Outcome of treatment after first relapse in adults with acute lymphoblastic leukemia initially treated by the LALA-94 trial.

Fifty-four percent of adults with acute lymphoblastic leukemia (ALL) who entered the LALA-94 trial experienced a first relapse. We examined the outcome of these 421 adult patients. One hundred and eighty-seven patients (44%) achieved a second complete remission (CR). The median disease-free survival (DFS) was 5.2 months with a 5-year DFS at 12%. Factors predicting a better outcome after relapse were any transplant performed in second CR (P<0.0001), a first CR duration >1 year (P=0.04) and platelet level >100 x 10(9)/l at relapse (P=0.04). Risk groups defined at diagnosis and treatment received in first CR did not influence the outcome after relapse. The best results were obtained in a subset of patients who were eligible for allogeneic stem cell transplantation (SCT). Geno-identical allogeneic SCT was performed in 55 patients, and 3 patients received donor lymphocyte infusions. Forty-four transplantations were performed from an unrelated donor (of which four were cord blood). We conclude that most adult patients with recurring ALL could not be rescued using current available therapies, although allogeneic SCT remains the best therapeutic option.

Clinical, cytogenetic and molecular characteristics of 14 T-ALL patients carrying the TCRbeta-HOXA rearrangement: a study of the Groupe Francophone de Cytogénétique Hématologique.

Recently, we and others described a new chromosomal rearrangement, that is, inv(7)(p15q34) and t(7;7)(p15;q34) involving the T-cell receptor beta (TCRbeta) (7q34) and the HOXA gene locus (7p15) in 5% of T-cell acute lymphoblastic leukemia (T-ALL) patients leading to transcriptional activation of especially HOXA10. To further address the clinical, immunophenotypical and molecular genetic findings of this chromosomal aberration, we studied 330 additional T-ALLs. This revealed TCRbeta-HOXA rearrangements in five additional patients, which brings the total to 14 cases in 424 patients (3.3%). Real-time quantitative PCR analysis for HOXA10 gene expression was performed in 170 T-ALL patients and detected HOXA10 overexpression in 25.2% of cases including all the cases with a TCRbeta-HOXA rearrangement (8.2%). In contrast, expression of the short HOXA10 transcript, HOXA10b, was almost exclusively found in the TCRbeta-HOXA rearranged cases, suggesting a specific role for the HOXA10b short transcript in TCRbeta-HOXA-mediated oncogenesis. Other molecular and/or cytogenetic aberrations frequently found in subtypes of T-ALL (SIL-TAL1, CALM-AF10, HOX11, HOX11L2) were not detected in the TCRbeta-HOXA rearranged cases except for deletion 9p21 and NOTCH1 activating mutations, which were present in 64 and 67%, respectively. In conclusion, this study defines TCRbeta-HOXA rearranged T-ALLs as a distinct cytogenetic subgroup by clinical, immunophenotypical and molecular genetic characteristics.

MoS2 formation induced by amorphous MoS3 species under lubricated friction.

Amide molybdate has been recently introduced as a friction modifier for tribological applications. Combined with zinc dithiophosphate (ZDDP) and fatty amines, it provides an ultralow friction coefficient. The ultimate product of Mo compound transformations in tribological contact, due to frictional heating and shearing, as well as chemical interactions with oil additives, is molybdenum sulfide (MoS2). Understanding the decomposition of amide molybdate leading to MoS2 is of primary importance to the optimization of the design of lubricant formulations. This study focuses on the investigation by Raman spectroscopy of amide molybdate decomposition intermediates. Raman spectra of tribofilms, obtained after friction tests under different temperatures and pressures, revealed the formation of an amorphous MoS3 intermediate coexisting with MoS2. However, under severe conditions, the tribofilms are mostly composed of MoS2.

Autologous stem cell transplantation in adults with acute lymphoblastic leukemia in first complete remission: analysis of the LALA-85, -87 and -94 trials.

To evaluate the results of autologous stem cell transplantation (ASCT) in a large population of adults with acute lymphoblastic leukemia (ALL) in first complete remission (CR), we performed an individual data-based overview of the last three trials from the LALA group. Overall, 349 patients with ALL prospectively randomized in the consecutive LALA-85, -87, and -94 trials to receive either ASCT or chemotherapy as post-CR treatment were analyzed. Eligibility criteria were 15-50-year-old patients without sibling donors in both LALA-85/87 trials and 15-55-year-old patients with high-risk ALL and no sibling donors in the LALA-94 trial. Intent-to-treat analysis, which compared 175 patients from the ASCT arm to 174 patients from the chemotherapy arm, showed that ASCT was associated with a lower cumulative incidence of relapse (66 vs 78% at 10 years; P=0.05), without significant gain in disease-free or overall survival. Despite a possible lack of statistical power, a nested case-control analysis performed in 85 patient pairs adjusted for time to transplant and prognostic covariates confirmed these intent-to-treat results in patients actually transplanted. Of interest, the reduced relapse risk after ASCT translated in better disease-free survival in the 300 rapid responders who reached CR after the first induction course.

NUP98 rearrangements in hematopoietic malignancies: a study of the Groupe Francophone de Cytogénétique Hématologique.

The NUP98 gene is fused with 19 different partner genes in various human hematopoietic malignancies. In order to gain additional clinico-hematological data and to identify new partners of NUP98, the Groupe Francophone de Cytogénétique Hématologique (GFCH) collected cases of hematological malignancies where a 11p15 rearrangement was detected. Fluorescence in situ hybridization (FISH) analysis showed that 35% of these patients (23/66) carried a rearrangement of the NUP98 locus. Genes of the HOXA cluster and the nuclear-receptor set domain (NSD) genes were frequently fused to NUP98, mainly in de novo myeloid malignancies whereas the DDX10 and TOP1 genes were equally rearranged in de novo and in therapy-related myeloid proliferations. Involvement of ADD3 and C6ORF80 genes were detected, respectively, in myeloid disorders and in T-cell acute lymphoblastic leukemia (T-ALL), whereas the RAP1GDS1 gene was fused to NUP98 in T-ALL. Three new chromosomal breakpoints: 3q22.1, 7p15 (in a localization distinct from the HOXA locus) and Xq28 were detected in rearrangements with the NUP98 gene locus. The present study as well as a review of the 73 cases previously reported in the literature allowed us to delineate some chromosomal, clinical and molecular features of patients carrying a NUP98 gene rearrangements.

AF15q14, a novel partner gene fused to the MLL gene in an acute myeloid leukaemia with a t(11;15)(q23;q14).

In haematopoietic malignancies the MLL gene, located on chromosome 11q23, is frequently disrupted by chromosome rearrangement, generally resulting in fusion to various partner genes. We have previously reported a t(11;15)(q23;q14) in a case of acute myeloblastic leukaemia. Here, we report the cloning of a novel MLL partner, AF15q14, at chromosome 15q14. In this translocation, the breakpoint occurred in exon 8 of MLL and exon 10 of AF15q14. The normal AF15q14 transcripts of approximately 8.5 kb in size, are expressed in different tumoral cell lines, in a variety of normal tissues, and in all the foetal tissues tested. Sequencing of AF15q14 cDNA revealed a putative open reading frame of 1833 amino acids that had no homology with any other known protein. The C-terminal end of the putative AF15q14 contained a bipartite nuclear localization site. The translocation t(11;15) preserved the open reading frame between MLL and the 3' end of AF15q14. The contribution of AF15q14 to the fusion protein was only 85 amino acids. Immunofluorescence staining experiments with expression vectors encoding these 85 amino acids confirmed the functionality of the predicted nuclear localization site.

Cytogenetic study of 75 erythroleukemias.

Chromosomal abnormalities of erythroleukemia (EL) are often described as complex and unspecific. A retrospective study of 75 EL defined following the WHO classification was performed by the Groupe Francophone de Cytogénétique Hématologique (GFCH) in order to reexamine the cytogenetics of this infrequent leukemia subtype. Clonal chromosomal abnormalities were found in 57 patients (76%), distributed in 4 subgroups according to their ploidy status: pseudodiploid (16%), hypodiploid (47%), hyperdiploid (19%), and 18% mixed cases associating 2 different clones (hypodiploid+hyperdiploid) or (pseudodiploid+hyperdiploid). Complex rearrangements and hypodiploid chromosome number were widely dominant (50%). Partial or entire monosomies represented 56% of abnormalities. Chromosomes 5 and 7 were the most frequently involved (41 and 33 times, respectively), followed by chromosomes 8, 16, and 21 (19 times each). Unbalanced abnormalities were more frequent than balanced. All these kinds of abnormalities were observed in de novo as well as in secondary EL. Four out of 7 cases of "pure erythroid" leukemia were associated with a BCR-ABL fusion. Lastly, no chromosome abnormality specific to EL could be established. However, the large overlap of chromosomal abnormality patterns of EL (pure erythroid form excepted) and refractory anemia with excess of blasts in transformation (RAEB-t) favors the hypothesis of similarities between these 2 hematologic disorders.

Characterization of translocation t(1;14)(p32;q11) in a T and in a B acute leukemia.

The TAL1 locus on chromosome band 1p32 is rearranged in 15 to 29% of human T-cell acute lymphoblastic leukemias (T-ALLs). These alterations consist of either a tald submicroscopic deletion (12-26% of T-ALL) or a t(1;14)(p32;q11) chromosomal translocation (3% of childhood T-ALL). Both types of alterations preferentially affect the 5' part of the TAL1 locus. Their main consequence appears to be transcriptional activation of the TAL1 gene. We have characterized two cases of t(1;14)(p32;q11) in ALL. Both affect the TCR delta gene segments at 14q11 and the 5' part of the TAL1 locus at 1p32. The first case represented a 'classical' t(1;14), associated with T-ALL. Its analysis indicates the use of a recombination signal-like sequence localized in the third exon of TAL1 in the translocation process. In the other case, the rearrangement to the D delta region occurred 5' to the TAL1 transcription start sites. This case exhibited a B-lymphoid immunophenotype thus suggesting that the putative oncogenicity of TAL1 activation is not restricted to T-cell malignancies.

CD34 expression is associated with major adverse prognostic factors in adult acute lymphoblastic leukemia.

Seventy-five adult patients with newly diagnosed acute lymphoblastic leukemia (ALL) were analyzed for CD34 expression on leukemic cells. CD34 was significantly associated with B-cell lineage ALL (p = 0.0002). In B-lineage ALL, CD34 positivity was significantly associated with expressions of CD9 (p = 0.001), CD19 (p = 0.00001) and CD22 (p = 0.002). CD34 was more expressed in B-ALLs with higher WBC cell count (p = 0.04), and higher percentage of peripheral blood leukemic cells (p = 0.005), total or partial monosomy of chromosome 7 (p = 0.0001) or Ph+ chromosome (p = 0.01); and less expressed in cases with hyperdiploidy (> or = 50 chromosomes) (p = 0.03). CD34 was more expressed in poor risk B-ALLs patients, defined according to Hoelzer criteria (p = 0.01). In T-lineage ALL, CD34 positivity was inversely correlated with the expression of CD10 (p = 0.05). After intensive induction therapy, 58 of 73 evaluable patients (79%) achieved a complete remission (CR). CD34 positivity was correlated with the persistence of blast cells in day 15 bone marrow aspirates (p = 0.001) and after one course of induction chemotherapy (p = 0.01). With a median follow-up of 11 months, no statistical differences were seen in leukemia-free survival and overall survival between CD34 positive and negative cases, even when stratifying by immunophenotype. We conclude that CD34 expression is associated with features of poor prognosis in adult ALL. Its study might therefore become useful in the design of future prognostic models.

Myeloid surface antigen expression in adult acute lymphoblastic leukemia.

The expression of myeloid surface markers was investigated in 41 cases of untreated adult acute lymphoblastic leukemia (ALL). Nineteen cases (46%) reacted with at least one myeloid monoclonal antibody (CD15 in 16 cases, CD13 in 10 cases, CD14 in five cases, and CD33 in four cases). Double-staining confirmed the coexpression of myeloid and lymphoid markers. In addition, 35 samples were tested for CD34 expression. Fourteen of the 17 myeloid-positive cases tested were positive for CD34 vs. eight of 18 negative cases (p less than 0.05). A t(9;22) translocation was found in eight cases, and a t(4;11) translocation in two cases, all expressing CD34 and myeloid antigens. These findings confirm the high frequency of myeloid markers on the surface of adult ALL blasts, and suggest that these leukemias may originate in a poorly differentiated precursor cell with mixed differentiation capacities.

High risk myelodysplastic syndrome coexistent with chronic lymphocytic leukemia for more than 9 years: inhibition of the myeloid clone by the lymphoid clone?

We describe a patient in whom the concomitant diagnosis of refractory anemia with excess of blasts (16% on initial marrow examination) and chronic lymphocytic leukemia was made more than 9 years ago. The myeloid clone showed a complex karyotypic abnormality. Evolution has so far been remarkably stable, without transformation into acute leukemia. Clonogenic assays showed that patient's serum inhibited the patient's own granulocyte-macrophage colony-forming units (CFU-GM). This inhibition was also present for a control subject's CFU-GM and acute myeloid leukemia clonogenic cells. This raises the problem of a down-regulation of the myeloid clone by the malignant lymphoid clone in this patient, and the possible mechanisms for this are discussed.

Clinical and biological characteristics of adult de novo and secondary acute myeloid leukemia with balanced 11q23 chromosomal anomaly or MLL gene rearrangement compared to cases with unbalanced 11q23 anomaly: confirmation of the existence of different entities with 11q23 breakpoint.

Although the presence of a chromosome 11q23 breakpoint is of recognized poor prognosis in acute lymphoblastic leukemia, its prognostic significance in acute myeloid leukemia (AML) has been the object of conflicting reports, perhaps reflecting the possibility of different entities. It has been found that only typical and generally balanced 11q23 chromosomal anomalies involve the MLL gene while atypical and generally unbalanced do not. To determine whether these two categories of AML patients had different initial characteristics and evolution, supporting different pathogenetic mechanisms, we analyzed clinical and biologic characteristics of newly diagnosed AML patients with balanced 11q23 breakpoint and/or MLL rearrangement seen over a 10-year period in our institution and compared them to cases with unbalanced 11q23 anomaly seen over the same period. These two categories of patients were compared with newly diagnosed patients with normal karyotype and no MLL rearrangement when tested, seen over the same period of time and treated similarly. Over this period, 442 newly diagnosed adult (> 15 years) AML seen in our institution had a successful karyotype performed before any therapy. Thirty-six cases (8%) had a chromosome 11q23 breakpoint including 19 cases with a balanced translocation or inversion and 17 cases with an unbalanced anomaly. Eighty-seven recently diagnosed cases of AML, for whom frozen cellular material was available, were analyzed by Southern blot for the presence of MLL gene rearrangement. Fourteen cases (16% of the tested cases) had a rearrangement of the MLL gene, including seven cases with an apparently successful karyotype not showing any 11q23 breakpoint and two cases with no available karyotype. The only case with unbalanced 11q23 chromosomal anomaly which was tested had no MLL rearrangement. There was a clear-cut clinical difference between the 28 patients having a balanced 11q23 anomaly/MLL rearrangement and the 17 patients having an unbalanced chromosomal anomaly: AML with unbalanced 11q23 anomalies occurred in older patients (P = 0.07) tended to be less frequently associated with previous exposure to topoisomerase II-active drugs and with M4/M5 FAB cytological subtypes, were always associated with other chromosomal anomalies (P < 0.0001), expressed more frequently the CD34 antigen (P = 0.05) and were of considerably poorer prognosis for achievement of CR (P = 0.005) and survival (P = 0.0005). When compared to the control population, patients with balanced anomalies had more frequent history of toxic exposure (P = 0.0003) particularly to topoisomerase II-active drugs, tended to be more frequently of M4/M5 FAB subtypes (P = 0.07), expressed more frequently HLA-DR antigen (P = 0.02) and had shorter DFS (P = 0.02). Patients with unbalanced anomalies had more frequent splenomegaly (P = 0.009), lower WBC count (P = 0.04), and much poorer prognosis for CR achievement (P = 0.0001), survival (P < 0.0001) and DFS (P = 0.01). This study confirms the high frequency of 11q23 chromosomal breakpoint/MLL rearrangement in adult AML and the probable existence of two different entities with different clinical features according to the presence of a balanced or unbalanced cytogenetic abnormality, the latter being not associated with MLL rearrangement.

Involvement of a human endogenous retroviral sequence (THE-7) in a t(7;14)(q21;q32) chromosomal translocation associated with a B cell chronic lymphocytic leukemia.

B cell chronic lymphocytic leukemias (B-CLL) like other blood cell malignancies are characterized by chromosomal anomalies directly involved in tumor pathogenesis. We report here the molecular characterization of a t(7;14)(q21;q32) chromosomal translocation observed during the course of a B-CLL. We show that this translocation led to the juxtaposition of the immunoglobulin heavy chain locus on chromosome 14 to an endogenous retroviral sequence belonging to the THE family (transposable-like human element) on chromosome 7q21. RT-PCR analysis demonstrated that this sequence is transcribed in most of the tumoral and normal tissue analyzed and in the B-CLL described here. These data raise the question of the role of transposable elements in the pathogeny of some leukemias or at least, in the occurrence of chromosomal rearrangements. Structural rearrangements of the 7q21-22 region are frequently encountered in myeloid disorders, and the work presented here could help in their characterization.

The translocations, t(11;19)(q23;p13.1) and t(11;19)(q23;p13.3): a cytogenetic and clinical profile of 53 patients. European 11q23 Workshop participants.

The EU Concerted Action Workshop on 11q23 Abnormalities in Hematological Malignancies collected 550 patients with abnormalities involving 11q23. Of these, 53 patients had a translocation involving chromosome 11, breakpoint q23, and chromosome 19, breakpoint p13. Karyogram review enabled each patient to be further defined as t(11;19)(q23;p13.1) (21 patients) or t(11;19)(q23;p13.3) (32 patients). There was a marked difference between the type of banding and the translocation identified: t(11;19)(q23;p13.1) was detected predominantly by R-banding, whereas t(11;19)(q23;p13.3) was detected almost solely by G-banding. Additional change was extremely rare in patients with t(11;19)(q23;p13.1) but occurred in nearly half of the patients with t(11;19)(q23;p13.3). Patients with t(11;19)(q23;p13.1) all had leukemia of a myeloid lineage, mostly acute myeloid leukemia (AML), and were predominantly adult. In contrast patients with t(11;19)(q23;p13.3) had malignancies of both myeloid and lymphoid lineage and were mainly infants less than 1 year old. The survival of both groups of patients was generally poor, over 50% of t(11;19)(q23;p13.1) patients died within 2 years of diagnosis and the median survival of acute lymphoblastic leukemia (ALL) patients with t(11;19)(q23;p13.3) was 17.6 months.

Expression of BCL-2 proto-oncogene in adult acute lymphoblastic leukemia.

The products of the BCL-2 gene prolong survival of lymphohematopoietic cells by inhibition of programmed cell death. We studied bcl-2 protein expression in a series of 43 adult acute lymphoblastic leukemia (ALL) at diagnosis, using a specific monoclonal antibody and flow cytometry. All samples expressed bcl-2 with a mean percentage of positive cells of 77.9. The level of bcl-2 in positive cells expressed as mean equivalent of soluble fluorescence (MESF) was highly variable ranging from 5 x 10(3) to 552 x 10(3) (mean +/- s.d.: 96.5 +/- 109 x 10(3)). Neither the percentage of positive cells nor bcl-2 MESF levels were correlated with initial characteristics including blood counts, immunological phenotype, or cytogenetics. The survival of leukemic cells maintained in cytokine-free liquid culture was not correlated with bcl-2 expression. However, cells from ALL with higher white blood cell (WBC) counts, with t(9;22) translocation, or expressing myeloid surface antigens exhibited significantly longer survival in this culture system. The outcome after intensive chemotherapy did not differ according to bcl-2 expression. Factors associated with poor outcome included WBC counts, presence of t(9;22) translocation, presence of myeloid antigens and prolonged survival of cultured cells. These results indicate that high levels of bcl-2 are not associated with distinct clinical or biological characteristics in ALL.

Long-term follow-up of patients with newly diagnosed adult acute lymphoblastic leukemia: a single institution experience of 378 consecutive patients over a 21-year period.

Although the prospect of long-term leukemia-free survival (LFS) after treatment for adult acute lymphoblastic leukemia (ALL) is widely accepted, few studies have reported long-term survival data. Three hundred and seventy-eight ALL patients, referred to our hospital from 1978 to 1999, were reviewed for long-term follow-up data. The analysis included data on 351 patients treated by standard chemotherapy according to 11 different successive and/or concomitant regimens. Complete remission (CR) was achieved in 299 patients (79%). Initial performance status, LDH level, immunophenotype, age, and risk group (defined according to Hoelzer's criteria) at diagnosis were of significant prognostic value for CR achievement. Median leukemia-free survival (LFS) was 14 months with a 3-year, a 5-year, and an 8-year LFS at 30%, 26%, and 24%, respectively. LFS was better in T cell lineage ALL than in B cell lineage ALL (P = 0.05). Younger age was also a favorable prognostic factor for LFS (P = 0.001). Philadelphia-positive (Ph+) ALL displayed a poor outcome since median LFS was 7 months with only 13% of survival at 3 years. Median overall survival (OS) of the entire cohort was 18 months with a 3-year, a 5-year, and an 8-year OS at 32%, 24%, and 22% respectively. Favorable prognostic factors for OS were younger age (P < 0.0001), and T cell lineage ALL (P = 0.001). Among non-T cell lineage ALL, standard-risk ALL confirmed a significant better outcome than high-risk ALL (P = 0.0003). It was apparent from this analysis that hazard rates for death and relapse were greatest in the first year, decreased substantially between years 1 and 2, then decrease further between years 2 and 3. Rates of death and relapse were quite low after 3-4 years. All patients relapsing after 3 years of CR were B or non-B non-T cell lineage ALL. Long-term survivors (LTS), defined as survival in CR > or =3 years, represented 23% of evaluable patients. Eighty-three patients remain alive in initial CR at >3 years, while only three were LTS after a second CR. Overall, no significant improvement was shown in terms of CR achievement and survival duration over the years. However, regarding survival, a significant improvement was demonstrated in T cell lineage ALL (P = 0.03). Furthermore, patients (aged less than 50 years) transplanted while in first CR did significantly better than those receiving only chemotherapy as post-remission therapy (P < 0.0001). The 3-year OS, after allogeneic transplantation in first CR, was 74% in T cell lineage ALL, while it was less than 50% in B cell lineage ALL. This single center study on a large cohort of ALL patients reflects the degree to which ALL treatment remains unsuccessful in adults. Only T cell lineage ALL outcomes have improved over the years. The results suggest a time (3 years) at which it becomes reasonable to speak of potential cure, provided the patient is in CR.

Dicentric (9;12) in acute lymphocytic leukemia and other hematological malignancies: report from a dic(9;12) study group.

Fourteen cases of dic(9;12)(p11-13;p11-12) in early B-lineage acute lymphoblastic leukemia (ALL) and other hematological malignancies are reported with a review of the literature. Altogether 36 cases were collected for analysis: ALL at diagnosis (31 cases) or in relapse (one case), chronic myeloid leukemia in lymphoid blast crisis (two cases), T-cell lymphoblastic lymphoma (one case) and T-cell non-Hodgkin's lymphoma (one case). We report the first cases of dic(9;12) with a T-cell phenotype. Dic(9;12) occurs predominantly in B-progenitor ALL of childhood and young adults (age range, 1-47 years, median 12 years) but not of infancy. One or more adverse clinical features, age > 10 years, WBC > 100 x 10(9)/l, pre-B immunophenotype, platelets < 100 x 10(9)/l, were found in over 90% of cases. Additional structural chromosomal changes or trisomy 8 were frequently present. Nevertheless with a median follow-up of 5 years, 29/31 cases (94%) remain in first remission conferring an excellent prognosis to this leukemia. Additional cases are being sought to confirm the prognostic value of this cytogenetic aberration in various hematological malignancies.

Molecular analysis of cyclin-dependent kinase inhibitors in human leukemias.

Recurrent anomalies of the short arm of chromosome 9, including interstitial deletions and translocations, have often been described. Recently two cyclin-dependent kinase inhibitors, known as P16 (INK4A/MTS1) and P15 (INK4B/MTS2), which map to 9p21, have been found deleted in a wide range of tumors and particularly in leukemic cells. We report here Southern blot analyses of cyclin-dependent kinase inhibitors (P16, P15, P21, and P27) status in primary tumoral cells of 121 patients with acute lymphoblastic leukemias, 85 patients with acute myeloid leukemias and 42 patients with B-chronic lymphocytic leukemias. P16 inactivation was found in 25 of 38 T-ALLs and in 28 of 83 B-lineage ALLs. In eight cases (three T-ALLs and five B-lineage ALLs), one or both alleles of P16 locus were rearranged. In these cases, breakpoints occurred within the two major breakpoints cluster regions previously described in T-ALLs. Homozygous P16 deletions were observed in two of 85 AMLs but in none of the 42 B-CLL cases tested. Our results suggest that P16 inactivation are the most frequent event observed in ALL (44%), are quite rare in AML (<2%) and seem to be absent in CLL. Search for P27 and P21 deletion was negative in B/T-lineage ALLs and monoallelic deletions of P27 were found in four AML cases (5%).

Immunophenotypic patterns and cytogenetic anomalies in acute non-lymphoblastic leukemia subtypes: a prospective study of 432 patients.

This study prospectively analysed the relationships between immunophenotypic and cytogenetic features of blast cells in 432 acute non-lymphoblastic leukemias (ANLL) at presentation. An abnormal karyotype was detected in 232 cases (54%). These abnormalities were related to immunophenotypic markers as detected using a consensual panel of monoclonal antibodies allowing lineage assignment and investigation of myeloid marker expression on blast cells. In univariate analysis, CD9, CD10, CD15, CD34 and TdT expression appeared significantly associated with chromosomal anomalies. Multivariate analysis identified CD34 and CD9 expression as independently predictive of the presence of at least one cytogenetic abnormality (P < 10(-4) and P < 0.03, respectively). Significant associations between immunophenotypic and karyotypic features were observed both within individual FAB subgroups and independently from morphological criteria. Specific features were seen in five ANLL entities: M0 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 of B lineage antigen/del(11)(q23) or t(9;11). More practically, and although the relationships demonstrated only represent a fraction of homogeneous immunophenotypic subgroups, identification of such immunophenotypic features should prompt careful karyotypic examination, eventually using molecular biology analysis on non-growing cells.

Cytogenetic heterogeneity in t(11;19) acute leukemia: clinical, hematological and cytogenetic analyses of 48 patients--updated published cases and 16 new observations.

We report on 16 cases of t(11;19) acute leukemia and review data of published observations: altogether updated data of 48 patients are analyzed. Four hematological groups could be distinguished: (i) 13 cases of acute lymphoblastic leukemia (ALL) of B lineage, mostly CD19+; (ii) eight cases of biphenotypic leukemia: CD19+ (most often) ALL but with simultaneous or inducible expression of differentiation marker of monocytic lineage. The B lineage and biphenotypic leukemias were predominantly found in female infants; (iii) four cases of T-ALL in children; and (iv) 23 acute non-lymphocytic leukemia (ANLL) cases generally of M4 or M5 subtype, predominantly in males. Cytogenetically, at least two subtypes were observed with possibly an identical breakpoint on 11q23 but discrete breakpoints on 19p: lymphoid, biphenotypic, and most congenital myeloid cases showed a distal breakpoint on 19p13 producing 11q- and 19p+ derivatives, while most older myeloid cases showed 11q+ and 19p- derivatives as a result of a more proximal breakpoint on 19p12 or p13.1. The latter type was clearly detected using R bands but barely visible using Q or G bands while the other translocation was easy to detect with G bands but could be missed with R bands. The white blood cell count is usually high in these t(11;19) acute leukemias and prognosis is poor, except for T-ALL cases.