title: B-cell transcription factor expression and immunoglobulin gene rearrangement frequency in acute myeloid leukemia with t(8;21)(q22;q22).
abstract: OBJECTIVE
  To assess a large series of patients with acute myeloid leukemia (AML) with t(8;21) for both IGH@ and IGK@ B-cell gene rearrangements and for expression of PAX5, OCT2, and Bob.1 by immunohistochemistry and expression of CD19, CD79a, CD20, and CD22 by flow cytometry immunophenotyping.
  
  
  METHODS
  A total of 48 cases of AML with t(8;21)(q22;q22) were evaluated by immunohistochemistry and/or heavy chain and light chain immunoglobulin rearrangement studies where paraffin-embedded and/or fresh frozen material was available for study; previously performed flow cytometry studies were also reviewed in available cases.
  
  
  RESULTS
  Our study yielded 1 of 19 cases of AML with t(8;21) with an IGH@ gene rearrangement; blasts were associated with weak PAX5 expression. In addition, expression of antigens CD79a by flow cytometry and OCT2 by immunohistochemistry were highly associated with PAX5 expression, and CD19 was expressed in most cases assessed.
  
  
  CONCLUSIONS
  Although B-cell antigen and B-cell transcription factor expression is seen in the majority of AMLs with t(8;21)(q22;q22) and correlates with PAX5 expression, immunoglobulin gene rearrangements are an uncommon event in this group of leukemias.
authors: Department of Pathology, Stanford University School of Medicine, 300 Pasteur Dr, Stanford, CA 94305, USA. ryancj@stanford.edu
authors: Ryan C
authors: RC
authors: Johnson
authors: Lisa
authors: L
authors: Ma
authors: Athena M
authors: AM
authors: Cherry
authors: Daniel A
authors: DA
authors: Arber
authors: Tracy I
authors: TI
authors: George
mesh_terms: D018941:Antigens, CD19 / Q000235:genetics / Q000378:metabolism; D018951:Antigens, CD20 / Q000235:genetics / Q000378:metabolism; D001402:B-Lymphocytes / Q000378:metabolism; D051925:CD79 Antigens / Q000235:genetics / Q000378:metabolism; D005260:Female; D015322:Gene Rearrangement, B-Lymphocyte; D005803:Genes, Immunoglobulin / Q000235:genetics*; D006801:Humans; D016130:Immunophenotyping; D015470:Leukemia, Myeloid, Acute / Q000235:genetics / Q000378:metabolism*; D008297:Male; D050813:Octamer Transcription Factor-2 / Q000235:genetics / Q000378:metabolism*; D051757:PAX5 Transcription Factor / Q000235:genetics* / Q000378:metabolism*; D051918:Sialic Acid Binding Ig-like Lectin 2 / Q000235:genetics / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*
chemical_list: D018941:Antigens, CD19; D018951:Antigens, CD20; D051925:CD79 Antigens; D050813:Octamer Transcription Factor-2; D051757:PAX5 Transcription Factor; C497281:PAX5 protein, human; C091546:POU2AF1 protein, human; D051918:Sialic Acid Binding Ig-like Lectin 2; D015534:Trans-Activators
keywords: Acute myeloid leukemia with t(8;21); CD19; CD79a; IGH@; IGK@; OCT2; PAX5