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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In multiple myeloma, sequence studies of VH genes used to encode clonal Ig in neoplastic plasma cells have shown a common pattern of extensive somatic hypermutation. A further consistent feature of these VH sequences is a complete lack of intraclonal variation. These findings indicate that the malignant cell arises at a mature, postfollicular stage of B-cell development. However, only a minority of cases have a distribution of somatic mutations in VH consistent with a prior role for antigen in selecting the B cell of origin. To complement these studies, and to take further the investigation of a role for antigen in the clonal history of myeloma, we have investigated tumor-derived VL sequences from bone marrows of 15 patients. All sequences (9V kappa and 6V lambda A) were potentially functional and 5 of 15 had evidence for N-region additions. All had undergone extensive somatic hypermutation, and showed no intraclonal variation. In 4 of 15 cases, the distribution of mutations revealed a significant (P < .05) clustering of replacement mutations in the CDR sequences, indicating a role for VL in selection by antigen. Comparison with the VH sequences used by the same tumor cells showed that, if significant clustering was present, it was in either VH or VL but not both. Altogether, 10 of 15 V-regions showed evidence for antigen selection, suggesting that the B cell of origin has behaved as a normal germinal center B cell. Deductions concerning a role for antigen selection may require both VH and VL sequences for validation.
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PMID:Myeloma VL and VH gene sequences reveal a complementary imprint of antigen selection in tumor cells. 924 72

Here we review our recent experience addressing the issue of positive selection and transplantation of hematopoietic CD34+ cells to reduce neoplastic contamination in peripheral blood (PB) autografts from patients with multiple myeloma (MM). We evaluated PB samples from 30 pretreated MM patients following the administration of high dose cyclophosphamide (Cy; 7g/m2 or 4g/m2) and granulocyte-colony stimulating factor (G-CSF), for collection of circulating stem cells (PBSC) to support hematopoietic reconstitution following myeloablative radio-chemotherapy. Twenty six patients showed adequate mobilization of CD34+ progenitor cells and were submitted to PBSC collection. Circulating hematopoietic CD34+ cells were highly enriched by avidin-biotin immunoabsorption, cryopreserved, and used to reconstitute BM function after myeloablative therapy in 13 patients. The median purity of the enriched CD34+ cell population was 89.5% (range 51-94%) with a 75-fold increase compared to the pretreatment samples. The median overall recovery of CD34+ cells and CFU-GM was 58% (range 33-95%) and 45% (range 7-100%), respectively. Positive selection of CD34+ cells resulted in 2.5-3 log of plasma cells and CD19+ B-lineage cells depletion as determined by immunofluorescence studies, although DNA analysis of CDR III region of IgH gene demonstrated the persistence of minimal residual disease (MRD) in 5 out of 6 patient samples studied. Myeloma patients were reinfused with enriched CD34+ cells after myeloablative therapy consisting of total body irradiation (TBI, 1000 cGy) and high dose Melphalan (140 mg/m2) or Melphalan (200 mg/m2) alone. They received a median of 5 x 10(6) CD34+ cells/kg and showed a rapid reconstitution of hematopoiesis: the median time to 0.5 x 10(9) neutrophils, 20 and 50 x 10(9) platelets/L of PB was 10, 11 and 12 days, respectively. When we analyzed the immunological reconstitution of this group of patients, we observed a rapid and full recovery of total lymphocyte and NK cell count, although the absolute CD4+ cell count was lower than pretreatment level. These results, as well as other clinically significant parameters, did not significantly differ from those of patients (=13) receiving unmanipulated PBSC following the same pretransplant conditioning regimen. The results of this trial demonstrate that positive selection of CD34+ cells reduces the contamination of myeloma cells from the apheresis products up to 3 log and provides a cell suspension capable of restoring a normal hematopoiesis after a TBI-containing conditioning regimen. Based on this pilot trial, we have recently started a clinical study involving a double autotransplant, conditioned with melphalan (200 mg/m2) followed by melphalan (140 mg/m2) and busulphan (14 mg/kg), supported by the reinfusion of highly purified CD34+ cells.
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PMID:Selection and transplantation of autologous hematopoietic CD34+ cells for patients with multiple myeloma. 957 Jun 75

Unfractionated peripheral blood stem cell (PBSC) grafts contain measurable quantities of myeloma cells and are therefore a potential source of relapse posttransplantation. In contrast, fluorescence-activated cell sorting (FACS)-sorted CD34+ Thy1+ Lin- peripheral blood cells are substantially enriched for stem cell activity, yet contain virtually no clonal myeloma cells. A study was performed in patients with symptomatic myeloma, who had received 12 months or less of preceding standard chemotherapy, to evaluate the feasibility of large scale purification of primitive hematopoietic stem cells in order to study engraftment kinetics posttransplantation and the degree of tumor cell contamination of this cell population, based on polymerase chain reaction (PCR) analysis for the patient-specific complementarity-determining region III (CDR III). PBSC were mobilized with high dose cyclophosphamide and granulocyte-macrophage colony-stimulating factor (GM-CSF). A combination of elutriation and chemical lysis was used to deplete PBSC collections of monocytes, granulocytes, erythrocytes, and platelets. Subsequently, CD34+ Thy1+ Lin- progenitor cells were purified with high speed cell sorting. Of the 10 evaluable patients, nine met the required minimum criteria of >/=7.2 x 10(5) cells/kg to support tandem transplants. After high dose melphalan (200 mg/m2) eight engrafted successfully, although granulocyte (absolute neutrophil count [ANC] >0.5 x 10(9)/L, 16 days) and platelet recovery (platelets > 50 x 10(9)/L, 39 days) was substantially delayed when compared with unmanipulated PBSC grafts; one patient required infusion of a reserve graft because of lack of evidence of engraftment by day +28. Three patients proceeded to a second graft with high dose melphalan and total body irradiation; two required infusion of a reserve graft and both died of infectious complications; one showed delayed, but complete, engraftment after this myeloablative regimen. Two of the nine evaluable patients attained a clinical complete remission (CR). The grafts from three patients were tested for tumor contamination and contained no detectable clonal myeloma cells. Larger quantities of purified cells may be required to resolve the problem of delayed engraftment.
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PMID:Collection, tumor contamination, and engraftment kinetics of highly purified hematopoietic progenitor cells to support high dose therapy in multiple myeloma. 961 43

Rheumatoid factors (RF) recognize conformational determinants located within the Fc portion of IgG. By analyzing a panel of monoclonal rheumatoid arthritis (RA)-derived RFs, we previously demonstrated that the somatically generated light chain complementarity-determining region 3 (CDR3) contributes to RF specificity. We have now generated a panel of heavy chain mutants of the B'20 Ab, a high affinity RA-derived IgM RF. B'20 also binds avidly to protein A and weakly to ssDNA and tetanus toxoid. B9601, a RF negative Ab that is highly homologous to B'20 but does not bind any of the Ags tested, and RC1, a low affinity polyreactive RF, were used to generate heavy chain mutants with framework (FR) and CDR switches. The mutated heavy chains were cotransfected into a myeloma cell line with the germline counterpart of the B'20 light chain, and the expressed Ig tested for antigenic specificity. We show that both RF specificity and polyreactivity of B'20 is dependent on its unique heavy chain CDR3 region. Replacement with a B9601 CDR3 shortened to the same length as the B'20 CDR3, and with only 5 amino acid differences, did not restore Fc binding. Conversely, absence of protein A binding of B9601 is due to the presence of a serine residue at position 82a in the B9601 heavy chain FR3 region. Together, our data suggest that Ig gene recombination events can generate B cells with autoantibody specificities in the preimmune repertoire. Abnormal release, activation, expansion, or mutation of such cells might all contribute to the generation of a high titer RF response in patients with RA.
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PMID:Rheumatoid factor specificity of a VH3-encoded antibody is dependent on the heavy chain CDR3 region and is independent of protein A binding. 972 22

Plasma cell dyscrasias may be responsible for Fanconi's syndrome, due to the toxicity of a free monoclonal kappa light chain toward kidney proximal tubules. Eight cases of Fanconi's syndrome were analyzed. We compared the structures of VkappaI variability subgroup V domains from five cases of Fanconi's syndrome and one myeloma without renal involvement. Among Fanconi cases, four putative structures were obtained after molecular modeling by homology, and the other had previously been refined by X-ray crystallography. The complete sequences of one VkappaI, one VkappaIII and N-terminal sequences of two VkappaI light chains, from patients with different forms of Fanconi's syndrome, were compared with four previously studied sequences. All three kappa chains responsible for a 'classical' form with intralysosomal crystals and a low mass myeloma, were encoded by the LCO2/O12 germline gene and had an unusual non-polar residue exposed to the solvent in the CDR-L1 loop. Of both VkappaI light chains from patients with Fanconi's syndrome without intracellular crystals, one derived from LCO2/O12 and the other from LCO8/O18 gene. Another feature that could be related to non-crystallization was the absence of accessible side chains in the CDR-L3 loop which is known to be implicated in dimer formation.
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PMID:Kappa light chain-associated Fanconi's syndrome: molecular analysis of monoclonal immunoglobulin light chains from patients with and without intracellular crystals. 1032 8

The aim of this study was to determine the presence of monoclonal myeloma precursor B cells in peripheral blood stem cell harvests and to investigate their role in the clinical outcome of multiple myeloma patients. A total of 39 multiple myeloma patients were treated with a sequential therapy including double high-dose melphalan therapy followed by a double transplant procedure. The apheresis products for the second transplant were purged using a panel of four or five different mouse monoclonal antibodies against B-cell antigens (CD10, CD19, CD20, CD22 and CD37). In 19/39 patients a tumour-specific CDR III signal was identified in the diagnostic bone marrow. Gene scan analysis after CDR III PCR of the magnetic bead isolated B-cell fraction from the apheresis products in these 19 patients revealed three different patterns: 32% of patients had a predominantly monoclonal B-cell population; 63% of patients had an identifiable monoclonal signal within an oligoclonal B-cell population. In only 1/19 patients were no monoclonal B cells identified in the B-cell population of the apheresis product. A correlation between the clonal pattern and the clinical response after sequential chemotherapy was found. Patients with a predominance of monoclonal myeloma or myeloma precursor B cells had an early relapse or achieved a minimal response or a partial remission. Patients with an oligo- and/or polyclonal pattern achieved a high percentage of partial as well as complete remissions.
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PMID:The relationship between monoclonal myeloma precursor B cells in the peripheral blood stem cell harvests and the clinical response of multiple myeloma patients. 1093 Oct 11

Polymerase chain reaction (PCR) based assays were found to be a realistic alternative to Southern blot hybridization for the assessment of clonal immunoglobulin heavy chain gene rearrangements. However, a comparison of the different PCR based studies reveals considerable variation in experimental design and marked differences in the reported results. This study compared different single- and double-step PCR assays relying on various FR3, FR2, FR1 and JH based primers for the detection of B cell clonality in acute lymphoblastic leukemias (ALL), non-Hodgkin's-lymphoma (NHL), multiple myeloma (MM), monoclonal gammopathies of unknown significance (MGUS) and three polyclonal gammopathies (PG). The highest monoclonality rate was observed using seminested CDR-III region amplification. This method achieved a monoclonal product in 6 of 13 pro-B ALL 21 of 29 c-ALL, 7 of 8 pre-B-ALL, 18 of 21 B-ALL, 14 of 17 B-NHL (intermediate or high grade) with bone marrow involvement, 0 of 9 B-NHL without bone marrow involvement, 9 of 9 low grade B-NHL (immunocytoma and including chronic lymphocytic leucemia), 13 of 19 MM, 2 of 9 MGUS, and 0 of 3 PG. Additional monoclonality was detected with nested CDR I PCR in 1 pro-B-ALL, 1 c-ALL, and 2 MM. CDR III IgH PCR has been confirmed as an efficient method for determining clonality in B-cell neoplasias. Some additional monoclonal products can be seen with CDR I-based PCR. Detection of monoclonality depends on the maturation grade of the neoplastic B-cell population.
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PMID:Detection of immunoglobulin heavy chain genes rearrangements in B-cell leukemias, lymphomas, multiple myelomas, monoclonal and polyclonal gammopathies. 1097 94

Reinfusion of myeloma progenitor cells may contribute to relapse of multiple myeloma after autologous stem cell transplantation. The aim of our study was to investigate whether monoclonal B-cells are present in the apheresis product and to evaluate the clinical relevance of these cells. Leukapheresis products of 55 patients were purged with anti-B-cell-Monoclonal antibodies (MoAbs) and immunobeads. Monoclonal B-cells were found in 85% of patients within the B-cell population. In one third of all myeloma patients, the majority of B-cells was represented by monoclonal myeloma progenitor B-cells, whereas in two thirds of patients monoclonal cells only represented a small part of the entire B-cell population. As shown by sequence analysis, monoclonal precursor B-cells and malignant plasma cells had the identical genetic CDR III sequence. The purging efficacy, using a negative selection system, was a median of 3 logs (range 1,5-3,5). No statistical difference in the purging efficacy was found when 3, 4 or 5 MoAbs against B-cells antigens were used. However, a tumor specific signal could be detected in the purged harvest of all patients, when the highly sensitive ASO-PCR approach was used. Furthermore, we found a direct correlation between the amount of remaining monoclonal cells after negative selection and the event free survival of myeloma patients. 10/15 patients with a median of 20 x 10(3) monoclonal cells in the purged product relapsed at a median of 1,4 years, whereas only 6/24 patients with an oligoclonal pattern including a low number of remaining monoclonal cells relapsed at a median of 2,2 years. The event free survival (EFS) was statistically different between the two groups (p = 0,014).
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PMID:Peripheral blood monoclonal B-cells predict the event free survival in multiple myeloma. 1137 52

A 74-year-old woman was admitted to our hospital in March 1998 for low-back pain. In 1990, she had a chemotherapy for diffuse mixed cell lymphoma. Biochemical and serologic assays revealed a total protein level of 9.7 g/dl and an IgG level of 4,530 mg/dl. Immunoelectrophoresis showed monoclonal IgG protein associated with two monoclonal kappa and lambda light chain components. Bone marrow examination showed proliferation of myeloma cells comprising up to 25% of all nucleated cells. Myeloma cells were immunohistochemically positive for IgG and kappa and lambda light chains. IgG contained equal amounts of IgG 1 and IgG 2 subtypes and the complementarity determining region 3 (CDR 3) of myeloma cells showed oligoclonality by polymerase chain reaction, suggesting the myeloma cells may have two components. The patient received melphalan and prednisone in combination, resulting in only a minor response. She eventually developed angioimmunoblastic T-cell lymphoma. Biclonal gammopathy associated with malignant lymphoma is rare in case of multiple myeloma and may provide some insight into the pathogenesis of plasma cell tumors.
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PMID:[Biclonal light chain gammopathy in multiple myeloma--a case report]. 1204 84

Multiple myeloma is characterized by malignant plasma cell-infiltration of bone marrow. Treatment with high-dose therapy results in a high rate of clinical remissions, but almost all patients ultimately relapse. Clinical staging and detection of relapse are limited in sensitivity. Therefore, we established molecular methods based on the highly clone-specific CDR regions of the immunoglobulin VH locus for sensitive and specific detection of residual myeloma cells after bone marrow transplantation. VDJ rearrangements were identified using a set of VH primers and a JH primer. Clone-specific rearrangements were detected by comparison with germ-line sequences. With the nested PCR approach, first-round amplification with the consensus primers was done followed by second amplification with myeloma-specific primers. The real-time quantitative PCR was performed using a myeloma-specific forward primer in combination with a JH consensus TaqMan probe and reverse primer. Sensitivity was tested using dilutions of myeloma cell lines into mononuclear cells. Nested PCR had a sensitivity of 10(-6) and TaqMan PCR of 10(-4) to 10(-5). Specificity was determined by testing different cell lines and patients' probes. These results were confirmed by follow up of 2 patients after allogeneic transplantation with dose-reduced conditioning. Molecular methods are very sensitive and specific tools for follow up of myeloma patients after allogeneic transplantation. By using the quantitative approach, it is possible to see kinetics of bone marrow tumor load, which can be used to guide therapeutic decisions like donor leukocyte infusions (DLI).
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PMID:Molecular methods for detection and quantification of myeloma cells after bone marrow transplantation: comparison between real-time quantitative and nested PCR. 1259 Jul 12


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