Leukemia (1998) 12, 34–43  1998 Stockton Press All rights reserved 0887-6924/98 $12.00 Immunophenotypic patterns and cytogenetic anomalies in acute non-lymphoblastic leukemia subtypes: a prospective study of 432 patients RO Casasnovas 1 , L Campos 2 , F Mugneret 3 , C Charrin 4 , MC Be ´ne ´ 5 , R Garand 6 , M Favre 7 , C Sartiaux 8 , I Chaumarel 9 , M Bernier 10 , G Faure 5 and E Solary 1 1 He ´ matologie Clinique, 3 Laboratoire de Cytoge ´ ne ´ tique, CHU Le Bocage, Dijon; 2 Laboratoire d’He ´ matologie, CHU St Etienne; 4 Laboratoire de Cytoge ´ ne ´ tique, Ho ˆ pital Edouard Herriot, Lyon; 5 Laboratoire d’Immunologie, Faculte ´ de Me ´ decine, Nancy; 7 Etablissement de Transfusion Sanguine, Grenoble; 8 Etablissement de Transfusion Sanguine, Lille; 9 Laboratoire d’He ´ matologie, Hopital Robert Debre ´ , Reims, France; and 10 Laboratoire d’He ´ matologie, Institut Jules Bordet, Bruxelles, Belgium This study prospectively analysed the relationships between observed to vary according to the type and number of lymph- immunophenotypic and cytogenetic features of blast cells in oid lineage antigens expressed. 9 The expression of some of 432 acute non-lymphoblastic leukemias (ANLL) at presentation. these antigens also appeared to be related to recurrent cyto- An abnormal karyotype was detected in 232 cases (54%). These genetic abnormalities considered as specific to ANLL sub- abnormalities were related to immunophenotypic markers as types. 12–16 For instance, CD19 expression was detected in detected using a consensual panel of monoclonal antibodies allowing lineage assignment and investigation of myeloid numerous ANLL with t(8;21) 3,16 and CD2 expression often marker expression on blast cells. In univariate analysis, CD9, appeared related to either inv(16) or t(15;17). 12–16 CD10, CD15, CD34 and TdT expression appeared significantly Here, we report a prospective multicentric study that was associated with chromosomal anomalies. Multivariate analysis designed to better characterise the relationships between cyto- identified CD34 and CD9 expression as independently predic- logic, immunophenotypic and cytogenetic features of ANLL tive of the presence of at least one cytogenetic abnormality at diagnosis. Using a well-defined panel of 24 monoclonal (P , 10 -4 and P , 0.03, respectively). Significant associations between immunophenotypic and karyotypic features were antibodies directed against myeloid and lymphoid lineage observed both within individual FAB subgroups and indepen- antigens, we observed significant correlation between pheno- dently from morphological criteria. Specific features were seen typic and cytogenetic ANLL subgroups. The expression of sev- in five ANLL entities: M0 or M1/B lineage antigen eral differentiation antigens appeared to be predictive of kary- positivity/t(9;22) or del(11)(q23); M2/CD13 2 /t(8;21); M4/CD13 1 , otypic anomalies. Moreover, several ANLL with a recurrent CD34 1 , CD36 1 /inv(16); M4 or M5/lack of B lineage cytogenetic abnormality could be associated with a specific antigen/del(11)(q23) or t(9;11). More practically, and although the relationships demonstrated only represent a fraction of immunophenotypic pattern. homogeneous immunophenotypic subgroups, identification of such immunophenotypic features should prompt careful kary- otypic examination, eventually using molecular biology analy- Materials and methods sis on non-growing cells. Keywords: acute non-lymphoblastic leukemia; immunophenotype; Patients chromosome abnormalities The study was initiated in March 1992 by the Groupe d’Etude Immunologique des Leuce ´ mies (GEIL), a French multicentric Introduction group that collects data from over 40 centers in France and Belgium. The endpoint of the present analysis was 30 Sep- In 1988, the morphologic, immunologic and cytogenetic tember 1994. Patients eligible for the study met the following working classification (MIC) of acute non-lymphoblastic leu- criteria: established diagnosis of ANLL and collection of a suf- kemia (ANLL) 1 underlined the correlations between some ficient number of blast cells for both immunophenotype and recurrent specific cytogenetic abnormalities and defined cyto- successful cytogenetic analysis. M0-ANLL were defined as logic subgroups. At that time, the relationships between cyto- previously reported. 2 FAB data were collected from each genetic features identified in ANLL and the immunophenotype center’s cytology laboratory. of blast cells remained poorly characterised. During the last 10 years, immunophenotypic analysis of ANLL blast cells has provided new information and become a powerful tool in Immunological phenotyping assigning undifferentiated acute leukaemia to the myeloid lin- eage. 2 Meanwhile, investigation of lymphoid lineage antigens Mononuclear cells were recovered from heparinized bone on blast cells from a large number of ANLL has demonstrated marrow (391 cases) or peripheral blood (41 cases) collected the high immunophenotypic heterogeneity of morphologically at diagnosis. The percentage of blast cells after separation on and cytogenetically well-defined diseases. 3–8 a Ficoll gradient was higher than 50% in M2 and M4 subtypes Molecular analyses attempting to correlate these immuno- and higher than 80% in the remaining cases. The immuno- phenotypic features to their genotypic counterpart did not phenotype was performed by flow cytometry on blast cells demonstrate any strict correlation between the rearrangement gated on their abnormal light scatter characteristics, using of immunoglobulin and T cell receptor genes and the monoclonal antibodies for the following antigens: CD9 expression of lymphoid lineage antigens on ANLL blast (IOB2), CD11b (FD11), CD13 (MY7), CD14 (UCHM1), cells. 3,9–11 However, the prevalence of genotypic changes was CD15a (SMY15a), CD16 (Leu11b), CD18 (IOT18), CD33 (MY9), CD34 (BI-3C5), CD35 (44-D), CD36 (OKM5), CDw65 (VIM2), CD41 (P2), CD42 (SZ2), T lymphoid differentiation Correspondence: RO Casasnovas, He ´ matologie Clinique, CHU Le antigens CD2 (CD2XII), CD5 (T1b), CD7 (I210B22), and B Bocage, 21034 Dijon, France; Fax: 33 3 80 29 36 05 Received 16 September 1997; accepted 18 September 1997 lymphoid differentiation antigens, CD10 (K141), CD19 (SB4),