title: Probiotic-associated high-titer anti-B in a group A platelet donor as a cause of severe hemolytic transfusion reactions.
abstract: BACKGROUND
  Hemolytic transfusion reactions (HTRs) can occur with transfusion of platelets (PLTs) containing ABO-incompatible plasma. Reported cases have involved group O donors. Two cases of PLT-mediated HTRs associated with the same group A plateletpheresis component, collected from a donor taking high doses of probiotics are reported.
  
  
  METHODS
  Case 1 was a 40-year-old 69-kg group B stem cell transplant patient who received one-half of a group A plateletpheresis component. Severe back pain occurred 10 minutes into the transfusion, accompanied by anemia and hyperbilirubinemia. Case 2 was a 5-year-old 26-kg group B male with aplastic anemia who received the other half of the same plateletpheresis component, volume reduced to 37 mL. Syncope occurred immediately after the transfusion, with laboratory evidence of hemolysis a few hours later.
  
  
  RESULTS
  Serologic investigation of posttransfusion samples from both patients revealed positive direct antiglobulin tests: C3d only for Case 1 and immunoglobulin (Ig)G and C3d for Case 2; the eluates contained anti-B. The group A donor's anti-B titer was 16,384 at saline and IgG phases. Donor lookback revealed that the donor had donated 134 apheresis PLTs over many years. For 3 years, he had intermittently taken probiotics; 3 weeks before the index donation, he began taking three tablets of probiotics every day. Lookback of prior group B recipients uncovered a case of acute hemolysis that was not recognized at the time. The solubilized probiotic inhibited anti-B in vitro.
  
  
  CONCLUSIONS
  Non-group O PLT donors can have high-titer anti-A or anti-B that might mediate HTRs, and probiotic ingestion in blood donors represents a novel mechanism of stimulating high-titer anti-B.
authors.affiliation: Department of Transfusion Medicine, Warren G Magnuson Clinical Center, and the Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Daniel-Johnson
authors.forename: Susan
authors.initials: S
authors.lastname: Leitman
authors.forename: Harvey
authors.initials: H
authors.lastname: Klein
authors.forename: Harvey
authors.initials: H
authors.lastname: Alter
authors.forename: Agnes
authors.initials: A
authors.lastname: Lee-Stroka
authors.forename: Phillip
authors.initials: P
authors.lastname: Scheinberg
authors.forename: Jeremy
authors.initials: J
authors.lastname: Pantin
authors.forename: Karen
authors.initials: K
authors.lastname: Quillen
mesh_terms: D000017:ABO Blood-Group System / Q000276:immunology*; D000328:Adult; D000368:Aged; D001782:Blood Donors; D001787:Blood Group Incompatibility / Q000276:immunology*; D002675:Child, Preschool; D005260:Female; D006461:Hemolysis / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017713:Platelet Transfusion / Q000009:adverse effects*; D010983:Plateletpheresis; D019936:Probiotics
chemical_list: D000017:ABO Blood-Group System