Sylvie Ramond

Adult biphenotypic acute leukaemia: an entity with poor prognosis which is related to unfavourable cytogenetics and P-glycoprotein over-expression.

Biphenotypic acute leukaemia (BAL) patients represented 8% of the 287 de novo consecutive adult acute leukaemias (23 BAL, 230 acute myeloid leukaemia (AML) and 34 acute lymphoblastic leukaemia (ALL)) referred to our department during the last 4‐year period. Of these 23 BAL patients, 14 patients showed myeloid morphology and nine cases lymphoid morphology according to FAB criteria. There were no differences between lymphoid and myeloid BAL according to clinical and biological presentation and treatment outcome. We confirm the poor prognosis of BAL when compared to AML or ALL seen during the same period of time, in terms of complete remission (47%, 62% and 82% respectively, BAL v AML, NS and BAL v ALL, P = 0.006) and 4‐year overall survival (8.1%, 25.8% and 23.8% respectively, BAL v AML, P = 0.05 and BAL v ALL, P = 0.003). Comparing adult BAL patients with AML patients, we found an increase in poor prognostic factors: CD34+ phenotype (82% v 60% respectively, P = 0.03), unfavourable karyotype (60% v 20%, P < 0.0001) and Pgp over‐expression by RT‐PCR (0.705 v 0.107, P < 0.0001) and flow cytometry (0.824 v 0.391, P = 0.0001). MRP and LRP were not found to be poor prognostic factors. Comparing BAL patients with ALL patients, we found also an increase in poor prognostic factors: age (51 v 39, P = 0.003) and CD34+ phenotype (82% v 50%, P = 0.02). We conclude that BAL patients need a more aggressive treatment procedure, including high‐dose AraC or the use of Pgp modulators for first‐line therapy.

Chronic neutrophilic leukemia. A study of four cases.

SummaryChronic neutrophilic leukemia (CNL) is a very rare entity, which has to be included among the chronic myeloid leukemias. Once an underlying cause of neutrophilia is excluded, the diagnosis of CNL is based on exclusion of chronic granulocytic and other types of chronic myeloid leukemias. The classification proposed by Sheperd et al. has proven to be helpful, but it must be completed by cytogenetic analysis and the search for bcr rearrangement by molecular biology methods, in order to confirm the absence of Philadelphia chromosome and of bcr-abl hybrid gene. We report here four cases of CNL, with confirmed absence of bcr rearrangement in two cases. Two patients died, 12 and 8 years after diagnosis, the second one following transformation into myelofibrosis with myeloid metaplasia. The other two died of acute myelogenous leukemia, the first one, 25 years after diagnosis of CNL, following a 3-year phase of acceleration. The last patient presented combined features of CNL and refractory anemia with excess of blasts, and was characterized by both progressive leukocytosis and severe thrombocytopenia; acute transformation into acute myelogenous leukemia occurred 6 months after diagnosis and death 1 month later. Among the 30 cases reported so far, plus the four presented here, combined myelodysplastic features were observed in five cases and transformation into acute myelogenous leukemia in six. Chronic neutrophilic leukemias should be reported regularity, in view of the uncertain and low frequency of this hematological disease.

Sequential emergence of MRp- and MDR1-gene over-expression as well as MDR1-gene translocation in homoharringtonine-selected K562 human leukemia cell lines

To investigate the mechanism of resistance to an anti‐neoplastic natural product homoharringtonine (HHT) in leukemic cells, we have established 5 sub‐lines of human myeloid leukemia K562 cells, designated as K‐H30, K‐H100, K‐H200, K‐H300 and K‐H400, which showed progressive resistance to different concentrations of HHT. These sub‐lines were cross‐resistant to daunorubicin, vincristine, etoposide and mitoxantrone, but not to melphalan. Immunofluorescence with monoclonal anti‐Pgp antibody MRK16 and Northern‐blot analysis demonstrated that resistance to HHT is related to the sequential emergence of MRP‐ and MDR1‐gene over‐expression. In the low‐level‐resistant K‐H30 sub‐line, the MDR1 gene was not over‐expressed, but the MRP gene was over‐expressed 2.1‐fold. In the intermediate‐level‐resistant K‐H100 and K‐H200 sublines, both the MRP and the MDR1 genes were over‐expressed. However, in the high‐level‐resistant K‐H300 and K‐H400 sublines, MDR1‐gene over‐expression predominated (20‐ and 21‐fold respectively). On the other hand, GSTπ‐gene expression was decreased in all 5 sub‐lines. Southern‐blot analysis revealed no MRP‐gene amplification in any of the 5 sub‐lines, whereas the MDR1 gene was amplified in the high‐level‐resistant K‐H300 and K‐H400 sub‐lines. The most interesting observation is a homogeneously staining region (HSR) found in chromosome 2 of the K‐H300 and K‐H400 sub‐lines. Chromosome painting and in situ hybridization demonstrated that this HSR was translocated from chromosome 7 and consisted of the amplified MDR1 gene, suggesting that there is a relationship between MDR1‐gene translocation and MDR1‐gene amplification.

Prognostic factors in elderly acute lymphoblastic leukaemia

A retrospective study was performed on 46 unselected acute lymphoblastic leukaemia (ALL) elderly patients aged 60 years or more. Only 50% of these patients were included in the EORTC cooperative clinical trials, thus confirming the important selection bias in most of the published series on elderly ALL patients. 43% of the elderly patients achieved a complete remission (CR). The median survival was 10 months and the 5‐year overall survival was only 7.6±4%. In multivariate analysis, W.H.O. performance status and peripheral blast counts at day 7 were found to significantly influence achievement of CR and survival. In patients with W.H.O. performance status 2, 35% died during induction treatment versus 4% in patients with W.H.O. performance status <2. Patients >70 years old showed a marked drop of the CR rate (27%) compared to those aged 60–69 (67%), and a very high death rate during the induction period (38% versus 4%). This suggests that ALL protocol treatments should be proposed until 70 years in patients with good‐performance status, whereas less intensive treatment should be offered to elderly patients with performance status 2 and/or age 70. Peripheral blast counts at day 7 may help to adjust the treatment during induction phase.

Over-expression of cyclin D1 in chronic B-cell malignancies with abnormality of chromosome 11q13

Accurate identification of B‐cell chronic malignancies is sometimes uncertain, despite careful cytologic and immunophenotypic evaluation. Cytogenetics and molecular biology studies may therefore prove useful, because some of these disorders are associated with nonrandom abnormalities, such as the t(11;14)(q13;q32) translocation and bcl‐1 rearrangement mainly observed in mantle‐cell lymphoma (MCL). We studied the expression of cyclin D1 in malignant lymphoid cells from the peripheral blood of 32 patients with various B‐cell chronic lympho‐proliferative disorders, using Northern blot (NB) and RNA in situ hybridization (ISH). Cytogenetic analysis was informative in 18 cases, and most of the missing karyotype data were from typical B‐CLL cases where a t(11;14) is unlikely to be found. Over‐expression of cyclin D1 mRNA was observed by both NB and ISH in four samples (MCL: two cases; lymphoplasmacytic lymphoma: one case, unclassified B‐cell chronic disorder: one case). In each of these cases there was an abnormality of chromosome 11q13, either a t(11;14)(q13;q32) translocation (three cases) or a del(11)(q13) without evidence of chromosome 14 involvement (one case). Cytogenetic and gene rearrangement studies are not available in all institutions and have some technical pitfalls. Because of its close association with bcl‐1 rearrangement and/or t(11;14), the demonstration of cyclin D1 mRNA over‐expression either by NB, or, more conveniently, by ISH, may represent additional information which could be of help for the identification of B‐cell malignancies.

Deciphering leukemic B-cell chronic lymphoproliferative disorders

Diagnosis of leukemic B-cell chronic lymphoproliferative disorders (B-CLPD) is a frequent challenge in hematology. In this multicentric study, we prospectively studied 165 new consecutive leukemic patients with B-CLPD selected on the basis of Royal Marsden Hospital scoring system ≤3. The primary aim of the study was to try to decipher the atypical cases and identify homogenous subgroups. Overall, morphological examination contributed to diagnosis in only 20% cases, all of them CD5 negative. Thirty additional cases were CD5 negative suggestive of leukemic marginal zone lymphoma in most cases. The significantly poorer survival of the 26 cyclin D1 positive cases justifies recommending its systematic determination among atypical B-CLPD. CD20 expression segregated clearly two subgroups among CD5 positive cyclin D1 negative B-CLPD. The 17 patients with the CD20 dim profile represent a homogeneous subgroup very close to typical B-cell chronic lymphocytic leukemia (B-CLL) on morphological, phenotypical and cytogenetical criteria. In contrast, the subgroup of 51 patients with a CD20 bright profile is heterogeneous. Their significantly lower p27 expression level suggest the presence of a proliferative component, underlying a more aggressive disease. Further genomic studies are warranted to establish their precise nature. These cases should not be included in the same therapeutic trials as B-CLL.

Submicroscopic insertion of RARα gene into chromosome 15 in two cases of acute promyelocytic leukemia

Abstract Acute promyelocytic leukemia (APL) is characterized by a specific translocation (15;17)(q22;q21), resulting in the formation of PML/RAR α chimeric transcripts. We report two female patients with PML/RAR α -positive classical APL, whose leukemic cells expressed a variant translocation, t(5;15)(q13;q22) and t(15;17)(q22;p13), respectively. Both translocations were confirmed by whole chromosome painting which revealed no apparent involvement of 17q. A two-color fluorescence in situ hybridization with a 5′ PML and a 3′ RAR α probe showed, in both cases, the presence of a PML-RAR α fusion gene, on the der(15)t(5;15) long arm, and on the der(17)t(15;17) short arm, respectively. These two complex rearrangements resulted most probably from a two-step mechanism: (1) a submicroscopic insertion into 15q of a 17q segment including the 3′ part of the RAR α gene; (2) a reciprocal translocation between der(15) and a variable chromosome arm, with a breakpoint distal and proximal to RAR α insertion in the case of t(5;15) and t(15;17), respectively. Molecular and prognosis significance of these variant translocations are discussed.

Another case of trisomy 4 with double minute chromosomes in acute non-lymphocytic leukemia

A further case of trisomy 4 with double minute chromosomes in acute non-lymphocytic leukemia is reported. The non-random association between these two cytogenetic abnormalities is reinforced. A possible relation with environmental exposure is discussed.

Acute myelomonocytic leukemia in a XYY man

A case of acute myeloid leukemia (M4) in a 29-year-old male with a 47,XYY karyotype is reported. This aneuploidy was found in both bone marrow cells and mitogen-stimulated lymphocytes. Monosomy 7 correlated with myelodysplastic features. The possible role of XYY in increasing the risk of leukemia is discussed.

A new acute lymphoblastic leukaemia cell line BEL‐1 with t(4; 11) (q21; q23) chromosomal translocation and a unique aberrant p27kip1 transcript

We have established a new cell line, designated BEL-1, from the peripheral blood of a 41-year-old female patient with relapsed acute lymphoblastic leukaemia (ALL). BEL-1 cells showed a proB cell immunophenotype, carried a t(4; 11)(q21; q23) chromosomal rearrangement, and expressed only a unique aberrant p27 transcript, in contrast to the original patient cells, which expressed both the normal and the aberrant transcript. The characteristics of the BEL-1 cell line are described below.