3q21 and 3q26 cytogenetic abnormalities in acute myeloblastic leukemia: biological and clinical features.

BACKGROUND AND OBJECTIVE: Acute myeloblastic leukemia (AML) with features of myelodysplastic syndrome (MDS) and abnormalities of megakaryocytopoiesis is often characterized by cytogenetic aberrations of the 3q21 and 3q26 bands involving inv(3)(q21q26) and (3;3)(q21;q26). These aberrations have been described in all FAB subtypes with the exception of M3, and in MDS and in megakaryoblastic crisis of chronic myeloid leukemia. We reviewed the biological and clinical features of 10 cases of AML with inv(3)(q21q26) and t(3;3)(q21;q26). DESIGN AND METHODS: Four hundred and sixteen patients with AML were studied in our Institute by cytogenetic analysis and 10 (2.4%) showed inv(3)(q21q26) (7 patients) or t(3;3)(q21;q26) (3 patients): 7 males, 3 females; median age, 43.5 yrs. We also used RT-PCR to investigate the pattern of expression of the EVI-1 gene in 5 patients. RESULTS: Additional chromosomal changes were demonstrated in 6 patients. In 5/10 cases a preceding MDS had been observed. A possible occupational exposure was established in 2 patients (a farmer and an histologist employing organic solvents) and another patient had a therapy-related leukemia. AML subtype was M1 in 9 patients and M2 in 1. A variable excess of micromegakaryocytes was observed in all the patients. In 5 patients the platelet count was normal or increased (median number: 172. 5x10(9)/L; range 55-440). Expression of EVI-1 gene was present in all the 5 patients studied. The clinical course and outcome was extremely poor: 9/10 patients were resistant and 1 patient showed a partial remission after induction therapy. Of the 9 patients resistant to the first line chemotherapy, 7 were also resistant to the second line chemotherapy. Three patients obtained a morphologic complete remission after third line chemotherapy (duration 1, 3 and 6 months); 2 of them were submitted to autologous bone marrow transplantation, but relapsed after 1 and 3 months. The median overall survival was 5.5 months. INTERPRETATION AND CONCLUSIONS: Our findings evidence a strong correlation between 3q21q26 chromosomal aberrations, abnormalities of megakaryocytopoiesis and lack of response to conventional chemotherapy and support the diagnostic and prognostic relevance of chromosome characterization in the classification of AML.

Autologous peripheral blood stem cell transplantation in acute myeloblastic leukaemia and myelodysplastic syndrome patients: evaluation of tumour cell contamination of leukaphereses by cytogenetic and molecular methods.

We evaluated 18 acute myeloblastic leukaemia (AML) and myelodysplastic syndrome (MDS) patients with abnormal karyotype at diagnosis who underwent peripheral blood stem cell (PBSC) transplantation. To evaluate the presence of residual tumour cells, bone marrow (BM) samples and PBSC collections were analysed by cytogenetics and in selected cases also by fluorescence in situ hybridisation (FISH) and molecular studies. All patients were considered to be in morphologic and cytogenetic complete remission (CR) at the time of mobilisation. Seven patients showed neoplastic cells in PBSC harvest and/or BM specimen before reinfusion. Cytogenetic studies revealed contamination in apheretic collections in one patient only, while three patients had BM but not PBSC contamination. Three more patients had leukaemic cells both in the BM and PBSC. All but one (with only BM contamination) of these patients relapsed within 9 months. However, five more patients relapsed after transplantation: in four cases there was no cytogenetic sign of contamination either in PBSC or BM cells and in one case no molecular evidence was revealed either. This study suggests that, whereas the presence of leukaemic cells in autologous grafts correlates with a poor prognosis, the lack of detection of tumour cells is not always predictive of long-term disease-free survival. More importantly, PBSC collections from AML patients are not contaminated by leukaemic cells if the BM is disease-free.

Amplification of third-complementary-determining-region (CDR-III) of heavy chain immunoglobulin gene (IgH) in one hundred adult acute leukemias.

We applied a simple polymerase chain reaction (PCR) based method for detecting immunoglobulin heavy-chain (IgH) gene rearrangement, using its CDR-III region to assess B-cell clonality in a series of 100 acute lymphoblastic leukemias (ALL) (84 B-cell lineage, 4 null-ALL and 12 T-ALL). The amplified CDR-III regions can be generated in all the B-lineage ALL and separated by size by polyacrylamide gel electrophoresis (PAGE), thereby providing a specific diagnostic marker for each B cell clone. Size heterogeneity resulting from independent IgH rearrangement events and the high resolution power after electrophoresis and silver staining of the PAGE gels can be used to generate a "fingerprint" of the PCR fragments representing either the spectrum of B-cell clonality in complex populations of B lymphocytes or the partially genomic configuration of the VH-N-DH-N-JH region. At diagnosis, we found the presence of one clonal IgH heavy-chain gene rearrangement in 80 B-cell lineage and null ALL and a biclonal rearrangement in 8 cases. The CDR-III bands were of sizes ranging from 80 to 130 bp. The PCR analysis of the IgH gene enabled us to obtain a CDR-III leukemia specific product in all cases, thereby providing a specific and diagnostic marker for each B-cell clone.

Detection of occasional and clonal chromosome aberrations in patients with acute non-lymphocytic leukemia after autologous bone marrow transplantation.

Clonal chromosome aberrations observed in patients who have relapsed after autologous bone marrow transplantation (ABMT) are usually related to the cytogenetic abnormalities observed at diagnosis. In order to assess this relationship, we evaluated 30 acute non-lymphocytic leukemia (ANLL) patients who underwent ABMT at out institution and had evaluable serial cytogenetic studies before and after ABMT. Seventeen patients (57%) showed no chromosome aberrations after ABMT in any of the studies performed, while 13 patients (43%) carried abnormalities. In eight out of 30 patients (27%0 the abnormal karyotype after ABMT was associated with hematologic relapse. The cytogenetic abnormalities were: (1) the same as at diagnosis without additional abnormalities in five patients; (2) the same as at diagnosis but with additional abnormalities in three patients. In one patient a different karyotype from that of diagnosis was detected and a myelodysplastic syndrome was clinically evaluable. Furthermore, occasional and single cell chromosome abnormalities were observed in four patients (13%), none of whom relapsed. The new and additional clonal cytogenetic abnormalities observed after ABMT were found in eight patients (27%), suggesting that this event may not be so frequent, that is presumably associated regimen. The re-appearance of the chromosome aberrations after ABMT and the relationship with the risk of relapse are discussed.

A new method of "in-cell reverse transcriptase-polymerase chain reaction" for the detection of BCR/ABL transcript in chronic myeloid leukemia patients.

Methods of detecting minimal residual disease (MRD) in chronic myeloid leukemia (CML) include chromosome analysis, Southern blotting, polymerase chain reaction (PCR) and fluorescent in situ hybridization (FISH) techniques. We report a novel method to detect intracellular messenger RNA (mRNA) by combining the techniques of reverse transcription (RT) and PCR performed directly inside the cells, without extraction of the nucleic acid. We applied this method, which we call "in-cell RT-PCR", to detect hybrid BCR/ABL transcript within single cells. After cellular permeabilization and fixation of single cells in suspension, the neoplastic mRNA was reverse transcribed into cDNA, and the cDNA was amplified by PCR with fluorescent primers, specific for bcr/abl. Flow cytometry was used to detect cells positive for the amplified DNA within the cell cytoplasm. After transferring the amplified cells onto slides by cytospin, the positive cells for BCR/ABL cDNA were observed by fluorescent microscopy. The technique was capable of detecting low abundancy signals and distinguishing different levels of gene expression. The amplification products were found in the cells and supernatants. The distribution was critically affected by the protease digestion condition. The specificity of amplification was confirmed by a nested RT-PCR of BCR/ABL performed on extracted mRNA from the same sample, and by reamplification of supernatants. We have used the technique to study 10 Ph+ CML patients and three normal subjects as controls. Four patients were 100% Ph+ at diagnosis time and RT-PCR+ at cytogenetic and molecular analysis, respectively. In-cell RT-PCR showed that the residual non-neoplastic cells could be observed in all cases. In two patients undergoing interferon-alpha (IFN-alpha) therapy and in four bone-marrow transplanted patients, the in-cell RT-PCR was used to compare the level of Ph+ positivity detected by cytogenetic analysis with the number of cells expressing BCR/ABL transcript. In this manner, we could estimate the MRD. Our preliminary application of the technique suggests that it is capable of accurately identifying cells transcribing bcr/abl, and that it may have significant clinical applications in the detection of MRD.

Four-chromosomes complex translocations in acute promyelocytic leukemia: description of two cases.

Two cases of acute promyelocytic leukemia with variant translocation involving 4 chromosomes are described. The karyotypes were 47,XX, +8,t(13;15;17;20)(q22;q22;q12;q13) and 46,XY,t(5;15;16;17)(q22;q22;p13;q12), respectively. Variant translocations in APL apparently do not follow any preferential routes since no recurrent breakpoint additional to those of chromosomes 15 and 17 has been found in any of the cases reported in the literature and in those described here. Moreover, it seems that the translocation of the RAR alpha gene from chromosome 17 to chromosome 15 is directly involved in the pathogenesis of the disease, while the reciprocal one is not, as demonstrated by variant translocations where 15q migrates to chromosomes other than 17.

FLAG (fludarabine+cytosine arabinoside+G-CSF) induces complete remission in acute-phase chronic myeloid leukaemia: a case report.

The adenine nucleoside analogue fludarabine phosphate in combination with cytosine-arabinoside (Ara-C) and granulocyte-colony stimulating factor (G-CSF) has recently proved effective in the treatment of poor-prognosis acute non-lymphoid leukaemia. We used this triple combination in a case of Ph1+ chronic myeloid leukaemia (CML) unresponsive to alpha interferon that had progressed to acute phase after 5 months of treatment with 6-mercaptopurine plus hydroxyurea. The patient was treated with four courses of fludarabine 30 mg/m2 + Ara-C 2 g/m2 (days 1-5) and G-CSF (from day 0 to polymorphonuclear (PMN) recovery). Bone marrow blasts decreased from 80% to less than 5%, and karyotyping showed a progressive clearance of Ph1+ metaphases (from 100% to 9% after the fourth course). The patient is presently receiving autologous bone marrow transplantation (ABMT). This therapeutic success in a patient for whom conventional treatment would usually be ineffective makes this combination worthy of further studies, in view of its wider use as a preparative regimen to ABMT in CML.

t(8;14)(q11;q32) in acute lymphoid leukemia: description of two cases.

An 8;14 chromosome translocation with breakpoints at q11 and q32, respectively, is described as the sole abnormality in bone marrow cells of two adult patients with common acute lymphoblastic leukemia (ALL). The Southern blot analysis revealed a rearrangement after BamHI and HindIII digestion and hybridization with a JH probe, thus demonstrating the involvement of the gene coding for the heavy chains of the immunoglobulins (IgH). Therefore, a pathogenetic mechanism similar to that observed in Burkitt's lymphoma and its variants, or in other lymphomas with t(11;14) or t(14;18), may be hypothesized. In all these cases IgH is juxtaposed to an oncogene (c-MYC, BCL-1, and BCL-2, respectively). A similar structure, with oncogene type potential, could be present on 8q11. The patients underwent a complete remission after induction therapy.