Oncolytic herpes simplex virus type 1 (HSV-1) in combination with lenalidomide for plasma cell neoplasms.

Oncolytic viruses exert an anti-tumour effect through two mechanisms: direct oncolytic and indirect immune-mediated mechanisms. Although oncolytic herpes simplex virus type 1 (HSV-1) has been approved for melanoma treatment and is being examined for its applicability to a broad spectrum of malignancies, it is not known whether it has an anti-myeloma effect. In the present study, we show that the third-generation oncolytic HSV-1, T-01, had a direct oncolytic effect on five of six human myeloma cell lines in vitro. The anti-tumour effect was enhanced in the presence of peripheral blood mononuclear cells (PBMCs) from healthy individuals and, to a lesser extent, from patients with myeloma. The enhancing effect of PBMCs was abrogated by blocking type I interferons (IFNs) or by depleting plasmacytoid dendritic cells (pDCs) or natural killer (NK) cells, suggesting that pDC-derived type I IFNs and NK cells dominated the anti-tumour effect. Furthermore, the combination of T-01 and lenalidomide exhibited enhanced cytotoxicity, and the triple combination of T-01, lenalidomide and IFN-α had a maximal effect. These data indicate that oncolytic HSV-1 represents a viable therapy for plasma cell neoplasms through direct oncolysis and immune activation governed by pDCs and NK cells. Lenalidomide is likely to augment the anti-myeloma effect of HSV-1.

IgA plasma cell neoplasms are characterized by poorer long-term survival and increased genomic complexity compared to IgG neoplasms.

The characteristics of the IgA plasma cell neoplasms are not clearly reported in the literature. The main goal of this study is to examine IgA plasma cell neoplasms (PCN) and to compare them to IgG lesions. After at least 5 years from the identification of an M protein, 98 cases were selected, the presentation and clinical evolution of 45 IgA neoplasms were compared to 43 cases of IgG gammopathies. The classification at presentation as monoclonal gammopathy of undermined significance (MGUS)-22 of 45 IgA and 20 of 43 IgG (49 vs 46%), plasma cell myeloma (PCM)-22 of 45 IgA and 22 of 43 IgG (49 vs 51%) and smoldering PCM (SPCM)-1 each (2% for both) was essentially identical. No solitary plasmacytomas were identified. At presentation, IgA patients were younger (66.5 ± 11.3 vs. 69.2 ± 10.7 years), less likely to have bone lesions (12/45 vs 18/43, p < 0.14) or immunoparesis (51% vs. 63%), differences statistically insignificant. Cases with normal fluorescence in-situ hybridization (FISH) results, 27% for IgA vs 61% for IgG (p < 0.037) were statistically different. The IgA patients had worse survival (80 vs 108 months median IgA vs IgG, p < 0.013), difference not detectable in the first 5 years, but substantial after 10. In conclusion, poorer long-term survival and increased genomic complexity by FISH are characteristics of IgA PCNs.

Primary pulmonary plasmacytoma presenting with rare IgG lambda monoclonal gammopathy.

Extramedullaryplasmacytoma (EMP) represents a peculiar and typically progressive malignancy that can originate outside the bone marrow. Primary pulmonary plasmacytoma (PPP) is a rare subset of EMP, confined to the lung. A 55-year-old man, diabetic, non-smoker presented to our clinic with a right chest wall swelling. A routine chest radiograph showed a well-circumscribed opacity in the right upper lung zone. A CT of the chest revealed a large right upper lobe mass with extensive local infiltration. Biopsy and immunohistochemical evaluation led to a diagnosis of PPP. Screening for multiple myeloma was negative. Serum immunofixation showed an IgG lambda monoclonal gammopathy, found in a minority of PPP patients. In view of disease extent, treatment with chemotherapy and radiotherapy was initiated. The patient is currently in out patient follow-up and has shown a favourable response to the treatment with a considerable decrease in serum IgG levels.

Atypical IgG4+ Plasmacytic Proliferations and Lymphomas: Characterization of 11 Cases.

OBJECTIVES: To report the clinicopathologic features of monotypic immunoglobulin G4+ (IgG4+) lymphoid and plasmacytic proliferations. METHODS: Cases were identified from the pathology files. Pathology and clinical materials were reviewed. RESULTS: Eleven cases of monotypic IgG4+ proliferations were identified at nodal, orbital, or salivary sites. Six cases (three men, three women; age, 57-94 years) met criteria for lymphoma or plasma cell neoplasia. Most contained frequent Mott cells. Five cases (three men, two women; age, 40-80 years) had restricted proliferations of atypical/monotypic IgG4+ plasma cells in a background of reactive lymphoid hyperplasia or inflammation. CONCLUSIONS: Monotypic IgG4+ proliferations include lymphomas, plasmacytic neoplasms, and a previously uncharacterized group of proliferations not meeting criteria for conventional hematolymphoid neoplasia. Distinct features included prominent Mott cells and/or monotypic plasma cells within follicles. The proliferations were infrequently associated with IgG4-related disease (IgG4-RD). Our findings raise questions regarding the relationship between clonal IgG4+ proliferations, reactive/inflammatory processes, and IgG4-RD.

Neoplastic plasma cells generate an inflammatory environment within bone marrow and markedly alter the distribution of T cells between lymphoid compartments.

Monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) are characterised by the accumulation of malignant plasma cells within bone marrow and lead to a range of abnormalities in the peripheral blood T cell repertoire. We investigated the level of inflammatory chemokines within the bone marrow and blood of patients with MGUS and MM and related this to the pattern of chemokine receptor expression on T cells in both compartments.The expression of a wide range of chemokine ligands for CXCR3 and CCR4 was markedly increased within the bone marrow of patients with MGUS and MM compared to healthy donors. The most marked effects were seen for CCL4 and CXCL9 which were increased by 4 and 6 fold respectively in the bone marrow of patients with myeloma. The expression of CXCR3 and CCR4, the major TH1 and TH2-associated chemokine receptors, was increased substantially on T cells within the bone marrow of patients whereas the percentage of CXCR3-expressing T cells within blood was correspondingly decreased. The presence of even small numbers of neoplastic plasma cells or associated stroma can therefore generate an inflammatory chemokine tumour microenvironment. This leads to the selective recruitment or retention of specific T cell subsets which is likely to underlie many of the features regarding the peripheral T cell repertoire in myeloma and may also contribute to the immune suppression associated with this disease. This local inflammatory reaction may represent a tumour-specific immune response or may itself play an important role in tumour progression and as such may offers a potential novel target for therapeutic intervention.

Tbo-Filgrastim versus Filgrastim during Mobilization and Neutrophil Engraftment for Autologous Stem Cell Transplantation.

There are limited data available supporting the use of the recombinant granulocyte colony-stimulating factor (G-CSF), tbo-filgrastim, rather than traditionally used filgrastim to mobilize peripheral blood stem cells (PBSC) or to accelerate engraftment after autologous stem cell transplantation (ASCT). We sought to compare the efficacy and cost of tbo-filgrastim to filgrastim in these settings. Patients diagnosed with lymphoma or plasma cell disorders undergoing G-CSF mobilization, with or without plerixafor, were included in this retrospective analysis. The primary outcome was total collected CD34(+) cells/kg. Secondary mobilization endpoints included peripheral CD34(+) cells/µL on days 4 and 5 of mobilization, adjunctive use of plerixafor, CD34(+) cells/kg collected on day 5, number of collection days and volumes processed, number of collections reaching 5 million CD34(+) cells/kg, and percent reaching target collection goal in 1 day. Secondary engraftment endpoints included time to neutrophil and platelet engraftment, number of blood product transfusions required before engraftment, events of febrile neutropenia, and length of stay. A total of 185 patients were included in the final analysis. Patients receiving filgrastim (n = 86) collected a median of 5.56 × 10(6) CD34(+) cells/kg, compared with a median of 5.85 × 10(6) CD34(+) cells/kg in the tbo-filgrastim group (n = 99; P = .58). There were no statistically significant differences in all secondary endpoints with the exception of apheresis volumes processed (tbo-filgrastim, 17.0 liters versus filgrastim, 19.7 liters; P < .01) and mean platelet transfusions (tbo-filgrastim, 1.7 units versus filgrastim, 1.4 units; P = .04). In conclusion, tbo-filgrastim demonstrated similar CD34(+) yield compared with filgrastim in mobilization and post-transplantation settings, with no clinically meaningful differences in secondary efficacy and safety endpoints. Furthermore, tbo-filgrastim utilization was associated with cost savings of approximately $1406 per patient utilizing average wholesale price.

CAR therapy for hematological cancers: can success seen in the treatment of B-cell acute lymphoblastic leukemia be applied to other hematological malignancies?

Chimeric antigen receptor (CAR) T-cell therapy has recently come into the spotlight due to impressive results in patients with B-cell acute lymphoblastic leukemia. By targeting CD19, a marker expressed most B-cell tumors, as well as normal B cells, CAR T-cell therapy has been investigated as a treatment strategy for B-cell leukemia and lymphoma. This review will discuss the successes of this therapy for the treatment of B-cell acute lymphoblastic leukemia and the challenges to this therapeutic strategy. We will also discuss application of CAR T-cell therapy to chronic lymphocytic leukemia and other B-cell malignancies including a follicular lymphoma, diffuse large B-cell lymphoma, as well as acute and plasma cell malignancies.

Utility of nine-color, 11-parameter flow cytometry for detection of plasma cell neoplasms: a comparison with bone marrow morphologic findings and concurrent M-protein studies in serum and urine.

OBJECTIVES: Multiparameter flow cytometry (MFC) is a widely available laboratory platform for the evaluation of plasma cell (PC) neoplasms. We assess the performance of a nine-color MFC assay that uses stain-lyse-fix processing of bone marrow aspirates, minimal wash steps, and high acquisition rates with analysis of up to 1.8 × 10(6) cells. METHODS: MFC results were compared with microscopic examinations, immunohistochemical studies, and serum/urine M-protein measurements from patients with documented or suspected PC neoplasms. RESULTS: Sensitivity exceeded that of microscopic examinations, with or without immunohistochemistry. In patients with PC myeloma, clonal PC detection by MFC fell in concert with M-protein levels. However, in a subset of patients, MFC detected clonal PCs after serum/urine studies turned negative. CONCLUSIONS: The nine-color analytic cocktail eliminates duplication of PC gating reagents required for evaluation of the same epitopes using a five- or six-color approach. Fewer analytic cocktails result in lower instrument acquisition times per case, a significant factor for the large data sets required for optimal residual disease assessment. Finally, concurrent analysis of nine epitopes and two light scatter parameters aids detection of residual disease, particularly when it is mixed with polyclonal PCs.

Low levels of interleukin-1 receptor antagonist (IL-1RA) predict engraftment syndrome after autologous stem cell transplantation in POEMS syndrome and other plasma cell neoplasms.

A rare, multisystem, plasma cell neoplasm, POEMS (polyradiculoneuropathy, organomegaly, endocrinopathy, M-spike, skin changes) syndrome is characterized by an abundance of proinflammatory and angiogenic cytokines. Patients with POEMS are known to have a high incidence of engraftment syndrome after autologous stem cell transplantation. We conducted a pilot study assessing levels of 30 different pro- and anti-inflammatory cytokines before and serially after transplantation in 18 patients with plasma cell neoplasms: POEMS syndrome (n = 9), multiple myeloma (n = 4), and amyloidosis (n = 5). We show that POEMS patients have higher pretransplantation levels of IL-4, IL-10, IL-13, IFN-α, and EGF as compared with those with non-POEMS plasma cell neoplasms. Higher pre- and posttransplantation IL-13 levels correlated with delayed neutrophil engraftment in POEMS patients. Low posttransplantation IL-1RA levels correlated with engraftment syndrome in both POEMS and non-POEMS patients. We conclude that differences in the peri-transplantation cytokine milieu may explain the higher transplantation morbidity in patients with POEMS syndrome. Our results need validation in a larger cohort.

Immunophenotypic analysis of myeloperoxidase-negative leukemia cutis and blastic plasmacytoid dendritic cell neoplasm.

Myeloid leukemia cutis (LC) and blastic plasmacytoid dendritic cell neoplasm (BPDCN) are morphologically indistinguishable malignancies that frequently manifest in the skin. Separating myeloperoxidase-negative LC from BPDCN may be particularly challenging. We identified a panel of immunohistochemical stains to distinguish myeloid LC (23 cases) from BPDCN (12 cases): myeloperoxidase, which stained 7 cases (30%) of LC and 0 cases (0%) of BPDCN; CD56, which stained 12 cases (52%) of LC and all 12 cases (100%) of BPDCN; CD4, which stained 2 cases (9%) of LC and all 12 cases (100%) of BPDCN; CD123, which stained 4 cases (17%) of LC and 10 cases (83%) of BPDCN; and Tcl-1, which stained 2 cases (9%) of LC and 9 (82%) of 11 cases of BPDCN. It is interesting that CD33 was not helpful; it stained 18 (78%) cases of LC and 11 cases (92%) of BPDCN. Our results indicate that a panel that includes CD4, CD56, CD123, and Tcl-1 can appropriately distinguish between these 2 entities.

Marginal zone B cell lymphomas with extensive plasmacytic differentiation are neoplasms of precursor plasma cells.

Occasional marginal zone lymphomas have extensive plasmacytic differentiation (P-MZL). We present an argument based on our data and previous published observations that P-MZL represent neoplasms of precursor plasma cells. Five P-MZL were analyzed by flow cytometry and the phenotype was compared with conventional MZL, plasma cell myeloma (PCM), reactive plasmacytoses (RP), and normal marrow plasma cells. The clonal cells in four of five P-MZL were CD19+, CD20(dim/⁻), CD38(bright), CD45++, CD56⁻, CD138⁻, and surface light chain(dim/⁻). One case was CD56+, CD138+, and CD19⁻. A separate clonal mature B cell population [CD20+, CD79b+] was not detected in any of these tumors. Hierarchical clustering demonstrated similarity between the neoplastic cells in four of the five P-MZL with plasma cells in RP comprised of precursor plasma cells. Analysis of normal bone marrow plasma cells revealed a CD45++CD38(bright)CD19+CD138⁻/+ precursor plasma cell population similar to the plasma cells in RP and P-MZL and a very small population of mature CD45+/⁻CD38(bright)CD138+CD19⁻ plasma cellsresembling the neoplastic cells in PCM. The findings suggest that P-MZL represents a malignancy of a plasma cell stage of differentiation distinct from the plasma cell stage corresponding to PCM. We propose the term precursor plasma cell neoplasm for these tumors.

Serum free light chain analysis in multiple myeloma and plasma cell dyscrasias.

After the development of a reliable method to detect free light chains in serum, several investigations have been conducted to explore their importance in plasma cell dyscrasias (PCD). Detection of monoclonal proteins is very important in the diagnosis and management of PCD, which include a broad spectrum of diseases such as multiple myeloma and also benign, premalignant disorders like monoclonal gammopathy of undetermined significance. The aim of this article is to summarize the recent studies and to highlight the importance of free light chain analysis in the diagnosis of PCD, its prognostic value and role in the management of this group of diseases.

Multiparametric flow cytometry profiling of neoplastic plasma cells in multiple myeloma.

BACKGROUND AND AIM: The clinical impact of multiparametric flow cytometry (MFC) in multiple myeloma (MM) is still unclear and under evaluation. Further progress relies on multiparametric profiling of the neoplastic plasma cell (PC) compartment to provide an accurate image of the stage of differentiation. The primary aim of this study was to perform global analysis of CD expression on the PC compartment and subsequently to evaluate the prognostic impact. Secondary aims were to study the diagnostic and predictive impact. DESIGN AND METHODS: The design included a retrospective analysis of MFC data generated from diagnostic bone marrow (BM) samples of 109 Nordic patients included in clinical trials within NMSG. Whole marrow were analyzed by MFC for identification of end-stage CD45(-) /CD38(++) neoplastic PC and registered the relative numbers of events and mean fluorescence intensity (MFI) staining for CD19, CD20, CD27, CD28, CD38, CD44, CD45, CD56, and isotypes for cluster analysis. RESULTS: The median MFC-PC number was 15%, and the median light microscopy (LM)-PC number was 35%. However, the numbers were significant correlated and the prognostic value with an increased relative risk (95% CI) of 3.1 (1.7-5.5) and 2.9 (1.4-6.2), P < 0.0003 and P < 0.004 of MFC-PC and LM-PC counts, respectively. Unsupervised clustering based on global MFI assessment on PC revealed two clusters based on CD expression profiling. Cluster I with high intensity for CD56, CD38, CD45, right-angle light-scatter signal (SSC), forward-angle light-scatter signal (FSC), and low for CD28, CD19, and a Cluster II, with low intensity of CD56, CD38, CD45, SSC, FSC, and high for CD28, CD19 with a median survival of 39 months and 19 months, respectively (P = 0.02). CONCLUSIONS: The MFC analysis of MM BM samples produces diagnostic, prognostic, and predictive information useful in clinical practice, which will be prospectively validated within the European Myeloma Network (EMN). © 2010 International Clinical Cytometry Society.

Anaplastic plasmacytomas: relationships to normal memory B cells and plasma cell neoplasms of immunodeficient and autoimmune mice.

Anaplastic plasmacytomas (APCTs) from NFS.V(+) congenic mice and pristane-induced plasmacytic PCTs from BALB/c mice were previously shown to be histologically and molecularly distinct subsets of plasma cell neoplasms (PCNs). Here we extended these comparisons, contrasting primary APCTs and PCTs by gene expression profiling in relation to the expression profiles of normal naïve, germinal centre, and memory B cells and plasma cells. We also sequenced immunoglobulin genes from APCT and APCT-derived cell lines and defined surface phenotypes and chromosomal features of the cell lines by flow cytometry and by spectral karyotyping and fluorescence in situ hybridization. The results indicate that APCTs share many features with normal memory cells and the plasma cell-related neoplasms (PLs) of FASL-deficient mice, suggesting that APCTs and PLs are related and that both derive from memory B cells. Published in 2010 by John Wiley & Sons, Ltd.

A counting strategy for estimating plasma cell number in CD138-stained bone marrow core biopsy sections.

Plasma cells are readily identified microscopically after immunostaining for the CD138 antigen, and CD138-stained bone marrow core biopsy sections have proved superior to Giemsa-stained aspirate smears and hematoxylineosin (H&E) sections for determining plasma cell percentages in marrow. The CD138-stained plasma cell percentage is generally obtained by visual estimation, after viewing the entire section. We propose an alternative method, in which the microscopist initially views the immunostained section under low- and medium-power magnification, then selects a single high-power field in which the relative concentration of plasma cells appears most representative of the section as a whole, and performs a manual differential count of plasma cells in that field. On 44 CD138-stained core biopsy specimens from patients with plasma cell myeloma, selected area counting provided plasma cell percentage values that were more closely correlated with total section plasma cell area, determined by computerized image cytometry, than were visual estimates. This simple method requires only slightly more time than visual appraisal, does not require extensive training or experience, and appears to provide a more accurate estimate of the plasma cell population within the entire specimen.