CORRELATION BETWEEN CD34 EXPRESSION AND CHROMOSOMAL-ABNORMALITIES BUTNOT CLINICAL OUTCOME IN ACUTE MYELOID-LEUKEMIA

The hemopoietic stem cell marker CD34 has been reported to be a useful predictor of treatment outcome in acute myeloid leukemia (AML), Previ ous data suggested that CD34 expression may be associated with other p oor prognosis factors in AML such as undifferentiated leukemia, second ary AML (SAML), and clonal abnormalities involving chromosome 5 and 7. In order to analyze the correlations between the clinicopathologic fe atures, cytogenetic and CD34 expression in AML, we retrospectively inv estigated 99 patients with newly diagnosed AML: 85 with de novo diseas e and 14 with secondary AML (SAML). Eighty-six patients who received t he same induction chemotherapy were available for clinical outcome. De fining a case as positive when greater than or equal to 20% of bone ma rrow cells collected at diagnosis expressed the CD34 antigen, forty-fi ve patients were included in the CD34 positive group, Ninety patients had adequate cytogenetic analysis, Thirty-two patients (72%) with CD34 positive AML exhibited an abnormal karyotype whereas 15 patients (28% ) with CD34 negative AML had abnormal metaphases (P <0.01). Monosomy 7 /7q- or monosomy 5/5q- occurred in 10 patients and 8 of them expressed the CD34 antigen (P <0.05). All patients with t(8;21) which is consid ered as a favorable factor in AML had levels of CD34 greater than or e qual to 20% (P <0.05). We did not find any association between CD34 ex pression and attainment of complete remission, overall survival, or di sease-free survival. In conclusion, the variations of CD34 expression in AML are correlated with cytogenetic abnormalities associated both w ith poor and favorable outcome, The evaluation of the correlations bet ween CD34 antigen and clinical outcome in AML should take into account the results of pretreatment karyotype. (C) 1996 Wiley-Liss, lnc.