Bleeding Patient with Anti-PP1Pk – Revisiting Autologous Frozen Red Blood Cells

Abstract

Abstract Introduction/Objective A 34-year-old Amish woman G11P8A2L8, with a known PP1Pk antibody, presented to her OB with vaginal hemorrhage secondary to an incomplete spontaneous abortion. Despite medical treatment, her hemoglobin decreased from 12 g/dL to 8.4 g/dL. She was air transferred to a tertiary care hospital for further management and antigen negative RBC transfusion. Upon arrival, her hemoglobin had decreased to 7.1 g/dL and her BP decreased to 92/64 mm Hg. Additional blood draws were discontinued to save blood wastage. Her blood pressure continued to decrease over the next several hours to a low of 78/36. The patient was briefly stabilized, and a successful dilation and curettage was performed. Methods/Case Report A national search was conducted for PP1Pk antigen negative blood. Her RBC phenotype: C+, c-, E-, e+, K-k-, Fy(a + b-), Jk(a+ b+), MN+, p, Le(a-b-). There was no history of blood product transfusion and the prior miscarriages where thought to be the source of alloimmunization. There was no known family history of the p (P- P1- Pk-) phenotype. Results (if a Case Study enter NA) One unit of PP1Pk antigen negative PRBCs was located approximately 48 hours after the patient’s admission, however, the consulting hematology team suggested withholding transfusion due the possibility of alloimmunization from other blood groups complicating future transfusions. She was treated with IV iron and discharged four days later with a hemoglobin level of 6 g/dL. She was asymptomatic upon discharge. Conclusion Anti-PP1Pk is a rare antibody (5.8 per 1 million people). In the Amish population, the incidence is approximately 1 in 5000 individuals. Our patient is planning for future pregnancies. Upon our suggestion, the patient was encouraged to consider frozen autologous blood donation after recovery and before the next pregnancy as well as close monitoring in high-risk maternal fetal medicine settings. In a patients and donors with anti PP1PK, we recommend advance planning including frozen autologous blood donation and family members RBC antigen studies. They should be encouraged to become regular blood donors for themselves and others.