Terminal deoxynucleotidyl transferase and CD7 expression in acute myeloid leukemias are not associated with a high frequency of immunoglobulin and/or T cell receptor gene rearrangement.
Within normal hemopoiesis, the intranuclear DNA polymerase TdT seems to be exclusively expressed by T and B lymphoid precursor cells. Double staining experiments showed that TdT can also be expressed in blast cells of certain acute myeloid leukemias. Recent reports described a very strong association between TdT expression and rearrangements of IgH and TcR genes in such AML specimens, suggesting a predominant lymphoid commitment of these TdT positive AML blasts. When submitting 24 serologically and morphologically well-characterized TdT positive AML specimens for additional genotypic analysis to determine the IgH and TcR gene configuration, we observed that only four had clonally rearranged IgH and/or TcR genes, whereas 20 had germ line configuration. This frequency is clearly lower than previously reported and not necessarily different from rearrangement frequencies reported for TdT negative AML (4-40%). It would seem to us, therefore, that the expression of TdT in otherwise well-defined AML blasts is not necessarily associated with a higher frequency of immunoglobulin and/or T cell receptor gene rearrangement.
Institute of Immunology, University of Vienna, Austria.
G
G
Willière
H
H
Stockinger
U
U
Köller
O
O
Majdic
E
E
Schnabl
D
D
Lutz
P
P
Bettelheim
W
W
Knapp
D019011:Antigens, CD7; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology*; D004253:DNA Nucleotidylexotransferase / Q000378:metabolism*; D015329:Gene Rearrangement, T-Lymphocyte / Q000235:genetics*; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007948:Leukemia, Monocytic, Acute / Q000201:enzymology / Q000235:genetics / Q000276:immunology; D015470:Leukemia, Myeloid, Acute / Q000201:enzymology / Q000235:genetics / Q000276:immunology; D015479:Leukemia, Myelomonocytic, Acute / Q000201:enzymology / Q000235:genetics / Q000276:immunology; D015473:Leukemia, Promyelocytic, Acute / Q000201:enzymology / Q000235:genetics / Q000276:immunology; D010641:Phenotype; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*
D019011:Antigens, CD7; D000945:Antigens, Differentiation, T-Lymphocyte; D007143:Immunoglobulin Heavy Chains; D011948:Receptors, Antigen, T-Cell; D004253:DNA Nucleotidylexotransferase