Objective: To analyze the biological characteristics and the treatment outcome of adult biphenotypic acute leukemia.
Methods: Immunophenotypes were examined using indirect immunofluorescence method. Biphenotypic acute leukemia (BAL) was diagnosed according to EGIL scoring system.
Results: (1) The incidence of BAL in acute leukemia was 3.4%. Percentage for coexpression of B lymphoid and myeloid antigens was 68.4%, for T lymphoid and myeloid antigens 21.1%, for B, T lymphoid and myeloid antigens 10.5%. (2) CD(34) was expressed in 43.75% of the BAL cases. (3) Cytogenetic analysis revealed normal and abnormal karyotypes in 41.7% and 58.3% of the BAL cases, respectively. (4) Six of 19 patients achieved completed remission (CR), but the disease free survivals were all less than 6 months. Treatment outcomes were negatively related to the expression of CD(34) antigen and cytogenetic findings. The BAL patients were poorly responded to therapeutic regimens directed to AML.
Conclusion: Coexpression of B/M antigens is the commonest subtype in BAL. BAL had a poor prognosis, especially treated with induction regimen directed to AML.