Molecular and clinical remissions in multiple myeloma: role of autologous and allogeneic transplantation of hematopoietic cells

PURPOSE

To describe molecular monitoring of minimal residual disease in patients with myeloma who have achieved complete remission (CR) after autologous or allogeneic transplantation of hematopoietic cells.

MATERIALS AND METHODS

Clonal markers based upon the rearrangement of immunoglobulin heavy-chain genes were generated for each patient and used for polymerase chain reaction (PCR) detection of residual myeloma cells. Fifty-one patients entered the program and 36 achieved CR. After transplantation, molecular monitoring was performed on 29 patients (15 autologous and 14 allogeneic transplants) who had molecular markers.

RESULTS

Our data show that molecular remissions are rarely achieved (7%) with high-dose chemotherapy followed by single or double autografting. In addition, virtually all peripheral blood progenitor cell and bone marrow samples contained residual myeloma cells, even when sample collection was scheduled after repeated courses of high-dose chemotherapy. All patients autografted with PCR-positive cells remain positive, and eight of 15 have relapsed. Two patients were autografted with PCR-negative cells: one is in clinical and molecular remission, and one relapsed 25 months after the transplant. In the allografting setting, a higher proportion of patients (50%) achieved molecular remission; there were two relapses, one in the PCR-positive group and one in the PCR-negative group.

CONCLUSION

This is the first large study of molecular remissions in myeloma patients to use a PCR-based approach utilizing patient-specific tumor markers. The sizeable fraction of patients who achieved molecular remission after allografting with peripheral blood progenitor cells represents a promising finding in an incurable disease.

Study of prenatal growth in the capuchin monkey (Cebus apella) by ultrasound

Capuchin monkey (Cebus apella) is a new world primate that in recent years has become important in biomedical research. The purpose of this study was to establish and correlate normal fetal growth parameters with gestational age in capuchin monkeys. In seven pregnant animals serial ultrasonic assessment of gestational sac (GS), embryo/fetal greatest length (GL), biparietal diameter (BPD), thorax height (TH), and femur length (FL) were performed. Identification of the GS was possible on day 23+/-2.8 (X +/- SE). The embryo and its heartbeat was detected on day 32.7+/-2.8, the GL being measurable thereafter. By day 45.4+/-1.4 BPD and TH were measurable. FL could only be measured from day 70.6+/-2.1. Predictive regression equations of gestational age (GA) were modeled with data obtained. In addition, preliminary data of fetal heart rate showed a decrease in frequency with advancing gestation.

Allogeneic transplantation of unmanipulated peripheral blood stem cells in patients with multiple myeloma

In multiple myeloma (MM), allogeneic bone marrow transplantation may produce complete and durable responses, but is accompanied by significant transplant-related mortality (TRM). To assess feasibility and possible advantages offered by the use of allogeneic, growth factor-primed PBSC instead of marrow, we analyzed the data of 10 patients with MM (IgG = 6, IgA = 1, BJ = 2, non-secreting = 1; stage II = 1, stage III = 8, plasma-cell leukemia = 1) who received an allogeneic transplant with PBSC. Their age ranged between 35 and 53 years (median 45). All were HLA-identical to their sibling donors. Prior to allograft, six patients received standard-dose chemotherapy (DAV or CY-Dexa) and four a sequential intensified scheme with autologous PBSC support. At the time of transplantation, three patients were in CR, three in PR, three had refractory disease, one progressive disease. Patients were conditioned with busulfan-melphalan (n = 9) or busulfan-cyclophosphamide (n = 1), and were allografted with unmanipulated PBSC obtained by apheresis after treatment with G-CSF alone (n = 6) or GM-CSF followed by G-CSF (n = 4). All patients engrafted, with 0.5 x 10(9)/l PMN and 50 x 10(9)/l platelets on (median) day 13. Four patients had > or =grade II acute GVHD (grade II in 3, grade III in 1). Following allograft, CR was achieved in 71% patients. Eight are currently alive, with six in CR at a median of 18.5 months (range 7-28) from the transplant. Two patients died, 1 and 4 months from the allograft, respectively, and one is alive with progression. A PCR analysis of IgH rearrangement showed that residual disease was no more molecularly detectable in four out of seven evaluated patients following allograft. The results suggest that PBSC may improve the therapeutic efficacy of allogeneic transplant in MM, not only by a reduction of TRM but also by an improvement of rate and quality of response.

G-CSF administration following peripheral blood progenitor cell (PBPC) autograft in lymphoid malignancies: evidence for clinical benefits and reduction of treatment costs

Clinical value and costs of G-CSF administration following autograft with mobilized peripheral blood progenitor cells (PBPC) were evaluated in two sequential groups of 20 patients each, treated for lymphoid neoplasms in the period February 1993 to January 1996. One group was given G-CSF (Filgrastim) (5 microg/kg/day), starting on day +1 until ANC was > 500/microl, the other received no G-CSF. All patients were conditioned with mitoxantrone 60 mg/m2 + L-PAM 180 mg/m2 and received large numbers of PBPC (median of 12 and 13 x 10(6) CD34+/kg, respectively). The median time to ANC > 500/microl was 10 days in the G-CSF group vs 14 days in controls (P < 0.0001). G-CSF was associated with a slightly faster platelet recovery (11 vs 13 days to plts > 20000/microl, P = 0.09). Median duration of fever (2.5 vs 5 days, P = 0.028), nonprophylactic antibiotics (8 vs 11 days, P = 0.019), and post-transplant hospitalization (13 vs 16 days, P = 0.0028) were also significantly reduced. The average cost per treatment in the G-CSF group amounted to about US$18241 as compared to US$21868 in the control group, implying a cost reduction of approximately 16%. Thus, G-CSF reduced morbidity with cost containment, supporting its use even if autograft is performed with large quantities of PBPC.

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.

Deregulation of MUM1/IRF4 by chromosomal translocation in multiple myeloma

The pathogenesis of multiple myeloma (MM), an incurable tumour causing the deregulated proliferation of terminally differentiated B cells, is unknown. Chromosomal translocations (14q1) affecting band 14q32 and unidentified partner chromosomes are common in this tumour, suggesting that they may cause the activation of novel oncogenes. By cloning the chromosomal breakpoints in an MM cell line, we show that the 14q+ translocation represents a t(6;14)x(p25;q32) and that this aberration is recurrent in MM, as it was found in two of eleven MM cell lines. The translocation juxtaposes the immunoglobulin heavy-chain (IgH) locus to MUM1 (multiple myeloma oncogene 1)/IRF4 gene, a member of the interferon regulatory factor (IRF) family known to be active in the control of B-cell proliferation and differentiation. As a result, the MUM1/IRF4 gene is overexpressed--an event that may contribute to tumorigenesis, a MUM1/IRF4 has oncogenic activity in vitro. These findings identify a novel genetic alteration associated with MM, with implications for the pathogenesis and diagnostics of this tumour.

Peripheral blood progenitor cell mobilization in patients with primary refractory lymphoma or at first relapse: comparison with patients at diagnosis and impact on clinical outcome

Peripheral blood progenitor cell (PBPC) mobilization was evaluated in 53 patients receiving the high-dose sequential (HDS) regimen: 27 had non-Hodgkin's lymphoma or Hodgkin's disease, primary refractory or at first relapse, 26 had non-Hodgkin's lymphoma at diagnosis. Mobilization was assessed following either 7 g/m2 cyclophosphamide (48 patients) or 2 g/m2 etoposide, both followed by G-CSF (filgrastim) at 5 microg/kg/d. PBPC mobilization was significantly higher in patients at diagnosis compared to refractory/relapsed patients (median peak values of circulating CFU-GM: 25,209/ml v 4270/ml, P < 0.0001 and CD34+ cells: 286/microl v 47/microl, P < 0.0001). All patients receiving HDS as up-front treatment mobilized enough PBPC for an autograft, often requiring a single leukapheresis; whereas only 15 patients under salvage treatment with HDS were able to complete PBPC autograft. Bone marrow (BM) cells, alone or with PBPC, were needed in six patients, and autograft could not be performed in six patients. Among refractory/relapsed patients, those having a high PBPC mobilization experienced a significantly longer EFS compared to those who had not; autograft completion also significantly enhanced EFS. Thus, the use of an effective mobilizing protocol does not ensure adequate PBPC mobilization in moderately pretreated patients; low mobilization must be considered as an early sign of poor outcome in patients receiving a high-dose salvage programme.

A novel nested-PCR strategy for the detection of rearranged immunoglobulin heavy-chain genes in B cell tumors

Several methods have been developed for the detection of minimal residual disease (MRD) in B cell tumors. Chromosomal translocations or the rearrangement of the immunoglobulin heavy chain (IgH) and T cell receptor genes are generally employed. We report a novel PCR method to detect MRD using IgH genes. IgH rearranged variable region (VDJ) were amplified from tumor specimens using consensus primers for variable and joining region genes. Complementarity-determining regions (CDR) were identified and used to generate tumor-specific primers. Two-round amplifications using primers derived from CDRs and joining or constant regions were performed for MRD detection. IgH nested-PCR approach was tested on a panel of 75 B cell tumors including acute lymphoblastic and chronic lymphocytic leukemias, non-Hodgkin's lymphomas and multiple myelomas. A VDJ sequence was obtained in 62 out of 75 cases (83%). Sensitivity using DNA or cDNA templates was 10(-5) and (-6), respectively. This method is specific and sensitive and provides a simple, non-radioactive approach for the evaluation of MRD in B cell tumors.

Analysis of the immunoglobulin heavy-chain gene rearrangement providing molecular evidence of second lymphoma in a patient in apparent relapse after autotransplantation

Development of a second lymphoma after autotransplantation is an unusual event. Its real incidence, however, could be underestimated, since histologic and immunophenotyping techniques are often unable to distinguish it from a relapse. We report a lymphoma patient in apparent relapse after 42 months of molecular remission achieved by autotransplantation. Sequencing analysis of the immunoglobulin heavy-chain genes showed that the rearrangement of variable, diversity and joining segments had changed between diagnosis and relapse and suggested that a second lymphoma had developed.

Molecular monitoring of minimal residual disease in follicular and mantle cell non-Hodgkin's lymphomas treated with high-dose chemotherapy and peripheral blood progenitor cell autografting

Minimal residual disease (MRD) was evaluated in 30 patients with follicular or mantle cell non-Hodgkin's lymphoma (NHL) undergoing an intensive treatment with high-dose sequential (HDS) chemotherapy and peripheral blood progenitor cell (PBPC) autografting. To minimize the potential tumor cell contamination, PBPC harvests were scheduled at the end of HDS pretransplant phase. All patients had advanced-stage disease and most of them presented with bone marrow (BM) involvement. A tumor marker could be generated in 90% of patients using bcl-2 or lg heavy-chain genes. MRD was analyzed on PBPC, BM harvests, and after autografting by polymerase chain reaction (PCR). All evaluable follicular and 6 of 9 mantle cell patients achieved clinical complete remission. PCR negativity of PBPC and/or BM harvests was documented in 68% of follicular and 12% of mantle cell lymphomas. Molecular remission of PBPC and/or BM harvests was achieved in 9 of 15 patients with overt marrow involvement and in all patients with only molecular marrow infiltration at onset. Molecular follow-up was conducted on 14 patients: all 7 evaluable patients who received at least one PCR-negative graft maintained the negative status at a median follow-up of 24 months and none of them relapsed so far. Thus, the results show that (1) a molecular marker to monitor MRD can be obtained in most follicular and mantle cell NHL patients, (2) the HDS regimen may provide PCR-negative PBPC and/or BM harvests even from patients with BM disease, and (3) autograft with at least one PCR-negative harvest is associated with a durable clinical and molecular remission.

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.

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.

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.

Long-term molecular remission after conventional chemotherapy in a patient with Philadelphia-negative acute lymphoblastic leukemia

Adult Philadelphia (Ph1) negative acute lymphoblastic leukemia (ALL) is usually treated with conventional chemotherapy regimens. Long-term disease-free survival is often achieved. The rearrangement of immunoglobulin heavy-chain genes has been used to evaluate minimal residual disease. A novel nested-polymerase chain reaction (PCR) approach was used here to study a patient in long-term complete remission (CR) after the BFM regimen. No evidence of tumor cell contamination was found in bone marrow cells collected after 93 months of CR. This finding supports the hypothesis that conventional chemotherapy can induce long-term molecular remission and cure in Ph1 negative ALL.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

[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.

B cell lymphoma-associated chromosomal translocation involves candidate oncogene lyt-10, homologous to NF-kappa B p50

A B cell lymphoma-associated chromosomal translocation, t(10;14)(q24;q32), juxtaposes the immunoglobulin C alpha 1 locus to a novel gene, lyt-10. The normal lyt-10 cDNA codes for a 98 kd protein which displays amino-terminal homology with the rel (DNA-binding) domain of the NF-kappa B-rel family of transcription factors and carboxy-terminal homology with the NF-kappa B p50 precursor protein, including the putative proteolytic cleavage domain (poly-G) and the ankyrin-like repeat domains. The lyt-10 protein can bind to kappa B sequences in vitro, although with different specificity from NF-kappa B p50, and in vitro DNA-binding is activated by removal of the ankyrin domain. Chromosomal translocation generates an lyt-10-C alpha 1 fusion gene coding for a protein that retains the rel effector domain, lacks the ankyrin regulatory domain, and binds kappa B sequences in vitro, suggesting its constitutive activation in vivo. Analogous rearrangements of the lyt-10 gene have been found in an additional three cases of lymphoid neoplasia. The lyt-10 gene defines a new subfamily (rel/poly-G/ankyrin) of NF-kappa B-rel transcription factors with potential for oncogenic activation in human cancer.

Dual rearrangement of immunoglobulin and T-cell receptor gene in a case of T-cell hairy-cell leukemia

We report a case of T-cell hairy-cell leukemia with a dual rearrangement of Ig- and T-cell receptor genes. The cytochemical, transmission electron microscopy, and surface antigens data (CD3+, CD8+, CD11+, HLA-DR+, CD19-, CD20-) were consistent with a T-cell hairy-cell leukemia. Molecular analysis according to Southern revealed a dual rearrangement of immunoglobulin heavy-chain (JH) and T-cell receptor beta (TcR beta) chain genes. Our findings suggest that the coexistence of JH and TcR gene rearrangements, frequently detected in acute leukemia, may also be observed in hematologic malignancies derived from more differentiated cells.

Analysis of the breakpoint cluster region in essential thrombocythemia

Essential thrombocythemia (ET) is a myeloproliferative disorder characterized by a platelet count higher than 1000 x 10(9)/l. Bone marrow karyotype aberrations are occasionally observed. The presence of cytogenetic and molecular markers of chronic myeloid leukemia (CML) was assessed in 25 patients with the clinical features of ET. One displayed a complex translocation (9; 15; 22) (q34.1 or q34.3; q26.1; q11), and another a Philadelphia chromosome with standard translocation (9; 22) (q34; q11). Southern blot analysis revealed a rearranged breakpoint cluster region (bcr) in each case. Both patients experienced a stormy disease course without a leukemic transformation. These data indicate that the Philadelphia chromosome rarely occurs in ET and strongly influences patient outcome.

Human homologue of Moloney leukemia virus integration-4 locus (MLVI-4), located 20 kilobases 3' of the myc gene, is rearranged in multiple myelomas

The structure of the c-myc locus and the flanking chromosomal region was investigated by Southern blot analysis of DNA from bone marrow aspirates from 42 patients with multiple myeloma. The main abnormality detected was the rearrangement of the MLVI-4 locus, 20 kilobases 3' of c-myc, which was observed in seven cases (16%). Two of these rearrangements were detected at the time of the initial diagnosis, four during treatment, and one at relapse, and their presence correlated with unresponsiveness to therapy. The MLVI-4 locus represents the human homologue of the Moloney leukemia virus integration-4 locus (Mlvi-4), a common region for provirus integration in Moloney murine leukemia virus-induced T-cell lymphomas in rodents. Provirus integration in this locus activates c-myc, and two additional genes, Mlvi-4 and Mlvi-1. The c-myc gene was rearranged in one patient; mutations involving the first exon of c-myc, frequently detected by altered restriction enzyme recognition sites in Burkitt's lymphomas, were not observed in these myelomas.

[Metadoxine in alcohol-related pathology]

Metadoxine is an active drug for treatment of acute and chronic alcohol intoxication, affecting both liver and brain function. The authors reviewed the international pharmacological and clinical literature on the drug which shows the potential usefulness of metadoxine in the treatment of alcohol-induced diseases. The case report concerns the results in 20 chronic alcoholics, admitted to the hospital for acute alcohol intake treated with metadoxine (one 500 mg tablet twice daily). Biohumoral hepatopathy parameters and clinical parameters of neuropsychic behaviour were examined simultaneously. Compared with a control group of patients undergoing traditional therapy (sedative and multi-vitamin drugs), metadoxine showed a significant improvement of the values of gamma-GT, GPT, blood ammonia, blood alcohol and of neuropsychic and behavioural parameters such as agitation, tremor, asterixis, sopor and depression. No side-effects or unfavourable reactions occurred during metadoxine treatment, which confirms the safety of this molecule.

Philadelphia-positive thrombocythemia with a complex translocation involving chromosomes 9, 15, and 22

We report a case of Philadelphia chromosome (Ph) positive thrombocythemia with a complex translocation. G-banding analysis showed the predominant karyotype to be 46,XX,t(9;15;22). Southern blot analysis revealed a rearrangement within the breakpoint cluster region on chromosome 22 similar to findings in chronic myeloid leukemia. These data suggest the presence of a complex Ph translocation involving t(9;15;22)(q34.1 or q34.3;q26.1;q11 or q13).

Nizatidine in the short-term treatment of duodenal ulcer--an Italian Multicenter Study

One hundred and seventy three patients suffering from duodenal ulcer, were selected for a double-blind, controlled and randomized parallel multicenter study, with interval endoscopic examinations. This study was undertaken to compare the efficacy and safety of nizatidine administered at a single dose (300 mg "nocte") versus ranitidine (300 mg "nocte") in the treatment of acute duodenal ulcer. One hundred and sixty five patients were found to meet every admission criterion and completed the study (86 on nizatidine and 79 on ranitidine). On admission to the study, both groups were seen to have been correctly selected and epidemiologically well-distributed as to history of duodenal ulcer, previous treatments and pre-study symptoms. The ulcer was considered healed when complete re-epithelialization had occurred in areas of ulcerated mucosa. Healing rates of duodenal ulcer proved to be globally similar in the two groups, both in the 4th week (nizatidine, 78%; ranitidine, 78%) and in the 8th week (nizatidine, 91%; ranitidine, 95%). After four weeks of treatment, 67% of the patients treated with nizatidine no longer had any symptoms, while 87% patients no longer suffered from day pain, and 91% had no nocturnal pain. As a result, intake of antacids quickly decreased during the first four weeks. A similar response was observed in the group receiving ranitidine. After administration at a single dose of 300 mg in the evening, nizatidine proved to be at least as effective and safe as 300 mg of ranitidine administered in the same way, with respect both to ulcer healing and symptom response.

Short-term treatment of reflux oesophagitis with ranitidine 300 mg nocte. Italian multicentre study

A multicentre study involving 9 Italian institutions was carried out to compare the efficacy and safety of ranitidine 150 mg b.i.d. and ranitidine 300 mg nocte in the treatment of reflux oesophagitis. 117 patients with histologically proven oesophagitis were randomly allocated to two comparable treatment groups. Efficacy and reliability were evaluated by clinical and laboratory tests at the beginning of the study, and at 3 and 6 weeks; endoscopy and biopsies were performed at the beginning and at 6 weeks. Treatment with ranitidine for 6 weeks led to total disappearance of gastro-oesophageal reflux symptoms in 60% of patients, with percentages of partial improvement varying between 85% and 95% of cases. Improvement in the results of endoscopic examination was 85%, of which 55% were cured. Microscopic examination revealed an improvement of 36% and 44%, with a cure rate of 18% and 26% respectively. With regard neither to the regression of symptoms nor to the macroscopic and microscopic inflammation of the oesophageal mucosa did statistical examination show significant differences in the therapeutic efficacy of ranitidine 150 mg b.i.d. or 300 mg nocte for treatment of reflux oesophagitis.

Measurement by bioluminescence technique of erythrocyte membrane Na+,K+-ATPase activity in hypertensive patients

Erythrocyte membrane Na+,K+-ATPase activity was measured using a bioluminescence technique in 28 hypertensive patients (24 with essential hypertension, 2 with renovascular hypertension and 2 with hypertension secondary to primary hyperaldosteronism) and in 28 normotensive control subjects matched for age and sex. Erythrocyte Na+,K+-ATPase activity was significantly reduced in the patients with essential hypertension (130.9 +/- 11.4 vs. 186.6 +/- 19.5 nmol ATP/mg prot per h; mean values +/- SEM; p less than 0.05) and in the patients with secondary hypertension. A significant negative correlation was found between erythrocyte Na+,K+-ATPase and systolic blood pressure (r = -0.603; p less than 0.01), but not between Na+,K+-ATPase and plasma renin activity or plasma aldosterone levels. These data confirm the findings of a number of previous studies reporting reduced activity of erythrocyte Na+,K+-ATPase possibly related to the presence of a circulatory inhibitor of sodium pump. The method, based on ATP assay by bioluminescence, presents a high degree of specificity as well as simple, rapid execution.

Increased basal and thrombin-induced free calcium in platelets of essential hypertensive patients

Intracellular free calcium, [Ca2+]i, was studied in platelets of essential hypertensive subjects and normotensive controls under basal conditions and after stimulation with epinephrine, norepinephrine, angiotensin II, ouabain, and thrombin, using the fluorescent calcium indicator quin 2. Basal [Ca2+]i was significantly higher in hypertensive subjects (n = 32) than in normotensive controls (n = 30; 167.4 +/- 5.0 vs 143.2 +/- 3.1 nmol/L; p less than 0.001). Epinephrine, norepinephrine, angiotensin II, and ouabain had no effect on platelet calcium, whereas thrombin induced a dose-dependent increase in [Ca2+]i in both the presence and absence of extracellular calcium. This [Ca2+]i increase in the presence of extracellular calcium, which depends mainly on calcium influx, was significantly higher (p less than 0.05) in platelets of hypertensive subjects at all thrombin concentrations (ranging from 0.025-0.1 U/ml), while the [Ca2+]i increase in the absence of extracellular calcium, which depends only on release from intracellular stores, was similar in hypertensive subjects and controls. These results suggest that, in essential hypertension, there is not only increased platelet resting [Ca2+]i but also an increase in agonist-mediated calcium influx, which appears to indicate a cell membrane abnormality in the platelets of subjects with essential hypertension.

Verapamil inhibits platelet aggregation by a calcium-independent mechanism

We studied the inhibitory effects of the calcium channel blocker verapamil both on platelet aggregation and intracellular calcium [Ca2+]i in platelets loaded with a fluorescent indicator (quin 2). The inhibitory effects of verapamil on the platelet aggregation response to both thrombin and ionomycin were seen to be clearly dissociated from the verapamil-induced inhibition of the [Ca2+]i increase produced by these agonists. Verapamil-induced inhibition of platelet aggregation was also obtained when using the "calcium-independent" agonist phorbol-myristate acetate (PMA). It may be deduced that a calcium-independent mechanism plays a role in verapamil-induced inhibition of platelet aggregation. We postulate that this mechanism may operate via a protein-kinase C pathway.

[H2 antagonists and the heart]

The large scale use of drugs that block tissue histamine receptors (H1 and H2) creates the problem of possible side effects due to the inhibition of the physiological role of histamine on certain systems and/or the direct action of histamine receptor blockers. In the case of H2 antagonists the effects on the heart so far reported are few but are considered important since they suggest the presence of physiological mechanisms that are as yet imperfectly understood. The literature on the cardiac effects of cimetidine and ranitidine is reviewed and the extent of the effect of the two drugs is outlined on the basis of an analysis of cases presented, experimental protocols and the various hypotheses put forward. Apart from the speculative interest of the study, a possible predisposition to the cardiac effects of cimetidine and ranitidine is identified in patients with major basal pathologies or in critical conditions. On the basis of the large numbers treated worldwide and the sporadic reports of cardiac effects it is concluded that the drugs are very easily handled even from the viewpoint of cardiac effects.

Spectrin extractability from erythrocytes in Duchenne muscular dystrophy patients and carriers and in other myopathies

Spectrin extractability was measured in the erythrocyte membranes from patients with Duchenne Muscular Dystrophy (DMD), from DMD definite carriers (in whom serum creatine kinase (CK) was also measured) and patients affected by other myopathies. After the extraction of spectrin from ghosts with EDTA, membrane proteins were examined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Spectrin extractability was also investigated in the presence of an excess of calcium. Spectrin extraction from erythrocyte ghosts was significantly reduced with respect to controls in DMD patients, in DMD definite carriers and in patients affected by limb-girdle dystrophy, but not in patients suffering from other non-dystrophic myopathies. Fifty percent of DMD definite carriers showed a reduced extraction of spectrin and some of them had normal serum CK. Reduced extractability was also observed in red blood cells incubated in media containing excess calcium. Our results could suggest that reduced spectrin extractability is connected with a modification of intracellular calcium levels.