Expression levels of asparagine synthetase in blasts from children and adults with acute lymphoblastic leukaemia

L-asparaginase is active in the treatment of acute lymphoblastic leukaemia (ALL) through the depletion of serum asparagine. Here we report that median asparagine synthetase (AS) mRNA levels were higher in acute myeloid leukaemia (AML) than ALL blasts in both children and adults, with intermediate levels in normal peripheral blood mononuclear cells (NPBMC). NPBMC versus child ALL (Tukeys multiple comparison test, P < 0.05); child ALL versus child AML (P < 0.001) and adult ALL versus adult AML (P < 0.01) were all significant and support the hypothesis that selectivity to treatment with l-asparaginase is due, at least in part, to lower AS expression.     

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.     

Susceptibility of AML cells to in vitro apoptosis correlates with heat shock protein 70 (hsp70) expression

Acute myeloid leukaemia (AML) cells from some individuals rapidly undergo apoptosis during in vitro culture. We have analysed this mode of cell death in AML cells harvested from patients at initial presentation and during subsequent treatment/relapse. Using flow cytometric analysis of propidium iodide-stained cells and quantitation of the subdiploid apoptotic peak, we observed that leukaemic cells from patients with AML displayed a heterogenous susceptibility to apoptosis in terms of the rate of accumulation of apoptotic cells. After 48 h incubation in the absence of added serum or exogenous growth factors the percentage of apoptotic cells ranged from 3% to 99%. This susceptibility to apoptosis correlated significantly with intracellular expression of hsp70 ( P =0.009), but not hsp90, and was also associated with the presence of p53 and low levels of expression of bcl-2.     

Patient perceptions of second transplants in myeloma: impact on recruitment in the British Society of Blood and Marrow Transplantation/UK Myeloma Forum Myeloma X Relapse (Intensive) Trial

The BCR/ABL1 fusion gene, usually carried by the Philadelphia chromosome (Ph) resulting from t(9;22)(q34;q11) or variants, is pathognomonic for chronic myeloid leukaemia (CML). It is also occasionally found in acute lymphoblastic leukaemia (ALL) mostly in adults and rarely in de novo acute myeloid leukaemia (AML). Array Comparative Genomic Hybridization (aCGH) was used to study six Ph(+)AML, three bi‐lineage and four Ph(+)ALL searching for specific genomic profiles. Surprisingly, loss of the IKZF1 and/or CDKN2A genes, the hallmark of Ph(+)ALL, were recurrent findings in Ph(+)AML and accompanied cryptic deletions within the immunoglobulin and T cell receptor genes. The latter two losses have been shown to be part of ‘hot spot’ genome imbalances associated with BCR/ABL1 positive pre‐B lymphoid phenotype in CML and Ph(+)ALL. We applied Significance Analysis of Microarrays (SAM) to data from the ‘hot spot’ regions to the Ph(+)AML and a further 40 BCR/ABL1(+) samples looking for differentiating features. After exclusion of the most dominant markers, SAM identified aberrations unique to de novo Ph(+)AML that involved relevant genes. While the biological and clinical significance of this specific genome signature remains to be uncovered, the unique loss within the immunoglobulin genes provides a simple test to enable the differentiation of clinically similar de novo Ph(+) AML and myeloid blast crisis of CML.     

Immunophenotypic and cytogenetic changes in acute leukaemia at relapse

To gain more insight into the immunophenotypic and cytogenetic changes in acute leukaemia at relapse, 99 Korean patients treated at a single institution were studied: acute myelogenous leukaemia (AML, n=46), acute lymphoblastic leukaemia (ALL, n=44) and biphenotypic and mixed leukaemia (n=9). Immunophenotypic changes at relapse were observed in 51 of 99 patients (51.5%) with almost even distribution in AML and ALL. Overall expression of aberrant markers on leukaemic cells was more frequent at relapse than at initial diagnosis (P < 0.05), and this finding was most prominent in B lineage ALL (41.4% versus 10.3%, P=0.007). Gain of aberrant CD13 or CD33 at relapse of B lineage ALL was most frequently observed. Cytogenetic changes at relapse were observed in 28 of 46 patients (60.8%). The initially abnormal karyotypes were more frequently associated with clonal changes at relapse compared to initially normal karyotypes (78.3% versus 43.5%, P=0.016). Cytogenetic changes were more frequent in B lineage ALL than in AML (90% versus 47.8%, P=0.05). In ALL, patients showing cytogenetic changes at relapse were significantly younger than those showing no changes (mean age of 15.0 versus 38.8, P=0.002), whereas in AML there was no significant difference between the two groups. In conclusion, the gain of aberrant markers and cytogenetic changes at relapse, which are suggestive of clonal instability, are more prevalent in B lineage ALL compared to AML, and lymphoid leukaemic cells of younger patients are more susceptible to clonal changes at relapse.     

Myelodysplastic relapse of de novo acute myeloid leukaemia with trilineage myelodysplasia: a previously unrecognized correlation

We describe the occurrence of an unusual mode of relapse in six of 24 patients who presented with de novo acute myeloid leukaemia (AML) associated with trilineage myelodysplasia (TMDS). After the induction of complete remission (CR) by intensive chemotherapy in five patients and following bone marrow transplantation (BMT) in one, the myelodysplastic state, but not overt AML, recurred. Relapse of myelodysplasia occurred at a median of 147 weeks (50-520) from presentation and in two instances was followed a year later by AML. In five cases, myelodysplastic relapse was treated with low-dose cytosine arabinoside given alone or with other chemotherapeutic agents. Three patients remain in CR after 1, 2 and 5 years. The reappearance of myelodysplastic features in these six patients was strongly correlated with the presence of TMDS at presentation of the AML. It was not observed once in the 136 AML patients, treated similarly, who did not have associated TMDS at presentation (P less than 0.001). Thus, relapse with myelodysplasia is not an effect of chemotherapy as has been previously postulated.     

Graft-versus-leukaemia activity associated with CMV-seropositive donor, post-transplant CMV infection, young donor age and chronic graft-versus-host disease in bone marrow allograft recipients. The Nordic Bone Marrow Transplantation Group

Risk factors for post-transplant relapse were analysed retrospectively in 163 patients treated with allogenic bone marrow transplantation for acute myeloid leukaemia (AML), acute lymphoblastic leukaemia (ALL) or lymphoblastic lymphoma in first to fourth remission or during relapse. Multifactorial analysis was performed according to Cox with fixed pretransplant covariates and post-transplant cytomegalovirus (CMV) infection and graft-versus-host (GVHD) as time-dependent covariates. Advanced stage of leukemia at the time of transplantation was an important risk factor for subsequent relapse. Furthermore, the study confirmed a graft-versus-leukaemia (GVL) activity associated with chronic GVHD, including de novo chronic GVHD (intensity factor 0.08, p = 0.004). In a model excluding chronic GVHD, female donor-to-male recipient (a risk factor for GVHD), was associated with decreased post-transplant relapse risk (intensity factor 0.3, p = 0.008), suggesting that an allo-reaction against a minor transplantation antigen (Hy) may mediate antileukaemic activity. A decrease of the relapse risk by a factor 0.18 was observed in recipients with AML as well as ALL when the donor was CMV seropositive (p = 0.0002). This effect was restricted to patients who had laboratory evidence of post-transplant CMV infection. When CMV infection occurred and donor was seropositive the relapse risk was reduced by a factor 0.035. The effect was not mediated through an increased occurrence of grade 2-4 acute or chronic GVHD and could not be explained by a statistical bias due to censoring of patients who died in remission. Rather, donor CMV immunity was associated with GVHD independent GVL activity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Glycophorin A mutations and risk of secondary leukaemia in patients treated for childhood acute lymphoblastic leukaemia

Survivors of childhood acute lymphoblastic leukaemia (ALL) have a higher than expected risk of developing secondary acute myeloid leukaemia (AML). The glycophorin A (GPA) mutation assay measures the frequency of variant NO and NN erythrocytes in MN heterozygotes. A raised variant frequency (Vf) has been shown in patients treated with chemotherapy known to be at risk of secondary leukaemia. ALL patients were investigated for increased Vf using the GPA assay. Vf's at diagnosis were not significantly different from controls (NO Vf P  = 0.193; NN Vf P  = 0.790). During treatment Vf's increased significantly (NO Vf P  = 0.001; NN Vf P  = 0.001). NO Vf returned to control values ( P  = 0.169) within 5 years from diagnosis but NN Vf remained significantly raised ( P  = 0.014). Three study patients developed secondary AML. At diagnosis of AML all three had significantly increased Vf. The first had a significantly raised Vf at routine follow-up 19 years following diagnosis of ALL then developed AML 3.5 years later. The second had a significantly raised NN Vf at diagnosis of ALL indicating possibly prior exposure to a mutagen or defective DNA repair involving erythroid stem cells. We conclude that a raised Vf detected by the GPA assay can act as a marker for the development of secondary induced leukaemia and can be used to screen individuals at a known high risk of this complication.     

Remission with morphological myelodysplasia in de novo acute myeloid leukaemia: implications for early relapse

Myelodysplastic features of remission bone marrow were investigated in 46 adults with de novo acute myeloid leukaemia (AML) according to the FAB morphological criteria for myelodysplastic syndromes (MDS). Compared with a group of 18 patients with the common type of acute lymphoblastic leukaemia in remission, micromegakaryocytes (30.4% v. 5.6%, P less than 0.05), multi-separated nuclear megakaryocytes (45.7% v. 0%, P less than 0.01), degranulated neutrophils (39.1% v. 5.6%, P less than 0.05), and neutrophils with hyposegmented nuclei (34.8% v. 0%, P less than 0.01) were significantly more common in the AML patients. In contrast, dyserythropoietic changes had a similar incidence in both groups. When compared with the clinical features at initial diagnosis in AML cases, the dysmegakaryocytic changes in remission marrow were found to be significantly more frequent in patients with monocytic involvement (mainly M4) or trilineage myelodysplasia (T-MDS AML). Disease-free survival was significantly shorter in patients with micromegakaryocytes (P less than 0.05) or neutrophils with hypogsegmented nuclei (P less than 0.05) than in those without these features. Overall survival was also significantly shorter in patients with micromegakaryocytes (P less than 0.05). These findings may help in developing new strategies for the post-remission therapy of AML, and also suggest that myelodysplastic changes in the remission marrow of de novo AML patients may be related to haematopoietic recovery by a preleukaemic clone which eventually leads to early leukaemic relapse. Dysplastic marrow, however, was not necessarily associated with peripheral pancytopenia in the present series, warranting basic research on such putative clonal remissions.     

Acute biphenotypic leukaemia (myeloid and null-ALL type) supervening in a myelodysplastic syndrome

An acute leukaemia was seen in a 72-year-old patient with a myelodysplastic syndrome (MDS) of 14 months duration, who had been treated only with steroids. The morphological appearance of the blast cells suggested a poorly differentiated cell type. Surface marker analysis, including double staining studies, showed the coexistence of a population of null acute lymphoblastic leukaemia (ALL) blast cells together with acute myeloid leukaemia type cells. No chromosomal alterations were detected. The change from a chronic MDS to an acute leukaemia of mixed (myeloid and null ALL) type suggests either transformation of a pre-existing abnormal clone or de novo appearance of two separate leukaemic clones.     

Dysplastic peripheral blood polymorphs link acute myeloblastic leukaemia in elderly to the myelodysplastic syndromes.

We studied dysplastic features in peripheral blood polymorphs from 80 patients with acute leukaemia. Thirty-seven patients with de novo acute myeloblastic leukaemia (AML) were compared to 26 patients with AML that had developed after a myelodysplastic phase (MDS-AML), and 17 cases of acute lymphoblastic leukaemia (ALL). Cytoplasmic hypogranulation in neutrophils, measured as a score value (G-score; normal range: 255-300), and the percentage of pelgeroid polymorphs (ppp; normal range: 0.5%) were studied retrospectively by reviewing the diagnostic peripheral blood smears. The mean G-score was decreased in MDS-AML (178 +/- 67.9), and in de novo AML (212 +/- 65.1), but not in ALL (275 +/- 24.3). When de novo AML patients were divided by age, the elderly (greater than 60 yr) had significantly (p = 0.0001) lower mean G-score than the younger (less than 45 yr) ones; 156 +/- 64.8 v 243 +/- 41.4. This age-related difference became accentuated when only patients with extreme hypogranulation (G-score less than 150) were studied. Elderly de novo AML patients also had significantly (p = 0.0057) higher mean ppp. By studying the degree of polymorph dysplasia in the peripheral blood, it seems possible to identify a subset of dysplastic elderly AML patients, who might have passed a (preleukaemic) MDS phase unnoticed.     

CD90/Thy-1 is preferentially expressed on blast cells of high risk acute myeloid leukaemias

Different transformation mechanisms have been proposed for elderly acute myeloid leukaemia (AML) and secondary AML (sAML) when compared with de novo AML or AML of younger patients. However, little is known regarding differences in the immunophenotypic profile of blast cells in these diseases. We systematically analysed, by flow cytometry, 148 patients affected by de novo (100 cases) or sAML (48 cases). By defining a cut-off level of 20% of CD34+ cells co-expressing CD90, the frequency of CD90+ cases was higher in sAML (40%) versus de novo AML (6%, P < 0.001), elderly AML (>60 years) (24%) versus AML of younger patients (10%, P = 0.010) and poor- versus good-risk karyotypes (according to the Medical Research Council classification, P < 0.001). The correlation between CD90 expression, sAML and unfavourable karyotypes was confirmed by analysing the subset of CD34+ AML cases alone (91/148). Consistently, univariate analysis showed that expression of CD90 was statistically relevant in predicting a shorter survival in CD90+ AML patients (P = 0.042). Our results, demonstrating CD90 expression in AML with unfavourable clinical and biological features, suggest an origin of these diseases from a CD90-expressing haemopoietic progenitor and indicate the use of CD90 as an additional marker of prognostic value in AML.     

Is there a graft‐versus‐leukaemia effect in the absence of graft‐versus‐host disease in patients undergoing bone marrow transplantation for acute leukaemia?

During a 13-year period, 5200 autografts, 1039 HLA-identical sibling transplants without acute or chronic graft-vs.-host disease (GVHD) and 67 twins were reported to the European Group for Blood and Marrow Transplantation EBMT. Follow-up time was a median of 32 months. Diagnoses were acute myeloid leukaemia (AML, 4521) and acute lymphoblastic leukaemia (ALL, 1785) in first complete remission. The probability of relapse at 5 years was 51 +/- 1% in the autografts, 45 +/- 8% in the twins and 34 +/- 2% among the HLA-identical siblings (auto vs. sibs, P < 0.0001). In multivariate analyses, the following factors were significantly associated with an increased risk of relapse: ALL vs. AML M3 [relapse rate (RR) 2.29, P < 0.0001], AML non-M3 vs. AML M3 (RR 1.8, P < 0.0001), autograft vs. sibling transplant (RR 1.76, P < 0.0001), interval diagnosis to transplantation < 261 d (RR 1.45, P < 0.001) and other conditioning vs. total body irradiation (RR 1.16, P = 0.001). Transplant-related mortality was the same in the three groups at approximately 10% at 2 years. Five-year leukaemia-free survival was 42 +/- 1% in the autografts, 44 +/- 8% in the twins and 58 +/- 2% among the siblings (auto vs. sibs, P < 0.0001). The factors significant for relapse were also significant in multivariate analyses for leukaemia-free survival. In addition, children had a significantly better leukaemia-free survival than adults (RR 0.82, P < 0.0001). Recipients of bone marrow from HLA-identical siblings without GVHD had a lower risk of relapse and a better leukaemia-free survival than recipients of autografts. This may be as a result of a graft-vs.-leukaemia effect in the absence of GVHD.     

Regulation of angiogenesis in the bone marrow of myelodysplastic syndromes transforming to overt leukaemia

To investigate the regulatory mechanisms of angiogenesis in the development of myelodysplastic syndromes (MDS) and its progression to overt leukaemia (OL), bone marrow samples from control, paired samples from MDS patients before and after transformation to OL (MDS --> OL) and de novo acute myeloid leukaemia (AML) were analysed. Immunohistochemical staining showed a significant increase of bone marrow microvascular density (MVD) in MDS and de novo AML compared with controls. Surprisingly, in MDS, MVD significantly decreased upon transformation to OL, which was also significantly lower than the MVD of de novo AML. This evidence was strengthened by the pattern of angiogenic mediator gene expression, confirming the importance of various angiogenic mediators including vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), tumour necrosis factor alpha (TNFalpha), hepatocyte growth factor (HGF) and the angiopoietin family of mediators (Ang-1 and Ang-2) as well as the receptors for angiogenic mediators, such as VEGF receptor 2 (VEGFR2) and the tyrosine kinase receptor, TIE2. By contrast, the anti-angiogenic mediator, transforming growth factor-beta (TGFbeta) exhibited significantly higher expression in the bone marrow of MDS --> OL, indicating the importance of this cytokine as the suppressive factor of angiogenesis in MDS. These findings indicate that the bone marrow microenvironment in MDS --> OL and de novo AML differs remarkably, suggesting the different efficacy of anti-angiogenic therapy between de novo AML and leukaemia secondary to MDS.     

In vitro sensitivity of leukemic cells to nucleoside derivatives in childhood acute leukemias: good activity in leukemic relapses

Nucleoside analogues such as fludarabine and cladribine are used in therapy of indolent lymphomas and leukemias in adults, while cytarabine is used mainly in protocols for acute leukemias. Mechanisms of their activity is based on inhibition of enzymes involved in DNA, RNA and protein synthesis. The objective of the study was the analysis of in vitro cellular drug sensitivity in childhood acute lymphoblastic (ALL) and myeloid (AML) leukemia. Isolated leukemic cells obtained from 264 patients, including 152 initial ALL, 45 relapsed ALL, 54 initial AML and 13 relapsed AML were tested for cytotoxicity for fludarabine, cladribine, and cytarabine by the MTT assay. Drug concentration lethal to 50% of tested cells was regarded as a value of drug resistance. Three tested nucleoside analogues showed highest cytotoxicity against initial ALL samples. Samples of relapsed ALL and initial AML were more resistant than ALL de novo ones. Unexpectedly, no differences were observed between initial and relapsed AML samples for all tested drugs, what suggests that nucleoside analogues are active drugs in relapsed AML, which is commonly regarded as a resistant disease. All tested drugs presented significant cross-resistance in each of analyzed subgroups. In summary, tested nucleoside analogues presented relatively good activity against childhood leukemias at relapse stage.     

Significance of trilineage myelodysplasia in de novo acute myeloid leukaemia during remission rather than at diagnosis

Patients with trilineage myelodysplasia (TMDS) in de novo acute myeloid leukaemia (AML) at diagnosis and remission were clinically evaluated between 1983 and 1996. AML with TMDS (AML/TMDS) was observed in 20 (12%) of 162 patients with de novo AML at diagnosis. Complete remission (CR) was achieved with combination chemotherapy in 12 (67%) of 18 AML/TMDS cases. This CR rate was relatively worse than the rate of 78% (106/136 cases) of AML without TMDS, but this difference was not significant. Disease-free survival curves also showed no difference between AML/TMDS and AML without TMDS. During remission, eight (67%) of 12 AML/TMDS cases had myelodysplastic remission marrow (AML/MRM). AML/MRM was also seen in seven (7%) of 106 AML cases without TMDS. The actuarial disease-free survival was significantly lower in AML/MRM than in AML without MRM ( P  = 0.0003). All of the AML/MRM cases exhibited early leukaemic relapse; median remission duration was only 9 months. Clonal changes occurred in two cases of AML/TMDS and five cases of AML/MRM at the time of relapse. These findings suggest that TMDS during remission predicts a poorer prognosis and early leukaemic relapse when compared with the absence of TMDS.     

Intracellular lactic dehydrogenase and phosphohexose isomerase activity in leukaemia and malignant lymphoma

Intracellular activities of total lactic dehydrogenase (LDH) and phosphohexose isomerase (PHI) were investigated in the leukaemic cells of 14 patients with acute myeloid leukaemia (AML), five with chronic myeloid leukaemia (CML), seven with acute lymphoblastic leukaemia (ALL), 19 with chronic lymphocytic leukaemia (CLL), 16 with leukaemic non-Hodgkin's lymphoma (NHL) and in the lymphocytes of 14 normal persons. Intracellular total LDH-activity of the blasts of AML and ALL was in the same range as the normal lymphocytes. Patients with CLL and NHL had significantly lower levels ( P <0.01) of total intracellular LDH than the controls. Intracellular PHI activity was consistently lower in the lymphoid malignancies (ALL, CLL, NHL) than in normal lymphocytes ( P <0.05), or in leukaemic myeloblasts ( P <0.01). The intracellular LDH/PHI index of the leukaemic lymphoblasts was significantly elevated as compared to lymphocytes from normal subjects ( P <0.0001) or to leukaemic cells from patients with AML ( P <0.001), with CLL ( P < 0.0001) or with NHL ( P < 0.001). The patients with CLL and NHL, on the other hand, had significantly lower levels of LDH/PHI ratio than the normal subjects ( P <0.0001 and P <0.025 respectively).     

Factors affecting the outcome of allogeneic bone marrow transplantation for adult patients with refractory or relapsed acute leukaemia

We evaluated the outcome of allogeneic bone marrow transplantation (BMT) for advanced acute myeloid leukaemia (AML) and acute lymphoblastic leukaemia (ALL) in 383 adult patients in nine Australian adult BMT centres between 1981 and 1997. The median overall survival for the group was 4.8 months, with an estimated 5-year survival of 18%. 28% of patients died of transplant-related toxicities within the first 100 d. Progressive disease was responsible for 48% of deaths. Multi-factor analysis demonstrated that AML (v ALL), disease status (second complete remission [CR2] v others), age (< 40 years) and duration of prior first complete remission (CR1) (> 6 months) were pre-transplant variables significantly associated with improved survival. Acute graft-versus-host disease (GVHD) of any grade reduced the rate of relapse in both AML and ALL, but only grades I-II were associated with improved survival. Both limited and extensive chronic GVHD were associated with increased survival. Only patients with AML in untreated first relapse or CR2, with a duration of CR1 > 6 months, or patients with T ALL, had a 5-year survival > 20%. Transplants for AML in induction failure or pre-B ALL in untreated first relapse or CR2 had an intermediate outcome, with 5-year survival of 10-20%. A 5-year survival of < 10% was observed for patients transplanted for ALL in induction failure or for pre-B ALL or AML in refractory first relapse or beyond CR2. These results suggest that for most adult patients with advanced acute leukaemia an allograft offers only a small chance of cure.