Childhood Common Acute Lymphoblastic Leukaemia Research Articles

In vitro substance P-dependent induction of bone marrow cells in common (CD10) acute lymphoblastic leukaemia

The aim of the present research was to investigate the possible in vitro stimulatory effect of substance P (SP) on blasts induction in childhood common acute lymphoblastic leukaemia (ALL). Bone marrow aspirates were incubated with SP receptor agonist or antagonist (spantide) and subsequently assayed for the presence of human interleukin (IL)-1b using ELISA kit. Blast cells incubated with SP receptor agonist were found to result in a significant increase of IL-1b concentration while incubated with spantide resulted in control levels of IL-1b. These findings suggest the novel possible role of SP in blasts proliferation in childhood ALL of common (CD10) origin.

Genetic susceptibility to childhood common acute lymphoblastic leukaemia is associated with polymorphic peptide-binding pocket profiles in HLA-DPB1*0201.

In a previous study, we obtained preliminary evidence in a small series of patients (n = 63) suggesting that susceptibility to childhood common acute lymphoblastic leukaemia (c-ALL) was associated with an allele at the HLA-DPB1 locus, DPB1*0201. We have now tested this hypothesis by comparing the frequency of children with leukaemia (n = 982) who typed for specific DPB1 alleles and two groups of non-leukaemic children, one consisting of children with solid tumours, excluding lymphomas (n = 409), the other consisting of normal infants (n = 864). We found that significantly more children with c-ALL and T-ALL, but not pro-B ALL or acute non-ALL typed for DPB1*0201 as compared with children with solid tumours [odds ratio (OR), 95% confidence interval (CI) for c-ALL: 1.76, 1.20-2.56; T-ALL: 1.93, 1.01-3.80] and normal infants (OR, 95% CI for c-ALL: 1.83, 1.34-2.48; T-ALL: 2.00, 1.10-3.82). In childhood c-ALL, significantly more children than those with solid tumours or normal infants typed for DPB1 alleles coding specific polymorphic amino acids lining the antigen-binding site of the DPbeta1*0201 allotypic protein, suggesting that susceptibility to childhood c-ALL may be influenced by DPbeta ABS amino acid polymorphisms shared by DPbeta1*0201 and other DPbeta1 allotypes. These results point to a mechanism of c-ALL susceptibility that involves the presentation of specific antigenic peptides, possibly derived from infectious agents, by DPbeta1*0201-related allotypic proteins, leading to the activation of helper T cells mediating proliferative stress on preleukaemic cells.

Near haploid childhood acute lymphoblastic leukemia masked by hyperdiploid line: detection by fluorescence in situ hybridization

Near-haploid (<30 chromosomes) acute lymphoblastic leukemia (ALL) is a rare and unique subgroup of childhood common ALL associated with a very poor outcome. It may be underdiagnosed when masked by a co-existing hyperdiploid line, which has to be distinguished from the common good-prognostic hyperdiploid (>50 chromosomes) ALL. We present three children in whom, by conventional cytogenetics, near-haploid ALL was detected on relapse. Using interphase FISH probes of chromosomes X, Y, 4, 12, and 21, we were able, in two cases, to trace the hidden near-haploid lines of approximately 5% and 20% of the cells, masked by hyperdiploid cells of approximately 80% and 70%, respectively; at relapse, the proportion was reversed, with predominant near-haploid lines of over 80% and residual hyperdiploidy of less than 10%. The near-haploid lines consisted of 24 and 27 chromosomes, and always retained the second copy of chromosome 21 or its derivative, as detected in one of our patients by SKY. The hyperdiploid clones were the exact duplicates of the near-haploid ones and contained four and two copies of the chromosomes represented in two and one copies in the near-haploid stem line, respectively. Unlike the common hyperdiploid ALL, no trisomies were observed. The patients were all aged >10 years, with WBC 0.7–30 × 10 9/L, and a common ALL phenotype. They were treated with the ALL-BFM-95 protocol, medium risk group, and responded well to 8 days of steroid therapy, but relapsed early, within 11 months, and died a few months later. Interphase FISH technique is recommended for the detection of cryptic near-haploid clones in the diagnostic survey of ALL. To assess the prognostic value of near-haploidy in the context of the ALL-BFM protocols, a larger cohort of patients is required.

Lack of association between childhood common acute lymphoblastic leukaemia and an HLA-C locus dimorphism influencing the specificity of natural killer cells.

Previous serological studies documenting an association between acute lymphoblastic leukaemia (ALL) and HLA-Cw antigens suggested that the HLA-C locus might influence susceptibility to ALL. However, associations with more than one Cw antigen suggest that polymorphic variants shared by more than Cw allele could be involved. Recent studies have shown that the HLA-C locus encodes two ligands (NK1 and NK2) recognized by receptors on natural killer (NK) cells. HLA-Cw alleles encoding these ligands are dimorphic, dependent on whether they encode one or other NK ligand. To determine whether susceptibility to the common (CD10+) form of childhood ALL (c-ALL) is associated with NK1 or NK2, we carried out a molecular analysis of 94 childhood c-ALL patients and 136 infant controls. We found no difference in the frequency of NK1 and NK2 alleles, phenotypes or genotypes between the patients and controls, suggesting that this does not explain the role of the HLA-C locus in susceptibility to childhood c-ALL.

Evidence that an HLA-DQA1-DQB1 haplotype influences susceptibility to childhood common acute lymphoblastic leukaemia in boys provides further support for an infection-related aetiology.

Comparison of DQA1 and DQB1 alleles in 60 children with common acute lymphoblastic leukaemia (c-ALL) and 78 newborn infant control subjects revealed that male but not female patients had a higher frequency of DQA1*0101/*0104 and DQB1*0501 than appropriate control subjects. The results suggest a male-associated susceptibility haplotype in c-ALL and supports an infectious aetiology.

Targeted superantigens for immunotherapy of haematopoietic tumours.

With the exception of childhood common acute lymphoblastic leukaemia (cALL), treatment of other hematopoietic B cell lineage tumours such as non-Hodgkin's lymphoma (B-NHL), adult ALL and multiple myeloma (MM) is unsatisfactory. Similarly, the therapeutic outcome of acute and chronic myeloid leukaemia (AML, CML) is frequently dismal. At the same time, leukaemia/lymphoma cells represent ideal targets for immunotherapy. The present review summarizes our preclinical experience with a novel type of cytotoxic T cell based immunotherapy for B-lineage and myeloid tumours. Staphylococcal enterotoxin-derived superantigens (SAgs) are among the most potent T cell activators known, linking the T cell receptor to HLA-DR on natural target cells. SAgs were genetically engineered to reduce DR binding and were then fused to Fab parts of tumour-directed monoclonal antibodies (mAbs). Using these "targeted" SAgs, highly efficient lysis of B-lineage (B-NHL, B-CLL, ALL, MM) and myeloid (AML, CML) tumour cells by T-cells was achieved in vitro and in an animal model. We are entering an interesting era of innovative cancer therapy based on novel man-made biotherapeutic agents.

Molecular analysis of HLA-DQB1 alleles in childhood common acute lymphoblastic leukaemia.

Epidemiological studies suggest that childhood common acute lymphoblastic leukaemia (c-ALL) may be the rare outcome of early post-natal infection with a common infectious agent. One of the factors that may determine whether a child succumbs to c-ALL is how it responds to the candidate infection. Since immune responses to infection are under the partial control of (human leucocyte antigen) HLA genes, an association between an HLA allele and c-ALL could provide support for an infectious aetiology. To define the limit of c-ALL susceptibility within the HLA region, we have compared HLA-DQB1 allele frequencies in a cohort of 62 children with c-ALL with 76 newborn controls, using group-specific polymerase chain reaction (PCR) amplification, and single-strand conformation polymorphism (SSCP) analysis. We find that a significant excess of children with c-ALL type for DQB1*05 [relative risk (RR): 2.54, uncorrected P=0.038], and a marginal excess with DQB1*0501 (RR: 2.18; P=0.095). Only 3 of the 62 children with c-ALL have the other susceptibility allele, DPB1*0201 as well as DQB1*0501, whereas 15 had one or the other allele. This suggests that HLA-associated susceptibility may be determined independently by at least two loci, and is not due to linkage disequilibrium. The combined relative risk of the two groups of children with DPB1*0201 and/or DQB1*0501 is 2.76 (P=0.0076). Analysis of amino acids encoded by exon 2 of DQB1 reveal additional complexity, with significant (P<0.05) or borderline-significant increases in Gly26, His30, Val57, Glu66-Val67 encoding motifs in c-ALL compared with controls. Since these amino acids are not restricted to DQB1*0501, our results suggest that, as with DPB1, the increased risk of c-ALL associated with DQB1 is determined by specific amino acid encoding motifs rather than by an individual allele. These results also suggest that HLA-associated susceptibility to c-ALL may not be restricted to the region bounded by DPB1 and DQB1.

5.2#48 - Significant increase in HLA-A3 alleles in childhood common acute lymphoblastic leukaemia

5.2#48 - Significant increase in HLA-A3 alleles in childhood common acute lymphoblastic leukaemia

Favorable Prognosis of Hyperdiploid Common Acute Lymphoblastic Leukemia May Be Explained by Sensitivity to Antimetabolites and Other Drugs: Results of an In Vitro Study

DNA hyperdiploidy is a favorable prognostic factor in childhood acute lymphoblastic leukemia (ALL). The explanation for this prognostic significance is largely unknown. We have studied whether DNA ploidy was related to cellular resistance to 12 drugs, assessed with the methyl-thiazol-tetrazolium assay, in samples of 74 children with common (CD10+ precursor B-cell) ALL. Sixteen patients had hyperdiploid ALL cells and 58 patients had nonhyperdiploid ALL cells. Hyperdiploid ALL cells were more sensitive to mercaptopurine (median, 9.0-fold; P = .000003), to thioguanine (1.4-fold; P = .023), to cytarabine (1.8-fold; P = .016), and to I-asparaginase (19.5-fold; P = .022) than were nonhyperdiploid ALL cells. In contrast, these two ploidy groups did not differ significantly in resistance to prednisolone, dexamethasone, vincristine, vindesine, daunorubicin, doxorubicin, mitoxantrone, and teniposide. The percentage of S-phase cells was higher (P = .05) in the hyperdiploid ALL samples (median, 8.5%) than in the nonhyperdiploid ALL samples (median, 5.7%). However, the percentage of cells in S-phase was not significantly related to in vitro drug resistance. We conclude that the favorable prognosis associated with DNA hyperdiploidy in childhood common ALL may be explained by a relative sensitivity of hyperdiploid common ALL cells to antimetabolites, especially to mercaptopurine and to I-asparaginase.

Light chain ratios and concentrations of immunoglobulins G, A, and M in childhood common acute lymphoblastic leukemia.

The light chain ratios and the concentrations of immunoglobulin G (IgG), IgA, and IgM were measured before, during, and after antileukemic therapy in 10 patients with common acute lymphoblastic leukemia. The concentrations of IgG, IgA, and IgM decreased substantially during treatment but recovered slowly after cessation of the therapy. The light chain ratios were not systematically affected, but at diagnosis the kappa/lambda ratios of total serum Igs, IgG, and in particular IgM were somewhat lower in the patient group compared with an age-matched reference group. It is concluded that, despite a decrease in serum Ig concentrations, virtually normal kappa/lambda ratios are preserved, indicating that kappa and lambda syntheses are affected to the same extent. These ratios remained normal for age during the recovery of the serum Ig concentrations; the features as described for the development of the light chain ratios in childhood were not observed.

CD10 antigen density in childhood common acute lymphoblastic leukaemia: Comparisons of race and sex

During the 25 month period from July 1989 until August 1991, 58 children with FAB defined acute lymphoblastic leukaemia (ALL) were referred for immunophenotypic analysis. Of these, 42 children with a common/pre-B phenotype (CD19/CD10-positive) were studied specifically to assess CD10 antigen density. A pattern of segregation was found between males and females and between black and white children. Black males, who are the worst prognostic group, had the lowest CD10 density, while white females, known to constitute the best prognostic group, had significantly higher CD10 antigen density than the other groups. Black females and white males occupied intermediate positions with respect to CD10 antigen density. A two way analysis of variance showed that although sex had contributed significantly to this variation ( p = 0.0038), the contribution of race was marginal ( p = 0.0530). It is hypothesized that low CD10 antigen density patterns in males and in Blacks could be causally related to poor prognosis.

116 SENSITIVITY TO PURINE ANTAGONISTS IN CHILDHOOD LEUKEMIA ASSESSED BY THE AUTOMATED MTT-ASSAY

We showed that in childhood common acute lymphoblastic leukemia (c-ALL), 51 nucleotidase (5′NT) positive cases have a poorer prognosis than 5′NT negative cases. This might be due to the breakdown of the cytotoxic nucleotides of 6-mercaptopurine (6-MP) by high cytoplasmic 5′NT activities. Alternatively, ccto 5′NT can provide purine requirements of the purine salvage pathway and therefore rescue cells from a blockage of purine de novo synthesis by 6-MP and/or methotrexate. To test these hypotheses we need to determine the relation between these enzymes and drug sensitivity. We have adapted the MTT assay, which has only been reported on in studies dealing with established cell lines, to assess the chemosensitivity of cells obtained directly from patients. The assay is based on the reduction of MTT to formazan by living but not by dead cells. Formazan production is quantitated automatically with a microplate spectrophotometer. Incubation of ALL cells with 6-MP (4-125 μg/ml) and 6-thioguanine (1.6-50 μg/ml) for 2-4 days resulted in dose-response curves covering the range from 0% to 100%; cell survival. Comparison of the MTT assay with a dye exclusion assay in 10 patients with ALL demonstrated an identical success rate and comparable dose-response curves for both assays. Because automated quantitation of the chemosensitivity of leukemic cell samples involving about 80 drug concentrations takes only a few minutes with the MTT assay, this assay is a rapid, efficient, and objective method of measuring sensitivity to purine antagonists in ALL patients.

Leukemic Cell Lysis by Autologous Lymphocytes in Childhood ALL: Generation of Cytolysis by Lymphocytes Activated With Cultured Non T Non B Leukemic Cell Lines

AbstractThe lysis of leukemic cells by autologous lymphocytes was studied in the common type of acute lymphoblastic leukemia (ALL) in childhood using the 10‐hour51Cr release assay. Peripheral blood lymphocytes (PBL) from common ALL patients lysed autologous leukemic cells (% lysis: 19–45%), when co‐cultivated in vitro with cultured non T non B leukemic cell lines (NALM 16, Reh and NALL 1). The effector cells were cytotoxic T lymphocytes (CTL) possessing Leu‐1 and Leu‐2a antigens. The effector CTL were cytotoxic not only for autologous leukemic cells but for cultured non T non B leukemic cell lines, whereas they did not lyse human T cell (CCRF‐CEM), B cell (Daudi) and natural killer cell lines (SPI‐802). Cold target competition assays demonstrated that leukemic cells from childhood common ALL and several non T non B leukemic cell lines shared an antigenic determinant(s) recognized by CTL.

Further heterogeneity of childhood common acute lymphoblastic leukemia.

In an attempt to look further at the problem of heterogeneity, we have studied the immunoglobulin (Ig) gene organization in leukemic cells from 20 children with acute lymphoblastic leukemia (common ALL). Nineteen cases were divided into two subgroups: 12 cases with rearrangement of the Ig heavy (H) chain genes and 7 cases with rearrangement of both the Ig H and light (L) chain genes. No Ig gene rearrangement was found in one case. These findings indicate that there is more heterogeneity among patients with common ALL than has previously been believed.