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Biomedical subjects

P Corradini

Publications and source records attributed to P Corradini.

At least 55 records · Page 3Linked to original sources
PubMed1997

Multiple myeloma: reduced plasma cell contamination in peripheral blood progenitor cell collections performed after repeated high-dose chemotherapy courses.

The possibility of reducing tumour cell contamination by cytotoxic drug courses prior to peripheral blood progenitor cell (PBPC) collection was evaluated in two consecutives groups of multiple myeloma (MM) patient candidates for autograft. All patients were at disease onset and received two VAD (vincristine, doxorubicin and dexamethasone) courses as initial debulking. In the first group (44 patients), mobilization and harvest were performed 'upfront', after a single cyclophosphamide (CY) administration of 4 g/m2; in the second group (17 patients), PBPC were collected at the end of a high-dose sequential chemotherapy programme, including: CY 5 g/m2, etoposide (VP16) 2 g/m2, a chemotherapy-free interval with three courses of high-dose dexamethasone, a final mobilizing CY at 7 g/m2. G-CSF was given following each high-dose cytotoxic drug. Cytofluorimetric analysis was performed to quantify progenitors (CD34+ cells) and plasma cells, identified by the high CD38 expression and/or CD38 and CD138 coexpression. Large amounts of PBPC were collected in either group (median harvested CD34+/kg: 15.8 x 10(6) and 13.4 x 10(6), respectively; P=0.9). Circulating plasma cells were significantly higher in patients mobilized 'upfront' compared to those who received the high-dose sequence (median peak values of CD38bright/microl: 39 and 10, respectively; P=0.02); a similar difference was observed in the amount of contaminating plasma cells in the harvest products (median CD38bright/kg: 7.4 x 10(6) and 1.3 x 10(6), respectively; P=0.02). The results demonstrate that an in vivo purging approach is feasible in myeloma patients through repeated high-dose chemotherapy courses; this may provide less-contaminated material suitable for further in vitro purging procedures.

Adult↗
PubMed1996

Eradication of polymerase chain reaction-detectable chronic lymphocytic leukemia cells is associated with improved outcome after bone marrow transplantation.

In chronic lymphocytic leukemia (CLL), clonal rearrangement of the immunoglobulin heavy chain locus (IgH) provides a useful marker for the detection of minimal residual disease (MRD) after treatment. At the time of initial presentation, DNA from patients with CLL was polymerase chain reaction (PCR)-amplified using consensus Variable (VH) and Joining (JH) region primers using complementarity determining region III consensus region primers or a panel of VH family-specific framework region 1 (FR1) primers. The clonal product was directly sequenced and patient-specific probes constructed using N region nucleotide sequences. We amplified and sequenced the CDRIII region and designed patient specific oligonucleotide probes for the detection of MRD in 55 of 66 patients (84%, 90% Confidence Intervals (CI): 74% to 90%) with poor prognosis CLL referred for autologous and allogeneic bone marrow transplantation (BMT). To determine the clinical utility of this technique, PCR amplification was performed on patient samples at the time of and following autologous (21 patients) and allogeneic (10 patients) BMT in whom serial bone marrow samples obtained after BMT were available for analysis. We show that the persistence of MRD after BMT is associated with increased probability of relapse. In all cases that have relapsed to date, the IgH CDRII region was identical at the time of initial presentation and at relapse suggesting that clonal evolution of the IgH locus is unusual in this disease. The finding that a significant number of patients remain disease free and with no evidence of PCR-detectable MRD after BMT suggests that high-dose therapy may contribute to improved outcome in selected patients with CLL.

Base Sequence↗
PubMed1996

Clinical and molecular remission after allogeneic blood cell transplantation in a patient with mantle-cell lymphoma.

Mantle-cell lymphoma (MCL) is a B-cell tumour with a usually poor prognosis, characterized by the proliferation of small cleaved lymphocytes with a diffuse growth pattern. We report a polymerase chain reaction-based analysis of minimal residual disease in a patient who achieved complete remission after allogeneic blood cell transplantation (BCT). Rearrangement of the immunoglobulin heavy-chain genes was used to generate a lymphoma-specific molecular marker. Lymphoma cells were not detectable in a bone marrow sample collected 12 months after BCT. Our findings suggest that allogeneic BCT may offer a curative approach to MCL.

Adult↗
PubMed1996

Elimination of bcl-2-IgH-positive follicular lymphoma cells from blood transplants with high recovery of hematopoietic progenitors by the miltenyi CD34+ cell sorting system.

Contamination of autologous blood cell transplants with cells of follicular non-Hodgkin's lymphoma (F-NHL) may contribute to relapse of the malignancy after potentially curative high doses of chemotherapy and radiotherapy. In an attempt to circumvent this limitation, we have evaluated various techniques of selection of CD34+ cells to eliminate malignant cells from blood cell transplants of five patients with F-NHL undergoing high-dose sequential therapy. The contamination of F-NHL cells was evaluated using a nested PCR assay for the detection of bcl-2-IgH rearrangement with a sensitivity of one F-NHL cell in 10(5) normal cells. In two experiments with blood cell transplant fractions of 0.5 x 10(9) nucleated cells, negative selection of CD34+ cells by removal of B cells and other mature cells that naturally adhere to nylon wool fibers decreased the number of CD19+ B cells detectable by flow cytometry but failed to eliminate bcl-2-IgH-positive F-NHL cells detectable by PCR. In contrast, positive selection of CD34+ cells by the Miltenyi MiniMACS high gradient magnetic cell sorting system in five separate experiments resulted in: (1) the elimination of F-NHL cells in four out of five cases as detected both flow cytometry and bclk-2-IgH PCR; (2) a highly purified population of hematopoietic progenitors comprising 90.8% +/- 2.3% CD34+ cells; and (3) the recovery of 77.9% +/- 3.2% CD34+ cells. These favorable results were confirmed on a large-scale with a blood cell transplant comprising 5.8 x 10(9) nucleated cells in which positive selection of CD34+ cells by the Miltenyi SuperMACS system resulted in: (1) the elimination of F-NHL cells as detected both by flow cytometry and bcl-2-IgH PCR; (2) a highly purified population of hematopoietic progenitors comprising 94.6% CD34+ cells; and (3) the recovery of 62.7% CD34+ cells. These results, attained with the newly available Super MACS system, compare favorable with previous techniques because they show the feasibility of eliminating F-NHL cells from blood cell transplants without relevant nonspecific loss of hematopoietic progenitors.

Adsorption↗
PubMed1995

Chromosomal translocations cause deregulated BCL6 expression by promoter substitution in B cell lymphoma.

The BCL6 gene codes for a zinc-finger transcription factor and is involved in chromosomal rearrangements in 30-40% of diffuse large-cell lymphoma (DLCL). These rearrangements cluster within the 5' regulatory region of BCL6 spanning its first non-coding exon. To determine the functional consequences of these alterations, we have analyzed the structure of the rearranged BCL6 alleles and their corresponding RNA and protein species in two DLCL biopsies and one tumor cell line which carried the t(3;14)(q27;q32) translocation involving the BCL6 and immunoglobulin heavy-chain (IgH) loci. In all three cases, the breakpoints were mapped within the IgH switch region and the BCL6 first intron, leading to the juxtaposition of part of the IgH locus upstream and in the same transcriptional orientation to the BCL6 coding exons. An analysis of cDNA clones showed that these recombinations generate chimeric IgH-BCL6 transcripts which initiated from IgH germline transcript promoters (I mu or I gamma 3), but retain a normal BCL6 coding domain. In the tumor cell line, the chimeric I gamma 3-BCL6 allele, but not the germline BCL6 gene, was transcriptionally active and produced a normal BCL6 protein. These findings indicate that t(3;14) translocations alter BCL6 expression by promoter substitution and imply that the consequence of these alterations is the deregulated expression of a normal BCL6 protein.

Alleles↗
PubMed1995

High-dose sequential chemoradiotherapy in multiple myeloma: residual tumor cells are detectable in bone marrow and peripheral blood cell harvests and after autografting.

Based on preliminary encouraging results in terms of response rate and survival, high-dose chemoradiotherapy has gained considerable interest in the treatment of patients with multiple myeloma (MM). We have evaluated the presence of residual myeloma cells in 15 of 18 patients enrolled in a high-dose sequential (HDS) chemoradiotherapy program followed by autografting. Our analysis has been performed both on bone marrow (BM) and peripheral blood (PB) cell harvests and after autografting. As it has been recently shown that B cells clonally related to malignant plasma cells are detectable in MM patients, we have developed a polymerase chain reaction (PCR)-based strategy to detect both residual B cells and plasma cells using clone-specific sequences derived from the rearrangement of Ig heavy chain (IgH) genes. The complementarity-determining regions (CDR) of IgH genes have been used to generate tumor-specific primers and probes. The constant (C) region usage defined the differentiation stage of residual myeloma cells. We report that plasma cells were detectable in PB and BM cell harvests and after transplantation in all assessable patients, irrespective of disease status. B cells were detectable in a consistent proportion of BM and PB samples at diagnosis, but only in one case at the time of PB and BM cell harvests. These cells became sometimes detectable after transplantation. Whether residual myeloma cells are clonogenic and contribute to relapse is currently unknown, and further investigations are required.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Haematological support of high-dose sequential chemotherapy: clinical evidence for reduction of toxicity and high response rates in poor risk lymphomas.

The toxicity and feasibility of a high-dose sequential (HDS) chemotherapy programme delivered with growth factor support were evaluated in patients with intermediate and high-grade non-Hodgkin's lymphoma (NHL) or with progressive Hodgkin's disease. The scheme includes the sequential administration of single cytotoxic drugs at very high doses followed by intensified treatment with circulating progenitor autograft. In some instances, the original HDS scheme, initially designed at the Milan Cancer Center, was partially modified and intensified with a preliminary debulking phase. The use of G-CSF (filgrastim) made toxicity in the high-dose phase acceptable and allowed good harvests of peripheral blood progenitor cells (PBPC); the use of PBPC in the final autografting phase resulted in low haematological toxicity. Of 71 patients with NHL treated at our institution with either the original or the intensified HDS version, the overall toxicity-related mortality was 5.6%, thus comparable to lethal toxicity commonly associated with conventional chemotherapy. Adequate PBPC harvests are crucial for good tolerability of the programme. Optimal harvests are generally obtained in patients without neoplastic marrow infiltration while patients with marrow disease often have a poorer mobilisation. However, an optimally time-spaced chemotherapy debulking might also restore sufficient mobilisation in these latter patients. In terms of therapeutic efficacy, HDS had produced promising results since the initial experience in relapsed patients. More recently, HDS was evaluated as first-line treatment in a series of 22 consecutive patients, presenting with advanced-stage, intermediate-grade NHL other than diffuse large cell subtype. A CR rate of 82% was obtained following HDS, with a projected survival of 86% at five years. Thus, delivery of an intensive high-dose chemotherapy programme with haematopoietic growth factor support was found to be feasible and reasonably safe. The high anti-tumour efficacy of such a scheme makes it suitable for wider applicability in all those chemosensitive tumours where a dose increase might enhance the chance of cure.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Rearrangements of the BCL6 gene in diffuse large cell non-Hodgkin's lymphoma.

The pathogenesis of non-Hodgkin's lymphoma (NHL) with a large cell component (DLLC, including diffuse large cell, DLCL; diffuse mixed cell, MX-D; and immunoblastic, IMB) is unknown. A novel candidate proto-oncogene, BCL6, that is involved in chromosome band 3q27 aberrations in NHL has been recently identified. We have investigated the incidence and disease-specificity of BCL6 rearrangements in a large panel of lymphoid tumors, including acute and chronic lymphoid leukemias (96 cases), various NHL types (125 cases), and multiple myelomas (23 cases). BCL6 rearrangements were found in 16/45 (35.5%) DLLC, more frequently in DLCL (15/33, 45%) than in MX-D (1/10, 10%), in 2/31 (6.4%) follicular NHL, and in no other tumor types. BCL6 rearrangements represent the first genetic lesion specifically and recurrently associated with DLLC and should prove useful for understanding the pathogenesis as well as for the clinical monitoring of these tumors.

DNA-Binding Proteins↗
PubMed1994

N- and K-ras oncogenes in plasma cell dyscrasias.

N- and K-ras oncogene mutations represent the most frequent molecular lesions in plasma cell dyscrasias. They are not randomly distributed since they are detectable in multiple myeloma (MM) (9-31%) and plasma cell leukemia (PCL) (30%), and not in monoclonal gammopathy of undetermined significance (MGUS) and solitary plasmacytoma (SP). Codons 12, 13 and 61 of N- and K-ras genes have been found mutated. Mutations affecting codon 61 of N-ras gene are the most frequent finding. A heterogeneous pattern of mutations is described with a prevalence of purine-pyrimidine transversions. Ras gene mutations have been predominantly detected in myelomas characterized by an advanced stage disease, and adverse prognostic parameters. These findings suggest that ras mutations represent a late molecular lesion and may be implicated in tumor progression rather than tumor initiation.

DNA Mutational Analysis↗
PubMed1994

Inactivation of tumor suppressor genes, p53 and Rb1, in plasma cell dyscrasias.

The role of loss or inactivation of the retinoblastoma (Rb1) and p53 tumor suppressor genes in the pathogenesis of various human malignancies has been well established, yet little is known regarding plasma cell dyscrasias. In the present study, the loss of Rb1 protein expression, and the presence of Rb1 gene rearrangements as well as the presence of p53 somatic mutations (exons 5 through 9) were investigated in a panel of plasma cell dyscrasias, including 15 monoclonal gammopathies of undetermined significance (MGUS), 63 multiple myelomas (MM), and 18 plasma cell leukemias (PCL). In the same panel of cases, we established the frequency of ras oncogene mutations, the main genetic lesion associated with MM. We report that loss of Rb1 protein and p53 mutations are detectable in 34.7 and 9.8% of MM and PCL primary cases; no lesion was found in MGUS. In advanced stage MM, and PCL cases, Rb1 and p53 inactivation, as well as ras mutations were detected. Our findings show that Rb1 and p53 inactivation are associated with aggressive plasma cell dyscrasias, suggesting a role for these lesions in tumor progression rather than initiation.

Base Sequence↗
PubMed1993

Rapid generation of antiplasma cell activity in the bone marrow of myeloma patients by CD3-activated T cells.

We have recently shown that peripheral blood T cells of multiple myeloma (MM) patients are very susceptible to stimulation of the T-cell receptor/CD3 complex with anti-CD3 monoclonal antibodies (MoAbs). CD3 stimulation is currently under clinical investigation as a nonspecific approach to boost antitumor effector mechanisms. The aim of this study was to determine whether the hyperreactivity of MM T cells to CD3 stimulation could be exploited to generate antitumor activity. Bone marrow mononuclear cells (BMMCs) from 65 MM patients were stimulated with the anti-CD3 MoAb OKT3 and the effect of this stimulation on autologous T cells and plasma cells was evaluated. The number of CD3+ CD25+ cells on day 6 was significantly higher in MM than the controls (30 normal individuals) (P = .001). Kinetic studies showed that 3H-thymidine incorporation peaked on day 3 and that the T-cell expansion peaked on days 5 and 6. In MM, T-cell activation markedly affected the survival of autologous plasma cells; their number in OKT3-treated cultures was significantly lower than in unstimulated cultures (P < .0001). T-cell activation and plasma cell decrease were not observed when T cells were removed from BMMC preparations. MM produced significantly higher levels of interferon-gamma (P = .005) and tumor necrosis factor-beta (P = .001), but lower levels of tumor necrosis factor-alpha (P < .001) than normal individuals. Interferon-gamma only was partially involved in CD3-induced plasma cell killing. Transwell cultures showed that the main mechanism by which CD3+ CD25+ cells affected plasma cells was direct cell-to-cell contact rather than cytokines. In conclusion, T cells in MM BMMCs possess distinct features in terms of susceptibility to CD3 stimulation and cytokine production compared with normal bone marrow T cells that can be exploited to generate antiplasma cell activity.

Antibodies, Monoclonal↗
PubMed1993

Evidence for a bone marrow B cell transcribing malignant plasma cell VDJ joined to C mu sequence in immunoglobulin (IgG)- and IgA-secreting multiple myelomas.

Multiple myeloma is a B cell malignancy characterized by the expansion of plasma cells producing monoclonal immunoglobulins (Ig). It has been regarded as a tumor arising at the B, pre-B lymphocyte, or even stem cell level. Precursor cells are presumed to proliferate and differentiate giving rise to the plasma cell clonal expansion. Antigenic features and specific Ig gene rearrangement shared by B lymphocytes and myeloma cells have supported this hypothesis. However, the existence of such a precursor is based upon indirect evidence and is still an open question. During differentiation, B cells rearrange variable (V) regions of Ig heavy chain genes, providing a specific marker of clonality. Using an anchor polymerase chain reaction assay, these rearranged regions from five patients with multiple myeloma were cloned and sequenced. The switch of the Ig constant (C) region was used to define the B cell differentiation stage: V regions are linked to C mu genes in pre-B and B lymphocytes (pre-switch B cells), but to C gamma or C alpha in post-switch B lymphocytes and plasma cells (post-switch B cells). Analysis of bone marrow cells at diagnosis revealed the presence of pre-switch B cells bearing plasma cell V regions still joined to the C mu gene. These cells were not identified in peripheral blood, where tumor post-switch B cells were detected. These pre-switch B cells may be regarded as potential myeloma cell precursors.

B-Lymphocytes↗
PubMed1993

Mutational activation of N- and K-ras oncogenes in plasma cell dyscrasias.

The frequency of N- and K-ras oncogene mutations was investigated in plasma cell dyscrasias. Genomic DNAs from 128 patients were selected for this study: 30 monoclonal gammopathies of undetermined significance, 8 solitary plasmacytomas, 77 multiple myelomas (MM), and 13 plasma cell leukemias (PCL). A two-step experimental approach was devised. All samples were screened for mutations by single-strand conformation polymorphism analysis. DNA fragments displaying an altered electrophoretic mobility were further studied by direct sequencing to confirm and characterize the nature of the mutations. Ras mutations are not randomly distributed because they are detectable only in MM (9%) and PCL (30.7%). N-ras codons 12, 13, and 61 and K-ras codon 12 were found to be mutated, but N-ras codon 61 mutation was the most frequent finding (63.6%). In conclusion, ras mutations were found in PCL, and in a subset of MM characterized by advanced-stage disease and adverse prognostic parameters. Furthermore, based on our findings, it is possible to speculate that ras mutations represent a late molecular lesion in the process of multistep carcinogenesis.

Base Sequence↗
PubMed1993

Detection of circulating tumor cells in multiple myeloma by a PCR-based method.

Multiple myeloma (MM) is a B-cell malignancy characterized by clonal expansion of plasma cells producing monoclonal immunoglobulins. It has been regarded as a tumor typically involving only the bone marrow. The existence of circulating tumor cells has been suggested from phenotypic and genotypic studies. However, this issue is still controversial due to the limitations of the methods so far used. We describe a novel polymerase chain reaction (PCR) based method using clone-specific immunoglobulin heavy-chain gene sequences as tumor markers. From such sequences patient-specific oligonucleotide primers and probes were generated, and used to detect tumor cells. Seven MM patients were selected for this study, and tumor cells were found in all peripheral blood samples. The demonstration of circulating tumor cells suggests some caution when using peripheral blood for autograft procedures, even though its contamination is lower than bone marrow. In conclusion, we describe a specific and sensitive PCR-based method for detecting minimal disease which is of general applicability to all lymphoid malignancies transcribing rearranged immunoglobulin heavy-chain genes.

Base Sequence↗
PubMed1993

[The role of infective intestinal complications on the course of Crohn's disease and ulcerative rectocolitis].

The authors studied the incidence of protozoal and bacterial infection in 41 cases of Crohn disease und ulcerative colitis; the effect of anti infective therapy on the clinical course has also been tested. Patients with ulcerative colitis are more frequently involved in this type of complication than those with Crohn disease. Therapy has a positive influence on the course of the disease; therefore systematic study of the faeces for bacteria and parasites is necessary for a correct understanding of chronic inflammatory bowel disease and for specific treatment.

Adolescent↗
PubMed1993

Detection of immunoglobulin gene rearrangement of B cell non-Hodgkin's lymphomas and leukemias in fresh, unfixed and formalin-fixed, paraffin-embedded tissue by polymerase chain reaction.

BACKGROUND: The majority of B cell nonHodgkin's lymphomas (NHLs) are composed of a genotypically identical cell population characterized by a unique immunoglobulin (Ig) VDJ gene rearrangement which is customarily documented by Southern blot hybridization analysis of fresh tissue. Sometimes, however, this approach cannot be used because of an insufficient quantity of tissue or the unavailability of fresh tissue. Therefore, alternative strategies should be designed in order to overcome these limitations. EXPERIMENTAL DESIGN: One possible alternative is the identification of Ig VDJ products of normal and neoplastic B cells by polymerase chain reaction (PCR) using mixed oligonucleotide primers recognizing the framework III region or Ig variable heavy chain leader sequences and universal Ig heavy chain joining region (JH) oligonucleotide primers. To determine whether the respective DNA samples are suitable for PCR amplification, control and unrelated genes should also be investigated (exon 5 of the p53 gene). In this study, genomic DNA was extracted from a well characterized panel of 139 human B cell lymphoid leukemias and NHLs derived from fresh (84) and/or paraffin-embedded (55) tissue, 19 normal peripheral lymphoid tissues, 9 Epstein-Barr virus infected lymphoblastoid cell lines and, as negative controls, 11 T cell LLs. Clonal Ig gene rearrangement products were assessed for the presence of a distinct PCR fragment after framework III-JH PCR amplification and electrophoretic separation and by DNA sequencing of the cloned PCR-Ig fragments. RESULTS: Eighty-eight of the 139 (63%) B-NHLs consisting of 53/84 (63%) fresh, unfixed and 35/55 (64%) formalin-fixed, paraffin-embedded samples, exhibited distinct PCR bands. Using this approach we were able to identify a single clonal B cell population mixed with 1,000 nonB cells or 5 polyclonal B cells. There was no difference in the detection of monoclonality among different B-NHL categories. PCR fragments were not identified in any of 27 normal lymphoid tissues or 11 T-lymphoid leukemias. To detect a larger number of Ig gene rearrangement products, genomic DNA of 12 B-NHL/lymphoblastoid cell lines were investigated using VH-specific leader and JH oligonucleotides by PCR. A single PCR product was obtained in 9 of 12 (75%) cases and their clonality was documented by DNA sequencing of the cloned PCR fragments. The clonality of 11 of the 12 (92%) cases could be demonstrated using both PCR approaches. CONCLUSIONS: Our results suggest that the monoclonality of human neoplastic B cells can be efficiently evaluated by PCR equally well from fresh, unfixed and formalin-fixed, paraffin-embedded tissues. This technique should prove to be a powerful tool in clinical diagnosis and research as well as in the retrospective analysis of archival pathologic specimens.

Base Sequence↗