Thrombocytosis as a presenting feature of acute lymphoblastic leukemia in childhood

To determine the incidence of thrombocytosis at presentation in acute lymphoblastic leukemia (ALL), medical records of all children diagnosed at the Children's Hospital of Pittsburgh from 1980 to 1987 were reviewed. Out of 217 such patients, 7 (3.2%) had platelet counts greater than 400,000/mm3. All of the seven were boys compared with a male:female ration of 1.4:1 in the entire ALL population. Other than sex, no characteristics were clearly associated with thrombocytosis, including white blood cell count, hemoglobin, lymphoblast morphology, and immunologic or chromosomal markers. Apart from ALL, no inflammatory or infectious process which might have caused a thrombocytosis, was detected in any of these patients. The period of induction therapy was notable for the preservation of platelet counts greater than 20,000/mm3 in all patients. However, of the seven children with thrombocytosis, two had major induction complications: one, a cavernous sinus thrombosis; and the other, gastrointestinal bleeding with duodenal perforation. We conclude that thrombocytosis at diagnosis can be seen in children, particularly boys, with ALL. Based on small numbers, this group of patients may be at risk for major events during induction therapy. Large numbers, longer follow-up, and platelet function studies on similar patients will be of interest.     

Prognostic significance of 2-hydroxyglutarate levels in acute myeloid leukemia in China

The 2-hydroxyglutarate (2-HG) has been reported to result from mutations of isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) genes and to function as an “oncometabolite.” To evaluate the clinical significance of serum 2-HG levels in hematologic malignancies, acute myeloid leukemia (AML) in particular, we analyzed this metabolite in distinct types of human leukemia and lymphoma and established the range of serum 2-HG in appropriate normal control individuals by using gas chromatograph–time-of-flight mass spectrometry. Aberrant serum 2-HG pattern was detected in the multicenter group of AML, with 62 of 367 (17%) patients having 2-HG levels above the cutoff value (2.01, log₂-transformed from 4.03 μg/mL). IDH1/2 mutations occurred in 27 of 31 (87%) AML cases with very high 2-HG, but were observed only in 9 of 31 (29%) patients with moderately high 2-HG, suggesting other genetic or biochemical events may exist in causing 2-HG elevation. Indeed, glutamine-related metabolites exhibited a pattern in favor of 2-HG synthesis in the high 2-HG group. In AML patients with cytogenetically normal AML (n = 234), high 2-HG represented a negative prognostic factor in both overall survival and event-free survival. Univariate and multivariate analyses confirmed high serum 2-HG as a strong prognostic predictor independent of other clinical and molecular features. We also demonstrated distinct gene-expression/DNA methylation profiles in AML blasts with high 2-HG compared with those with normal ones, supporting a role that 2-HG plays in leukemogenesis.Acute myeloid leukemia (AML) represents a group of clonal hematopoietic progenitor malignancies with considerable diversities in clinical and biological features (1). In addition to clinical parameter, such as age and white blood cell counts (WBC), a variety of biomarkers have been shown to be predictive of outcome in AML patients, including cytogenetic characteristics and patterns of recurrent gene mutations in the blasts, as exemplified by nucleophosmin (NPM1), fms-related tyrosine kinase 3 (FLT3), and CCAAT/enhancer binding protein-alpha (CEBPA) (1). Even with the remarkable progress of genomic studies on AML (2, 3), clinically useful biomarkers with prognostic values are still needed in a part of cases for better clinical management, particularly in cytogenetically normal AML (CN-AML) patients. Of note, gene mutations of isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) were reported recently not only in gliomas but also in AML (4, 5). The prognostic significance of these mutations appears controversial in AML (6–10), although a metaanalysis suggests a poor outcome in cases with IDH1 mutations (11).IDHs are key enzymes that participate in the tricarboxylic acid metabolic cycle. Three members (IDH1, IDH2, and IDH3) are encoded by the IDH gene family and their activities are NADP(+)/NAD(+)-dependent. IDH1 and IDH2 catalyze the oxidative decarboxylation of isocitrate to α-ketoglutarate (α-KG). Mutant enzymes form a heterodimer, which display reduced catalytic activity to produce α-KG but a newly acquired activity to convert α-KG to 2-hydroxyglutarate (2-HG) (12). Recent studies have suggested that 2-HG may be an “oncometabolite” and play a role in driving malignant phenotype (13–15). Interestingly, 2-HG has been shown to competitively inhibit α-KG–dependent dioxygenases, such as the ten-eleven-translocation 2 (TET2) enzyme, and disturb the epigenetic regulatory network, leading to genome-wide histone and DNA damages with hypermethylation (12–14). Notably, in patients with d-2-hydroxyglutaric aciduria, there is an elevated risk of brain tumors (15). 2-HG can be metabolized by the enzyme 2-HG dehydrogenase (D2HGDH), but until now the possible contribution of genetic variants of this enzyme to the turnover of 2-HG has not yet been addressed.Although IDH1/2 mutations are biomarkers in gliomas, the serum levels of 2-HG in these mutations are usually normal (16). In AML harboring IDH1/2 mutations, serum 2-HG concentrations were elevated in some cases (17–21). Very recent reports suggested that high 2-HG could predict IDH1/2 mutations in AML and be used as a marker for minimal residual disease during clinical remission (21, 22). However, the significance of serum 2-HG levels in prognosis remains obscure. In this work, we examined the levels of 2-HG as a part of the metabolomic study in a large series of AML cases, as well as other hematologic malignancies and healthy controls, and characterized their relevant clinical and molecular features. In particular, we attempted to address the potential prognostic value of 2-HG in AML.     

Outcome and lineage involvement in t(12;21) childhood acute lymphoblastic leukaemia

The t(12;21)(p13;q22) translocation has been described recently as the most recurrent genetic lesion in paediatric acute lymphoblastic leukaemias (ALLs). It has also been associated with B-precursor lineage involvement and good outcome.
We tested 51 diagnostic paediatric ALLs and found 11 cases with molecular evidence of the t(12;21). Interestingly, amongst t(12;21) positive patients, we report three cases with hybrid phenotype, and two cases showing an aggressive and fatal disease. Our data show that the t(12;21) does not represent an independent good-risk indicator. Long follow-ups and additional molecular investigations are needed to assess the prognostic and pathogenetic relevance of t(12;21) in childhood ALLs.     

The periodic acid-Schiff reaction and prognosis in children with acute lymphoblastic leukemia.

We evaluated the intensity of the periodic acid-Schiff (PAS) stain reaction by examining 200 lymphoblasts from the initial marrow aspirate specimen of 38 children with acute lymphoblastic leukemia (ALL). The patients were separated into low, intermediate, and high groups according to mean PAS score. The groups were then compared in terms of age, sex, initial hematologic values, T- and B-lymphocyte markers, percentage of patients in remission six months after diagnosis, and percentage surviving. Significant differences were found between the low group and the other two groups with respect to sex, height of initial white blood cell (WBC) count, outlook for continued remission at six months, and overall survival (P < 0.05). The low-score patients were predominantly males, whereas the other PAS-score groups contained approximately equal numbers of males and females. The low-score patients had a higher median initial WBC than the others, but all three groups had a similar proportion of patients with initial WBC under 20,000/cu mm. Low-score patients were less likely to be in remission six months from diagnosis, and they had shorter survival than the intermediate- and high-score patients (P < 0.05). The results suggest that children with ALL whose lymphoblasts stain weakly with PAS have a worse prognosis than those with intermediate or high PAS reactivity. PAS reactivity may vary independently of the WBC at diagnosis in children with ALL, because children with a low PAS score have a poor outlook even with initial WBC under 20,000/cu mm.     

Functional polymorphisms in the NBS1 gene and acute lymphoblastic leukemia susceptibility in a Chinese population

As a component of the MRN complex (which is a heterotrimeric protein complex consisting of MRE11, RAD50 and NBS1), NBS1 plays an important role in cellular response to DNA damage and the maintenance of chromosomal integrity. Leukemia is common in NBS1 germ line–mutated patients. The NBS1 E185Q polymorphism (8360G>C, rs1805794) has been frequently studied in some cancers with discordant results, but its association with acute lymphoblastic leukemia (ALL) in Chinese population has not been investigated. Besides, there is no report about the association between NBS1 3′UTR variant rs2735383 and ALL risk. In this study, a multiple centre case–control analysis was performed to assess the association between NBS1 polymorphisms and ALL risk. The genotypes and haplotypes were determined in 175 cases and 350 controls, and the associations with risk of ALL were estimated by logistic regression. We observed significant difference in genotype frequencies at the rs1805794 C/G site between cases and controls (P_trend < 0.0001). The allele C increases the risk of ALL in a dose‐dependent response manner. These findings suggest that E185Q polymorphism in NBS1 may be a genetic modifier for developing ALL.     

Lymphoblast cell size and prognosis in acute lymphoblastic leukemia in childhood

Summary The significance of cell size as a prognostic indicator in acute lymphoblastic leukemia (ALL) is controversial. Accuracy in measurement of cell size can be improved by determination of cell areas instead of single cell diameters. In the present study cell areas of 200 cells were determined in pretreatment bone marrows of 35 children with ALL. For better comparison with other studies which had used cell diameters only, the measured area was expressed as circle area from which the circle diameter was calculated. Cells with a diameter of > 12m were defined as macrolymphoblasts (MLB). Several clinical characteristics considered to be risk factors in ALL were ascertained for each patient. The duration of first complete remission was used to assess the prognostic significance of cell size and of number of risk factors. In contrast to previous reports patients with more than 25% MLB had longer remissions. However, nearly all patients of this group had no or one risk factor only. When patients with more than one risk factor were excluded from statistical analysis, the group with more than 25 % MLB had no longer a better prognosis compared to the group with 25% MLB or less. Thus, in this study the percentage of MLB was not an independent prognostic indicator for risk of relapse in ALL.     

Chemoimmunotherapy in acute lymphoblastic leukemia

ALL blast cells express a variety of specific antigens e.g. CD19, CD20, CD22, CD33, and CD52, which serve as targets for Monoclonal Antibodies (MoAbs). So far, the most experience is available for anti-CD20 (rituximab), which has been combined with chemotherapy for treatment of mature B-ALL/Burkitt's lymphoma. Studies with rituximab have also been completed in B-precursor ALL. Another antigen, CD19, is of great interest due to a very high rate of expression in ALL. It can be targeted by a bispecific monoclonal antibody, Blinatumomab, directed against CD19 and CD3. Smaller studies or case reports are also available for the anti CD52 antibody (Alemtuzumab), for anti CD22 (Epratuzumab) or anti CD33 (Gemtuzumab). Available data demonstrate that MoAb therapy in ALL is a highly promising targeted treatment. However, several details for an optimal treatment approach e.g. the required level of antigen expression, timing, schedule, dosage and stage of disease still need to be defined.     

The impact of CYP3A5*3 on risk and prognosis in childhood acute lymphoblastic leukemia

Objectives: Acute lymphoblastic leukemia (ALL) is the most common cancer in childhood; however, little is known of the molecular etiology and environmental exposures causing the disease. Cytochrome P450 3A5 (CYP3A5) plays a crucial role in the catalytic oxidation of endogenous metabolites and toxic substances, including chemotherapeutic agents. The aim of this study was to investigate the role of a single-nucleotide polymorphism (CYP3A5*3 6986A>G), which renders low enzyme activity, in the risk of developing ALL and in the outcome for children with ALL. Patients and methods: Six hundred and sixteen childhood patients with ALL and 203 controls were genotyped by allelic discrimination. Results: Individuals with the A allele had a 64% increased risk of developing childhood ALL (odds ratio = 1.64; 95% CI, 1.009-2.657). In general, event-free survival (EFS) did not differ in relation to CYP3A5 genotype. However, for patients with T-ALL, presence of the A allele was associated with better prognosis (EFS = 94.1%), while patients with the low-activity GG genotype only had an EFS of 61.5% (P = 0.015). Thus, for patients with T-ALL having no A allele and therefore low expression of CYP3A5, the risk of experiencing an event was almost eight times higher compared to those having at least one A allele (P = 0.045, hazard ratio = 7.749; 95% CI, 1.044-57.52). Conclusions: This study shows that genetics may play a role in the risk of developing childhood ALL and indicates that improved treatment stratification of childhood patients with ALL may require addition of host genetic information.     

AICDA expression in BCR/ABL1-positive acute lymphoblastic leukaemia is associated with a peculiar gene expression profile

Activation-induced cytidine deaminase (AICDA) initiates somatic hypermutation and class-switch recombination of immunoglobulin (Ig) genes and induces mutations also in non-Ig genes. AICDA aberrant expression was detected in B-lineage acute lymphoblastic leukaemia (B-ALL), particularly BCR/ABL1+ B-ALL; patients expressing AICDA carried more copy number alterations than 'AICDA-negative' cases. To determine the role of AICDA, AICDA expression and gene expression profiling were studied in adult BCR/ABL1+ B-ALL. Patients displaying the full-length isoform AICDA are characterized by up-regulation of DNA repair/replication and cell cycle genes, suggesting their involvement in the genetic instability of BCR/ABL1+ B-ALL.     

Expression of the BCRP gene (ABCG2/MXR/ABCP) in childhood acute lymphoblastic leukaemia

The breast cancer resistance protein (BCRP), also known as mitoxantrone resistance protein (MXR) or placenta ABC protein (ABC-P), is the second member of the ABCG subfamily of ABC transport proteins (gene symbol ABCG2). BCRP has been detected in acute myeloid leukaemia and in breast, colon and gastric cancer but there has been no reports regarding BCRP expression in acute lymphoblastic leukaemia (ALL). We report the first results of BCRP expression in childhood ALL. Sixty-seven children (47 initial stage, 20 relapses) with ALL were analysed for BCRP gene expression by TaqMan real-time polymerase chain reaction. The expression of BCRP in mononuclear cells obtained from the bone marrow (BM) and peripheral blood (PB) of healthy donors was also investigated. There was no relationship between BCRP expression and age, sex, initial blast cell count, prednisolone response or BM response on d 15 and 33. Patients with T-lineage ALL showed a lower expression of BCRP (P = 0.044). Kaplan-Meier analysis of the relapse-free interval showed no prognostic significance of BCRP expression when different levels of BCRP expression were used as cut-off points. No significant difference in expression of BCRP mRNA was measured between initial-stage and relapsed-stage ALL or between normal MNC obtained from BM and ALL patients. The results indicate a low expression of BCRP in childhood ALL. Relationships between BCRP and clinical, molecular or in vivo resistance characteristics of the patients were not observed.     

Genomic profiling of adult acute lymphoblastic leukemia by single nucleotide polymorphism oligonucleotide microarray and comparison to pediatric acute lymphoblastic leukemia

Background

Differences in survival have been reported between pediatric and adult acute lymphoblastic leukemia. The inferior prognosis in adult acute lymphoblastic leukemia is not fully understood but could be attributed, in part, to differences in genomic alterations found in adult as compared to in pediatric acute lymphoblastic leukemia.

Design and Methods

We compared two different sets of high-density single nucleotide polymorphism array genotyping data from 75 new diagnostic adult and 399 previously published diagnostic pediatric acute lymphoblastic leukemia samples. The patients’ samples were randomly acquired from among Caucasian and Asian populations and hybridized to either Affymetrix 50K or 250K single nucleotide polymorphism arrays. The array data were investigated with Copy Number Analysis for GeneChips (CNAG) software for allele-specific copy number analysis.

Results

The high density single nucleotide polymorphism array analysis of 75 samples of adult acute lymphoblastic leukemia led to the identification of numerous cryptic and submicroscopic genomic lesions with a mean of 7.6 genomic alterations per sample. The patterns and frequencies of lesions detected in the adult samples largely reproduced known genomic hallmarks detected in previous single nucleotide polymorphism-array studies of pediatric acute lymphoblastic leukemia, such as common deletions of 3p14.2 (FHIT), 5q33.3 (EBF), 6q, 9p21.3 (CDKN2A/B), 9p13.2 (PAX5), 13q14.2 (RB1) and 17q11.2 (NF1). Some differences between adult and pediatric acute lymphoblastic leukemia were identified when the pediatric data set was partitioned into hyperdiploid and non-hyperdiploid cases and then compared to the nearly exclusively non-hyperdiploid adult samples. In this analysis, adult samples had a higher rate of deletions of chromosome 17p (TP53) and duplication of 17q.

Conclusions

Our analysis of adult acute lymphoblastic leukemia cases led to the identification of new potential target lesions relevant for the pathogenesis of acute lymphoblastic leukemia. However, no unequivocal pattern of submicroscopic genomic alterations was found to separate adult acute lymphoblastic leukemia from pediatric acute lymphoblastic leukemia. Therefore, apart from different therapy regimen, differences of prognosis between adult and pediatric acute lymphoblastic leukemia are probably based on genetic subgroups according to cytogenetically detectable lesions but not focal genomic copy number microlesions.     

Four-agent induction/consolidation therapy for childhood acute lymphoblastic leukemia: an Indian experience.

During 1984-1986, a total of 128 children with acute lymphoblastic leukemia (ALL) were treated with an induction-consolidation regimen consisting of doxorubicin, vincristine, cytosine-arabinoside, and prednisolone. One hundred two (80%) patients belonged to high-risk group. The complete remission rate for all the patients was 91%. The event-free survival at 5 years was 32.0% +/- 23%. On multivariate analysis the event-free survival and disease-free survival was not altered by age, sex, WBC count, platelet count, LDH level, and surface phenotype. Infection due to prolonged marrow aplasia was a common complication, leading to mortality of 8 patients during induction and 33 patients during first remission. The relapse rate has been 36% (42 patients). The predominance of high-risk ALL in the Indian population underscores the need for intensive therapy. Improved supportive care during induction and remission seems essential to decrease therapy-related mortality, leading to improved survival.     

An unusual presentation of pediatric acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is one of the most common hematological malignancies occurring in children. We report an interesting case of ALL with an unusual presentation. This 3 year old boy came with a 6 month history of multiple pathological fractures, generalized osteopenia and vertebral compression. All the possible causesresponsible for this condition were ruled out. His complete blood count which was normal initially evolved into cytopenias. His physical examination revealed generalized lymphadenopathy and hepatosplenomegaly. The complete blood count showed pancytopenia with blasts in peripheral smear. Bone marrow aspirate was suggestive of B ALL. Pediatric ALL patients usually present with symptoms due to cytopenias, fever and bone pains. Although asymptomatic skeletal involvement may be seen in 40–60% of patients at presentation, pathological fractures and vertebral compressions are very rare. Therefore a high index of suspicion is needed to diagnose such cases. Moreover, these patients are usually associated with good prognostic features.     

Prognostic impact of CD200 and CD56 expression in adult acute lymphoblastic leukemia patients

Background: The aim of the study is to determine the prognostic relevance of CD200/ CD56 expression in adult acute lymphoblastic leukemia patients.

Methods: The expression of CD200 and CD56 by blast cells was assessed by flow cytometry before the start of chemotherapy in 70 B-ALL patients.

Results: Positive expression of CD200 was detected in forty-six patients (66%) and CD56 was detected in 7 patients (10%) out of 70 patients, respectively. Only three patients (4.3%) had co-expression for CD200⁺ and CD56⁺. Splenomegaly and thrombocytopenia were frequently observed more in CD200⁺ patients. Increased frequency of CD34⁺ was associated with CD200⁺and CD56⁺ patients. The CD200⁺ and CD56⁺ subgroups of B-ALL patients had inferior OS and disease free survival compared to CD 200^? and CD 56^? patients.

Conclusions: CD200⁺ and/or CD56⁺ positive expression in B-ALL patients at diagnosis is a poor prognostic biomarker. Identification of CD200⁺ and CD56⁺ expression at diagnosis is recommended for a better stratification of adult B-ALL patients.