MGUS to myeloma: a mysterious gammopathy of underexplored significance

Single-cell sequencing reveals the mechanisms of multiple myeloma progression: clarity or confusion?

Multiple myeloma (MM), the second most common hematologic malignancy, is characterized by the clonal expansion of myeloma cells and accumulation of genetic lesions. MM progression is accompanied by increased aggressiveness and drug resistance. Even the goal of "cure" remains hard to reach for most patients, advances in diagnosis and treatment have allowed some to achieve durable remissions and transition to plateau phase. Single-cell sequencing, with its powerful ability to analyze cellular heterogeneity and molecular patterns at ground-breaking resolution, is informative for deciphering tumors and their microenvironment. In this review, we summarize the new insights of studies facilitated by emerging single-cell sequencing into clonal evolution, myeloma-supported microenvironment transformation, epigenetic changes, and novel prognostic and therapeutic strategies for MM, revealing the key mechanisms underlying MM progression and the direction of future efforts. With the continuous expansion of the research scope and optimization of related technologies, single-cell sequencing is expected to revolutionize our understanding of the biology and evolutionary dynamics of MM and contribute to the radical and precise improvement of treatment.

Updates on mechanisms of disease progression in precursor myeloma: Monoclonal gammopathy of undermined significance and smoldering myeloma

Monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) are premalignant stages in the development of multiple myeloma (MM). Advances in detection, risk stratification, and therapeutic intervention have transformed our understanding of disease progression. Sensitive techniques like mass spectrometry have identified smaller monoclonal gammopathies, such as monoclonal gammopathy of indeterminate potential (MGIP), which may precede MGUS. Risk stratification models for MGUS and SMM, including the Mayo Clinic, PETHEMA, 2/20/20, IMWG, and PANGEA models, leverage tumor burden markers and cytogenetic abnormalities to predict prognosis. Genomic studies have revealed mutations, structural changes, and mutational signatures that predict progression. Immune microenvironmental alterations underscore the multifactorial nature of disease evolution, while epigenetics is emerging as a source of tumoral and microenvironmental changes. Therapies for high-risk SMM, including lenalidomide, daratumumab, and next-generation immunotherapies, demonstrate efficacy in delaying progression to MM but raise concerns regarding safety in asymptomatic patients. Future research must refine prognostic models, integrate genomic and immunophenotypic data, and establish consensus on optimal strategies for early intervention. This comprehensive review highlights the biological, clinical, and therapeutic advancements in MM and its precursors, emphasizing the importance of early risk assessment and targeted treatment to improve outcomes.

Emerging therapies in Multiple Myeloma: Leveraging immune checkpoint inhibitors for improved outcomes

BACKGROUND:

Multiple Myeloma is a hematological malignancy characterized by the proliferation of clonal plasma cells and associated with severe clinical manifestations. Despite advancements in diagnosis and management, Multiple Myeloma remains incurable, necessitating further research into more effective therapies.

AIM:

The primary objective of this review is to provide an informative and critical summary of the Multiple Myeloma microenvironment, and emerging revolutionary therapeutic approaches with potential combination therapy to improve the quality of life for Multiple Myeloma patients.

EMERGING APPROACHES:

Recent advancements in immunotherapy, particularly immune checkpoint inhibitors (ICIs), have shown improvements in immune response against Multiple Myeloma. ICIs target inhibitory pathways such as PD-1/PD-L1 and CTLA-4, potentially overcoming tumor-induced immunosuppression. Combination therapies integrate ICIs with proteasome inhibitors, immunomodulators, and monoclonal antibodies to enhance the anti-tumor immune response. Additionally, Chimeric Antigen Receptor T-cell (CAR-T) therapy has demonstrated effectiveness against Multiple Myeloma, particularly when coupled with ICIs to decrease resistance and relapse.

CHALLENGES:

Although the efficacy of ICIs in treating Multiple Myeloma has been hindered by the complexity of the tumor microenvironment and immune evasion mechanisms, this challenge has led to the exploration of combination therapies. Potential side effects are still a big challenge for newly recognized ICIs and combination treatment.

FUTURE DIRECTIONS:

Investigations of new immune checkpoints and the development of targeted therapies against these markers are in progress, creating possibilities for more personalized and effective treatment strategies. Continuous research and robust clinical trials are needed to comprehend the complex dynamics of the Multiple Myeloma microenvironment to develop revolutionary therapeutic targets.

The FGF/FGFR/c-Myc axis as a promising therapeutic target in multiple myeloma

Among blood cancers, multiple myeloma (MM) represents the second most common neoplasm and is characterized by the accumulation and proliferation of monoclonal plasma cells within the bone marrow. Despite the last few decades being characterized by the development of different therapeutic strategies against MM, at present such disease is still considered incurable. Although MM is highly heterogeneous in terms of genetic and molecular subtypes, about 67% of MM cases are associated with abnormal activity of the transcription factor c-Myc, which has so far revealed a protein extremely difficult to target. We have recently demonstrated that activation of fibroblast growth factor (FGF) signaling protects MM cells from oxidative stress-induced apoptosis by stabilizing the oncoprotein c-Myc. Accordingly, secretion of FGF ligands and autocrine activation of FGF receptors (FGFR) is observed in MM cells and FGFR3 genomic alterations represent some 15-20% MM cases and are associated with poor outcome. Thus, FGF/FGFR blockade may represent a promising strategy to indirectly target c-Myc in MM. On this basis, the present review aims at providing an overview of recently explored connections between the FGF/FGFR system and c-Myc oncoprotein, sustaining the therapeutic potential of targeting the FGF/FGFR/c-Myc axis in MM by using inhibitors targeting FGF ligands or FGF receptors. Importantly, the provided findings may represent the rationale for using FDA approved FGFR TK inhibitors (i.e. Pemigatinib, Futibatinib, Erdafitinib) for the treatment of MM patients presenting with an aberrant activation of this axis.

Deep hematologic response to RD treatment in patients with multiple myeloma is associated with overexpression of IL-17R in CD138+ plasma cells

Lenalidomide (LEN) is widely used immunomodulatory drug (IMiD). Nonetheless, despite its efficacy, over time patients become resistant to LEN and relapse. Due to high clinical relevance, drug resistance in MM is being thoroughly investigated. However, less is known about predictors of good response to LEN-based treatment. The aim of this study was to identify molecular pathways associated with good and long response to LEN. The study included newly diagnosed MM patients (NDMM) and MM patients treated with first-line LEN and dexamethasone (RD) who achieved and least very good partial remission (VGPR). RNA was isolated from MM cells and new-generation sequencing was performed. Obtained results were validated with qRT-PCR. A global increase in gene expression was found in the RD group compared to NDMM, suggesting the involvement of epigenetic mechanisms. Moreover, upregulation of genes controlling the interaction within MM niche was detected. Next, genes controlling immune response were upregulated. In particular, the gene encoding the IL-17 receptor was overexpressed in the RD group which is a novel finding. This should be emphasized because IL-17-related signaling can potentially be targeted, providing the rationale for future research. Establishing the molecular background associated with long-lasting and profound response to LEN may improve LEN-based chemotherapy regimens and facilitate the development of adjuvant therapies to enhance its anti-MM activity.

SOHO State of the Art Updates and Next Questions: Diagnosis and Management of Monoclonal Gammopathy of Undetermined Significance and Smoldering Multiple Myeloma

Monoclonal proteins are common, with a prevalence in the United States around 5% and the incidence increases with age. Although most patients are asymptomatic, the vast majority of cases are caused by a clonal plasma cell disorder. Monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) are asymptomatic precursor conditions with variable risk of progression to multiple myeloma (MM). In recent years, significant progress has been made to better understand the factors that lead to the development of symptoms and progression to myeloma. In this review, we summarize the current diagnosis treatment guidelines for MGUS and SMM and highlight recent advances that underscore a shifting paradigm in the evaluation and management of plasma cell precursor conditions.

Optimal cut-off values and diagnostic significance of clinical laboratory indicators in newly diagnosed multiple myeloma

OBJECTIVE

This study aims to identify clinical laboratory parameters for the diagnosis of newly diagnosed multiple myeloma (NDMM), establish optimal cutoffs for early screening, and develop a diagnostic model for precise diagnosis.

METHODS

The study conducted a retrospective analysis of 279 NDMM patients and 553 healthy subjects at Zhejiang Province People's Hospital between January 2008 and June 2023. Multifactor LR was employed to explore clinical laboratory indicators with diagnostic value for NDMM, determine optimal cutoff values and contract a diagnostic model. The diagnostic efficacy and clinical utility were evaluated using receiver operating characteristic curves (ROC), sensitivity, specificity, and other indicators.

RESULTS

Multifactor analysis revealed that hemoglobin (Hb), albumin (Alb), and platelet distribution width (PDW) were significant diagnostic factors for NDMM. Optimal cutoff values for Hb, Alb, and PDW in MM diagnosis were determined, and the results showed a significant increase in the probability of NDMM diagnosis when Alb was below 39.3 g/L, Hb was below 11.6 g/dL, and PDW was below 14.1 fL. The diagnostic model constructed from the development cohort demonstrated a high area under the ROC curve of 0.960 (95% CI 0.942-0.978) and exhibited good sensitivity (0.860), specificity (0.957). The area under the curve (AUC) value of the diagnostic model in the external validation cohort was 0.979, confirming its good diagnostic efficacy and generalization.

CONCLUSIONS

The optimal cutoff values for Hb, Alb, and PDW and the diagnostic model designed in the study provided good accuracy and sensitivity for the initial screening and diagnosis of NDMM.

Immune status and selection of patients for immunotherapy in myeloma: a proposal

ABSTRACT

Newer immune-based approaches based on recruitment and redirection of endogenous and/or synthetic immunity such as chimeric antigen receptor T cells or bispecific antibodies are transforming the clinical management of multiple myeloma (MM). Contributions of the immune system to the antitumor effects of myeloma therapies are also increasingly appreciated. Clinical malignancy in MM originates in the setting of systemic immune alterations that begin early in myelomagenesis and regional changes in immunity affected by spatial contexture. Preexisting and therapy-induced changes in immune cells correlate with outcomes in patients with MM including after immune therapies. Here, we discuss insights from and limitations of available data about immune status and outcomes after immune therapies in patients with MM. Preexisting variation in systemic and/or regional immunity is emerging as a major determinant of the efficacy of current immune therapies as well as vaccines. However, MM is a multifocal malignancy. As with solid tumors, integrating spatial aspects of the tumor and consideration of immune targets with the biology of immune cells may be critical to optimizing the application of immune therapy, including T-cell redirection, in MM. We propose 5 distinct spatial immune types of MM that may provide an initial framework for the optimal application of specific immune therapies in MM: immune depleted, immune permissive, immune excluded, immune suppressed, and immune resistant. Such considerations may also help optimize rational patient selection for emerging immune therapies to improve outcomes.

Immune-Pathogenesis of Myeloma

This research indicates that monoclonal gammopathy of undetermined significance (MGUS) and myeloma may stem from chronic immune activation and inflammation, causing immune dysfunction and spatial immune exclusion. As the conditions progress, a shift toward myeloma involves ongoing immune impairment, affecting both innate and adaptive immunity. Intriguingly, even in advanced myeloma stages, susceptibility to immune effector cells persists. This insight highlights the intricate interplay between immune responses and the development of these conditions, paving the way for potential therapeutic interventions targeting immune modulation in the management of MGUS and myeloma.

Different evasion strategies in multiple myeloma

Multiple myeloma is the second most common malignant hematologic malignancy which evolved different strategies for immune escape from the host immune surveillance and drug resistance, including uncontrolled proliferation of malignant plasma cells in the bone marrow, genetic mutations, or deletion of tumor antigens to escape from special targets and so. Therefore, it is a big challenge to efficiently treat multiple myeloma patients. Despite recent applications of immunomodulatory drugs (IMiDS), protease inhibitors (PI), targeted monoclonal antibodies (mAb), and even hematopoietic stem cell transplantation (HSCT), it remains hardly curable. Summarizing the possible evasion strategies can help design specific drugs for multiple myeloma treatment. This review aims to provide an integrative overview of the intrinsic and extrinsic evasion mechanisms as well as recently discovered microbiota utilized by multiple myeloma for immune evasion and drug resistance, hopefully providing a theoretical basis for the rational design of specific immunotherapies or drug combinations to prevent the uncontrolled proliferation of MM, overcome drug resistance and improve patient survival.

Natural killer cells affect the natural course, drug resistance, and prognosis of multiple myeloma

Multiple myeloma (MM), a stage-developed plasma cell malignancy, evolves from monoclonal gammopathy of undetermined significance (MGUS) or smoldering MM (SMM). Emerging therapies including immunomodulatory drugs, proteasome inhibitors, monoclonal antibodies, chimeric antigen-T/natural killer (NK) cells, bispecific T-cell engagers, selective inhibitors of nuclear export, and small-molecule targeted therapy have considerably improved patient survival. However, MM remains incurable owing to inevitable drug resistance and post-relapse rapid progression. NK cells with germline-encoded receptors are involved in the natural evolution of MGUS/SMM to active MM. NK cells actively recognize aberrant plasma cells undergoing malignant transformation but are yet to proliferate during the elimination phase, a process that has not been revealed in the immune editing theory. They are potential effector cells that have been neglected in the therapeutic process. Herein, we characterized changes in NK cells regarding disease evolution and elucidated its role in the early clinical monitoring of MM. Additionally, we systematically explored dynamic changes in NK cells from treated patients who are in remission or relapse to explore future combination therapy strategies to overcome drug resistance.

Role of Natural Killer T (NKT) Cells in Myeloma Biology and Therapy

Natural Killer T (NKT) cells are distinct innate lymphocytes that recognize lipid antigens in the context of nonpolymorphic molecule CD1d. Multiple myeloma (MM) is a hematologic malignancy wherein malignant plasma cells express CD1d and are sensitive to lysis by NKT cells. Progressive malignancy in MM is characterized by NKT cell dysfunction. Several studies have tried to harness the anti-tumor properties of NKT cells in MM to mediate tumor regression. NKT cells are also attractive targets for approaches at immune redirection in MM with chimeric-antigen receptor NKT (CAR-NKT) and bispecific antibodies. In addition to the commonly studied invariant-NKT (iNKT) cells, MM patients often also exhibit alterations in type-II NKT cells and their ligands. In patients and mouse models with Gaucher disease (GD), an inherited lipid-storage disorder with markedly increased risk for MM, distinct type-II NKT cells exhibit a T-follicular helper (NKT-TFH) phenotype and provide help to lipid-specific B cells. Chronic immune activation in this setting eventually sets the stage for malignancy, which can be targeted in both mouse models and GD patients by reducing the underlying antigen. NKT cells are thus integrally linked to MM pathogenesis and an attractive target for MM immunotherapy.

Impact of viral hepatitis therapy in multiple myeloma and other monoclonal gammopathies linked to hepatitis B or C viruses

Subsets of multiple myeloma (MM) and monoclonal gammopathies of undetermined significance (MGUS) present with a monoclonal immunoglobulin specific for hepatitis C virus (HCV), thus are presumably HCV-driven, and antiviral treatment can lead to the disappearance of antigen stimulation and improved control of clonal plasma cells. Here we studied the role of hepatitis B virus (HBV) in the pathogenesis of MGUS and MM in 45 HBV-infected patients with monoclonal gammopathy. We analyzed the specificity of recognition of the monoclonal immunoglobulin of these patients and validated the efficacy of antiviral treatment (AVT). For 18 of 45 (40%) HBV-infected patients, the target of the monoclonal immunoglobulin was identified: the most frequent target was HBV (n=11), followed by other infectious pathogens (n=6) and glucosylsphingosine (n=1). Two patients whose monoclonal immunoglobulin targeted HBV (HBx and HBcAg), implying that their gammopathy was HBV-driven, received AVT and the gammopathy did not progress. AVT efficacy was then investigated in a large cohort of HBV-infected MM patients (n=1367) who received or did not receive anti-HBV treatments and compared to a cohort of HCV-infected MM patients (n=1220). AVT significantly improved patient probability of overall survival (P=0.016 for the HBV-positive cohort, P=0.005 for the HCV-positive cohort). Altogether, MGUS and MM disease can be HBV- or HCV-driven in infected patients, and the study demonstrates the importance of AVT in such patients.

CAR T-Cell Therapy for Multiple Myeloma: A Clinical Practice-Oriented Review

The emergence of chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment of hematologic malignancies, including multiple myeloma (MM). Two BCMA-directed CAR T-cell products - idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel) - have received US Food and Drug Administration (FDA) approval for patients with relapsed/refractory MM who underwent four or more prior lines of therapy (including an immunomodulatory agent, a proteasome inhibitor, and an anti-CD38 monoclonal antibody). Despite producing unprecedented response rates in an otherwise difficult to treat patient population, CAR T-cell therapies are commonly associated with immune-related adverse events (e.g., cytokine release syndrome and neurotoxicity), cytopenias, and infections. Moreover, many patients continue to exhibit relapse post-treatment, with resistance mechanisms yet to be fully understood. Ongoing basic, translational, and clinical research efforts are poised to generate deeper insights into the optimal utilization of these therapies, improve their efficacy, minimize associated toxicity, and identify new target antigens in patients with MM.

5-Aza-2'-Deoxycytidine Alters the Methylation Profile of Bortezomib-Resistant U266 Multiple Myeloma Cells and Affects Their Proliferative Potential

Multiple myeloma (MM) is a plasma cell malignancy that accounts for 1% of all cancers and is the second-most-common hematological neoplasm. Bortezomib (BTZ) is a proteasome inhibitor widely implemented in the treatment of MM alone or in combination with other agents. The development of resistance to chemotherapy is one of the greatest challenges of modern oncology. Therefore, it is crucial to discover and implement new adjuvant therapies that can bypass therapeutic resistance. In this paper, we investigated the in vitro effect of methylation inhibitor 5-Aza-2'-deoxycytidine on the proliferative potential of MM cells and the development of resistance to BTZ. We demonstrate that alterations in the DNA methylation profile are associated with BTZ resistance. Moreover, the addition of methylation inhibitor 5-Aza-2'-deoxycytidine to BTZ-resistant MM cells led to a reduction in the proliferation of the BTZ-resistant phenotype, resulting in the restoration of sensitivity to BTZ. However, further in vitro and ex vivo studies are required before adjuvant therapy can be incorporated into existing treatment regimens.

A study to identify novel biomarkers associated with multiple myeloma

Background. multiple myeloma (mm) is a plasma cell cancer that affects white blood cells. plasma cells from the bone marrow grow abnormally, as a consequence of which patients have high amounts of monoclonal immunoglobulin in their blood and urine, poor renal function, and recurring infections due to this condition. osteolytic bone lesions and immunodeficiency also impact multiple myeloma patients’ longevity and quality of life. The disease accounts for 13 % of all hematological malignancies worldwide, making it the second most common blood cancer.

Material and Methods. The studies investigating mm biomarkers from 2000 to 2021 are collected from various databases. “multiple myeloma”, “biomarkers”, “genetic markers”, “prognostic markers”, “epidemiology of multiple myeloma”, and “risk factors for multiple myeloma” are the key phrases utilized to gather the articles.

Results. The scientific and medical research progressed into mm, and the number of cases increased over time and continues to rise, prompting researchers and clinicians to discover new consequences of the disease and new markers for prognosis, diagnosis, detection, and treatment of cancer in the earliest stages. Prognostic and predictive signs for illness recurrence and response to medication may be detected adequately by innovative potential biomarkers, which are more accurate than current approaches.

Conclusion. treatment for multiple myeloma includes a variety of chemotherapeutic medicines, including immune modulators and proteasome inhibitors; however, most patients still experience recurrence after completing treatment. There have been numerous novel techniques for managing multiple myeloma, and this review summarises the most commonly used and the new ones that have appeared in the previously published articles.

Myeloperoxidase creates a permissive microenvironmental niche for the progression of multiple myeloma

Expression of myeloperoxidase (MPO), a key inflammatory enzyme restricted to myeloid cells, is negatively associated with the development of solid tumours. Activated myeloid cell populations are increased in multiple myeloma (MM); however, the functional consequences of myeloid-derived MPO within the myeloma microenvironment are unknown. Here, the role of MPO in MM pathogenesis was investigated, and the capacity for pharmacological inhibition of MPO to impede MM progression was evaluated. In the 5TGM1-KaLwRij mouse model of myeloma, the early stages of tumour development were associated with an increase in CD11b+ myeloid cell populations and an increase in Mpo expression within the bone marrow (BM). Interestingly, MM tumour cell homing was increased towards sites of elevated myeloid cell numbers and MPO activity within the BM. Mechanistically, MPO induced the expression of key MM growth factors, resulting in tumour cell proliferation and suppressed cytotoxic T-cell activity. Notably, tumour growth studies in mice treated with a small-molecule irreversible inhibitor of MPO (4-ABAH) demonstrated a significant reduction in overall MM tumour burden. Taken together, our data demonstrate that MPO contributes to MM tumour growth, and that MPO-specific inhibitors may provide a new therapeutic strategy to limit MM disease progression.

The Association of Agent Orange (AO) Exposure with Monoclonal Gammopathy of Undetermined Significance (MGUS) to Multiple Myeloma (MM) Progression: A Population-based Study of Vietnam War Era Veterans

Background

Herbicide and pesticide exposure (e.g., agent orange [AO]) is associated with an increased risk of multiple myeloma (MM) due to the contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Monoclonal gammopathy of undetermined significance (MGUS) is the precursor state to MM; however, not all patients with MGUS progress to MM. It is unclear whether AO exposure increases the risk of progression of MGUS to MM.

Purpose

We aimed to determine the association between AO exposure and progression to MM in a nation-wide study of U.S. Veterans with MGUS.

Patients and Methods

This is a population-based cohort study of Vietnam Era Veterans diagnosed with MGUS. A natural language processing (NLP) algorithm was used to confirm MGUS and progression to MM. The association between AO and progression was analyzed using multivariable Fine-Gray subdistribution hazard model with death as a competing event. Veterans who served during the Vietnam War Era from 1/9/1962-5/7/1975 and were diagnosed with MGUS between 10/1/1999-12/31/2021 were included. We excluded patients with missing BMI values, progression within 1 year after MGUS diagnosis date, non-IgG or IgA MGUS, or birth years outside of the range of the AO exposed group, and race other than Black and White. AO exposure and service during 1/9/1962-;5/7/1975 and stratified according to TCDD exposure levels by three time periods: 1/9/1962-11/30/1965 (high), 12/1/1965-12/31/1970 (medium), or 1/1/1971-5/7/1975 (low). The association between AO and progression was analyzed using multivariable Fine-Gray subdistribution hazard model with death as a competing event.

Results

We identified 10,847 Veterans with MGUS, of whom 7,996 had AO exposure. Overall, 7.4% of MGUS patients progressed to MM over a median follow-up of 5.2 years. In multivariable analysis, AO exposure from 1/9/1962-11/30/1965, high TCDD exposure, was associated with an increased risk of progression (adjusted hazard ratio 1.48; 95% confidence interval 1.02-2.16), compared to Veterans with no exposure.

Conclusions

In patients with MGUS, the high Agent Orange exposure time period is associated with a 48% increased risk of progression to multiple myeloma. This suggests that patients with MGUS and prior Agent Orange exposure or occupational exposure to TCDD (eg. Agricultural workers) may require thorough screening for plasma cell dyscrasias.

Growth and dormancy control of myeloma cells by mesenchymal stem cells

Bone marrow mesenchymal stem cells (MSCs) may have contrasting impacts on the progression of multiple myeloma (MM). Priming normal MSCs, by culturing them with MM cells, mimics the MSC-induced MM growth. We studied the contrasting effects of conditioned medium (CM) from unprimed or primed MSCs on growth of MM cells from newly diagnosed cases. We elucidated potential molecular pathways using global gene expression profiling and focused on the role of the mTOR2 component, RICTOR, as a novel mediator of dormancy in MM. Primed MSCs CM consistently increased proportions of proliferating cells and supported MM growth in 3-day (n = 20) and 10-day (n = 12) cultures, effects that were partially mediated through the IGF1 axis. In contrast, unprimed MSCs CM inhibited growth of MM cells in cases mainly from stages I/II MM. The genes most overexpressed in MM cells treated with primed MSCs CM were associated with cell cycle, DNA-damage repair, and proliferation; genes most overexpressed in MM cells treated with unprimed MSCs CM were associated with dormancy pathways including RICTOR (mTOR2 pathway), CXCR4, and BCL2. RICTOR protein level was induced by unprimed MSCs CM and was lower in KI67+ proliferating MM cells treated with primed MSCs CM. RICTOR was underexpressed in clinical relapse samples compared with baseline samples of the same patients. Inhibiting RICTOR expression in primary MM cells promoted their growth, and enforced expression of RICTOR in MM cell lines inhibited their growth. Our findings suggest that, after prolonged interactions with MM cells, bone marrow MSCs shift from MM-repressive to MM-permissive. AVAILABILITY OF DATA AND MATERIALS: Our institutional GEP data of MM cells from newly diagnosed patients used to show RICTOR expression have been deposited at Gene Expression Omnibus (GEO: GSE2658, https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE2658).

EDNRA-Expressing Mesenchymal Cells Are Expanded in Myeloma Interstitial Bone Marrow and Associated with Disease Progression

Multiple myeloma (MM) induces dysfunctional bone marrow (BM) mesenchymal cells and neoangiogenesis. Pericytes and smooth muscle cells (SMCs) could detach from vessels and become cancer-associated fibroblasts. We found that the pericyte and SMC marker endothelin receptor type A (EDNRA) is overexpressed in whole MM bone biopsies; we sought to characterize its expression. EDNRA expression gradually increased with disease progression. High-risk MM patients had higher EDNRA expression than low-risk MM patients and EDNRA expression was highest in focal lesions. High EDNRA expression was associated with high expression of pericyte markers (e.g., RGS5, POSTN, and CD146) and the angiogenic marker FLT1. A single-cell analysis of unexpanded BM mesenchymal cells detected EDNRA expression in a subset of cells that coexpressed mesenchymal cell markers and had higher expression of proliferation genes. Immunohistochemistry revealed that the number of EDNRA+ cells in the interstitial BM increased as MM progressed; EDNRA+ cells were prevalent in areas near the MM focal growth. EDNRA+ cells were detached from CD34+ angiogenic cells and coexpressed RGS5 and periostin. Therefore, they likely originated from pericytes or SMCs. These findings identify a novel microenvironmental biomarker in MM and suggest that the presence of detached EDNRA+ cells indicates disrupted vasculature and increased angiogenesis.

Machine Learning Approach for Rapid, Accurate Point-of-Care Prediction of M-Spike Values in Multiple Myeloma

PURPOSE

The gold standard for monitoring response status in patients with multiple myeloma (MM) is serum and urine protein electrophoresis which quantify M-spike proteins; however, the turnaround time for results is 3-7 days which delays treatment decisions. We hypothesized that machine learning (ML) could integrate readily available clinical and laboratory data to rapidly and accurately predict patient M-spike values.

METHODS

A retrospective chart review was performed using the deidentified, electronic medical records of 171 patients with MM.

RESULTS

Random forest (RF) analysis identified the weighted value of each independent variable (N = 43) integrated into the ML algorithm. Pearson and Spearman coefficients indicated that the ML-predicted M-spike values correlated highly with laboratory-measured serum protein electrophoresis values. Feature selected RF modeling revealed that only two variables-the first lagged M-spike and serum total protein-accurately predicted the M-spike.

CONCLUSION

Taken together, our results demonstrate the feasibility and prognostic potential of ML tools that integrate electronic data to longitudinally monitor disease burden. ML tools support the seamless, secure exchange of patient information to expedite and personalize clinical decision making and overcome geographic, financial, and social barriers that currently limit the access of underserved populations to cancer care specialists so that the benefits of medical progress are not limited to selected groups.

Direct Mass Spectrometry-Based Detection and Antibody Sequencing of Monoclonal Gammopathy of Undetermined Significance from Patient Serum: A Case Study

Monoclonal gammopathy of undetermined significance (MGUS) is a plasma cell disorder characterized by the presence of a predominant monoclonal antibody (i.e., M-protein) in serum, without clinical symptoms. Here we present a case study in which we detect MGUS by liquid-chromatography coupled with mass spectrometry (LC-MS) profiling of IgG1 in human serum. We detected a Fab-glycosylated M-protein and determined the full heavy and light chain sequences by bottom-up proteomics techniques using multiple proteases, further validated by top-down LC-MS. Moreover, the composition and location of the Fab-glycan could be determined in CDR1 of the heavy chain. The outlined approach adds to an expanding mass spectrometry-based toolkit to characterize monoclonal gammopathies such as MGUS and multiple myeloma, with fine molecular detail. The ability to detect monoclonal gammopathies and determine M-protein sequences straight from blood samples by mass spectrometry provides new opportunities to understand the molecular mechanisms of such diseases.

Regulation of antigen-specific T cell infiltration and spatial architecture in multiple myeloma and premalignancy

Entry of antigen-specific T cells into human tumors is critical for immunotherapy, but the underlying mechanisms are poorly understood. Here, we combined high-dimensional spatial analyses with in vitro and in vivo modeling to study the mechanisms underlying immune infiltration in human multiple myeloma (MM) and its precursor monoclonal gammopathy of undetermined significance (MGUS). Clustered tumor growth was a feature of MM but not MGUS biopsies, and this growth pattern was reproduced in humanized mouse models. MM biopsies exhibited intralesional as well as spatial heterogeneity, with coexistence of T cell-rich and T cell-sparse regions and the presence of areas of T cell exclusion. In vitro studies demonstrated that T cell entry into MM clusters was regulated by agonistic signals and CD2-CD58 interactions. Upon adoptive transfer, antigen-specific T cells localized to the tumor site but required in situ DC-mediated antigen presentation for tumor entry. C-type lectin domain family 9 member A-positive (CLEC9A+) DCs appeared to mark portals of entry for gradients of T cell infiltration in MM biopsies, and their proximity to T cell factor 1-positive (TCF1+) T cells correlated with disease state and risk status. These data illustrate a role for tumor-associated DCs and in situ activation in promoting the infiltration of antigen-specific T cells in MM and provide insights into spatial alterations in tumor/immune cells with malignant evolution.

The Interpretation of Mirror Pattern Bands During Oligoclonal Immunoglobulin Isoelectric Focusing Electrophoresis: A Retrospective Study

OBJECTIVE

Mirror patterns are incidental types that accompany the analysis of the oligoclonal band (OCB) in cerebrospinal fluid (CSF). However, their interpretation remains controversial. In this study, we analyzed all graphic results of mirror patterns from 86 patients to provide an optimal interpretation scheme for mirror patterns.

METHODS

Matched CSF and serum specimens were obtained from patients with various neurological disorders that required OCB analysis. A total of 86 patients were screened and serum immunofixation electrophoresis (IFE) was performed in all 86. The interobserver agreement for interpreting mirror patterns by visual inspection was tested. The method agreement between the visual inspection and IFE was also evaluated. The CSF/serum albumin quotient (QALB) was calculated to determine the blood-brain barrier integrity of all patients.

RESULTS

Of the 86 patients with mirror patterns, 19.8% (17/86) had typical mirror bands and most (80.2%) had atypical mirror bands. There was a good agreement between the 2 observers in interpreting typical mirror patterns. However, kappa statistics analysis showed poor agreement regarding the interpretation of atypical mirror bands by visual observation alone (kappa value, -0.026 to 0.314 between 2 observers). The disagreement was pronounced between the visual inspection and validation of IFE (kappa value, -0.0238 to 0.176 between the first observer and IFE; -0.322 to 0.118 between the second observer and IFE). The normal QALB rates in the type V groups were significantly higher than those in the type IV group and the positive QALB rates in the type IV were significantly higher than those in the type V.

CONCLUSION

Visual inspection to interpret mirror pattern bands is unreliable. Considering the completely different clinical significance between type IV and type V and high risk of potential misinterpretations, it is necessary to perform IFE on all the atypical mirror types to discriminate atypical type IV from atypical type V.

A gene signature can predict risk of MGUS progressing to multiple myeloma

Multiple myeloma is preceded by monoclonal gammopathy of undetermined significance (MGUS). Serum markers are currently used to stratify MGUS patients into clinical risk groups. A molecular signature predicting MGUS progression has not been produced. We have explored the use of gene expression profiling to risk-stratify MGUS and developed an optimized signature based on large samples with long-term follow-up. Microarrays of plasma cell mRNA from 334 MGUS with stable disease and 40 MGUS that progressed to MM within 10 years, was used to define a molecular signature of MGUS risk. After a three-fold cross-validation analysis, the top thirty-six genes that appeared in each validation and maximized the concordance between risk score and MGUS progression were included in the gene signature (GS36). The GS36 accurately predicted MGUS progression (C-statistic is 0.928). An optimal cut-point for risk of progression by the GS36 score was found to be 0.7, which identified a subset of 61 patients with a 10-year progression probability of 54.1%. The remainder of the 313 patients had a probability of progression of only 2.2%. The sensitivity and specificity were 82.5% and 91.6%. Furthermore, combination of GS36, free light chain ratio and immunoparesis identified a subset of MGUS patients with 82.4% risk of progression to MM within 10 years. A gene expression signature combined with serum markers created a highly robust model for predicting risk of MGUS progression. These findings strongly support the inclusion of genomic analysis in the management of MGUS to identify patients who may benefit from more frequent monitoring.

Medical practitioners' knowledge and awareness of multiple myeloma at public hospitals, Gauteng, South Africa

BACKGROUND

 Multiple myeloma (MM) is a plasma cell malignancy associated with morbidity and mortality worldwide, and most patients are referred for specialist care very late with complications. The low index of suspicion among medical practitioners is among the reasons for the delay in MM diagnosis and management. This study aimed to determine the level of awareness and knowledge of MM among medical practitioners working in public hospitals of Tshwane Municipality, Gauteng Province, South Africa.

METHODS

 A cross-sectional descriptive study on 74 doctors working in three district, one regional and one central hospital using a convenience sampling.

RESULTS

 Seventy-four medical practitioners participated in this study. Their median age was 37 years with an interquartile range of 43-30 years. The majority (85%) of the respondents were aware of MM, while 74% were knowledgeable regarding MM presentations and diagnostic investigations.

CONCLUSION

 The findings highlighted a high level of awareness and knowledge of MM among the study population, but almost all of the participants requested an educational information brochure on MM.Contribution: Medical practitioners have a high level of awareness of multiple myeloma; however, there is a discrepancy between this level of awareness and the delayed presentation of patients at the public hospitals. As primary healthcare in South Africa is nurse-driven, the study indicates that not all primary healthcare providers may be aware of this disease. Future awareness campaigns should target other primary healthcare providers, including nurses and private general practitioners.

A Rare Case of Gastrointestinal Amyloidosis Due to Monoclonal Gammopathy of Undetermined Significance

Amyloidosis of the gastrointestinal (GI) tract is caused by the deposition of fibrils made of serum proteins into extracellular spaces. It is an uncommon disease with a poor prognosis, requiring prompt diagnosis and treatment. Treatment for amyloid light chain (AL)-type amyloidosis involves supportive care as well as addressing any underlying plasma cell dyscrasias. We present the case of a 64-year-old female diagnosed with AL-type GI amyloidosis with associated monoclonal gammopathy of undetermined significance. Unfortunately, the treatment was initiated nine months after the initial presentation, and she died one month later. Awareness of GI amyloidosis may allow for faster diagnosis and treatment in future patients.

Immune dysregulation in multiple myeloma: the current and future role of cell-based immunotherapy

Immune dysregulation is a hallmark of clinically active multiple myeloma (MM). Interactions between malignant clonal cells and immune cells within the bone marrow microenvironment are associated with the formation of a milieu favorable to tumor progression. IL-10, TGF-β and other immunoregulatory pathways are upregulated, promoting angiogenesis, tumor cell survival and inhibition of the native immune response. Transcriptomic evaluation of the bone marrow microenvironment reveals polarization of the T cell repertoire towards exhaustion and predominance of accessory cells with immunosuppressive qualities. These changes facilitate the immune escape of tumor cells and functional deficiencies that manifest as an increased risk of infection and a reduction in response to vaccinations. Immunotherapy with Chimeric Antigen Receptor (CAR) T cells and other cellular-based approaches have transformed outcomes for patients with advanced MM. Characterization of the immune milieu and identification of biomarkers predictive of treatment response are essential to increasing durability and allowing for the incorporation of novel strategies such as cancer vaccines. This paper will review the current use of cancer vaccines and CAR T cell therapy in MM as well as potential opportunities to expand and improve the application of these platforms.

Liquid biopsy by analysis of circulating myeloma cells and cell-free nucleic acids: a novel noninvasive approach of disease evaluation in multiple myeloma

Multiple myeloma (MM) is an incurable hematological cancer with high spatial- and temporal-heterogeneity. Invasive single-point bone marrow sampling cannot capture the tumor heterogeneity and is difficult to repeat for serial assessments. Liquid biopsy is a technique for identifying and analyzing circulating MM cells and cell products produced by tumors and released into the circulation, allowing for the minimally invasive and comprehensive detection of disease burden and molecular alterations in MM and monitoring treatment response and disease progression. Furthermore, liquid biopsy can provide complementary information to conventional detection approaches and improve their prognostic values. This article reviewed the technologies and applications of liquid biopsy in MM.

Preclinical models for prediction of immunotherapy outcomes and immune evasion mechanisms in genetically heterogeneous multiple myeloma

The historical lack of preclinical models reflecting the genetic heterogeneity of multiple myeloma (MM) hampers the advance of therapeutic discoveries. To circumvent this limitation, we screened mice engineered to carry eight MM lesions (NF-κB, KRAS, MYC, TP53, BCL2, cyclin D1, MMSET/NSD2 and c-MAF) combinatorially activated in B lymphocytes following T cell-driven immunization. Fifteen genetically diverse models developed bone marrow (BM) tumors fulfilling MM pathogenesis. Integrative analyses of ∼500 mice and ∼1,000 patients revealed a common MAPK-MYC genetic pathway that accelerated time to progression from precursor states across genetically heterogeneous MM. MYC-dependent time to progression conditioned immune evasion mechanisms that remodeled the BM microenvironment differently. Rapid MYC-driven progressors exhibited a high number of activated/exhausted CD8⁺ T cells with reduced immunosuppressive regulatory T (T_reg) cells, while late MYC acquisition in slow progressors was associated with lower CD8⁺ T cell infiltration and more abundant T_reg cells. Single-cell transcriptomics and functional assays defined a high ratio of CD8⁺ T cells versus T_reg cells as a predictor of response to immune checkpoint blockade (ICB). In clinical series, high CD8⁺ T/T_reg cell ratios underlie early progression in untreated smoldering MM, and correlated with early relapse in newly diagnosed patients with MM under Len/Dex therapy. In ICB-refractory MM models, increasing CD8⁺ T cell cytotoxicity or depleting T_reg cells reversed immunotherapy resistance and yielded prolonged MM control. Our experimental models enable the correlation of MM genetic and immunological traits with preclinical therapy responses, which may inform the next-generation immunotherapy trials.

The immune system in multiple myeloma and precursor states: Lessons and implications for immunotherapy and interception

Multiple myeloma (MM) and its precursor monoclonal gammopathy of undetermined significance (MGUS) are distinct disorders that likely originate in the setting of chronic immune activation. Evolution of these lesions is impacted by cross-talk with both innate and adaptive immune systems of the host. Harnessing the immune system may, therefore, be an attractive strategy to prevent clinical malignancy. While clinical MM is characterized by both regional and systemic immune suppression and paresis, immune-based approaches, particularly redirecting T cells have shown remarkable efficacy in MM patients. Optimal application and sequencing of these new immune therapies and their integration into clinical MM management may depend on the underlying immune status, in turn impacted by host, tumor, and environmental features. Immune therapies carry the potential to achieve durable unmaintained responses and cures in MM.

Monoclonal Gammopathy of Undetermined Significance: A Comprehensive Review

Monoclonal Gammopathy of Undetermined Significance (MGUS) is an asymptomatic premalignant plasma cell dyscrasia with a predominate rise of the IgG immunoglobulin fraction without end-organ damage, often diagnosed incidentally. Despite its progression into various subsequent forms of hematological malignancies, MGUS remains underdiagnosed. A literature search was conducted using the Medline, Cochrane, Embase, and Google Scholar databases, including articles published until December 2022. Keywords used encompassed "Monoclonal Gammopathy of Undetermined Significance," "Plasma Cell dyscrasia," "Monoclonal gammopathy of renal significance," and "IgM Monoclonal gammopathy of Undetermined Significance," This study aimed to conduct a critical review to update knowledge regarding the pathophysiology, risk factors, clinical features, diagnostic protocols, complications, and current and novel treatments for MGUS. We recommend a multidisciplinary approach to manage MGUS due to the complexity of the illness's etiology, diagnosis, and therapy. This comprehensive review also highlights future prospects, such as developing screening protocols for at-risk populations, prevention of disease progression by early diagnosis through genome-wide association studies, and management using Daratumumab and NSAIDs.

Bispecific Antibodies for the Treatment of Multiple Myeloma

PURPOSE OF REVIEW

Advances in multiple myeloma therapies have greatly improved outcomes for patients living with the disease, although to date there is yet to be a cure. Cellular and immunotherapies, approved or in development, offer the promise of significantly advancing toward that possibility. The aim of this review is to provide a synopsis and commentary on the current and future states of bispecific agents aimed at harnessing the antineoplastic potential of T-cells in treating and eradicating myeloma.

RECENT FINDINGS

Numerous bispecific agents are in clinical development with some on the precipice of regulatory approval. While BCMA remains the principal target, some agents are directed at novel targets such as GPRC5D and FcRH5. The constructs vary in design and pharmacokinetics which has dosing and administration implications. The toxicity profiles of these agents generally reflect that of other immune therapies, including cytokine release syndrome and rarely neurotoxicity, although immunosuppression has also led to elevated infection risks. However, the toxicities are generally manageable and offset by unprecedented efficacy seen in such heavily pretreated cohorts. Bispecific agents are poised to significantly alter the treatment paradigms for myeloma. They provide a convenient "off-the-shelf" platform with often deep and durable responses. Toxicities are often limited in duration and severity. In the early-phase trials, many patients have been able to remain on treatment for extended periods, even among those with high-risk features. Upcoming trials are likely to explore earlier implementation of these agents in order to offer this therapeutic opportunity to broader cohorts.

Treating Multiple Myeloma in the Context of the Bone Marrow Microenvironment

The treatment landscape of multiple myeloma (MM) has evolved considerably with the FDA-approval of at least 15 drugs over the past two decades. Together with the use of autologous stem cell transplantation, these novel therapies have resulted in significant survival benefit for patients with MM. In particular, our improved understanding of the BM and immune microenvironment has led to the development of highly effective immunotherapies that have demonstrated unprecedented response rates even in the multiple refractory disease setting. However, MM remains challenging to treat especially in a high-risk setting. A key mediator of therapeutic resistance in MM is the bone marrow (BM) microenvironment; a deeper understanding is necessary to facilitate the development of therapies that target MM in the context of the BM milieu to elicit deeper and more durable responses with the ultimate goal of long-term control or a cure of MM. In this review, we discuss our current understanding of the role the BM microenvironment plays in MM pathogenesis, with a focus on its immunosuppressive nature. We also review FDA-approved immunotherapies currently in clinical use and highlight promising immunotherapeutic approaches on the horizon.

Periodontitis and Its Inflammatory Changes Linked to Various Systemic Diseases: A Review of Its Underlying Mechanisms

Periodontitis is a chronic inflammatory disease of the gums. The incidence of periodontitis is increasing all over the world. In patients with periodontitis, there is gradual destruction of the periodontal ligament and the alveolar bone, and later, in advanced stages, there is tooth loss. Different microorganisms, the host’s immune response, and various environmental factors interact in the progression of this chronic inflammatory disease. In the present review, we discuss the epidemiology, clinical features, diagnosis, and complications of periodontitis. We also discuss the association of chronic inflammation found in periodontitis with various other systemic diseases, which include cardiovascular, respiratory, diabetes, Alzheimer’s, cancer, adverse pregnancy, and multiple myeloma, and also highlight microbial carcinogenesis and the microRNAs involved. The latest updates on the molecular mechanism, possible biomarkers, and treatment procedures may be beneficial for diagnostic and therapeutic purposes.

How I approach smoldering multiple myeloma

The current standard of care in smoldering multiple myeloma (SMM) is close surveillance, outside of clinical trials. Efforts are being made to understand the pathobiologic process that leads to the progression of SMM to active MM. This review provides a critical description of available data, including risk factors and risk models of progression, as well as clinical trials investigating interventions for this patient population. We describe 2 cases in which patients were seen before the concept of a myeloma-defining event was established. Today, based on the International Myeloma Working Group criteria, both patients would have been identified as experiencing myeloma-defining events, and therapy would have been initiated. These cases show that occasionally, patients can undergo observation only, even when they exceed criteria for high-risk SMM.

High Expression of the Costimulatory Checkpoint Factor DNAM-1 by CD4+ T-Cells from Multiple Myeloma Patients Refractory to Daratumumab-Containing Regimens

Multiple myeloma is an incurable disease characterized by unregulated growth of malignant plasma cells in the bone marrow (BM). Tumor-induced dysfunction of T-cells may be responsible for immune evasion and failure of immunotherapy. Therefore, a better understanding of the phenotype of T-cells at the tumor site is needed. We assessed the expression of immune regulatory receptors on T-cell subsets from peripheral blood (PB) and BM using multicolor flow cytometry. Paired PB and BM samples were collected from newly diagnosed, treatment-naïve myeloma patients (n = 19) and patients progressing during treatment with the CD38 monoclonal antibody daratumumab alone or in combination with other anti-myeloma drugs (n = 39). We observed that CD4+ T-cells from both PB and BM of patients relapsing on daratumumab have a higher expression of the costimulatory checkpoint receptor DNAM-1. The potential role of DNAM-1+CD4+ T-cells in the development of resistance to daratumumab needs further exploration. We also observed that the inhibitory checkpoint receptor TIGIT is more frequently expressed by BM CD8+ T-cells from myeloma patients than PD-1 and CTLA-4, which supports the hypothesis that TIGIT may play a central role in the immune escape of the malignant plasma cells.

The Evolution Of Immune Dysfunction In Multiple Myeloma

OBJECTIVES

This review discusses the role of immune dysfunction at the different stages of MM.

METHODS

Narrative review RESULTS: Multiple myeloma (MM) is a complex disease and immune dysfunction has been known to play an important role in disease pathogenesis, progression, and drug resistance. MM is known to be preceded by asymptomatic precursor states and progression from the precursor states to MM is likely related to a progressive impairment of the immune system.

CONCLUSIONS

An understanding of the role of the immune system in the progression of MM is important to guide the development of immunotherapeutic strategies for this disease.

Clinical Considerations for Immunoparesis in Multiple Myeloma

Simple Summary

Immunoparesis in multiple myeloma is defined as the suppression of one or more of the uninvolved immunoglobulins, AKA, polyclonal immunoglobulin. The extent of immunoparesis is an independent prognostic factor in patients with newly diagnosed multiple myeloma. Myeloma patients with suppressed uninvolved immunoglobulins at diagnosis have shorter median overall survival (OS) and progression-free survival (PFS). This review article summarizes immunoparesis in myeloma patients, contributing factors, its impact on myeloma progression, general outcomes, and infectious complications.

Abstract

Multiple myeloma is a relatively common clonal plasma cell disorder, comprising 17% of hematologic malignancies. One of the hallmark features of this disease is immunoparesis, which is characterized by the suppression of immunoglobulin polyclonality. Though not entirely elucidated, the mechanism behind this process can be attributed to the changes in the tumor microenvironment. All treating clinicians must consider potential complications related to immunoparesis in the management of multiple myeloma. Though not explicitly described in large data series, the increased risk of infection in multiple myeloma is likely, at least in part, due to immunoglobulin suppression. Additionally, the presence of immunoparesis serves as a prognostic factor, conveying poorer survival and a higher risk of relapse. Even in the era of novel agents, these findings are preserved, and immunoglobulin recovery also serves as a sign of improved outcome following autologous HSCT. Though not within the diagnostic criteria for multiple myeloma, the presence and degree of immunoparesis should be at diagnosis for prognostication, and immunoglobulin recovery should be tracked following myeloablative therapy and autologous HSCT.

COVID-19 Vaccine Responses in Patients With Plasma Cell Dyscrasias After Complete Vaccination

INTRODUCTION

Due to functional hypogammaglobulinemia, patients with multiple myeloma are at increased risk for infection and generally have poorer responses to vaccines. In this study, we examined antibody responses after complete COVID-19 vaccination in patients with plasma cell dyscrasias, most of whom were receiving treatment.

PATIENTS AND METHODS

Real world study of consecutive patients with multiple myeloma and other plasma cell dyscrasias (PCD) were evaluated after complete vaccination with either the 2-shot mRNA vaccines from BioNTech and Moderna or the 1-shot adenoviral vector vaccine from Johnson & Johnson (J&J). Patients received vaccines 1-4 months before antibody testing without controlling for the type of vaccine or the timing of drug therapy. Patients with a clinical history or antibody evidence of prior infection were excluded. Antinucleocapsid and quantitative anti-spike antibody levels were measured with the Roche Elecys assay.

RESULTS

Ninety-five percent of patients had detectable antibody responses. Multivariate analysis showed that higher age, ongoing anti-CD38 monoclonal antibody therapy and the J&J vaccine negatively affected quantitative response. A small number of ineffectively vaccinated patients receiving IVIG subsequently had detectable nucleocapsid and spike antibodies confirming the presence of the latter in currently administered IVIG.

CONCLUSIONS

Nearly all PCD had detectable anti-spike antibodies after vaccination but age, anti-CD38 monoclonal antibody therapy, and the single-shot J&J vaccine negatively affected responses. In patients who received the J&J vaccine, second doses or heterologous mRNA vaccines should be tested. Quantitative antibody testing might make future management more rational, particularly in patients with poor responses.

Plasma cell-free RNA profiling distinguishes cancers from pre-malignant conditions in solid and hematologic malignancies

Cell-free RNA (cfRNA) in plasma reflects phenotypic alterations of both localized sites of cancer and the systemic host response. Here we report that cfRNA sequencing enables the discovery of messenger RNA (mRNA) biomarkers in plasma with the tissue of origin-specific to cancer types and precancerous conditions in both solid and hematologic malignancies. To explore the diagnostic potential of total cfRNA from blood, we sequenced plasma samples of eight hepatocellular carcinoma (HCC) and ten multiple myeloma (MM) patients, 12 patients of their respective precancerous conditions, and 20 non-cancer (NC) donors. We identified distinct gene sets and built classification models using Random Forest and linear discriminant analysis algorithms that could distinguish cancer patients from premalignant conditions and NC individuals with high accuracy. Plasma cfRNA biomarkers of HCC are liver-specific genes and biomarkers of MM are highly expressed in the bone marrow compared to other tissues and are related to cell cycle processes. The cfRNA level of these biomarkers displayed a gradual transition from noncancerous states through precancerous conditions and cancer. Sequencing data were cross-validated by quantitative reverse transcription PCR and cfRNA biomarkers were validated in an independent sample set (20 HCC, 9 MM, and 10 NC) with AUC greater than 0.86. cfRNA results observed in precancerous conditions require further validation. This work demonstrates a proof of principle for using mRNA transcripts in plasma with a small panel of genes to distinguish between cancers, noncancerous states, and precancerous conditions.

Characterizing the mutational landscape of MM and its precursor MGUS

Mutational Signatures and Tumor mutational burden (TMB) have emerged as prognostic biomarkers in cancer genomics. However, the association of TMB with overall survival (OS) is still unknown in newly diagnosed multiple myeloma (NDMM) patients. Further, the change in the mutational spectrum involving both synonymous and non-synonymous mutations as MGUS progresses to MM is unexplored. This study addresses both these aspects via extensive evaluation of the mutations in MGUS and NDMM. WES data of 1018 NDMM patients and 61 MGUS patients collected from three different global regions were analyzed in this study. Single base substitutions, mutational signatures and TMB were inferred from the variants identified in MGUS and MM patients. The cutoff value for TMB was estimated to divide patients into low TMB and high TMB (hypermutators) groups. This study finds a change in the mutational spectrum with a statistically significant increase from MGUS to MM. There was a statistically significant increase in the frequency of all the three categories of variants, non-synonymous (NS), synonymous (SYN), and others (OTH), from MGUS to MM (P<0.05). However, there was a statistically significant rise in the TMB values for TMB_NS and TMB_SYN only. We also observed that 3' and 5'UTR mutations were more frequent in MM and might be responsible for driving MGUS to MM via regulatory binding sites. NDMM patients were also examined separately along with their survival outcomes. The frequency of hypermutators was low in MM with poor OS and PFS outcome. We observed a statistically significant rise in the frequency of C>A and C>T substitutions and a statistically significant decline in T>G substitutions in the MM patients with poor outcomes. Additionally, there was a statistically significant increase in the TMB of the patients with poor outcome compared to patients with a superior outcome. A statistically significant association between the APOBEC activity and poor overall survival in MM was discovered. These findings have potential clinical relevance and can assist in designing risk-adapted therapies to inhibit the progression of MGUS to MM and prolong the overall survival in high-risk MM patients.

What Do the Elevated Protein Levels Mean in My Patients with Myeloma, Amyloidosis, and Related Disorders?

Multiple myeloma, light chain amyloidosis, and other plasma cell dyscrasias are characterized, in part, by abnormal production of paraproteins that are often responsible for the sequelae of those diseases. These paraproteins are whole or fragmented immunoglobulins produced by clonal antibody-secreting cells (usually plasma cells, but occasionally, B lymphocytes). Significant heterogeneity exists in the presentation of these diseases, ranging from incidental detection of a monoclonal protein in an asymptomatic patient, to life-threatening manifestations that require urgent diagnostic confirmation and intervention. Successful management of such scenarios requires a fundamental understanding of the laboratory assays at one's disposal, their role in the workup of paraproteinemias, and the interpretation thereof. This review broadly covers these assays and their roles in the diagnosis, prognosis, and management of these diseases.

Evaluation of Diffuse Bone Marrow Infiltration Pattern in Monoclonal Plasma Cell Diseases by Quantitative Whole-body Magnetic Resonance Imaging

RATIONALE AND OBJECTIVES

To analyze diffuse infiltration pattern in monoclonal plasma cell diseases by diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) and quantitative chemical-shift encoded MRI.

MATERIALS AND METHODS

Ninety-nine patients with monoclonal plasma cell diseases and 15 healthy control subjects were retrospectively analyzed. All patients underwent whole-body MRI (including DWIBS and mDIXON Quant) and were divided into three groups: monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and multiple myeloma (MM). Apparent diffusion coefficient (ADC), fat fraction (FF), and T2* values for each group were calculated then analyzed by one-way ANOVA and receiver operating characteristic curve. Correlations of ADC, FF, and T2* with clinical indices were analyzed with Spearman correlation test.

RESULTS

The ADC and T2* values of MM were significantly higher than those of the healthy control, MGUS and SMM (ADC: p = 0.003, p = 0.003, and p = 0.042; T2*: all with p < 0.001). The FF values of MM were significantly lower than those of the healthy control, MGUS and SMM (p < 0.001, p < 0.001 and p = 0.034). The ADC, FF, and T2* thresholds for recognizing MM and MGUS+SMM were 0.51 × 10^-3 mm²/s, 31.14%, and 10.53 ms, respectively. The ADC, FF, and T2* values were identified to be significantly associated with bone marrow plasma cells and hemoglobin in patients (all with p < 0.001).

CONCLUSION

ADC, FF, and T2* were significantly correlated with clinical indices related to monoclonal plasma cell diseases. MM with the diffuse infiltration pattern can be distinguished more objectively from MGUS and SMM by quantitative functional MRI parameters.

Cellular Interaction Analysis Characterizing Immunosuppressive Microenvironment Functions in MM Tumorigenesis From Precursor Stages

Cell–cell interaction event (CCEs) dysregulation may relate to the heterogeneity of the tumor microenvironment (TME) and would affect therapeutic responses and clinical outcomes. To reveal the alteration of the immune microenvironment in bone marrow from a healthy state to multiple myeloma (MM), scRNA-seq data of the four states, including healthy state normal bone marrow (NBM) and three disease states (MGUS, SMM, and MM), were collected for analysis. With immune microenvironment reconstruction, the cell types, including NK cells, CD8⁺ T cells, and CD4⁺ T cells, with a higher percentage in disease states were associated with prognosis of MM patients. Furthermore, CCEs were annotated and dysregulated CCEs were identified. The number of CCEs were significantly changed between disease states and NBM. The dysregulated CCEs participated in regulation of immune cell proliferation and immune response, such as MIF-TNFRSF14 interacted between early B cells and CD8⁺ T cells. Moreover, CCE genes related to drug response, including bortezomib and melphalan, provide candidate therapeutic markers for MM treatment. Furthermore, MM patients were separated into three risk groups based on the CCE prognostic signature. Immunoregulation-related differentiation and activation of CD4⁺ T cells corresponded to the progression status with moderate risk. These results provide a comprehensive understanding of the critical role of intercellular communication in the immune microenvironment over the evolution of premalignant MM, which is related to the tumorigenesis and progression of MM, which moreover, suggests a way of potential target selection for clinical intervention.