title: Acute hemolytic transfusion reaction due to anti-Le(b).
abstract: BACKGROUND
  Anti-Le(b) is usually a clinically insignificant antibody of immunoglobulin M subclass most often found in the sera of pregnant women or individuals that are Le(a-b-). We report a case of an acute hemolytic transfusion reaction due to a hemolytic anti-Le(b) that was not seen in the pretransfusion antibody detection test, but was strongly reactive in posttransfusion testing.
  
  
  METHODS
  A 30-year-old African-American woman with metastatic renal cell carcinoma was receiving chemotherapy. She was anemic with hemoglobin (Hb) of 7.2 g/dL and had a negative antibody detection test by the solid-phase red blood cell adherence method. She was transfused with 2 RBC units without incident. Nine days later her Hb was 7.9 g/dL again with a negative antibody detection test. Transfusion of an additional RBC unit was begun. During the transfusion she developed chills, nausea, hypertension, and red-brown urine. The posttransfusion sample plasma was grossly hemolyzed with a strongly positive direct antiglobulin test (DAT) by gel. By comparison the pretransfusion plasma was normal appearing and the DAT was weaker. The eluate was negative on both occasions. Anti-Le(b) was detected in the posttransfusion sample by MTS gel (Ortho Diagnostics). Both RBC units she had received before the RBC unit that caused the reaction were Le(b+) as was the implicated RBC unit.
  
  
  CONCLUSIONS
  This case illustrates that anti-Le(b) which is usually clinically insignificant can occasionally cause severe hemolytic transfusion reactions. Only three other reported cases of anti-Le(b) causing hemolytic transfusion reactions could be found in the literature, two of which were in abstract form only.
authors.affiliation: Immunohematology Reference Laboratory, Blood Systems Laboratories, Tempe, Arizona.
authors.forename: Mehraboon S
authors.initials: MS
authors.lastname: Irani
authors.affiliation: Immunohematology Reference Laboratory, Blood Systems Laboratories, Tempe, Arizona.
authors.forename: Dolores
authors.initials: D
authors.lastname: Figueroa
authors.affiliation: Immunohematology Reference Laboratory, Blood Systems Laboratories, Tempe, Arizona.
authors.forename: Gail
authors.initials: G
authors.lastname: Savage
mesh_terms: D000328:Adult; D001787:Blood Group Incompatibility / Q000097:blood / Q000628:therapy; D002292:Carcinoma, Renal Cell / Q000097:blood / Q000628:therapy; D017707:Erythrocyte Transfusion; D005260:Female; D006461:Hemolysis; D006801:Humans; D007518:Isoantibodies / Q000097:blood*; D007680:Kidney Neoplasms / Q000097:blood / Q000628:therapy; D007983:Lewis Blood Group Antigens / Q000097:blood*; D009844:Oligosaccharides / Q000097:blood*
chemical_list: D007518:Isoantibodies; D007983:Lewis Blood Group Antigens; D009844:Oligosaccharides; C404741:galactopyranosyl-1-3-galactopyranosyl-1-3(4)-N-acetylglucosamine