Flow cytometry in the diagnosis and classification of malignant lymphoma and leukemia

DNA content and light scatter were measured by flow cytometry (FCM) in 103 patients including 43 patients with non-Hodgkin's lymphoma (NHL), eight patients with Hodgkin's disease (HD), 17 patients with acute lymphoblastic leukemia (ALL), ten patients with acute nonlymphocytic leukemia (ANLL), and 25 patients with chronic lymphoid leukemias. Controls consisted of 42 nonneoplastic specimens obtained from lymph nodes, spleen, bone marrow, and peripheral blood. Each specimen was analyzed after staining with a hypotonic solution of propidium iodide using nuclei isolated from chicken erythrocytes as an internal standard. The DNA content and light scatter of the human populations was expressed as a ratio between the DNA content (or light scatter) of the human G0--G1 cells and that of the chicken erythrocytes nuclei. The mean DNA ratio for the 42 nonneoplastic samples was 2.58 +/- 0.045 (SD). In these samples the DNA coefficient of variation of the human G0--G1 peak ranged from 1.48--3.28% (mean, 2.33 +/- 0.54%). The FCM data in the NHL was compared to morphologic diagnoses made according to the "working formulation of NHL for clinical usage" recently proposed by a panel of international experts. Eight of 17 (47%) low grade NHL, one of two (50%) mycosis fungoides, ten of 14 (71%) intermediate grade NHL, nine of ten (90%) high grade NHL, nine of 17 (53%) ALL, three of ten (30%) ANLL, and seven of 25 (28%) chronic lymphoid leukemias had abnormal DNA ratios indicative of aneuploidy. In addition, several cases had normal DNA ratios but G0--G1 coefficients of variation outside of the normal range. All cases of HD had normal DNA values except one case with a small percentage of near tetraploid cells. The mean percentage of cells with S-phase DNA content for the low grade NHL (2.2 +/- 0.8%) was significantly lower than that of the intermediate grade NHL (12.1 +/- 4.9%; P less than 0.0001). The mean S-phase value for the intermediate grade NHL was significantly lower than that of the high grade NHL (22.6 +/- 11.1%; P less than 0.001). The three prognostic categories of NHL designated by the new formulation were clearly distinguishable by the FCM data. Light scatter was not particularly useful for distinguishing nonneoplastic from neoplastic populations. The mean light scatter coefficient of variation of the ALL (15.2%) was significantly lower than that of ANLL (20.5%), however (P less than 0.04).     

Streptococcal erythrogenic toxin spe A gene detection by polymerase chain reaction in strains isolated in Albania

A considerable proportion of cases of myeloproliferative and lymphoproliferative disorders exhibit renal involvement. However, it is unclear whether the cytologic features, immunophenotype or grade of malignancy of the cells infiltrating the kidney differ from those of the primary tumor. This study was performed on 120 autopsy cases with the following diagnoses: acute myelogenous leukemia (AML, n = 22; subtypes M1 + M2, n = 12, subtype M4, n = 10), chronic myelogenous leukemia (CML, n = 7), agnogenic myeloid metaplasia/myelofibrosis (AMM/MF, n = 6), acute lymphocytic leukemia (ALL, n = 6), chronic lymphocytic leukemia (CLL, n = 9), other low-grade non-Hodgkin's lymphomas (low-grade NHL, n = 24), high-grade NHL (n = 21) and multiple myeloma (MM, n = 25). Renal involvement was investigated by light microscopy and immunohistochemistry. It was found in 34% of the cases, and was most common in ALL (83%) and low-grade NHL (50%) and least common in high-grade NHL (10%) and MM (12%). Dense infiltration of almost the entire kidney was most commonly seen in AML, low-grade NHL and ALL. Infiltration was bilateral and involved both the cortex and medulla in the majority of cases. When involvement of other organs was compared with that of the kidney, the lung was found to be involved in approximately the same number of cases, but liver involvement was more common and heart involvement less common. Reactive lymphocytic infiltration of the kidney was found in 18 of the 120 cases (15%), and was distinguished from scanty tumorous infiltration by immunohistochemical staining. No major phenotypical differences were found between the tumor cells infiltrating the kidney and those of the primary tumors in the bone marrow or lymph nodes. However, in one case of CML, the cells infiltrating the kidney were negative for KP1 and chloroacetate esterase, but could be identified by reactivity for CD34. The grade of malignancy in NHL was similar in both the nodal and renal manifestations.     

Expression of VLA molecules on acute leukemia cells: relationship with disease characteristics

VLA molecules are involved in the adhesion of hematopoietic cells to the bone marrow stroma and play a role in the mediation of cellular interactions and migrations that are potentially important in the biology of acute leukemia (AL). We studied the expression of VLA-2 (CD49b), VLA-4 (CD49d), and VLA-5 (CD49e) by indirect immunofluorescence on leukemic cells from 67 patients with acute myelogenous leukemia (AML) and 40 patients with acute lymphoblastic leukemia (ALL). VLA-2, VLA-4, and VLA-5 were expressed, respectively, on 13 +/- 17%, 33 +/- 29%, and 36 +/- 30% of AML cells with 20, 54 and 61% positive cases and on 22 +/- 27%, 40 +/- 30%, and 39 +/- 29% of ALL cells with 29, 60, and 61% positive cases. Significant difference was neither noted between French-American-British (FAB) subtypes in AML or ALL nor between immunologic subtypes in ALL. There were highly significant correlations between the expression of the three beta 1-integrins tested in both AML and ALL. In AML, expression of both VLA-4 and VLA-5 was associated with that of CD14 (p = 0.003 and p = 0.01, respectively) and CD19 (p = 0.006 and p = 0.009, respectively). Expression of VLA-5 was correlated with that of CD15 (p = 0.004). Expression of VLA-4 was associated with both a high initial blast cell count (p = 0.01) and high percentage of bone marrow blast cell involvement (p = 0.003). In ALL, expression of VLA molecules was correlated neither with differentiation antigen nor with hematologic features. In AML, as in ALL, no significant correlation was noted between expression of VLA molecules and evolution of the disease.     

c-Cbl tyrosine phosphorylation and subcellular localization in human primary leukemic cells

Several studies indicate that a number of signal-transducing molecules involved in the proliferation, differentiation, and functional activation of normal hemopoietic cells may be constitutively activated in primary leukemic cells and play a role in the outcome or in the progression of these neoplastic disorders. In this study we show that the product of the proto-oncogene c-Cbl, whose function is still unknown, is constitutively tyrosine phosphorylated not only in cells from chronic myelogenous leukemias (CMLs) in the blast phase, but also in cells from acute myeloblastic leukemias (AMLs), Ph-negative acute T-lymphoblastic leukemias (T-ALLs), and Ph-negative pre-B lymphoblastic leukemias (pre-B ALL). Moreover, in acute leukemia cells, c-Cbl was not stably complexed with the tyrosine-phosphorylated adaptor protein CrkL. The analysis of Grb2/c-Cbl interaction demonstrated that, in both acute leukemia and CML blasts, c-Cbl was stably complexed with the N-terminal Src homology (SH) 3 domain of Grb2 and, in blasts from ALL patients, with the Grb2 SH2 domain. The analysis of c-Cbl subcellular distribution showed that in all cases of leukemia tested, as well as in growth factor-stimulated M-07e cells, c-Cbl was present in the cytosolic, in the membrane, and in the detergent-insoluble fractions. Finally, in polymorphonuclear neutrophils (PMNs) from CML patients, c-Cbl was found stably associated with the detergent-insoluble fraction, whereas in PMNs from normal donors, it was detected only in the cytosolic fraction. Our findings that c-Cbl is constitutively tyrosine phosphorylated and associated with the detergent-insoluble fraction in AML and ALL blasts and in PMNs from CML patients suggest that this event represents a common step in the neoplastic transformation of both myeloid and lymphoid progenitor cells.     

Internal tandem duplication of the FLT3 gene is preferentially seen in acute myeloid leukemia and myelodysplastic syndrome among various hematological malignancies. A study on a large series of patients and cell lines

In this study, we examined a large number of patients to clarify the distribution and frequency of a recently described FLT3 tandem duplication among hematopoietic malignancies, including 112 acute myelocytic leukemia (AML), 55 acute lymphoblastic leukemia (ALL), 37 myelodysplastic syndrome (MDS), 20 chronic myelogenous leukemia (CML), 30 non-Hodgkin's lymphoma (NHL), 14 adult T cell leukemia, 15 chronic lymphocytic leukemia (CLL) and 38 multiple myeloma (MM). We also evaluated 71 cell lines derived from 11 AML, 31 ALL, two hairy cell leukemia, three acute unclassified leukemia, 10 CML, 12 NHL including six Burkitt's lymphoma, and two MM. Using genomic PCR of exon 11 coding for the juxtamembrane (JM) domain and first amino acids of the 5'-tyrosine kinase (TK) domain, this length mutation was found only in AML (22/112, 20%) and MDS (1/37). According to the FAB subclassification, they were 5/18 (28%) of M1, 4/29 (14%) of M2, 3/17 (18%) of M3, 6/24 (25%) of M4, 4/20 (20%) of M5 and 1/9 of refractory anemia with excess of blast in transformation. In the various cell lines examined, this abnormality was determined in only one derived from AML and never found in other hematological malignancies. The sequence analysis of the abnormal PCR products revealed that 23 of 24 showed internal tandem duplication with or without insertion of nucleotides. In one AML, insertion and deletion without duplication was determined. All 24 lengthened sequences were in-frame. Duplication takes place in the sequence coding for the JM domain and leaves the TK domain intact. In conclusion, we emphasize that the length mutation of FLT3 at JM/TK-I domains were restricted to AML and MDS. Since all these mutations resulted in in-frame, this abnormality might function for the proliferation of leukemic cells.     

Cellular characteristics of acute leukemia cells simultaneously expressing CD13/CD33, CD7 and CD19

Of 832 acute leukemia patients, including 580 acute myeloblastic leukemia (AML), 197 pre-B acute lymphoblastic leukemia (ALL) and 55 pre-T ALL, 26 cases (3.1%) of CD13/CD33+CD7+CD19+ acute leukemia were found. A total of 20 patients were diagnosed as AML, two as pre-B ALL and four as pre-T ALL. Based on the relative intensity of expression of CD7 and CD19, CD13/CD33+CD7+CD19+ acute leukemia patients were subclassified into three categories. Type I (CD7 > CD19) included ten AML and four pre-T ALL, having cellular characteristics similar to CD7+ AML and CD13/CD33+CD7+ ALL. Type II (CD7 < CD19) consisted of four AML with t(8;21) and two pre-B ALL. Type III (CD7 = CD19) included six AML. CD13/CD33+CD7+CD19+ acute leukemia frequently expressed stem cell associated molecules, such as CD34 (88.5%), HLA-DR (96.2%) and mRNA for MDR1 (72.2%), GATA-2 (87.5%) and SCL (25.0%). Simultaneous expression of cytoplasmic CD3 and myeloperoxidase in some leukemia cells implies that CD13/CD33+CD7+CD19+ acute leukemia cells have the potential to differentiate into various lineages. These data suggest that a small population of acute leukemia patients with distinct phenotype, CD13/CD33+CD7+CD19+ acute leukemia, may originate from hematopoietic stem cells.     

Deletions of the short arm of chromosome 9, including the interferon-alpha/-beta genes, in acute lymphocytic leukemia. Studies on loss of heterozygosity, parental origin of deleted genes and prognosis

A restriction fragment length polymorphism (RFLP) analysis of the alpha- and beta-interferon (IFN) genes was performed in malignant cells from 52 patients with acute lymphocytic leukemia (ALL). Normal cell DNA was available for comparison in 23 of the patients. Ten patients were found to have gross alterations of their alpha- and beta-IFN genes. Leukemic cells from 2 ALL patients showed a complete loss of alpha- and beta-IFN genes. Seven patients had a hemizygous loss of one of the alpha- and beta-IFN alleles, as shown by RFLP analysis and/or loss of signal intensity. In one other patient the malignant clone was reduced to homozygosity with regard to the alpha- and beta-IFN genes, without loss of signal intensity. In patients without hemizygous deletions, the overall incidence of complete homozygosity for the alpha- and beta polymorphisms was higher than expected. Analysis of the data indicates that the total frequency of ALL clones with gross alterations of the IFN-loci is around 30%. A 9p24 probe detected hemizygous deletions in 2 cases of IFN gene deletions. In the other tested cases the deletions were interstitial. No deletions of 9p24 were detected in patients without allelic losses of IFN genes. In 5 cases of allelic IFN gene deletions, DNA from parents was available for comparison. In 4 cases the deleted allele was derived from the mother, whereas in the fifth it originated from the father. Pediatric ALL patients with IFN-gene deletions or homozygosity for all polymorphisms in the IFN-loci had a significantly worse prognosis than heterozygotes. We conclude that deletion of alpha- and beta-IFN genes is a relatively common event in ALL and that RFLP analysis of the IFN genes may provide additional prognostic information in childhood ALL. Whether or not the IFNs act as tumor-suppressor genes in this disease is not yet known.     

A single subtype of Epstein-Barr virus in members of multiple sclerosis clusters

In the blast cells of children with acute lymphoblastic leukemia (ALL) more than 50 chromosomes can be observed in a quarter of cases. As a rule these children have a good prognosis. However, some of these patients develop a relapse of their basic disease. There is only poor information about the significance of distinct additional chromosomes for the prognosis. The white blood cell count (WBC) at the time of diagnosis is a further very important prognostic factor in childhood ALL. Therefore we compared the relation between trisomy of distinct chromosomes and the initial white blood cell count of 41 children with common ALL and hyperdiploid karyotype. The modal chromosome number ranged from 50 to 60 chromosomes. Most frequently, the chromosomes X, 4, 6, 8, 10, 17, 18 and 21 were multiplied. Additionally, in 25 of the 41 cases structural chromosome aberrations were observed. The average WBC was estimated as 9.6 Gpt/l with a range from 1.8 to 41.5 Gpt/l. The initial WBC was slightly increased in patients with the additional chromosome X, 6, 11, 12 or 19 and distinctly decreased in children with the additional chromosome 8 or 9 in their hyperdiploid blast cells. No patient with an additional Chromosome 9 showed a WBC higher than 10 Gpt/l and only 2 out of the 12 children with an additional chromosome 8 revealed an initial WBC higher than 10 Gpt/l. Additional structural chromosome aberrations were without influence on the WBC.     

Expression of FLT3 receptor and response to FLT3 ligand by leukemic cells

The novel hematopoietic growth factor FLT3 ligand (FL) is the cognate ligand for the FLT3, tyrosine kinase receptor (R), also referred to as FLK-2 and STK-1. The FLT3R belongs to a family of receptor tyrosine kinases involved in hematopoiesis that also includes KIT, the receptor for SCF (stem cell factor), and FMS. the receptor for M-CSF (macrophage colony- stimulating factor). Restricted FLT3R expression was seen on human and murine hematopoietic progenitor cells. In functional assays recombinant FL stimulated the proliferation and colony formation of human hematopoietic progenitor cells, i.e. CD34+ cord and peripheral blood, bone marrow and fetal liver cells. Synergy was reported for co-stimulation with G-CSF (granulocyte-CSF). GM-CSF (granulocyte-macrophage CSF), M-CSF, interleukin-3 (IL-3), PIXY-321 (an IL-3/GM-CSF fusion protein) and SCF. In the mouse, FL potently enhanced growth of various types of progenitor/precursor cells in synergy with G-CSF, GM-CSF, M-CSF, IL-3, IL-6, IL-7, IL-11, IL-12 and SCF. The well-documented involvement of this ligand-receptor pair in physiological hematopoiesis brought forth the question whether FLT3R and FL might also have a role in the pathobiology of leukemia. At the mRNA level FLT3R was expressed by most (80-100%) cases of AML (acute myeloid leukemia) throughout the different morphological subtypes (MO-M7), of ALL(acute lymphoblastic leukemia) of the immunological subtypes T-ALL and BCP-ALL (B cell precursor ALL including pre-pre B-ALL, cALL and pre B-ALL), of AMLL (acute mixed-lineage leukemia), and of CML (chronic myeloid leukemia) in lymphoid or mixed blast crisis. Analysis of cell surface expression of FLT3R by flow cytometry confirmed these observations for AML (66% positivity when the data from all studies are combined), BCP-ALL (64%) and CML lymphoid blast crisis (86%) whereas less than 30% of T-ALL were FLT3R+. The myeloid, monocytic and pre B cell type categories also contained the highest proportions of FLT3R+ leukemia cell lines . In contrast to the selective expression of the receptor, FL expression was detected in 90-100% of the various cell types of leukemia cell lines from all hematopoietic cell lineages. The potential of FL to induce proliferation of leukemia cells in vitro was also examined in primary and continuously cultured leukemia cells. The data on FL-stimulated leukemia cell growth underline the extensive heterogeneity of primary AML and ALL samples in terms of cytokine-inducible DNA synthesis that has been seen with other effective cytokines. While the majority of T-ALL (0-33% of the cases responded proliferatively; mean 11%) and BCP-ALL (0-30%; mean 20%) failed to proliferate in the presence of FL despite strong expression of surface FLT3R, FL caused a proliferative response in a significantly higher percentage of AML cases (22-90%; mean 53%). In the panel of leukemia cell lines examined only myeloid and monocytic growth factor- dependent cell lines increased their proliferation upon incubation with FL, whereas all growth factor-independent cell lines were refractory to stimulation. Combinations of FL with G-CSF, GM-CSF, M-CSF, IL-3, PIXY- 321 or SCF and FL with IL-3 or IL-7 had synergistic or additive mitogenic effects on primary AML and ALL cells, respectively. The potent stimulation of the myelomonocytic cell lines was further augmented by addition of bFGF (basic fibroblast growth factor), GM-CSF, IL-3 or SCF. The inhibitory effects of TGF-beta 1 (transforming growth factor-beta 1) on FL- supported proliferation were abrogated by bFGF. Taken together, these results demonstrate the expression of functional FLT3R capable of mediating FL- dependent mitogenic signaling in a subset of AML and ALL cases further underline the heterogeneity of AML and ALL samples in their proliferative response to cytokine.     

Useful panel of antibodies for the classification of acute leukemia by immunohistochemical methods in bone marrow trephine biopsy specimens

To evaluate the feasibility of acute leukemia typing on routinely processed bone marrow biopsy specimens, 72 cases of previously established acute leukemia covering the spectrum of 17 known subtypes were studied immunohistochemically. Most leukemic myeloblasts were positive for myeloperoxidase in 16 (84%) of 19 cases of acute myeloid leukemia, M1-M4, and M6. Most leukemic cells in 11 of 12 M4 and M5 cases were positive for CD68 (PG-M1). All six M6 cases stained with hemoglobin. Leukemic megakaryoblasts in three of four M7 cases were positive for factor VIII-related antigen. Almost all leukemic cells of 8 T-lineage acute lymphoblastic leukemia (ALL) and 19 B-lineage ALL cases were positive for CD3 and CD79a (HM57), respectively. Staining with CD20 (L26) was positive in the more differentiated B-lineage ALL cases and strongest in L3. Immunohistochemical typing of acute leukemia is possible for most types using this panel of cell lineage-specific antibodies.     

Ultrastructural localization of DNA in leukemic cells using osmium ammine B

In order to determine whether there were any differences in distribution of nuclear DNA between acute lymphocytic leukemia (ALL) and acute myelogenous leukemia (AML), the localization of DNA in blasts from the bone marrow or buffy coat of 30 patients with ALL and 30 patients with AML was examined ultrastructurally by staining with osmium ammine B. By the ultrastructural cytochemistry, DNA in ALL cells was clumped in the nuclei, while in AML cells, it was dispersed. DNA had accumulated around the nucleoli of some blasts, and flecks of DNA were observed in nucleoli of a majority of blasts. The perinucleolar and intranucleolar DNA distribution could be classified into four types. The types with abundant perinucleolar DNA were frequently observed in ALL blasts, while the majority of AML blasts showed scant perinucleolar DNA. The types with intranucleolar flecks of DNA were more prominent in leukemic cells than in normal immature leukocytes. In conclusion, the pattern of distribution of DNA in the nuclei of leukemic cells differs between ALL and AML.     

Prognostic value of P-glycoprotein and leukocyte differentiation antigens in chronic myeloid leukemia

P-glycoprotein (Pgp) mediated multidrug resistance is often the cause of therapy failure in some tumors. Pgp expression was shown to have prognostic value in several hematological malignancies, especially in acute myeloblastic leukemia (AML) and acute lymphoblastic leukemia (ALL). In chronic myeloid leukemia (CML) Pgp is expressed by peripheral blood (PB) cells more often in the terminal disease stages (20-50% of patients have Pgp+ phenotype). Sequential studies show that Pgp+ cells often disappear from the PB during the course of therapy. Nevertheless Pgp expression has some prognostic value in blast crisis (BC) predicting shorter BC, while CD13 has the same predictive value in BC. 10% of patients formed a distinct group with large numbers of Pgp+CD34+ blasts in the PB and also had shorter BC. Cases with inactive Pgp were found in chronic and accelerated phases of CML but not in BC.     

Continuous infusion etoposide/carboplatin for treatment of refractory acute leukemia

Etoposide (125 mg/m2/d) and carboplatin (200 mg/m2/d) were administered by continuous 5-day intravenous infusion to 10 patients with relapsed or refractory acute leukemia (7 ANLL, 1 ALL, 2 blast crisis of CGL). No complete or partial response was observed despite dose-limiting toxicity characterized by severe diarrhea in four patients and neutropenic colitis in two additional cases. We cannot recommend the present schedule of drug administration for the treatment of acute leukemia.     

Differential CD95 expression and function in T and B lineage acute lymphoblastic leukemia cells

CD95 (Fas/APO-1) is a cell surface receptor able to trigger apoptosis in a variety of cell types. The expression and function of the CD95 antigen on leukemic blasts from 42 patients with B lineage and 53 patients with T lineage acute lymphoblastic leukemia (ALL) were investigated using immunofluorescence staining and apoptosis assays. The CD95 surface antigen was expressed in most ALL cases, with the T lineage ALL usually showing a higher intensity of surface CD95 expression as compared with the B lineage ALL cells (relative fluorescence intensity, RFI: 4.8 +/- 0.47 vs 2.2 +/- 0.23, respectively, P < 0.01). Functional studies disclosed that upon oligomerization by anti-CD95 monoclonal antibodies the CD95 protein was either not able to initiate apoptosis of leukemic cells (75% of cases) or induced low rates of apoptosis (20% of cases). Only in 5% of cases did the apoptosis rate exceed the 20% level of the CD95-specific apoptosis. Most of the CD95-sensitive cases were found among T lineage ALLs (38% of T lineage vs 10% of B lineage ALLs). Overall, the extent of CD95-induced apoptosis did not correlate with the expression level of CD95. Similarly, no significant correlation between expression level and functionality of CD95 in human leukemia cell lines of B and T cell origin could be observed. Bcl-2 protein has been associated with prolonged cell survival and has been shown to block partially CD95-mediated apoptosis, but for ALL cells no correlation between bcl-2 expression and spontaneous or CD95-mediated apoptosis could be found. The results obtained in this study indicate that, despite constitutive expression of CD95, the ALL cells are mainly resistant to CD95-triggering. More detailed investigations of the molecular mechanisms involved in the intracellular apoptotic signal transduction, such as interactions of the bcl-2 and the other members of the bcl-2 family, and functionality of the interleukin-1beta converting enzyme (ICE) like-proteases, may give new insights into key events responsible for the resistance or sensitivity to the induction of apoptosis in acute leukemia.     

O-acetyl sialic acid binding lectin as a probe for detection of subtle change on cell surface induced during acute lymphoblastic leukemia (ALL) and its clinical application

A novel probe, a 9-O-acetylated sialic acid binding lectin, namely achatininH (ATNH) has been used for the detection of changes on the cell surface during acute lymphoblastic leukemia (ALL). ATNH does not agglutinate normal human erythrocytes, however it is capable of agglutinating erythrocytes and peripheral blood mononuclear cells (PBMC) of patients suffering from ALL. The differential expression of a key receptor, 9-O-acetylated sialo glyco conjugate (9-O-AcSG), on PBMC was observed using a simple lymphoproliferative assay (LA). The extent of expression of 9-O-AcSG was used as an index to distinguish ALL patients of different clinical stages and assess the probability of relapse. The amount of ATNH needed for maximum stimulation served as a tool to indirectly measure the extent of expression of 9-O-AcSG on PBMC surface. The acetylated sialo glycoconjugate was expressed at a very high concentration during acute phase of the disease. Subsequently it decreased during treatment persisted during maintenance therapy and reappeared with relapse. PBMC of normal human donors required 80 times more ATNH in comparison to the untreated acute phase ALL patients. No cross reactivity was found in non Hodgkin's lymphoma, chronic myelogenous leukemia and thalassaemia patients.     

The effect of cytokines, including IL4, IL7, stem cell factor, insulin-like growth factor on childhood acute lymphoblastic leukemia

We have investigated the effects of some interleukins, such as interleukin (IL) 4, IL7, stem cell factor (SCF) and insulin-like growth factor (IGF-1), known to be involved in human lymphopoiesis, on proliferation, clonal growth and differentiation of cells from two acute lymphoblastic leukemia (ALL) derived pre-B cell lines, that is, Nalm 1, Nalm 6 and purified blasts from 37 childhood ALL. IL4 did not display any promoting activity, an inhibitory effect being observed in two patients. IL7 showed an heterogeneous responsiveness, not related to immunophenotype or cytogenetic features, proliferation and clonal growth being observed in a minority of ALL. In other patients no or even inhibitory effects on proliferation were observed. In one case this inhibition of DNA synthesis was accompanied by maturation of the cells, as demonstrated by the induced expression of surface immunoglobulins (slg); other IL7 treated samples failed to express slg, but showed a decreased expression of terminal deoxynucleotidyl transferase and cALL antigen, suggesting that the cells have a potential of limited maturation by IL7. SCF, known to synergize with IL7 in the most primitive stages of normal B cell development, did not enhance the IL7 response in B cell precursor ALL. Finally IGF-1 failed to induce a proliferative response and clonal growth in BCP ALL either alone or in combination with IL7.     

Epipodophyllotoxin-related acute myeloid leukemia: a study of 35 cases

To define better the risk of epipodophyllotoxin-related acute myeloid leukemia (AML) after extended follow-up and to assess responses to intensive salvage therapy, all patients who developed this complication after treatment for acute lymphoblastic leukemia (ALL) or non-Hodgkin lymphoma (NHL) in consecutive clinical trials at St Jude Children's Research Hospital from 1979 to 1994 were studied. Cases with 'lineage switch' or 'clonal selection' were excluded. Epipodophyllotoxin-related AML developed in 32 of 1140 patients treated for ALL and in three of 332 treated for NHL; it was a first adverse event in 25 and two cases, respectively. The complication was diagnosed at 12-130 months (median 34 months) after the initiation of treatment with epipodophyllotoxins; all but one of the cases occurred within 73 months, indicating that the risk is negligible after 6 years. The predominant karyotypic feature was 11q23 translocations (71% of cases); 21q22 rearrangements were rare. In a stepwise Cox regression analysis, two factors increased the risk of this complication: weekly or twice weekly administration of epipodophyllotoxins (P < 0.001); and the administration of asparaginase immediately before epipodophyllotoxin therapy (P < 0.001). Initial responses to salvage therapy were comparable to those reported for de novo AML: 92% of the evaluable patients entered complete remission after combination treatment. Single-agent therapy with 2-chlorodeoxyadenosine induced complete or partial remissions in one-half of the patients treated. The long-term survival rate was dismal. Of the 17 evaluable patients treated exclusively with chemotherapy, only one is alive at 84 months, compared to three of 16 patients who underwent bone marrow transplantation (alive at 10, 23 and 73 months). Cases of epipodophyllotoxin-related AML constitute a unique clinical syndrome that will require innovative strategies for cure.