DUAL REARRANGEMENT OF IMMUNOGLOBULIN AND T-CELL RECEPTOR GENES IN A CASE OF PHILADELPHIA-CHROMOSOME-POSITIVE ACUTE-LEUKEMIA

A 48-year-old patient was admitted to our hospital for leukocytosis. T he blast cells were positive for peroxidase and he was tentatively dia gnosed as acute myeloid leukemia according to the French-American-Brit ish criteria. By flow cytometry, the bone marrow cells were positive f or CD10, CD13, CD33 and HLA-DR, but two-color analysis revealed that m ost of the CD13- and CD33-positive cells did not express CD10. The mar row cells had Philadelphia chromosome with no additional abnormalities . Major bcr-abl fusion gene was observed by the reverse transcriptase- polymerase chain reaction method. Southern blot analysis disclosed rea rrangement of both immunoglobulin heavy chain and T-cell receptor beta chain genes. He received combined chemotherapy for myeloid lineage an d lymphoid lineage, but the response was quite poor. He died 64 days a fter admission due to pulmonary bleeding. Although the association of Phl with multilineage differentiation is unclear, our case has signifi cant implication for further investigation of the relationship between Ph-1-positive cells and lineage selection.