title: Fatal hemolytic transfusion reaction resulting from ABO mistyping of a patient with acquired B antigen detectable only by some monoclonal anti-B reagents.
abstract: BACKGROUND
  Some monoclonal anti-B reagents are prepared exclusively from an anti-B clone, ES4, that is known to detect acquired B antigens that are not detectable by other anti-B clones or polyclonal anti-B reagents.
  
  
  METHODS
  A 92-year-old group A, Rh-negative man with diverticulitis was mistyped as group AB with the use of a monoclonal anti-B. The hospital did not detect anti-B in the patient's serum. After a negative antibody screen, blood was issued through an abbreviated crossmatch (i.e., immediate-spin crossmatch). The patient was given 3 units of group AB blood and 1 unit of group A blood, and no problems were reported. After the transfusion of a ¿fourth unit of AB blood the patient had a severe hemolytic transfusion reaction which resulted in kidney failure and death 10 days later. After the transfusion reaction, the patient's pretransfusion red cells were found to be group A with an acquired B antigen. The monoclonal anti-B used the hospital was formulated from the ES4 clone. A sample of the patient's serum taken before the transfusion was later found to contain a weak anti-B, detectable most obviously by the antiglobulin test, which was not performed at the crossmatch stage. The manufacturers of monoclonal anti-B reagents prepared from ES4 have since modified their reagents (i.e., lowered the pH) so that they now detect only the strongest examples of acquired B antigen.
  
  
  CONCLUSIONS
  A fatal hemolytic transfusion reaction resulted because a monoclonal anti-B that detected acquired B antigen was used to type red cells from an elderly man whose serum had weak anti-B that was not detected by abbreviated compatibility testing.
authors.affiliation: American Red Cross Blood Services, Southern California Region, Los Angeles, 90006, USA.
authors.forename: G
authors.initials: G
authors.lastname: Garratty
authors.forename: P
authors.initials: P
authors.lastname: Arndt
authors.forename: A
authors.initials: A
authors.lastname: Co
authors.forename: K
authors.initials: K
authors.lastname: Rodberg
authors.forename: M
authors.initials: M
authors.lastname: Furmanski
mesh_terms: D000017:ABO Blood-Group System / Q000276:immunology*; D000368:Aged; D000369:Aged, 80 and over; D001787:Blood Group Incompatibility; D017809:Fatal Outcome; D006801:Humans; D008297:Male; D065227:Transfusion Reaction
chemical_list: D000017:ABO Blood-Group System