%0 Journal Article %J Transfusion %D 1996 %T Fatal hemolytic transfusion reaction resulting from ABO mistyping of a patient with acquired B antigen detectable only by some monoclonal anti-B reagents. %A Garratty, G %A Arndt, P %A Co, A %A Rodberg, K %A Furmanski, M %K *ABO Blood-Group System/im [Immunology] %K *Blood Group Incompatibility %K *Blood Transfusion/ae [Adverse Effects] %K Aged %K Aged, 80 and over %K Fatal Outcome %K Humans %K Male %X 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., CASE REPORT: 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., CONCLUSION: 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. %B Transfusion %I Garratty,G. American Red Cross Blood Services, Southern California Region, Los Angeles, 90006, USA. %C UNITED STATES %V 36 %P 351 - 7 %8 1996 %@ 0041-1132 %G eng %N 4 %< http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=reference&D=med4&NEWS=N&AN=8623139