Monoclonal gammopathy of undetermined significance and bone health outcomes: a systematic review and exploratory meta-analysis

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.

[Osteoporosis-Definition, risk assessment, diagnosis, prevention and treatment (update 2024) : Guidelines of the Austrian Society for Bone and Mineral Research]

BACKGROUND

Austria is among the countries with the highest incidence and prevalence of osteoporotic fractures worldwide. Guidelines for the prevention and management of osteoporosis were first published in 2010 under the auspices of the then Federation of Austrian Social Security Institutions and updated in 2017. The present comprehensively updated guidelines of the Austrian Society for Bone and Mineral Research are aimed at physicians of all specialties as well as decision makers and institutions in the Austrian healthcare system. The aim of these guidelines is to strengthen and improve the quality of medical care of patients with osteoporosis and osteoporotic fractures in Austria.

METHODS

These evidence-based recommendations were compiled taking randomized controlled trials, systematic reviews and meta-analyses as well as European and international reference guidelines published before 1 June 2023 into consideration. The grading of recommendations used ("conditional" and "strong") are based on the strength of the evidence. The evidence levels used mutual conversions of SIGN (1++ to 3) to NOGG criteria (Ia to IV).

RESULTS

The guidelines include all aspects associated with osteoporosis and osteoporotic fractures, such as secondary causes, prevention, diagnosis, estimation of the 10-year fracture risk using FRAX®, determination of Austria-specific FRAX®-based intervention thresholds, drug-based and non-drug-based treatment options and treatment monitoring. Recommendations for the office-based setting and decision makers and institutions in the Austrian healthcare system consider structured care models and options for osteoporosis-specific screening.

CONCLUSION

The guidelines present comprehensive, evidence-based information and instructions for the treatment of osteoporosis. It is expected that the quality of medical care for patients with this clinical picture will be substantially improved at all levels of the Austrian healthcare system.

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.

Monoclonal Gammopathies of Clinical Significance: A Critical Appraisal

Monoclonal gammopathies of clinical significance (MGCSs) represent a group of diseases featuring the association of a nonmalignant B cells or plasma cells clone, the production of an M-protein, and singularly, the existence of organ damage. They present a current framework that is difficult to approach from a practical clinical perspective. Several points should be addressed in order to move further toward a better understanding. Overall, these entities are only partially included in the international classifications of diseases. Its definition and classification remain ambiguous. Remarkably, its real incidence is unknown, provided that a diagnostic biopsy is mandatory in most cases. In fact, amyloidosis AL is the final diagnosis in a large percentage of patients with renal significance. On the other hand, many of these young entities are syndromes that are based on a dynamic set of diagnostic criteria, challenging a timely diagnosis. Moreover, a specific risk score for progression is lacking. Despite the key role of the clinical laboratory in the diagnosis and prognosis of these patients, information about laboratory biomarkers is limited. Besides, the evidence accumulated for many of these entities is scarce. Hence, national and international registries are stimulated. In particular, IgM MGCS deserves special attention. Until now, therapy is far from being standardized, and it should be planned on a risk and patient-adapted basis. Finally, a comprehensive and coordinated multidisciplinary approach is needed, and specific clinical trials are encouraged.

[Monoclonal gammopathy of (un)known significance]

Monoclonal gammopathies are a frequently diagnosed entity. However, the diagnosis is not always clinically relevant. The diagnosis of a monoclonal gammopathy requires serum electrophoresis, immunofixation and free light chain measurement. Sometimes, monoclonal gammopathies occur in the course of transient or autoimmune inflammation. Further diagnostics should only be performed after risk assessment according to Mayo criteria. In non-low risk patients, a symptomatic myeloma has to be ruled out via SLiM-CRAB criteria. The diagnostic work-up should include whole-body MRI and a bone marrow puncture as well as a 24 h urine sample. If it does not imply myeloma, the diagnosis of MGUS is confirmed and a follow-up after 6 months is recommended. After that, low-risk patients only need SLiM-CRAB screening at clinical signs of progression. All other patients should receive serologic follow-ups once a year. Importantly, MGUS patients show higher morbidity. Amongst a higher prevalence of osteoporosis and immunodeficiency, a wide array of MGUS-associated diseases such as AL amyloidosis, deposition diseases and Fc binding-dependent effects can occur. This article gives an overview over the work-up, observation and caveats of monoclonal gammopathy of (un)known significance.

Multiple myeloma screening within a fracture liaison service (FLS)

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.

Secondary Osteoporosis

Osteoporosis is a global public health problem, with fractures contributing to significant morbidity and mortality. Although postmenopausal osteoporosis is most common, up to 30% of postmenopausal women, > 50% of premenopausal women, and between 50% and 80% of men have secondary osteoporosis. Exclusion of secondary causes is important, as treatment of such patients often commences by treating the underlying condition. These are varied but often neglected, ranging from endocrine to chronic inflammatory and genetic conditions. General screening is recommended for all patients with osteoporosis, with advanced investigations reserved for premenopausal women and men aged < 50 years, for older patients in whom classical risk factors for osteoporosis are absent, and for all patients with the lowest bone mass (Z-score ≤ -2). The response of secondary osteoporosis to conventional anti-osteoporosis therapy may be inadequate if the underlying condition is unrecognized and untreated. Bone densitometry, using dual-energy x-ray absorptiometry, may underestimate fracture risk in some chronic diseases, including glucocorticoid-induced osteoporosis, type 2 diabetes, and obesity, and may overestimate fracture risk in others (eg, Turner syndrome). FRAX and trabecular bone score may provide additional information regarding fracture risk in secondary osteoporosis, but their use is limited to adults aged ≥ 40 years and ≥ 50 years, respectively. In addition, FRAX requires adjustment in some chronic conditions, such as glucocorticoid use, type 2 diabetes, and HIV. In most conditions, evidence for antiresorptive or anabolic therapy is limited to increases in bone mass. Current osteoporosis management guidelines also neglect secondary osteoporosis and these existing evidence gaps are discussed.

Vitamin D Deficiency, Osteoporosis and Effect on Autoimmune Diseases and Hematopoiesis: A Review

Vitamin D (VD) is essential for bone homeostasis, but it is also involved in pleiotropic effects on various organs and tissues. In adults, VD deficiency can cause or exacerbate osteoporosis and induce osteomalacia. However, every tissue and cell in the body has a VD receptor, including the brain, heart, stomach, pancreas, skin, gonads, and immune cells, and a deficiency may modify the function of these organs. Thus, the wide-ranging actions of VD help to explain why a reduction in VD amount has been correlated with numerous chronic diseases. In fact, VD deficiency increases the risk of osteoporosis and several other diseases and complications characterized by impaired bone metabolisms, such as autoimmune diseases, inflammatory bowel diseases, allergy, endocrinological diseases, hematological malignancies, and bone marrow transplantation. This review aims to investigate the link between VD deficiency, osteoporosis, and its concomitant diseases. Further epidemiological and mechanistic studies are necessary in order to ascertain the real role of hypovitaminosis in causing the reported diseases; however, adequate vitamin supplementation and restoration of metabolic normality could be useful for better management of these pathologies.

Untangling fracture risk in monoclonal gammopathy of undetermined significance: A population-based cohort study

OBJECTIVE

Monoclonal gammopathy of undetermined significance (MGUS) is the asymptomatic precursor of multiple myeloma (MM). Lytic bone lesions and fractures are hallmarks of MM and although there are no lytic lesions in MGUS, it has also been associated with fractures. The causes of fractures in MGUS are currently unclear but potential causes include inherent MGUS bone disease, undiagnosed MM, and peripheral neuropathy (PN). We therefore conducted a large population-based study including 8395 individuals with MGUS and 30 851 matched controls from Sweden.

METHODS

Data on fractures, PN, and confounders were acquired from high-quality registers in Sweden.

RESULTS

Monoclonal gammopathy of undetermined significance and PN were independently associated with fractures (hazard ratio [HR]: 1.29; 95% confidence interval [95% CI]: 1.21-1.37; P < .001 and HR: 1.34; 95% CI: 1.16-1.55; P < .001). Imminent MGUS progression increased the risk of fractures (odds ratio: 1.66; 95% CI: 1.27-2.16; P < .001). Fractures were not associated with long-term risk of MGUS progression (HR: 1.08; 95% CI: 0.77-1.53; P = .64).

DISCUSSION

Based on these findings, we speculate that MGUS leads to fractures through at least 3 independent mechanisms: undetected MGUS progression to MM, MGUS inherent bone disease, and PN through falls. These findings highlight the need for further study of MGUS inherent bone disease and can inform further research into fracture prevention in MGUS.

Impact of whole-body vibration exercise on physical performance and bone turnover in patients with monoclonal gammopathy of undetermined significance

OBJECTIVE

Monoclonal Gammopathy of Undetermined Significance (MGUS) is a risk factor for reduced physical performance, osteoporosis, and fractures due to compromised musculoskeletal metabolism. In this condition it is unknown whether whole-body vibration (WBV) exercise favorably alters physical performance and bone metabolism.

METHODS

To evaluate the effect of three-months WBV exercise (30 min; 2x/week) including an optional three-month extension on physical performance, bone metabolism and bone mineral density. Endpoints included functional assessments, bone turnover markers and bone mineral density assessed by peripheral quantitative computed tomography of the tibia.

RESULTS

Fifteen MGUS patients (median age 62.0, nine female) completed the first three months of which ten completed the three-month extension. Measures of physical functioning including chair rise test, timed up and go and 6-minute walk test improved (p = 0.007; p = 0.009; p = 0.005) after three and six months of WBV exercise. Total tibial bone mineral density remained unaltered (p > 0.05). WBV exercise tended to increase levels of sclerostin (p = 0.093) with a transient increase in osteoclast resorption markers (N-terminal telopeptide of collagen type 1, tartrate resistant acid phosphatase 5b) after three months while Dickkopf-1 (p = 0.093), procollagen I N-terminal propeptide (p = 0.074) and total alkaline phosphatase (p = 0.016) appeared to decline. No exercise-related adverse events were reported.

CONCLUSION

WBV exercise in MGUS patients improves indicators of physical performance. Observed trends in bone turnover markers and changes in distal tibial bone mineral density may indicate a regulatory effect of WBV exercise on bone metabolism and warrants further evaluation by large scale studies.

Diagnosis and Management of Monoclonal Gammopathy and Smoldering Multiple Myeloma

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.

Use of trabecular bone score for risk stratification of patients with monoclonal gammopathy of undetermined significance

Monoclonal gammopathy of undetermined significance (MGUS) is a common finding in clinical practice. The risk for developing MGUS increases with aging in parallel with age-associated increases in fracture risk. Although there is good evidence that patients with MGUS suffer from increased fracture risk, no standardized guidelines exist for the evaluation and/or management of skeletal health in patients with MGUS. Trabecular bone score (TBS), a texture index derived from lumbar spine (LS) dual-energy x-ray absorptiometry (DXA) images, provides information about trabecular microarchitecture independent of bone mineral density (BMD). We retrospectively identified 155 adult patients diagnosed with MGUS between 2005 and 2018. This group was matched 1:1 to a control group for sex, age and BMI. TBS was performed retrospectively, and values categorized as low (≤1.23), intermediate (1.23-1.31) or normal (>1.31). Patients had a mean ± SD age of 69.6 ± 10.0. BMD was performed within a median of 28 months (IQR 1-78) of MGUS diagnosis. Cases had a non-statistically significant higher rate of fractures compared to control subjects (27 vs. 17, respectively, p = 0.1). Patients with MGUS had a significantly lower TBS (1.31 ± 0.13 vs. 1.34 ± 0.12, respectively, p < 0.05) and lower LS BMD (1.215 ± 0.223 vs. 1.275 ± 0.247, p < 0.05) compared to controls. Although fractures occurred more commonly in those control subjects with significantly lower TBS values, this was not the case in subjects with MGUS (TBS 1.299 vs. 1.313 in cases with vs. without fractures p = 0.313). Similarly, there was no difference in T-scores in cases with or without fractures (-1.33 vs. -1.37, respectively, p = 0.56). Despite patients with MGUS having a significantly increased fracture risk compared to age-, sex- and BMI-matched control subjects, neither assessment of BMD nor TBS, obtained within two years of MGUS diagnosis, were able to accurately risk stratify MGUS patients. Unlike control subjects, patients with MGUS tend to fracture despite normal BMD and intermediate or normal TBS values, suggesting that deterioration of cortical rather than trabecular skeletal components may be more important for the increased fracture risk seen in MGUS.

A Single-Center Retrospective Study to Investigate the Follow-Up of Patients with Monoclonal Proteinemia by Community Physicians in the UK

Background

We determined the detection rate of monoclonal gammopathy of undetermined significance (MGUS) and follow-up of MGUS patients in a center that uses reflex testing at globulin levels outside the reference range as part of its routine service to detect monoclonal protein (M-protein). We recorded the natural history and follow-up of these patients. This is one of the first reports on the diagnosis and follow-up of MGUS patients within the UK.

Patients and Methods

A total of 163 patients diagnosed in 2006 and 393 patients with M-protein on long-term follow-up in 2006 were followed over a period of 10 years (y) by community physicians with laboratory support.

Results

In 2006, newly diagnosed patients with an M-protein and total number of patients as a percentage of the Worcestershire population were, respectively, 0.025%, 0.045% (at 45–49y); 0.1%, 0.25% (at 60–64y); and 0.26%, 1.12% (at 75–79y). Patients with M-protein had a survival of 35.5% at 10 y and 43.5% at >10y follow-up. Kaplan–Meier analysis of patients with an M-protein showed that lymphoplasma-cell proliferative disorders (LPD)-free survival was 91% for both 10y and >10y follow-up. LPD-free survival decreased to approximately 73% when competing causes (death due to unrelated causes, transient M-protein, loss to follow-up) were censored. Progression to LPD occurred at initial M-protein values of 3g/L at diagnosis. During follow-up, 38.3% died without evidence of LPD, 12% were diagnosed with transient M-protein, 8.7% developed LPD, 10.9% had stable M-protein, 4.9% showed increasing M-protein, and 25.2% were lost to follow-up. Survival curves showed that M-protein isotype contributed to LPD-free survival in the order IgG=IgM>IgA>biclonal M-protein.

Conclusion

Geographical variations in the diagnosis and follow-up of MGUS patients in the UK need investigation. From public health viewpoint, it is essential to determine MGUS follow-up to improve clinical care and individualise risk-based follow-up of patients.

Bone tissue quality in patients with monoclonal gammopathy of uncertain significance

INTRODUCTION

Monoclonal gammopathy of uncertain significance (MGUS) is highly prevalent in older adults and affects bone structure, with osteoporosis and increased risk of fractures in up to 14% of affected patients. Dual-energy X-ray absorptiometry (DXA), the standard technique for diagnosing osteoporosis, is ineffective to reveal microstructure and bone quality in this disease.

MATERIALS AND METHODS

We conducted a cross-sectional study of patients with MGUS, recruited consecutively from the Hematology and Internal Medicine Departments of Hospital del Mar, Barcelona, between January 2011 and January 2018. Medical records, clinical results and spinal X-ray images were collected. Bone mineral density (BMD) at hip and spine was measured by DXA and Bone Material Strength index (BMSi) by impact microindentation on the tibial mid-shaft.

RESULTS

Thirty-nine patients with MGUS and 65 age-matched controls without previous fractures were included. In the MGUS group, 11 (28.2%) patients had prevalent fractures, nearly half of them vertebral (n = 5, 45.45%). Compared to controls, MGUS patients had significantly lower BMSi, a mean (SD) of 70.72 (9.70) vs. 78.29 (8.70), p = 0.001, and lower spinal BMD values (0.900 [0.159] vs. 1.003 [0.168], respectively, p = 0.012), but no significant differences at femoral neck and total hip. No association was observed between BMSi and DXA. Bone remodeling markers (procollagen type-1 N propeptide, bone-alkaline phosphatase and C-terminal telopeptide of type I collagen) did not differ between the two groups.

CONCLUSIONS

Spinal BMD and mechanical properties of bone tissue, as measured by impact microindentation, were impaired in patients with MGUS. These changes in bone tissue mechanical resistance were independent of DXA levels.

Monoclonal Gammopathy of Undetermined Significance (MGUS)-Not So Asymptomatic after All

Monoclonal Gammopathy of Undetermined Significance (MGUS) is considered to be a benign precursor condition that may progress to a lymphoproliferative disease or multiple myeloma. Most patients do not progress to an overt condition, but nevertheless, MGUS is associated with a shortened life expectancy and, in a minority of cases, a number of co-morbid conditions that include an increased fracture risk, renal impairment, peripheral neuropathy, secondary immunodeficiency, and cardiovascular disease. This review aims to consolidate current evidence for the significance of these co-morbidities before considering how best to approach these symptoms and signs, which are often encountered in primary care or within a number of specialties in secondary care.

Hematological Diseases and Osteoporosis

Secondary osteoporosis is a common clinical problem faced by bone specialists, with a higher frequency in men than in women. One of several causes of secondary osteoporosis is hematological disease. There are numerous hematological diseases that can have a deleterious impact on bone health. In the literature, there is an abundance of evidence of bone involvement in patients affected by multiple myeloma, systemic mastocytosis, thalassemia, and hemophilia; some skeletal disorders are also reported in sickle cell disease. Recently, monoclonal gammopathy of undetermined significance appears to increase fracture risk, predominantly in male subjects. The pathogenetic mechanisms responsible for these bone loss effects have not yet been completely clarified. Many soluble factors, in particular cytokines that regulate bone metabolism, appear to play an important role. An integrated approach to these hematological diseases, with the help of a bone specialist, could reduce the bone fracture rate and improve the quality of life of these patients.

Added Value of Impact Microindentation in the Evaluation of Bone Fragility: A Systematic Review of the Literature

The current gold standard for the diagnosis of osteoporosis and the prediction of fracture risk is the measurement of bone mineral density (BMD) using dual energy x-ray absorptiometry (DXA). A low BMD is clearly associated with increased fracture risk, but BMD is not the only determinant of bone strength, particularly in secondary osteoporosis and metabolic bone disorders in which components other than BMD are affected and DXA often underestimates true fracture risk. Material properties of bone which significantly contribute to bone strength have become evaluable in vivo with the impact microindentation (IMI) technique using the OsteoProbe® device. The question arises whether this new tool is of added value in the evaluation of bone fragility. To this effect, we conducted a systematic review of all clinical studies using IMI in vivo in humans also addressing practical aspects of the technique and differences in study design, which may impact outcome. Search data generated 38 studies showing that IMI can identify patients with primary osteoporosis and fractures, patients with secondary osteoporosis due to various underlying systemic disorders, and scarce longitudinal data also show that this tool can detect changes in bone material strength index (BMSi), following bone-modifying therapy including use of corticosteroids. However, this main outcome parameter was not always concordant between studies. This systematic review also identified a number of factors that impact on BMSi outcome. These include subject- and disease-related factors such as the relationship between BMSi and age, geographical region and the presence of fractures, and technique- and operator-related factors. Taken together, findings from this systematic review confirm the added value of IMI for the evaluation and follow-up of elements of bone fragility, particularly in secondary osteoporosis. Notwithstanding, the high variability of BMSi outcome between studies calls for age-dependent reference values, and for the harmonization of study protocols. Prospective multicenter trials using standard operating procedures are required to establish the value of IMI in the prediction of future fracture risk, before this technique is introduced in routine clinical practice.

MGUS bone

A 65-year-old man was referred to our hospital to undergo orthopedic surgery due to severe cervical ossification of the posterior longitudinal ligament. Computed tomography scanning showed a massive osteolytic lesion in his pelvis. Other screening examinations including detection of bone mineral density and osteoporosis biomarkers, bone scintigram and ¹⁸F-fluorodeoxyglucose-positron emission tomography were all normal. Bone marrow aspiration revealed slightly increased plasmacytes at 3.8%. These findings led to a diagnosis of monoclonal gammopathy with undetermined significance (MGUS). Architectural osteolytic bone associated with MGUS without apparent abnormality in bone mineral metabolism could be a common occurrence prior to onset or occurrence of multiple myeloma.

[Differential diagnoses of osteoporosis]

The differential diagnoses of osteoporosis in geriatric and trauma patients are very important as they may induce different therapies. On average approximately 20% of women and 50% of men have secondary causes of osteoporosis. The foundation of the diagnostics is a basic osteological laboratory investigation with which the most important secondary causes can be identified. From a geriatric and traumatological point of view vitamin D deficiency with secondary hyperparathyroidism, primary hyperparathyroidism, male hypogonadism, multiple myeloma and monoclonal gammopathy of unclear significance (MGUS) are of particular importance.

Testing and management for monoclonal gammopathy of uncertain significance and myeloma patients presenting with osteoporosis and fragility fractures

Multiple myeloma, the second most frequent blood cancer, and its precursor, monoclonal gammopathy of uncertain significance, are associated with an increased risk of fragility fractures. However, current guidelines fail to offer explicit indications for healthcare professionals in terms of testing and thresholds for onward referral. The purpose of this review is to present the association of these conditions and metabolic bone disease and to highlight the importance of considering a diagnosis of monoclonal gammopathy of uncertain significance and myeloma in the context of a secondary fracture prevention assessment and of a multidisciplinary approach in managing these patients.

Biological secondary contributors to osteoporosis in fractured patients, is an early systematic assay relevant?

OBJECTIVE

To evaluate the prevalence of biological abnormalities leading to secondary osteoporosis in recently fractured patients.

METHODS

Adults older than 50, hospitalized for a non-vertebral fracture from July 2015 to October 2016, were assessed for bone fragility contributors in the orthopedics department. Bone mineral density (BMD) measurements and vertebral fracture assessment (VFA) were performed within 3 months. We assessed the prevalence of biological abnormalities in all the patients with recent fracture and in subgroups.

RESULTS

Among 439 hospitalized patients for non-vertebral low trauma fracture, 372 had biological tests (285 women, mean age 77.5 ± 13 years) and 353 (94.6%) had at least ≥ 1 biological abnormality, most frequently vitamin D insufficiency (< 75 nmol/L) (80%). Hypercalcemia was found in 22 (7.7%) patients, explained by possible primary hyperparathyroidism in 6 cases, and by the other causes of hypercalcemia including postoperative low albumin. A high PTH level was observed in 64 (20.8%) patients. We found 3 monoclonal bands. Results were similar in patients with and without vertebral fracture or osteoporosis. Finally, many biological abnormalities can be explained by the postoperative context (low TSH, hypogammaglobulinemia, low albumin, low alkaline phosphatase) and need a control.

CONCLUSION

This study performed in patient with recent low trauma non-vertebral fractures showed that 94.6% of patients had at least one contributor to bone fragility, which was the vitamin D insufficiency in most of cases. We found a high proportion of biological abnormalities which require additional explorations but most of them can be explained by the postoperative context.

Disrupted radial and tibial microarchitecture in patients with monoclonal gammopathy of undetermined significance

Patients with monoclonal gammopathy of undetermined significance (MGUS) had abnormalities in volumetric BMD (vBMD), microarchitecture, and stiffness at both the radius and tibia by high-resolution peripheral quantitative CT compared to matched controls. This is the first report demonstrating that patients with MGUS have microarchitectural deficits at multiple skeletal sites.

INTRODUCTION

Fracture risk is elevated in patients with monoclonal gammopathy of undetermined significance (MGUS). However, the pathogenesis of bone disease in these patients is poorly understood. Prior work using high-resolution peripheral CT (HRpQCT) demonstrated abnormal microarchitecture at the radius, with predominantly cortical abnormalities. We hypothesized that patients with MGUS have abnormal microarchitecture at both radius and tibia compared to controls, reflecting global skeletal effects of the disease.

METHODS

This case-control study enrolled 36 subjects; patients with MGUS (n = 12) were matched 1:2 by age, sex, and race to controls (n = 24). Areal BMD (aBMD) was measured by DXA, vBMD, and microarchitecture by HRpQCT, and whole bone stiffness by finite element analysis. Serum was drawn for markers of bone metabolism and inflammation.

RESULTS

By DXA, MGUS patients had lower aBMD at the lumbar spine, femoral neck, and 1/3 radius. Markers of bone metabolism and inflammation did not differ. By HRpQCT at the radius, MGUS patients had lower total, trabecular and cortical density, lower trabecular number, and greater trabecular separation and heterogeneity. At the tibia, MGUS patients had lower total and trabecular density, lower trabecular number, greater separation and heterogeneity, and lower whole bone stiffness.

CONCLUSIONS

Patients with MGUS had lower vBMD, cortical, and trabecular abnormalities at the radius compared to matched controls. At the tibia, trabecular abnormalities predominated. These results suggest that in addition to previously described cortical deficits, deterioration of trabecular bone may contribute to a generalized skeletal fragility in patients with MGUS.

Understanding and managing secondary osteoporosis

INTRODUCTION

The term secondary osteoporosis (SO) identifies a reduction of bone mass related to a well-established disease or pharmacological agent. The identification of the underlying disease often represents a challenging situation in clinical practice.

AREAS COVERED

The prevalence of SO in the real world may vary, ranging from 17% to 80%; therefore, search for a form of SO represents a pillar when evaluating patients with osteoporosis. Guidelines for treatment of specific secondary forms of osteoporosis, such as glucocorticoid-induced osteoporosis, have been published even though often neglected in clinical practice. For the majority of SO, there are currently no specific guidelines concerning treatment with only few trials showing the effect of bone-active drugs on fracture risk reduction.

EXPERT OPINION

Healthcare professionals should be aware of the secondary forms of osteoporosis, in particular when the reason for reduced skeletal resistance is uncertain or when bone mineral density results are unsatisfactory in a patient compliant to therapy. In a few cases (such as, for example: no response to therapy, better classification of bone involvement in patients with kidney failure, suspicion of rare metabolic bone disease) bone biopsy is needed to investigate the patient. This review highlights recent advances in understanding and managing SO.

Vertebral fractures cascade: potential causes and risk factors

We performed a study to identify potential causes and risk factors of vertebral fracture cascade. Vertebral fracture cascade is a severe clinical event in patients with bone fragility. Only half of patients have an identified cause of secondary osteoporosis.

INTRODUCTION

Vertebral fracture (VF) is the most common osteoporotic fracture, and a strong risk factor of subsequent VFs leading to VF cascade (VFC). We prompted a study to identify potential causes and risk factors of VFC.

METHODS

VFC observations were collected retrospectively between January 2016 and April 2017. VFC was defined as an occurrence of at least three VFs within 1 year.

RESULTS

We included in 10 centers a total of 113 patients with VFC (79.6% of women, median age 73, median number of VFs in the cascade, 5). We observed 40.5% and 30.9% of patients with previous major fractures and a previous VF, respectively, and 68.6% with densitometric osteoporosis; 18.9% of patients were currently receiving oral glucocorticoids and 37.1% in the past. VFC was attributed by the physician to postmenopausal osteoporosis in 54% of patients. A secondary osteoporosis associated with the VFC was diagnosed in 52 patients: glucocorticoid-induced osteoporosis (25.7%), non-malignant hemopathies (6.2%), alcoholism (4.4%), use of aromatase inhibitors (3.6%), primary hyperparathyroidism (2.7%), hypercorticism (2.7%), anorexia nervosa (2.7%), and pregnancy and lactation-associated osteoporosis (1.8%). A total of 11.8% of cases were reported following a vertebroplasty procedure. A total of 31.5% patients previously received an anti-osteoporotic treatment. In six patients, VFC occurred early after discontinuation of an anti-osteoporotic treatment, in the year after the last dose effect was depleted: five after denosumab and one after odanacatib.

CONCLUSION

The results of this retrospective study showed that only half of VFC occurred in patients with a secondary cause of osteoporosis. Prospective studies are needed to further explore the determinants of this severe complication of osteoporosis.

Bone Health and Survival in Women With Multiple Myeloma

BACKGROUND

Multiple myeloma (MM) is a disease of aging adults resulting in osteolytic and/or osteoporotic bone disease. Primary osteoporosis is also highly prevalent in aging adults and is associated with increased mortality. It is unknown how concurrent osteoporosis is associated with outcomes in patients who develop MM.

PATIENTS AND METHODS

We identified 362 women with MM of the 161,808 enrolled in the Women's Health Initiative (WHI) dataset and evaluated bone health using the Fracture Risk Assessment Tool (FRAX) to identify clinical factors that affect overall MM survival in post-menopausal women, as measured from the time of diagnosis.

RESULTS

Of the 362 participants who developed incident MM, with an average 10.5 years of follow-up, 226 died, including 71 with high FRAX scores and 155 with low FRAX scores. On average, women with high FRAX scores were 8.3 years older at enrollment (95% confidence interval [CI], 7.2-9.3 years) and 8.0 years older at time of MM diagnosis (95% CI, 7.0-9.2 years) compared with those with low FRAX scores. MM mortality for women with high FRAX scores was greater (covariate-adjusted hazard ratio scores [aHR] 1.51; 95% CI, 1.01-2.25; P = .044) compared with those with low FRAX scores.

CONCLUSION

Higher fracture risk, measured by FRAX, was associated with higher MM mortality in post-menopausal women, independent of many other clinical factors.

Bone disease in monoclonal gammopathy of undetermined significance: results from a screened population-based study

Previous studies have shown that individuals with monoclonal gammopathy of undetermined significance (MGUS) have an increased risk of fractures, although the underlying mechanisms remain unknown. Our aim was to analyze bone mineral density (BMD), bone volume, and risk of fractures among individuals with MGUS. We performed a screening using the Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study cohort, consisting of 5764 elderly individuals, identifying 300 individuals with MGUS, and 275 with light-chain MGUS. Quantitative computerized tomography was performed in the lumbar spine and hip to evaluate BMD and bone geometry. Analysis of variance and the Tukey honest significance test were used to compare the groups. Hospital records were used to record fractures, with a mean follow-up of 6.9 years. Cox proportional hazard was used to compare fracture risk. No difference was found in BMD between subjects with MGUS and others in the spine (P = .34) or in total hip (P = .30). Individuals with MGUS had a significant increase in bone volume compared with others in the spine (P < .001) and total hip (P < .001). Overall, the risk of fractures was not significantly increased in individuals with MGUS (hazard ratio [HR], 1.19; 95% confidence interval [CI], 0.94-1.50). Men with MGUS had a significantly increased fracture risk, compared with other men (HR, 1.46; 95% CI, 1.03-2.08). Our results show that although individuals with MGUS do not have decreased BMD, bone volume is increased, and MGUS men have a 50% increased fracture risk. These results indicate that bone disease and fractures in MGUS differ from processes known from osteoporosis.