 57 antibodies were detected. We identified 39 antibodies by the three methods. Twelve antibodies reacted by the BSA method and the LISS method but did not react with the PEG method (8 anti-I, 1 anti-P1, 1 anti-Lea(a), and two antibodies missed by the PEG method because they did not react with anti-IgG: 1 anti-M and 1 anti-K). Three antibodies reacted only with the LISS method (3 anti-I). Four clinically significant antibodies were detected only by the PEG method (2 anti-Jka, 1 anti-Jkb, 1 anti-c). The serum from a patient with delayed hemolytic transfusion reaction and no antibody detectable by the LISS and the BSA methods was tested by the PEG method. We were able to detect an anti-Jka by PEG in the pretransfusion sample. In 24 (60%) of 40 samples with clinically significant antibodies, PEG antiglobulin reactions were stronger (total score 221) than LISS antiglobulin reactions (total score 170) and BSA antiglobulin reaction (total score 184); in 14 (35%) of 40 samples, they were identical, and in 2 (5%) agglutination in the PEG method was weaker. CONCLUSION: In our experience, the polyethylene glycol antiglobulin test is more sensitive than LISS and BSA in detecting clinically significant antibodies and is an acceptable technique for routine compatibility test.