Debra Smith1,2, Thandar Aye2, Lay See Er2, Theresa Nester2,3, Meghan Delaney2,3,4. 1. Oklahoma Blood Institute, Oklahoma City, OK, USA. 2. Immunohematology and RBC Genomics Reference Laboratory, Bloodworks NW, Seattle, WA, USA. 3. Department of Laboratory Medicine, University of Washington, Seattle, WA, USA. 4. Pathology & Laboratory Medicine Division, Children's National Health System, Washington, DC, USA.
Abstract
BACKGROUND: Here we report a case of acute hemolytic transfusion reaction (HTR) due to anti-P1 and review our institutional database for prevalence of anti-P1 antibodies and frequency of anti-P1-mediated HTR. Anti-P1 antibodies, reported to be present in up to two-thirds of P2 individuals, are usually clinically insignificant. However, rare cases of acute HTR due to anti-P1 are reported. Case Report: We report the clinical and laboratory features of a mild acute HTR due to an IgM anti-P1 not detected by a routinely used antibody screening method. We reviewed our institutional database to investigate prevalence of anti-P1 antibodies identified in our patient population and frequency of HTR in patients with anti-P1. RESULTS: Analysis of RBC transfusion recipient data over the 10-year period from 2006 to 2015 showed prevalence of anti-P1 identified in our laboratory of 174 per 100,000 individuals. Frequency of HTR in patients with anti-P1 identified in our laboratory over a 10-year period was 1 in 1,429 RBC transfusions (0.07%). Conclusion: Our reported case of HTR mediated by IgM anti-P1 reactive at 37 °C confirms the potential of antibody screening methods designed to detect IgG antibodies to miss rare clinically significant IgM antibodies.
BACKGROUND: Here we report a case of acute hemolytic transfusion reaction (HTR) due to anti-P1 and review our institutional database for prevalence of anti-P1 antibodies and frequency of anti-P1-mediated HTR. Anti-P1 antibodies, reported to be present in up to two-thirds of P2 individuals, are usually clinically insignificant. However, rare cases of acute HTR due to anti-P1 are reported. Case Report: We report the clinical and laboratory features of a mild acute HTR due to an IgM anti-P1 not detected by a routinely used antibody screening method. We reviewed our institutional database to investigate prevalence of anti-P1 antibodies identified in our patient population and frequency of HTR in patients with anti-P1. RESULTS: Analysis of RBC transfusion recipient data over the 10-year period from 2006 to 2015 showed prevalence of anti-P1 identified in our laboratory of 174 per 100,000 individuals. Frequency of HTR in patients with anti-P1 identified in our laboratory over a 10-year period was 1 in 1,429 RBC transfusions (0.07%). Conclusion: Our reported case of HTR mediated by IgM anti-P1 reactive at 37 °C confirms the potential of antibody screening methods designed to detect IgG antibodies to miss rare clinically significant IgM antibodies.