Cardiovascular Morbidity in Monoclonal Gammopathy of Undetermined Significance: A Danish Nationwide Study

Senescence profiling of monoclonal gammopathies reveals paracrine senescence as a crucial defense against disease progression

Multiple myeloma (MM) is a plasma cell (PC) malignancy that is preceded by monoclonal gammopathy of undetermined significance (MGUS) and/or smoldering multiple myeloma (SMM). MGUS and SMM PCs exhibit the same primary oncogenic abnormalities as MM but lack the end-organ damage that defines proliferative disease, suggesting that clonal PCs in these precursor conditions could exhibit senescence or senescence-like growth arrest. Herein we identified monoclonal gammopathy patient-derived PCs that exhibit senescence features and found that senescent PCs were significantly increased in MGUS patients compared to SMM or MM. Spatial analysis of senescent PCs in stable MGUS and SMM patient biopsies demonstrated the activation of local paracrine senescence in the bone marrow microenvironment. Stable MGUS and SMM patients also exhibited disease-specific senescence-associated secretory phenotype (SASP) signatures that significantly correlated with PC burden and clonal antibody. In contrast, progressing MGUS, SMM, and new MM patients lacked local paracrine senescence responses and robust activation of disease specific SASP signatures. Overall, these data suggest that failure to activate tumor-specific paracrine senescence responses is key to disease progression in monoclonal gammopathies.

Monoclonal Gammopathy of Undetermined Significance and Associated Cardiovascular Outcomes in a Hospital Setting-A Fresh Perspective

There is a paucity of data on the cardiovascular implications of monoclonal gammopathy of undetermined significance, especially among hospitalized patients. Our study aimed to investigate the association between MGUS and cardiovascular outcomes in a hospital setting using the National Inpatient Sample database. MGUS patients were sampled using ICD-10 codes. The patients were stratified into two cohorts based on the presence or absence of MGUS. Comorbidities and cardiovascular outcomes were collected using ICD 10 DM codes. CV outcomes were evaluated before and after 1:1 matching for age, gender, and race. Furthermore, a sensitivity analysis was performed on the matched population, which excluded patients with diabetes mellitus, prior myocardial infarction, chronic kidney disease (stages 3-5), dialysis, hypertension, obesity, metabolic syndrome, cancer, antiplatelets, and oral anticoagulant use and was adjusted for smoking, dyslipidemia, and aspirin use to evaluate the cardiovascular outcomes. MGUS patients had more heart failure, atrial fibrillation, venous thromboembolism, aortic aneurysm, aortic stenosis, aortic regurgitation, mitral stenosis, mitral regurgitation, conduction disorder, cor pulmonale, peripheral vascular disease, and acute myocardial infarction. After matching, MGUS was associated with heart failure, atrial fibrillation, venous thromboembolism, aortic stenosis, mitral regurgitation, conduction disorder, cor pulmonale, and peripheral vascular disease. MGUS was linked to a wide spectrum of cardiovascular diseases in an inpatient setting. Further studies are needed to formulate appropriate recommendations for the screening and management of cardiovascular complications in individuals with MGUS.

Monoclonal Gammopathy of Undetermined Cardiovascular Significance; Current Evidence and Novel Insights

Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant condition characterized by the presence of low levels of a monoclonal protein in the serum and a low percentage of clonal plasma cells in the bone marrow. MGUS may progress to multiple myeloma or other plasma cell disorders at a rate of 1% annually. However, MGUS may also have adverse effects on the cardiovascular system independent of its malignant potential. Emerging data have shown that MGUS is associated with cardiovascular disease. The mechanisms underlying this association are not fully understood but may involve genetic abnormalities, vascular calcification, cryoglobulinemia, cold agglutinin disease, autoantibodies and the direct or indirect effects of the monoclonal protein on the vascular endothelium. Herein, we review current evidence in this field and we suggest that patients with MGUS may benefit from regular cardiovascular risk assessment to prevent severe cardiovascular complications, in parallel with close hematological follow-up to monitor potential disease progression.

Screening for and diagnosis of monoclonal gammopathy

Monoclonal gammopathy is a spectrum of disorders characterised by clonal proliferation of plasma cells or lymphocytes, which produce abnormal immunoglobulin or its components (monoclonal proteins). Monoclonal gammopathies are often categorised as low-tumour-burden diseases (eg, amyloid light chain (AL) amyloidosis), premalignant disorders (such as monoclonal gammopathy of undetermined significance and smouldering multiple myeloma), and malignancies (eg, multiple myeloma and Waldenström's macroglobulinaemia). Such diversity of concentration and structure makes monoclonal protein a challenging clonal marker. This article provides an overview on initial laboratory testing of monoclonal gammopathy to guide clinicians and laboratory professionals in the selection and interpretation of appropriate investigations.

Outcomes of Patients with Monoclonal Gammopathy of Undetermined Significance with and without Atrial Fibrillation: A Retrospective Cohort Analysis of the Nationwide Inpatient Sample Database

BACKGROUND

Monoclonal gammopathy of undetermined significance (MGUS) is a non-malignant precursor of multiple myeloma (MM). MGUS has been suggested to be associated with a higher risk of cardiovascular diseases, including AFIB, but it is still unclear whether this association is real. Studies are lacking on the impact of atrial fibrillation on health outcomes in this population. The association of AFIB in this population is lagging and merits further investigation.

METHODS

The study conducted a retrospective analysis of the Nationwide Inpatient Sample (NIS) for 2018, including adult patients with primary diagnoses of MGUS and AFIB. Patients were divided into two groups based on AFIB presence. Outcomes assessed included complications, length of stay, mortality, hospital charges, and discharge disposition.

RESULTS

The study included 9007 patients with MGUS of whom 2404 had AFIB. Patients with both MGUS and AFIB had higher rates of acute kidney injury [AKI] (31.5% vs. 27.5%; p = 0.002) and pericarditis (2% vs. 1.2%; p = 0.029). They also had longer hospital stays (5 vs. 4 days; p < 0.001) and higher hospitalization costs ($43,729 vs. $41,169; p < 0.001).

CONCLUSIONS

The study showed that the prevalence of AFIB in MGUS patients is high. Patients with AFIB had increased rates of complications (AKI and pericarditis) and higher mortality compared to patients without AFIB. Further studies screening for AFIB in this patient population are warranted.

Arginase Inhibition Mitigates Bortezomib-Exacerbated Cardiotoxicity in Multiple Myeloma

BACKGROUND

Multiple myeloma (MM) is associated with increased cardiovascular morbidity and mortality, while MM therapies also result in adverse cardiac effects. Endothelial dysfunction and impaired nitric oxide (NO) pathway is their possible mediator.

OBJECTIVE

Since MM is associated with increased arginase expression, resulting in the consumption of ʟ-arginine, precursor for NO synthesis, our aim was to test if cardiotoxicity mediated by MM and MM therapeutic, bortezomib (a proteasome inhibitor), can be ameliorated by an arginase inhibitor through improved endothelial function.

METHODS

We used a mouse Vĸ*MYC model of non-light chain MM. Cardiac function was assessed by echocardiography.

RESULTS

MM resulted in progressive left ventricular (LV) systolic dysfunction, and bortezomib exacerbated this effect, leading to significant impairment of LV performance. An arginase inhibitor, OAT-1746, protected the heart against bortezomib- or MM-induced toxicity but did not completely prevent the effects of the MM+bortezomib combination. MM was associated with improved endothelial function (assessed as NO production) vs. healthy controls, while bortezomib did not affect it. OAT-1746 improved endothelial function only in healthy mice. NO plasma concentration was increased by OAT-1746 but was not affected by MM or bortezomib.

CONCLUSIONS

Bortezomib exacerbates MM-mediated LV systolic dysfunction in a mouse model of MM, while an arginase inhibitor partially prevents it. Endothelium does not mediate either these adverse or beneficial effects. This suggests that proteasome inhibitors should be used with caution in patients with advanced myeloma, where the summation of cardiotoxicity could be expected. Therapies aimed at the NO pathway, in particular arginase inhibitors, could offer promise in the prevention/treatment of cardiotoxicity in MM.