IMMUNOPHENOTYPIC PATTERNS AND CYTOGENETIC ANOMALIES IN ACUTE NONLYMPHOBLASTIC LEUKEMIA SUBTYPES - A PROSPECTIVE-STUDY OF 432 PATIENTS

This study prospectively analysed the relationships between immunophen otypic and cytogenetic features of blast cells in 432 acute non-lympho blastic leukemias (ANLL) at presentation. an abnormal karyotype was de tected in 232 cases (54%). These abnormalities were related to immunop henotypic markers as detected using a consensual panel of monoclonal a ntibodies allowing lineage assignment end investigation of myeloid mar ker expression an blast cells. In univariate analysis, CD9, CD10, CD15 , CD34 and TdT expression appeared significantly associated with chrom osomal anomalies. Multivariate analysis identified CD34 and CD9 expres sion as independently predictive of the presence of at least one cytog enentic abnormality (P < 10(-4) and P < 0.03, respectively). Significa nt associations between immunophenotypic and karyotypic features were observed both within individual FAB subgroups and independently from m orphological criteria. Specific features were seen in five ANLL entiti es: MO or M1/B lineage antigen positivity/t(9;22) or del(11)(q23); M2/ CD13(-)/t(8;21); M4/CD13(+), CD34(+), CD36(+)/inv(16); M4 or M5/lack o f B lineage antigen/del(11)(q23) or t(9;11). More practically, and alt hough the relationships demonstrated only represent a fraction of homo geneous immunophenotypic subgroups, identification of such immunopheno typic features should prompt careful karyotypic examination, eventuall y using molecular biology analysis on non-growing cells.