Multiple myeloma--an update on diagnosis and treatment

Immunophenotypic Profile and Measurable Residual Disease Monitoring in Multiple Myeloma: A Prospective Study From a Tertiary Care Centre in Southern India

BACKGROUND

Multiple myeloma (MM) immunophenotyping (IPT) and measurable residual disease (MRD) monitoring by flow cytometry is a surrogate for progression-free survival and overall survival in clinical trials. However, plasma cell enumeration is challenging owing to morphological discrepancies and plasma cell (PC) loss during the sample processing.

METHODS

In (n=87) newly diagnosed MM patients, we evaluated the immunophenotype of PCs at baseline, and for a subset of 35 patients MRD at post-induction was quantified and analyzed for association with outcomes and survival. The software Statistical Package for Social Sciences (SPSS), version 16.0 (SPSS Inc., Chicago, IL, USA) was used for all the statistical analysis.

RESULTS

Immunophenotyping showed strong positive expression of CD56 (83%), CD200 (94%), CD38 (92%), and CD117 (91%) and negative/weak expression of CD19 (83%), CD45 (89%), CD27 (74%), and CD81 (90%) respectively. Negative/weak expression of CD19 was significantly associated with age ≥56 years (p<0.048), with lower albumin (<3.4g/dL, p<0.001). Strong positive CD56 expression was significantly associated with the presence of M-protein (p<0.03). Strong positive CD117 expression was significantly associated with lower albumin (p<0.02). Strong positive CD200 expression was significantly associated with a good response (p<0.02). The median (IQR) value of bone marrow (BM)-MRD% was 0.005 (0.002-0.034). We found that there was no significant difference in the correlation, association, and survival outcomes with MRD%.

CONCLUSION

This study sheds light on the utility of IPT as an invaluable diagnostic tool in disease management. The findings of this study could be important when it comes to modifying the criteria for high-risk diseases and implementing a risk-adapted first therapy in clinical practice.

Quantification of circulating clonal plasma cells by multiparametric flow cytometry as a prognostic marker in patients with newly diagnosed multiple myeloma

BACKGROUND

Studies have shown that the quantification of circulating clonal plasma cells (cCPCs) in peripheral blood using flow cytometry could be used as a prognostic predictor of poor outcome in multiple myeloma (MM).

METHODS

In 66 newly diagnosed MM, cCPCs were quantified (cCPC%) and analysed for association with outcome and survival. Single-tube combined surface (CD45/CD19/CD138/CD38/CD56/CD27/CD81 as per availability) and cytoplasmic (kappa/lambda) staining was done using pre-titrated volumes of antibodies. In 26 patients, repeat cCPC% was assessed post-induction therapy. For association studies, treatment response has been taken as good (VGPR and above) and poor (PR and below). All statistical analyses were performed with SPSS software version 16.0.

RESULTS

There was no significant association between cCPC% at baseline with staging (p = 0.43), β2 -microglobulin (p = 0.27) and albumin (p = 0.08). There was a significant difference between the pre-induction and post-induction cCPC% (p = 0.0001). The patients were segregated using a cut-off of ≥0.197 and <0.197 based on the median values of baseline cCPC%. The post-induction outcome was available for 47 patients among whom 33 (70%) had VGPR and above. There was a significant association between higher cCPC% at baseline with poor treatment response (p = 0.008). The median OS in the study patients was 42 (CI 28.14-43.03) months and the median PFS was 39 (CI 28.49-49.04) months. Higher cCPC% showed a lower median PFS (30 vs. 39 months) and OS (35 vs. 41 months) compared to lower cCPC% though it was not statistically significant.

CONCLUSION

Flow cytometric baseline cCPC% in newly diagnosed MM was associated with poor treatment response and survival.

Metabolic cross-talk within the bone marrow milieu: focus on multiple myeloma

Cancer cells are well-known for their capacity to adapt their metabolism to their increasing energy demands which is necessary for tumor progression. This is no different for Multiple Myeloma (MM), a hematological cancer which develops in the bone marrow (BM), whereby the malignant plasma cells accumulate and impair normal BM functions. It has become clear that the hypoxic BM environment contributes to metabolic rewiring of the MM cells, including changes in metabolite levels, increased/decreased activity of metabolic enzymes and metabolic shifts. These adaptations will lead to a pro-tumoral environment stimulating MM growth and drug resistance In this review, we discuss the identified metabolic changes in MM and the BM microenvironment and summarize how these identified changes have been targeted (by inhibitors, genetic approaches or deprivation studies) in order to block MM progression and survival.

Measuring the global, regional, and national burden of multiple myeloma from 1990 to 2019

Background

Multiple myeloma (MM) is a major health concern. Understanding the different burden and tendency of MM in different regions is crucial for formulating specific local strategies. Therefore, we evaluated the epidemiologic patterns and explored the risk factors for MM death.

Methods

Data on MM were collected from the 2019 Global Burden of Disease study. We used incidence, mortality, and disability adjusted life-years to estimate the global, regional, and national burden of MM.

Results

In 2019, there were 155,688 (95% UI, 136,585 – 172,577) MM cases worldwide, of which 84,516 (54.3%, 70,924 – 94,910) were of men. The age-standardized incidence rate (ASIR) was 1.72/100,000 persons (95% UI, 1.59–1.93) in 1990 and 1.92/100,000 persons (95% UI, 1.68–2.12) in 2019. The number of MM deaths increased 1.19-fold from 51,862 (95% UI, 47,710–58,979) in 1990 to 113,474 (95% UI, 99,527 – 121,735) in 2019; the age-standardized death rate (ASDR) was 1.42/100,000 persons (95% UI, 1.24–1.52) in 2019. In recent 15 years, ASDR showed a steady tendency for men, and a downward tendency for women. Countries with high social-demographic indexes exhibited a higher ASIR and ASDR. Australasia, North America, and Western Europe had the highest ASIR and ASDR, with 46.3% incident cases and 41.8% death cases. Monaco had the highest ASIR and ASDR, which was almost half as high as the second highest country Barbados. In addition, United Arab Emirates and Qatar had the largest growth multiple in ASIR and ASDR, which was twice the third country Djibouti.

Conclusions

Globally, incident and death MM cases have more than doubled over the past 30 years. The increasing global burden may continue with population aging, whereas mortality may continue to decrease with the progression of medical technology. The global burden pattern of MM was diverse, therefore specific local strategies based on different burden patterns for MM are necessary.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08280-y.

Pregnancy and Its Successful Outcome in a Patient with Multiple Myeloma

Multiple myeloma is a B-cell neoplastic disorder and represents 1% of all cancers and 13% of hematological malignancies. It is predominantly a disease of elderly, and less than 3% of all cases are below the age of 40 years. We present the case of a 29-year-old lady with multiple myeloma who had spontaneous conception during maintenance therapy and subsequently a successful pregnancy outcome. She gave birth to a healthy female infant through normal vaginal delivery and subsequently could remain off therapy for 5 years. Since the patient had a history of abortions and stillbirth, it was a precious pregnancy and we could successfully salvage both the mother and the baby. Young female patients of myeloma who are in remission can be encouraged to start a family during their reproductive years with the support of a comprehensive care team of hematologists/oncologists and obstetricians.

Granulocytic myeloid-derived suppressor cells promote angiogenesis in the context of multiple myeloma

Multiple myeloma (MM) is a plasma cell malignancy characterized by the accumulation of tumor cells in the bone marrow (BM) and is associated with immunosuppression, angiogenesis and osteolysis. Myeloid-derived suppressor cells (MDSCs) represent a heterogeneous population of immature, immunosuppressive myeloid cells that promote tumor progression through different mechanisms.

In this work, we studied the contribution of MDSC subsets to different disease-promoting aspects in MM. We observed an expansion of polymorphonuclear/granulocytic (PMN-)MDSCs in two immunocompetent murine MM models, while this was not observed for monocytic (MO-)MDSCs. Both MDSC subpopulations from MM-bearing mice were immunosuppressive, but PMN-MDSCs displayed a higher suppressive potential. Soluble factors secreted by MM cells increased the viability of MDSCs, whereas the presence of MDSCs did not affect the proliferation of MM cells in vitro or in vivo. Interestingly, we observed a pro-angiogenic effect of PMN-MDSCs in the context of MM using the chick chorioallantoic membrane assay. Consistently, MM-derived PMN-MDSCs showed an up-regulation of angiogenesis-related factors and reduced PMN-MDSC levels were associated with less angiogenesis in vivo. Finally, we identified MO-MDSCs as osteoclast precursors.

These results suggest that MDSC subpopulations play diverging roles in MM. We show for the first time that PMN-MDSCs exert a pro-angiogenic role in MM.

Bone marrow IRF4 level in multiple myeloma: an indicator of peripheral blood Th17 and disease

Interferon regulator factor 4 (IRF4) is characterized to be a member of interferon regulatory family, which is predominantly expressed in bone marrow plasma cells of patients with multiple myeloma (MM). Recent studies indicated IRF4 is critical for T-help cells (Th17) differentiation and interleukin-17 (IL-17) secretion. Here, a total of 58 MM patients were enrolled in this study, the proportions of Th17 cells and T regulatory (Treg) cells in peripheral blood mononuclear cells (PBMCs) were determined by flow cytometric analysis. Immunohistochemistry was employed to detect the IRF4 expression in bone marrow. Herein, we observed a significant increase of IRF4 in bone marrow accompanied with a notable up-regulation of Th17 cells in PBMC within MM patients compared with healthy donors. Furthermore, the proportions of Th17 cells and serum IL-17 levels were higher in patients with stage III than stage I & II MM patients, and those parameters were positively correlated with the expression of IRF4 in these cases. These results for the first time indicate that a crosstalk between IRF4 and Th17 cells is associated with MM prognosis, and IRF4 may be served an important target for MM immunotherapy.

Logic-Based and Cellular Pharmacodynamic Modeling of Bortezomib Responses in U266 Human Myeloma Cells

Systems models of biological networks show promise for informing drug target selection/qualification, identifying lead compounds and factors regulating disease progression, rationalizing combinatorial regimens, and explaining sources of intersubject variability and adverse drug reactions. However, most models of biological systems are qualitative and are not easily coupled with dynamical models of drug exposure-response relationships. In this proof-of-concept study, logic-based modeling of signal transduction pathways in U266 multiple myeloma (MM) cells is used to guide the development of a simple dynamical model linking bortezomib exposure to cellular outcomes. Bortezomib is a commonly used first-line agent in MM treatment; however, knowledge of the signal transduction pathways regulating bortezomib-mediated cell cytotoxicity is incomplete. A Boolean network model of 66 nodes was constructed that includes major survival and apoptotic pathways and was updated using responses to several chemical probes. Simulated responses to bortezomib were in good agreement with experimental data, and a reduction algorithm was used to identify key signaling proteins. Bortezomib-mediated apoptosis was not associated with suppression of nuclear factor κB (NFκB) protein inhibition in this cell line, which contradicts a major hypothesis of bortezomib pharmacodynamics. A pharmacodynamic model was developed that included three critical proteins (phospho-NFκB, BclxL, and cleaved poly (ADP ribose) polymerase). Model-fitted protein dynamics and cell proliferation profiles agreed with experimental data, and the model-predicted IC50 (3.5 nM) is comparable to the experimental value (1.5 nM). The cell-based pharmacodynamic model successfully links bortezomib exposure to MM cellular proliferation via protein dynamics, and this model may show utility in exploring bortezomib-based combination regimens.

Type-B lactic acidosis associated with progressive multiple myeloma

We report a 64-year-old lady with stage II, Immunoglobulin-G lambda multiple myeloma (MM) (standard risk), who presented with type-B lactic acidosis (LA), and multi-organ dysfunction associating myeloma progression, and ending in imminent death. In the context of literature review of all previously reported similar cases, this report highlights and discusses the association of type-B LA and MM (especially progressive disease), and also emphasizes the poor outcome. Early recognition of this condition with intensive supportive care, and treatment of multiple myeloma may improve outcomes.

Myeloid-derived suppressor cells as therapeutic target in hematological malignancies

Myeloid-derived suppressor cells (MDSC) are a heterogeneous population of immature myeloid cells that accumulate during pathological conditions such as cancer and are associated with a poor clinical outcome. MDSC expansion hampers the host anti-tumor immune response by inhibition of T cell proliferation, cytokine secretion, and recruitment of regulatory T cells. In addition, MDSC exert non-immunological functions including the promotion of angiogenesis, tumor invasion, and metastasis. Recent years, MDSC are considered as a potential target in solid tumors and hematological malignancies to enhance the effects of currently used immune modulating agents. This review focuses on the characteristics, distribution, functions, cell–cell interactions, and targeting of MDSC in hematological malignancies including multiple myeloma, lymphoma, and leukemia.

Calmodulin antagonists induce cell cycle arrest and apoptosis in vitro and inhibit tumor growth in vivo in human multiple myeloma

Background

Human multiple myeloma (MM) is an incurable hematological malignancy for which novel therapeutic agents are needed. Calmodulin (CaM) antagonists have been reported to induce apoptosis and inhibit tumor cell invasion and metastasis in various tumor models. However, the antitumor effects of CaM antagonists on MM are poorly understood. In this study, we investigated the antitumor effects of naphthalenesulfonamide derivative selective CaM antagonists W-7 and W-13 on MM cell lines both in vitro and in vivo.

Methods

The proliferative ability was analyzed by the WST-8 assay. Cell cycle was evaluated by flow cytometry after staining of cells with PI. Apoptosis was quantified by flow cytometry after double-staining of cells by Annexin-V/PI. Molecular changes of cell cycle and apoptosis were determined by Western blot. Intracellular calcium levels and mitochondrial membrane potentials were determined using Fluo-4/AM dye and JC-10 dye, respectively. Moreover, we examined the in vivo anti-MM effects of CaM antagonists using a murine xenograft model of the human MM cell line.

Results

Treatment with W-7 and W-13 resulted in the dose-dependent inhibition of cell proliferation in various MM cell lines. W-7 and W-13 induced G1 phase cell cycle arrest by downregulating cyclins and upregulating p21^cip1. In addition, W-7 and W-13 induced apoptosis via caspase activation; this occurred partly through the elevation of intracellular calcium levels and mitochondrial membrane potential depolarization and through inhibition of the STAT3 phosphorylation and subsequent downregulation of Mcl-1 protein. In tumor xenograft mouse models, tumor growth rates in CaM antagonist-treated groups were significantly reduced compared with those in the vehicle-treated groups.

Conclusions

Our results demonstrate that CaM antagonists induce cell cycle arrest, induce apoptosis via caspase activation, and inhibit tumor growth in a murine MM model and raise the possibility that inhibition of CaM might be a useful therapeutic strategy for the treatment of MM.

Establishment of a murine graft-versus-myeloma model using allogeneic stem cell transplantation

Background

Multiple myeloma (MM) is a malignant plasma cell disorder with poor long-term survival and high recurrence rates. Despite evidence of graft-versus-myeloma (GvM) effects, the use of allogeneic hematopoietic stem cell transplantation (allo-SCT) remains controversial in MM. In the current study, we investigated the anti-myeloma effects of allo-SCT from B10.D2 mice into MHC-matched myeloma-bearing Balb/cJ mice, with concomitant development of chronic graft-versus-host disease (GvHD).

Methods and results

Balb/cJ mice were injected intravenously with luciferase-transfected MOPC315.BM cells, and received an allogeneic (B10.D2 donor) or autologous (Balb/cJ donor) transplant 30 days later. We observed a GvM effect in 94% of the allogeneic transplanted mice, as the luciferase signal completely disappeared after transplantation, whereas all the autologous transplanted mice showed myeloma progression. Lower serum paraprotein levels and lower myeloma infiltration in bone marrow and spleen in the allogeneic setting confirmed the observed GvM effect. In addition, the treated mice also displayed chronic GvHD symptoms. In vivo and in vitro data suggested the involvement of effector memory CD4 and CD8 T cells associated with the GvM response. The essential role of CD8 T cells was demonstrated in vivo where CD8 T-cell depletion of the graft resulted in reduced GvM effects. Finally, TCR Vβ spectratyping analysis identified Vβ families within CD4 and CD8 T cells, which were associated with both GvM effects and GvHD, whereas other Vβ families within CD4 T cells were associated exclusively with either GvM or GvHD responses.

Conclusions

We successfully established an immunocompetent murine model of graft-versus-myeloma. This is the first murine GvM model using immunocompetent mice that develop MM which closely resembles human MM disease and that are treated after disease establishment with an allo-SCT. Importantly, using TCR Vβ spectratyping, we also demonstrated the presence of GvM unique responses potentially associated with the curative capacity of this immunotherapeutic approach.

Mithramycin exerts an anti-myeloma effect and displays anti-angiogenic effects through up-regulation of anti-angiogenic factors

Mithramycin (MTM), a cytotoxic compound, is currently being investigated for its anti-angiogenic activity that seems to be mediated through an inhibition of the transcription factor SP1. In this study we evaluated its anti-myeloma effects in the syngenic 5TGM1 model in vitro as well as in vivo. In vitro, MTM inhibited DNA synthesis of 5TGM1 cells with an IC50 of 400 nM and induced an arrest in cell cycle progression at the G1/S transition point. Western-blot revealed an up-regulation of p53, p21 and p27 and an inhibition of c-Myc, while SP1 remained unaffected. In rat aortic ring assays, a strong anti-angiogenic effect was seen, which could be explained by a decrease of VEGF production and an up-regulation of anti-angiogenic proteins such as IP10 after MTM treatment. The administration of MTM to mice injected with 5TGM1 decreased 5TGM1 cell invasion into bone marrow and myeloma neovascularisation. These data suggest that MTM displays anti-myeloma and anti-angiogenic effects that are not mediated by an inhibition of SP1 but rather through c-Myc inhibition and p53 activation.

The effects of forodesine in murine and human multiple myeloma cells

Multiple myeloma (MM) is the second most commonly diagnosed hematological malignancy, characterized by a monoclonal proliferation of malignant cells in the bone marrow. Despite recent advances in treatment strategies, MM remains incurable and new therapeutical targets are needed. Recently forodesine, a purine nucleoside phosphorylase inhibitor, was found to induce apoptosis in leukemic cells of chronic lymphocytic leukemia patients by increasing the dGTP levels. We therefore tested whether forodesine was able to inhibit proliferation and/or induce apoptosis in both murine and human MM cells through a similar pathway. We found that after 48 hours of treatment with forodesine there was a slight dGTP increase in 5T33MM and RPMI-8226 MM cells associated with partial inhibition of proliferation and a limited induction of apoptosis. When investigating the pathways leading to cell cycle arrest and apoptosis, we observed an upregulation of p27, caspase 3, and BIM. We can conclude that forodesine has some effects on MM cells but not as impressive as the known effects in leukemic cells. Forodesine might be however potentiating towards other established cytotoxic drugs in MM.

Poor hematopoietic stem cell mobilizers in multiple myeloma: a single institution experience

In a single institution, in a group of 28 myeloma patients deemed eligible for autologous transplant, stem cell mobilization was attempted using filgrastim: 26 individuals were given 31 autografts employing 1-4 (median three) apheresis sessions, to obtain a target stem cell dose of 1 x 10(6) CD34 +ve viable cells / Kg of the recipient. The median number of grafted CD34 cells was 7.56 x 10(6) / Kg of the recipient; the range being 0.92 to 14.8. By defining as poor mobilizers individuals in which a cell collection of < 1 x 10(6) CD34 viable cells / Kg was obtained, a subset of eight poor mobilizers was identified; in two patients the autograft was aborted because of an extremely poor CD34 +ve cell yield (< 0.2 x 10(6) CD34 +ve viable cells / Kg of the recipient) after four apheresis sessions. The long-term overall survival of the patients grafted with > 1 x 10(6) CD34 +ve viable cells / Kg was better (80% at 80 months) than those grafted with < 1 x 10(6) CD34 +ve viable cells / Kg (67% at 76 months). Methods to improve stem cell mobilization are needed and may result in obtaining better results when autografting multiple myeloma patients.