CORRELATION OF CYTOGENETIC RESULTS WITH IMMUNOPHENOTYPE, GENOTYPE, CLINICAL-FEATURES, AND RAS MUTATION IN ACUTE MYELOID-LEUKEMIA - A STUDY OF 235 CHINESE PATIENTS IN TAIWAN

Of 235 consecutive patients with de novo acute myeloid leukemia (AML), clonal chromosomal abnormalities were detected in 151 (64 %) of them. Twenty-four of the 71 patients with M2 AML had t(8;21), 35 of the 35 M3 patients had t(15;17), and 11 of the 45 M4 leukemia disclosed inv(1 6). Six of the eight patients with 11q23 abnormality had M4 or M5 subt ype of leukemia. The incidence of t(15;17) and t(8;21) was higher in o ur patients than in patients from most Western countries, Immunophenot yping was performed on 197 patients, Patients with t(15;17) were assoc iated with negativity to HLA-DR, CD11b, and CD34. Patients with t(8;21 ) expressed CD13 and CD33 less frequently than other patients, but all showed CD15 positivity. Coexpression of lymphoid-associated antigens on the leukemic blasts was detected in 52 patients (26%), including al l 7 patients with t(9;22), 3 of the 8 patients with t/del(11) (q23), 2 of the 25 patients with t(15;17), and 2 of the 22 patients with t(8;2 1). Seven (35%) of the 20 patients coexpressing lymphoid markers showe d immunoglobulin heavy chain or T-cell receptor p-chain gene rearrange ments, while only 2 (4%) of the 53 patients without lymphoid antigen e xpression did so. Patients with inv(16), t(8;21), and t(15;17) had a b etter prognosis than other patients. Of all surface antigens tested, o nly CD15, CD11b, and HLA-DR were of prognostic value: CD15 with a high er complete remission (CR) rate and CD11b or HLA-DR with a shorter CR duration. N-ras mutations were detected in 7 (18%) of the 40 patients in the study, including two of the three patients with inv(16). This s tudy demonstrated differences in clinical features, immunophenotypes, and genotypes among different cytogenetic subgroups.