Search

Background: Heart failure (HF) with preserved ejection fraction (HFpEF) and monoclonal gammopathy of uncertain significance (MGUS) are two entities that share pathophysiological mechanisms. The aim herein, was to assess the prevalence of MGUS in patients with HFpEF and no left ventricular (LV) hypertrophy, as well as its association with a pre-specified clinical endpoint at 12 months. Methods: The present study prospectively enrolled 69 patients admitted with HF, with ejection fraction ≥ 50%, and LV wall thickness < 12 mm. All patients were screened for MGUS. Clinical events were determined over a 12 month follow-up. The pre-specified composite clinical endpoint was readmission for HF or death. Results: The prevalence of MGUS in this population was 13%. There were no differences in the incidence of the composite clinical endpoint between patients with and without MGUS. Multivariate analysis showed that treatment with angiotensin converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) was associated with fewer clinical events (HR: 0.153, 95% CI: 0.037–0.622, p = 0.009) and indicated a trend to lower risk of readmission for HF and death. Beta-blockers were associated with lower rates of the composite clinical endpoint (HR: 0.192, 95% CI: 0.05–0.736, p = = 0.016), readmission for HF (HR: 0.272, 95% CI: 0.087–0.851, p = 0.025) and indicated a trend to lower mortality. Moreover, potassium serum levels > 5 mEq/L were associated with higher rates of the composite endpoint (HR: 6.074, 95% CI: 1.6–22.65, p = 0.007). Conclusions: The prevalence of MGUS in patients with HFpEF without hypertrophy was 3-fold that of the general population. There was no significant correlation between clinical outcomes and the presence of MGUS. Beta-blockers and ACEIs/ARBs reduced the composite of mortality and readmissions for HF in HFpEF patients. Hyperpotassemia was related to worse prognosis, This work was supported by grants from Instituto de Salut Carlos III (PI19/00655), financed jointly with European Regional Development Funds (ERDF)

La enfermedad por coronavirus de 2019 (COVID-19) es una emergencia sanitaria pública global con numerosas facetas clínicas que incluyen renopatía aguda y enfermedad cerebrovascular aguda. Es necesario un conocimiento adicional de su mecanismo patogénico. Los trastornos de coagulación están claramente incluidos en dichos mecanismos. La gammapatía monoclonal se caracteriza por la sobreproducción de inmunoglobulina monoclonal causada por proliferación clonal. Utilizando un estudio postmortem de biopsias básicas percutáneas ecoguiadas, el objetivo de este informe es presentar nuestras observaciones sobre la patología del síndrome respiratorio agudo severo por infección de coronavirus 2 (SARS-CoV2) con gammapatía monoclonal. La presentación clínica fue insuficiencia renal aguda. Los hallazgos patológicos revelaron nefropatía por depósito de cadenas ligeras kappa. La inmunohistoquímica de SARS-CoV-2 fue positiva en ciertas células tubulares renales. La presencia de megacariocitos alveolares (alta densidad) fue un hallazgo notable, que explica probablemente el resultado final del paciente (enfermedad cerebrovascular aguda). El estudio inmunohistoquímico frente a SARS-CoV-2 no verifica el efecto patogénico del virus y, por tanto, su contribución a la nefropatía aguda.

Multiple myeloma (MM) remains incurable. Although early diagnosis improves outcomes, it has been unclear which populations to target for screening with serum electrophoresis, serum free light chains and urine electrophoresis. Here, we assessed the value of MM screening in a Fracture Liaison Service, finding that 1 per 195 fragility fractures has undiagnosed MM, which can be expedited to Haematology Services. Purpose A key role of the Fracture Liaison Service (FLS) is screening for secondary causes of osteoporosis. In 2019, the Royal Osteoporosis Society recommended that all patients attending FLS who are recommended anti-osteoporosis therapy have universal screening for myeloma based on serum electrophoresis, serum free light chains and urine electrophoresis. Here, we examined the impact of universal myeloma screening within an FLS. Methods We sampled all patients seen by the Oxfordshire FLS between January and April 2018. The completion rates and outcomes of screening were checked using the hospital and FLS databases. Results Of 950 patients identified by the FLS, 628 were eligible for MM screening; 473 (75%) of these were female, and the average age was 78.4 years. Overall, 584 had some form of myeloma screening, of which 577 (92%) had serum electrophoresis, 525 (84%) had serum free light chains and 407 (65%) had urine electrophoresis measured. A total of 327 (59%) patients had complete screening. Three patients (0.5%) had newly diagnosed myeloma and were urgently referred to Haematology Services. Furthermore, 46 (8%) patients had a detectable serum paraprotein with a likely diagnosis of monoclonal gammopathy of uncertain significance (MGUS) and referred for community annual surveillance according to local guidelines. Conclusion Addition of universal myeloma screening to laboratory testing identified myeloma in 1 per 195 patients, and its precursor state MGUS in 1 per 13 patients, which may have otherwise been missed. Further analysis with long-term follow-up is needed to clearly define the value of diagnosing MGUS within the FLS setting and establish the benefits vs. costs and methods to improve screening completion rates.

Monoclonal gammopathy of ocular significance (MGOS) is a rare subset of monoclonal gammopathy of clinical significance occurring secondary to plasma cell disorders and causing ocular manifestations. We identified 23 patients with paraproteinemic keratopathy (PPK) in the setting of monoclonal gammopathy of unknown significance (MGUS, 10), smoldering multiple myeloma (SMM, 3) or multiple myeloma (MM, 10). Many of these patients with PPK (11/23) presented decreased vision. All patients with MM and 40% of those with other diagnoses such as SMM and MGUS received systemic therapy with or without autologous stem cell transplantation. Four eyes of four patients were treated by penetrating keratoplasty. In most cases, neither ocular nor hematologic treatment afforded a durable improvement in the visual acuity (recurrence after a median of 11 months), despite initial responses. Further studies will be required to determine the optimal strategy to treat and prevent the relapse of ocular symptoms in patients with PPK.

Background Monoclonal gammopathy is a biological reality encountered in approximately 1% of the general population. In the absence of clinical and biological signs, it is considered of undetermined significance; however, it can be a biological signature of a monoclonal lymphocytic or plasma-cell proliferation. Their localisation to the oral mucosa remains rare and difficult to diagnose, particularly in indolent forms that escape imaging techniques. Case presentation Here, we report the case of a 73-year-old woman with a history of IgM kappa gammopathy followed for 13 years. The patient did not have a chronic infection or an autoimmune disease, and all the biological investigations and radiological explorations were unremarkable during this period. The discovery of a submucosal nodule in the cheek led to the diagnosis of MALT lymphoma and regression of half of the IgM kappa level after resection. The review of the literature shows the dominance of clinical signs (i.e., a mass or swelling) in the diagnosis of primary MALT lymphomas of the oral cavity after surgical resection. Conclusions Our case illustrates the role of examination of the oral cavity in the context of a monoclonal gammopathy. The absence of clinical and radiological evidence in favor of lymphoplasmacytic proliferation, does not exclude a primary indolent MALT lymphoma of the oral mucosa.

BackgroundC3 glomerulopathy associated with monoclonal gammopathy (C3G-MIg) is a rare entity. Herein we analysed the clinical and histologic features of a cohort of C3G-MIg patients.MethodsWe conducted a retrospective, multicentre, observational study. Patients diagnosed with C3G-MIg between 1995 and 2021 were enrolled. All had genetic studies of the alternative complement pathway. The degree of disease activity and chronicity were analysed using the C3G histologic index. Descriptive statistics and propensity score matching (PSM) analysis were used to evaluate the main outcome of the study [kidney failure (KF)].ResultsThe study group included 23 patients with a median age 63 of years [interquartile range (IQR) 48–70], and 57% were males. Immunoglobulin G kappa was the most frequent MIg (65%). The diagnosis of C3G-MIg was made in transplanted kidneys in seven patients (30%). Five (22%) patients had C3 nephritic factor and five (22%) had anti-factor H antibodies. One patient carried a pathogenic variant in the CFH gene. During a follow-up of 40 months (IQR 14–69), nine patients (39%) reached KF and these patients had a significantly higher total chronicity score on kidney biopsy. Patients who received clone-targeted therapy had a significantly higher survival compared with other management. Those who achieved haematological response had a significantly higher kidney survival. Outcome was remarkably poor in kidney transplant recipients, with five of them (71%) reaching KF. By PSM (adjusting for age, kidney function, proteinuria and chronicity score), no significant differences were observed in kidney survival between C3G patients with/without MIg.ConclusionsThe C3G histologic index can be used in patients with C3G-MIg to predict kidney prognosis, with higher chronicity scores being associated with worse outcomes. Clone-targeted therapies and the development of a haematological response are associated with better kidney prognosis.

Central Illustration

Background Serum protein electrophoresis (SPE) is a common clinical laboratory test, mainly indicated for the diagnosis and follow-up of monoclonal gammopathies. A time-consuming and potentially subjective human expertise is required for SPE analysis to detect possible pitfalls and to provide a clinically relevant interpretation. Methods An expert-annotated SPE dataset of 159 969 entries was used to develop SPECTR (serum protein electrophoresis computer-assisted recognition), a deep learning-based artificial intelligence, which analyzes and interprets raw SPE curves produced by an analytical system into text comments that can be used by practitioners. It was designed following academic recommendations for SPE interpretation, using a transparent architecture avoiding the “black box” effect. SPECTR was validated on an external, independent cohort of 70 362 SPEs and challenged by a panel of 9 independent experts from other hospital centers. Results SPECTR was able to identify accurately both quantitative abnormalities (r ≥ 0.98 for fractions quantification) and qualitative abnormalities [receiver operating characteristic–area under curve (ROC–AUC) ≥ 0.90 for M-spikes, restricted heterogeneity of immunoglobulins, and beta-gamma bridging]. Furthermore, it showed highly accurate at both detecting (ROC–AUC ≥ 0.99) and quantifying (r = 0.99) M-spikes. It proved highly reproducible and resilient to minor variations and its agreement with human experts was higher (κ = 0.632) than experts between each other (κ = 0.624). Conclusions SPECTR is an algorithm based on artificial intelligence suitable to high-throughput SPEs analyses and interpretation. It aims at improving SPE reproducibility and reliability. It is freely available in open access through an online tool providing fully editable validation assistance for SPE.

Castleman disease is a rare lymphoproliferative disorder. Co-presentation with polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes (POEMS syndrome) has been documented in 11-30% of Castleman disease cases. POEMS syndrome is a rare paraneoplastic disorder characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes. Not all features are required to make the diagnosis. We report a case of a woman who presented with a 1-year history of a left-side supraclavicular swelling associated with constitutional symptoms and symmetrical paresthesia of the lower limbs. In addition, she had skin hyperpigmentation, multiple supra and infra-diaphragmatic lymphadenopathies, hepatosplenomegaly and osteosclerotic lesions. Serum immunofixation was positive for immunoglobulin G-kappa gammopathy. A lymph node excisional biopsy was compatible with Castleman disease. The diagnosis of POEMS syndrome associated with Castleman disease was made. Our patient started treatment with a combination of bortezomib, cyclophosphamide, and dexamethasone with clinical and analytical improvement. Current treatment of POEMS syndrome associated with Castleman disease is focused on the management of POEMS syndrome. Early diagnosis requires a high index of suspicion and is crucial to reduce morbidity and mortality. This case report aims to raise awareness about this rare entity. J Med Cases. 2021;12(10):400-404 doi: https://doi.org/10.14740/jmc3759

Cutaneous macroglobulinosis is a rare manifestation of Waldenstrom macroglobulinemia when there is deposition of IgM in the dermis. The clinical presentation varies from skin colored to pink papules and ulcerative nodules on trunk, extensor surfaces of upper and lower limbs to hyperkeratotic lesions on the soles. We herein report a 78-year-old-male with Waldenstrom macroglobulinemia who presented with serpiginous purpura. The differential diagnoses included occlusion of vessel lumen by the lymphoplasmacytoid cells, high level of IgM or cryoglobulin, as well as small to medium vasculitis secondary to Waldenstrom macroglobulinemia. The histopathology revealed vasculopathy and vasculitis, while further immunohistochemistry highlighted deposition in the vessel lumen and vessel wall with IgM, suggesting the diagnosis of cutaneous macroglobulinosis. In this case report, we discuss this rare presentation and reviewed previous cases of cutaneous macroglobulinosis.

International audience; Monoclonal gammopathies of renal significance (MGRS) encompass a remarkable variety of kidney diseases that result from intrinsic nephrotoxic properties of certain monoclonal Igs or their subunits. Effective disease-modifying treatments rely on the targeting of a malignant B-cell clone that may be demonstrable but often is quite hypothetical. Hence, convincing arguments for the genuine monoclonal character of the causative mono-isotypic Ig tissue deposits is needed for design of appropriate treatment strategies. The purpose of this article was to critically analyze distinct situations of suspected MGRS that occur in the practice of pathologists, nephrologists, hematologists, and immunologists. A particular focus of interest is the group of conditions known as proliferative glomerulonephritis with mono-isotypic immunoglobulin deposits (PGNMIDs), which illustrates the difficulties and ambiguities surrounding a definitive assignment of MGRS status.

Crystalcryoglobulinemia refers to the extracellular deposition of crystals in the systemic vasculature, leading to vascular injury, thrombosis, and occlusion. This entity is usually described as a complication of multiple myeloma, although it can also occur in the setting of a monoclonal gammopathy of renal significance. Synchronous presentation of a monoclonal gammopathy and renal cell carcinoma is rare. Hypothetically, as both neoplasms’ growth depends on certain cytokines such as interleukin-6, it is possible that cytokine production from one neoplasm may stimulate the growth of the other. In this report, we describe a case of crystalcryoglobulinemia in a patient with a monoclonal gammopathy of renal significance and concomitant renal cell carcinoma. Additionally, we performed a systematic review of the literature and analyzed data of 61 reported cases of crystalcryoglobulinemia and of 40 reported cases describing the association between multiple myeloma and renal cell carcinoma.

Monoclonal Gammopathy of Renal Significance Monoclonal gammopathy of renal significance is a B-cell or plasma-cell clonal disorder that does not meet the criteria for cancer but produces a monoclon...

Amyloid light chain (AL) cardiomyopathy is the most malignant specific cardiomyopathy. According to international recommendations, it should be ruled out non‐invasively using the serum free light chain (FLC) ratio and immunofixation electrophoresis in both serum and urine. Here, we report on a 69‐year‐old female patient with new‐onset heart failure with mid‐range ejection fraction. Cardiac imaging was highly suggestive of cardiac amyloidosis. Amyloid scintigraphy showed faint myocardial tracer uptake according to Perugini Score 1, but immunofixation was negative and the FLC ratio was normal, despite a slight increase in lambda FLCs. Endomyocardial biopsy revealed advanced myocardial lambda immunoglobulin light chain deposition. Clinically relevant extracardiac amyloid organ infiltration could not be detected. Conclusively, non‐invasive testing can in rare cases fail to exclude isolated AL amyloid cardiomyopathy. We suggest that even slight increases in serum lambda or kappa FLCs should be considered abnormal in suspected cardiac amyloidosis if non‐invasive testing delivers discrepant results.

Despite the benign nature of monoclonal gammopathy of undetermined significance (MGUS), mounting data are associating MGUS with the development of organ dysfunction, specifically monoclonal gammopathy of renal significance (MGRS) and monoclonal gammopathy of neurological significance (MGNS), which could be associated with substantial morbidity. Emerging evidence suggests that patients with MGRS and MGNS could benefit from treatments used for myeloma, Waldenström macroglobulinemia, or chronic lymphocytic leukemia, depending on the underlying pathology. However, the treatment of MGRS and MGNS is not standardized, and potentially effective therapies might not be reimbursed because these conditions do not formally meet the criteria for malignant processes. The present review aims at establishing standards for the evaluation and management of MGRS and MGNS, which can facilitate the diagnosis of and provide therapeutic options for treating practitioners and patients affected by these conditions. The careful design and execution of clinical trials for patients with MGRS and MGNS are positively encouraged.

Lymphoproliferative diseases have been associated with various autoimmune diseases. We experienced a case of non-chronic lymphocytic leukemia type monoclonal B-cell lymphocytosis (MBL) that was exacerbated by increasing prednisolone for dermatomyositis and then improved by decreasing the dosage. Because MBL is difficult to diagnose, cases like ours may not be rare. These findings will facilitate our understanding of the mechanism underlying lymphoproliferative diseases and autoimmune diseases.

Context.— In laboratory testing for monoclonal gammopathies, paraproteins are identified via serum immunofixation or serum immunosubtraction, and immunoturbidimetric quantitation of serum immunoglobulins is often used. Objective.— To evaluate methodologic differences between serum immunofixation and serum immunosubtraction, as well as in the quantitation of serum immunoglobulins on different clinical chemical platforms. Design.— Three hundred twenty-two unique routine patient samples were blinded and used for comparison between serum immunofixation on Sebia's HYDRASIS 2 and serum immunosubtraction on Sebia's CAPILLARYS 2, as well as between quantitation results of immunoglobulin A, G, and M on Abbott's ARCHITECT c16000PLUS and Roche's Cobas c 502 module. Microsoft Excel 2019 with the add-on Abacus 2.0 and MedCalc were used for statistical analysis and graphic depiction via bubble diagram, Passing-Bablok regressions, and Bland-Altman plots. Results.— The median age of patients was 75 years, and samples with paraproteinemia were nearly evenly split between sexes. Paraprotein identification differed remarkably between immunofixation and immunosubtraction. Quantitation of serum immunoglobulins showed higher values on Abbott's ARCHITECT c16000PLUS when compared with Roche's Cobas c 502 module. Conclusions.— Identification of paraproteins via serum immunosubtraction is inferior to serum immunofixation, which can have implications on the diagnosis and monitoring of patients with monoclonal gammopathy. If immunoturbidimetric quantitation of immunoglobulins is used for follow-up, the same clinical-chemical platform should be used consistently.

The term monoclonal gammopathy of renal significance MGRS means a group of renal diseases resulting from the presence of the monoclonal protein produced by plasmatic cells or other clones of B cells. The patients with MGRS do not fulfill the diagnostics criteria both of multiple myeloma and other neoplasm originating from B cells. The involvement of different renal structures in the course of MGRS results the dysfunction of kidneys. The monoclonal protein may injure the glomerular structures (including vascular) as well as tubular structures (interstitial in more wide sense). The early diagnosis of MGRS is difficult and the late detection of the disease is connected with high risk of irreversible renal damage. Therefore, the multidisciplinary cooperation – including general practitioners, nephrologists, hematologists and nephro-pathologists – is particularly important for the diagnostics and treatment of MGRS cases. This new hemato-nephrological meta-disease entity is connected with relatively high morbidity and mortality as well as relapses in transplanted kidney. The decision of the treatment initiation against the toxic clone in MGRS cases results mainly from the nephrological reasons. The article presents current diagnostic and therapeutic possibilities that may be used in MGRS patients. The main purpose of this article was to present the current state of knowledge regarding the diagnostics and treatment of MGRS.

Background Acquired von Willebrand syndrome (AVWS) has been associated with monoclonal gammopathy of undetermined significance (MGUS), with limited data on its management. Methods We conducted a systematic literature search in Medline (Ovid), Embase, and Scopus up to September 11, 2019, for studies reporting on the management of AVWS associated with MGUS (AVWS‐MGUS). Data on patient characteristics, laboratory parameters at presentation, and clinical and laboratory outcomes were extracted. Objectives To describe the clinical presentation and outcomes of different therapeutic approaches. Results Seventy‐five studies were included in the final review, for a total of 137 patients. Most patients had von Willebrand factor ristocetin cofactor activity

Monoclonal gammopathy (M-proteinemia) is a premalignant plasma cell disorder. The prevalence of M-proteinemia increases with age and is affected by genetic or environmental factors. Atomic bomb (A-bomb) survivors in Hiroshima are in an age range when they are susceptible to M-proteinemia. The prevalence and incidence of M-proteinemia in Hiroshima A-bomb survivors were investigated for 30 years (1989–2018) to examine the influence of radiation exposure. The overall prevalence of M-proteinemia among 38,602 A-bomb survivors was 2.4%. M-proteinemia prevalence at age 70 years and monoclonal gammopathy of undetermined significance (MGUS) incidence were not associated with radiation exposure category. Males had a 2.30-fold higher prevalence and a 2.08-fold higher incidence than females. The risk of incidence for MGUS was 4.32-fold higher in persons aged

Mass spectrometry has recently been proposed as a novel sensitive screening tool for monoclonal gammopathies. In a small study we have tested the ability of quantitative immunoprecipitation mass spectrometry (QIP-MS) to identify low level monoclonal immunoglobulins not currently detected by the initial serum protein electrophoresis (SPEP) screen. QIP-MS positively identified the primary monoclonal immunoglobulins in all 11 patient samples alongside additional monoclonal immunoglobulins in a subset of patient samples. We conclude that QIP-MS has clinical utility as a first-line screening tool for monoclonal gammopathy investigation, identifying monoclonality in patients with higher sensitivity and resolution compared to the current standard methods.

Fifty-eight-year-old male admitted for evaluation of nephrotic syndrome and chronic diarrhoea was detected to have Immunoglobulin light chain amyloidosis (AL Amyloidosis) which was congo red inconclusive from renal biopsy. Bone marrow biopsy showed monoclonal plasma cells of 40% and light chain assay showed predominance of immunoglobulin lambda light chain. The diagnosis was neither fitting into the current diagnostic criteria for light chain Monoclonal Gammopathy of Renal Significance (MGRS) nor light chain myeloma. Literature is scarce regarding patients with AL amyloidosis having underlying clonal expansion not meeting the criteria of light chain myeloma or light chain MGRS.

Monoclonal gammopathy is encountered quite frequently in the general population. This type of hematologic abnormality may be mild, referred to as monoclonal gammopathy of undetermined significance or related to different types of hematologic malignancies. The association of a peripheral neuropathy with monoclonal gammopathy is also fairly common, and hemopathy may be discovered in an investigation of peripheral neuropathy. In such a situation, it is essential to determine the exact nature of the hematologic process in order not to miss a malignant disease and thus initiate the appropriate treatment (in conjunction with hematologists and oncologists). In this respect, nerve biopsy (discussed on a case-by-case basis) is of great value in the management of such patients. We therefore propose to present the objectives and main interests of nerve biopsy in this situation.

The presence of monoclonal proteins is common, with a prevalence in the United States around 5% that increases with age. Although most patients are asymptomatic, most 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. In recent years, significant progress has been made to better understand the factors that lead to the development of symptoms and progression to myeloma. This review summarizes the current diagnosis treatment guidelines for MGUS and SMM and highlights recent advances that underscore a shifting paradigm in the evaluation and management of plasma cell precursor conditions.

PURPOSE Serum protein electrophoresis (SPEP) is a clinical tool used to screen for monoclonal gammopathy, thus it is a critical tool in the evaluation of patients with multiple myeloma. However, SPEP laboratory results are usually returned as short text reports, which are not amenable to simple computerized processing for large-scale studies. We applied natural language processing (NLP) to detect monoclonal gammopathy in SPEP laboratory results and compared its performance at multiple hospitals using both a rules-based manual system and a machine-learning algorithm. METHODS We used the data from the VA Corporate Data Warehouse, which comprises data from 20 million unique individuals. SPEP reports were collected from July to December 2015 at 5 Veterans Affairs Medical Centers. Of these reports, we annotated the presence or absence of monoclonal gammopathy in 300 reports. We applied a machine learning–based NLP and a manual rules-based NLP to detect monoclonal gammopathy in SPEP reports at each of the hospitals, then applied the model from 1 hospital to each of the other hospitals. RESULTS The learning system achieved an area under the receiver operating characteristic curve of 0.997, and the rules-based system achieved an accuracy of 0.99. When a model trained on 1 hospital’s data was applied to a different hospital, however, accuracy varied greatly, and the learning-based models performed better than the rules-based model. CONCLUSION Binary classification of short clinical texts such as SPEP reports may be a particularly attractive target on which to train highly accurate NLP systems.

Multiple myeloma (MM) is a hematological malignancy characterized by abnormal plasma cell proliferation within the bone marrow which leads to progressive bone marrow failure, skeletal osteolytic lesions, and renal insufficiency, thus severely affecting the quality of life. MM is always preceded by monoclonal gammopathy of uncertain significance (MGUS), which progresses to asymptomatic-MM (aMM) or symptomatic-MM (sMM) at a rate of 1% per year. Despite impressive progress in the therapy of the disease, MM remains incurable. Based on these premises, the identification of biomarkers of MGUS progression to MM is a crucial issue in disease management. In this regard, exosomes (EXs) and their precious biomolecular cargo could play a pivotal role in MM detection, stratification, and follow-up. Raman spectroscopy, a label- and manipulation-free technique, and its enhanced version, surface-enhanced Raman spectroscopy (SERS), have been used for characterizing MGUS, aMM, and sMM patient-derived EXs. Here, we have demonstrated the capability of Raman spectroscopy for discriminating EXs along the progression from MGUS to aMM and sMM, thus providing useful clinical indications for patient care. The used SERS devices, based on random nanostructures, have shown good potential in terms of sensitivity, but further developments are needed for achieving reproducible and quantitative SERS results.

Patients with monoclonal gammopathy of renal significance should be treated with clone‐directed therapy against sources of monoclonal proteins in order to prevent progression to more advanced monoclonal gammopathies and renal failure.