Tocilizumab potentially prevents bone loss in patients with anticitrullinated protein antibody-positive rheumatoid arthritis

Risk of fracture in women with glucocorticoid requiring diseases is independent from glucocorticoid use: An analysis on a nation-wide database

OBJECTIVE

Glucocorticoid-induced osteoporosis (GIOP) is a common cause of secondary osteoporosis. However, glucocorticoid requiring diseases pose a risk themselves for fracture. The aim of the present study was to determine the risk of fracture associated with variety of glucocorticoid requiring diseases independently from glucocorticoid use and other risk factors for osteoporosis.

METHODS

We conducted a retrospective cross-sectional analysis of a nation-wide cohort (DeFRACalc79 database). We used multivariable regression analysis adjusting for several risk factors for fracture and glucocorticoid intake to estimate the independent role of glucocorticoid requiring illnesses on fracture risk.

RESULTS

We found that patients with rheumatoid arthritis, connective tissue diseases, chronic obstructive pulmonary disease (COPD) and neurological diseases were at greater risk of vertebral or hip fracture (crude ORs 1.31, 1.20, 1.92 and 2.97 respectively). After adjusting for potential confounders COPD and neurological diseases remained significantly associated with an increased risk of vertebral or hip fractures (aORs 1.33, 95 % CI 1.18-1.49 and 2.43, 95 % CI 2.17-2.74). Rheumatoid arthritis, COPD, IBD and neurological diseases also significantly increased the risk of non-vertebral, non-hip fractures (aORs 1.23, 1.42, 1.52 and 1.94 respectively).

CONCLUSION

Some glucocorticoid requiring diseases were independently associated with an increased risk of fractures. COPD and neurological diseases with both vertebral and non-vertebral fracture risk while RA and IBD were independently associated only with non-vertebral, non-hip fractures.

Potential alleviation of bone mineral density loss with Janus kinase inhibitors in rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is characterized by localized bone loss, general osteoporosis and increased fracture risks. Tumour necrosis factor inhibitors (TNFi), non-tumour necrosis factor inhibitors (non-TNFi) biologic, Janus kinase inhibitors (JAKi) had shown the suppression effects to osteoclast activation and improvement of bone mineral density (BMD). Anti-cyclic citrullinated peptide antibody (ACPA) is associated with osteoclast activation and the resultant bone loss. However, few studies have compared BMD changes among patients with RA treated with targeted therapies that have different mechanisms of action.

METHODS

This retrospective study recruited patients with RA who had undergone BMD testing twice. Changes in the BMD were compared using the generalized estimating equation (GEE) in treatment groups that received conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs), TNFi, non-TNFi biologics, and JAKi.

RESULTS

In total, 362 patients with RA were enrolled (csDMARDs, n = 153, TNFi, n = 71, non-TNFi biologics, n = 108, JAKi, n = 30). We observed greater changes in femoral BMD (left, 0.06, 95% CI 0.01-0.12, p = 0.016; right, 0.09, 95% CI 0.04-0.15, p = 0.001 by GEE) following JAKi treatment as compared with other treatments. Compared to the ACPA-negative group, patients with ACPA positivity exhibited greater improvement in the femoral BMD (left, 0.09, 95% CI 0.02-0.15, p = 0.008; right, 0.11, 95% CI 0.05-0.18, p = 0.001).

CONCLUSION

Compared to other targeted therapies, JAKi might exert a more potent effect to prevent BMD loss, specifically in ACPA-positive patients with RA, and could be a potential therapeutic option to mitigate generalized bone loss. Key Points •JAKi therapy inhibits systemic bone loss in patients with RA. •ACPA-positive RA patients exhibited a greater BMD improvement than ACPA-negative RA patients. •JAKi might more potently prevent BMD decline than conventional synthetic or biological DMARDs.

Association between disease-modifying antirheumatic drugs and bone turnover biomarkers

Rheumatoid arthritis (RA) has been linked to an increased risk of osteoporosis as well as fractures. Patients diagnosed with RA had a 25% increased risk of osteoporotic fracture, according to a recent population-based cohort study that compared them to people without RA. Several studies have found a correlation between osteoporosis and the presence of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1, and 6. These cytokines play a crucial part in the process of bone resorption by boosting osteoclast activation and encouraging osteoclast differentiation. Based on the correlation between RA, osteoporosis, and inflammation, it is possible that systemic immunosuppression with disease-modifying antirheumatic drugs (DMARDs) can help individuals with RA have a lower chance of developing osteoporosis and osteoporotic fractures. There is little information on how different DMARDs, biologic or non-biologic, affect RA patients' bone metabolism. In this study, we present an overview of the influence that targeted therapies, such as biologics, non-biologics, and small molecule inhibitors, have on bone homeostasis in RA patients.

Positive Effects of Biologics on Osteoporosis in Rheumatoid Arthritis

Osteoporosis is a systemic skeletal disorder that causes vulnerability of bones to fracture owing to reduction in bone density and deterioration of the bone tissue microstructure. The prevalence of osteoporosis is higher in patients with autoimmune inflammatory rheumatic diseases, including rheumatoid arthritis (RA), than in those of the general population. In this autoimmune inflammatory rheumatic disease, in addition to known risk factors for osteoporosis, various factors such as chronic inflammation, autoantibodies, metabolic disorders, drugs, and decreased physical activity contribute to additional risk. In RA, disease-related inflammation plays an important role in local or systemic bone loss, and active treatment for inflammation can help prevent osteoporosis. In addition to conventional synthetic disease-modifying anti-rheumatic drugs that have been traditionally used for treatment of RA, biologic DMARDs and targeted synthetic DMARDs have been widely used. These agents can be employed more selectively and precisely based on disease pathogenesis. It has been reported that these drugs can inhibit bone loss by not only reducing inflammation in RA, but also by inhibiting bone resorption and promoting bone formation. In this review, the pathogenesis and research results of the increase in osteoporosis in RA are reviewed, and the effects of biological agents on osteoporosis are discussed.

The prospects of interleukin-6 inhibition in rheumatoid arthritis: Olokizumab (novel monoclonal antibodies to IL-6)

Rheumatoid arthritis (RA) is a chronic immune-mediated rheumatic diseases (IMRDs) manifested with progressive destruction of joints, systemic inflammation of visceral organs and a wide range of co-morbidities associated with chronic inflammation. Among the cytokines involved in the pathogenesis of RA and certain other IMRDs, the role of interleukin (IL) 6 is of special interest. The introduction of mAbs tocilizumab (TCZ) and later sarilumab (SAR), both blocking the receptor of this cytokine, into clinical practice was an important achievement in the treatment of IIRDs at the beginning of the 21st century. As a novel approach in the treatment of RA, the humanized mAb against IL-6 olokizumab (OKZ) is in development by the Russian company R-PHARM under the license agreement with UCB Pharma. The review examines new data on efficacy and safety of OKZ in RA and the prospects of its use in rheumatology

The effect of disease-modifying antirheumatic drugs (DMARDs) on bone homeostasis in rheumatoid arthritis (RA) patients

The autoimmune disease known as rheumatoid arthritis (RA) has been linked to the deterioration of bone. Bone erosion is a hallmark of RA and is linked to the severity of the disease as well as a poor functional result. Erosion of periarticular cortical bone is a common feature seen on plain radiographs of patients with RA. This characteristic feature is the result of excessive bone resorption and inadequate formation of bone. It has been determined that there is a complex interaction between the inflammatory condition seen in RA and bone destruction. Increased knowledge of the pathways and other mechanisms involved in osteoclastogenesis has resulted from advances in both animal and clinical investigations. Also, Biological and targeted medicines have modified RA's bone metabolism. Here, we provide a narrative overview of the literature on the pathomechanisms of bone structure involved in biological and targeted treatments for RA and also, the clinical implications of disease-modifying antirheumatic drugs (DMARDs) are discussed. In light of the fact that these newer treatments present patients with RA with new possibilities for disease improvement and symptom control, it is imperative that additional rigorous evidence be gathered to provide a clinical reference for both patients and their treating physicians.

The Effect of Anti-rheumatic Drugs on the Skeleton

The therapeutic armamentarium for rheumatoid arthritis has increased substantially over the last 20 years. Historically antirheumatic treatment was started late in the disease course and frequently included prolonged high-dose glucocorticoid treatment which was associated with accelerated generalised bone loss and increased vertebral and non-vertebral fracture risk. Newer biologic and targeted synthetic treatments and a combination of conventional synthetic DMARDs prevent accelerated systemic bone loss and may even allow repair of cortical bone erosions. Emerging data also gives new insight on the impact of long-term conventional synthetic DMARDs on bone health and fracture risk and highlights the need for ongoing studies for better understanding of "established therapeutics". An interesting new antirheumatic treatment effect is the potential of erosion repair with the use of biologic DMARDs and janus kinase inhibitors. Although several newer anti-rheumatic drugs seem to have favorable effects on bone mineral density in RA patients, these effects are modest and do not seem to influence the fracture risk thus far. We summarize recent developments and findings of the impact of anti-rheumatic treatments on localized and systemic bone integrity and health.

Cytokine-mediated immunomodulation of osteoclastogenesis

Cytokines are an important set of proteins regulating bone homeostasis. In inflammation induced bone resorption, cytokines, such as RANKL, TNF-α, M-CSF, are indispensable for the differentiation and activation of resorption-driving osteoclasts, the process we know as osteoclastogenesis. On the other hand, immune system produces a number of regulatory cytokines, including IL-4, IL-10 and IFNs, and limits excessive activation of osteoclastogenesis and bone loss during inflammation. These unique properties make cytokines powerful targets as rheostat to maintain bone homeostasis and for potential immunotherapies of inflammatory bone diseases. In this review, we summarize recent advances in cytokine-mediated regulation of osteoclastogenesis and provide insights of potential translational impact of bench-side research into clinical treatment of bone disease.

Pathomechanisms of bone loss in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease, in which the inflammatory processes involve the skeletal system and there is marked destruction of the bones and the surrounding structures. In this review, we discuss the current concepts of osteoimmunology in RA, which represent the molecular crosstalk between the immune and skeletal systems, resulting in the disruption of bone remodeling. Bone loss in RA can be focal or generalized, leading to secondary osteoporosis. We have summarized the recent studies of bone loss in RA, which focused on the molecular aspects, such as cytokines, autoantibodies, receptor activator of nuclear kappa-β ligand (RANKL) and osteoprotegerin (OPG). Apart from the above molecules, the role of aryl hydrocarbon receptor (Ahr), which is a potential key mediator in this process through the generation of the Th17 cells, is discussed. Hence, this review highlights the key insights into molecular mechanisms of bone loss in RA.

Consensus statement on blocking interleukin-6 receptor and interleukin-6 in inflammatory conditions: an update

BACKGROUND

Targeting interleukin (IL)-6 has become a major therapeutic strategy in the treatment of immune-mediated inflammatory disease. Interference with the IL-6 pathway can be directed at the specific receptor using anti-IL-6Rα antibodies or by directly inhibiting the IL-6 cytokine. This paper is an update of a previous consensus document, based on most recent evidence and expert opinion, that aims to inform on the medical use of interfering with the IL-6 pathway.

METHODS

A systematic literature research was performed that focused on IL-6-pathway inhibitors in inflammatory diseases. Evidence was put in context by a large group of international experts and patients in a subsequent consensus process. All were involved in formulating the consensus statements, and in the preparation of this document.

RESULTS

The consensus process covered relevant aspects of dosing and populations for different indications of IL-6 pathway inhibitors that are approved across the world, including rheumatoid arthritis, polyarticular-course and systemic juvenile idiopathic arthritis, giant cell arteritis, Takayasu arteritis, adult-onset Still's disease, Castleman's disease, chimeric antigen receptor-T-cell-induced cytokine release syndrome, neuromyelitis optica spectrum disorder and severe COVID-19. Also addressed were other clinical aspects of the use of IL-6 pathway inhibitors, including pretreatment screening, safety, contraindications and monitoring.

CONCLUSIONS

The document provides a comprehensive consensus on the use of IL-6 inhibition to treat inflammatory disorders to inform healthcare professionals (including researchers), patients, administrators and payers.

Mechanisms of Systemic Osteoporosis in Rheumatoid Arthritis

Rheumatoid arthritis (RA), an autoimmune disease, is characterized by the presence of symmetric polyarthritis predominantly of the small joints that leads to severe cartilage and bone destruction. Based on animal and human data, the pathophysiology of osteoporosis, a frequent comorbidity in conjunction with RA, was delineated. Autoimmune inflammatory processes, which lead to a systemic upregulation of inflammatory and osteoclastogenic cytokines, the production of autoantibodies, and Th cell senescence with a presumed disability to control the systemic immune system's and osteoclastogenic status, may play important roles in the pathophysiology of osteoporosis in RA. Consequently, osteoclast activity increases, osteoblast function decreases and bone metabolic and mechanical properties deteriorate. Although a number of disease-modifying drugs to treat joint inflammation are available, data on the ability of these drugs to prevent fragility fractures are limited. Thus, specific treatment of osteoporosis should be considered in patients with RA and an associated increased risk of fragility fractures.

Secondary Osteoporosis and Metabolic Bone Diseases

Fragility fracture is a worldwide problem and a main cause of disability and impaired quality of life. It is primarily caused by osteoporosis, characterized by impaired bone quantity and or quality. Proper diagnosis of osteoporosis is essential for prevention of fragility fractures. Osteoporosis can be primary in postmenopausal women because of estrogen deficiency. Secondary forms of osteoporosis are not uncommon in both men and women. Most systemic illnesses and organ dysfunction can lead to osteoporosis. The kidney plays a crucial role in maintaining physiological bone homeostasis by controlling minerals, electrolytes, acid-base, vitamin D and parathyroid function. Chronic kidney disease with its uremic milieu disturbs this balance, leading to renal osteodystrophy. Diabetes mellitus represents the most common secondary cause of osteoporosis. Thyroid and parathyroid disorders can dysregulate the osteoblast/osteoclast functions. Gastrointestinal disorders, malnutrition and malabsorption can result in mineral and vitamin D deficiencies and bone loss. Patients with chronic liver disease have a higher risk of fracture due to hepatic osteodystrophy. Proinflammatory cytokines in infectious, autoimmune, and hematological disorders can stimulate osteoclastogenesis, leading to osteoporosis. Moreover, drug-induced osteoporosis is not uncommon. In this review, we focus on causes, pathogenesis, and management of secondary osteoporosis.

Effects of Biological/Targeted Therapies on Bone Mineral Density in Inflammatory Arthritis

Inflammatory arthritis has been reported to be associated with the development of osteoporosis. Recent research has investigated the mechanisms of bone metabolism in chronic inflammatory arthritis such as rheumatoid arthritis (RA) and spondyloarthritis (SpA). Progress in both animal and clinical studies has provided a better understanding of the osteoclastogenesis-related pathways regarding the receptor activator of nuclear factor-κB ligand (RANKL), anti-citrullinated protein antibodies (ACPAs), and Wnt signaling and Dickkopf-related protein 1 (Dkk-1). The complex interplay between inflammatory cytokines and bone destruction has been elucidated, especially that in the interleukin-17/23 (IL-17/23) axis and Janus kinase and signal transducer and activator of transcription (JAK-STAT) signaling. Moreover, advances in biological and targeted therapies have achieved essential modifications to the bone metabolism of these inflammatory arthritis types. In this narrative review, we discuss recent findings on the pathogenic effects on bone in RA and SpA. Proinflammatory cytokines, autoantibodies, and multiple signaling pathways play an essential role in bone destruction in RA and SpA patients. We also reviewed the underlying pathomechanisms of bone structure in biological and targeted therapies of RA and SpA. The clinical implications of tumor necrosis factor inhibitors, abatacept, rituximab, tocilizumab, Janus kinase inhibitors, and inhibitors of the IL-17/23 axis are discussed. Since these novel therapeutics provide new options for disease improvement and symptom control in patients with RA and SpA, further rigorous evidence is warranted to provide a clinical reference for physicians and patients.

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.

Incidence and risk factors for vertebral fracture in rheumatoid arthritis: an update meta-analysis

OBJECTIVES

This study was conducted to investigate the prevalence of vertebral fracture (VF) and its risk in patients with rheumatoid arthritis (RA) as compared to healthy individuals, and to explore the underlying risk factors.

METHODS

The electronic databases of PubMed, EMBASE, and the Cochrane Library were applied to search for the relevant literatures, which reported the prevalence of VF in both RA patients and healthy controls (up to Mar 31, 2021). The non-weighted prevalence of VF, pooled estimates of odds ratio (OR), and its 95% confidence intervals (CI) were calculated with the use of random-effects model; between-study heterogeneity was evaluated by Cochrane Q statistic, then was quantified with I². Publication bias was evaluated using Egger's linear regression test.

RESULTS

A number of 867 literatures were identified after searching for online databases, based on the inclusion and exclusion criteria, 11 eligible studies, which comprising 3805 RA patients and 59,517 healthy participants, were finally incorporated in meta-analysis. The results showed that RA patients had an increased prevalence of VF (20.29 vs 8.63%), and an elevated risk for VF (OR = 3.04, 95% CI 1.97-4.71) as compared to healthy population. Additional subgroup analysis suggested that age, body mass index (BMI), disease activity, and drug therapy might be associated with risk of VF in RA.

CONCLUSIONS

Overall, our study demonstrated an increased risk of VF in patients with RA, suggesting that age, race, BMI, disease activity, and drug therapy may be represented as risk factors contributing to the occurrence of VF in RA. Key Points • RA patients had the increased prevalence and risk of vertebral fracture (VF) as compared to healthy population. • Age, race, BMI, disease activity, and drug therapy might be associated with VF in RA. • Our findings would be helpful for the early evaluation of RA patients with high VF risk.

Systemic effects of IL-6 blockade in rheumatoid arthritis beyond the joints

Interleukin (IL)-6 is produced locally in response to an inflammatory stimulus, and is able to induce systemic manifestations at distance from the site of inflammation. Its unique signaling mechanism, including classical and trans-signaling pathways, leads to a major expansion in the number of cell types responding to IL-6. This pleiotropic cytokine is a key factor in the pathogenesis of rheumatoid arthritis (RA) and is involved in many extra-articular manifestations that accompany the disease. Thus, IL-6 blockade is associated with various biological effects beyond the joints. In this review, the systemic effects of IL-6 in RA comorbidities and the consequences of its blockade will be discussed, including anemia of chronic disease, cardiovascular risks, bone and muscle functions, and neuro-psychological manifestations.

Cytokine Networks in the Pathogenesis of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic systemic inflammation causing progressive joint damage that can lead to lifelong disability. The pathogenesis of RA involves a complex network of various cytokines and cells that trigger synovial cell proliferation and cause damage to both cartilage and bone. Involvement of the cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-6 is central to the pathogenesis of RA, but recent research has revealed that other cytokines such as IL-7, IL-17, IL-21, IL-23, granulocyte macrophage colony-stimulating factor (GM-CSF), IL-1β, IL-18, IL-33, and IL-2 also play a role. Clarification of RA pathology has led to the development of therapeutic agents such as biological disease-modifying anti-rheumatic drugs (DMARDs) and Janus kinase (JAK) inhibitors, and further details of the immunological background to RA are emerging. This review covers existing knowledge regarding the roles of cytokines, related immune cells and the immune system in RA, manipulation of which may offer the potential for even safer and more effective treatments in the future.

Bone-sparing effects of rituximab and body composition analysis in a cohort of postmenopausal women affected by rheumatoid arthritis - retrospective study

Objective

Osteoporosis is the most common bone tissue disease and it is characterized by a reduced bone mineral density (BMD). The main physiopathological mechanisms converge on the uncoupling between bone formation and resorption, thus leading to an enhanced risk of fractures. Several papers have documented the inverse relationships linking high inflammatory cytokines, anti-citrullinated protein antibodies, rheumatoid factor, and BMD in rheumatoid arthritis (RA). Rituximab (RTX) is a chimeric monoclonal antibody directed against the CD20 receptor of B cells. Since the Food and Drug Administration approved it for RA in 2006, there have been many clinical experiences regarding its use. Nevertheless, few studies evaluate the effect of rituximab on BMD. RA is a disease characterized by immune dysfunction with high levels of inflammatory cytokines, autoantibodies, and it is reasonable that a B cell depleting therapy could restore a physiological cytokine balance, thus exerting an osteoprotective effect on the bone tissue. The purpose of this paper is to highlight any difference in BMD and to assess differences in body composition over a retrospective 18-month follow-up period after RTX treatment with a B cell depleting therapy.

Material and methods

We analyzed by dual energy X-ray absorptiometry BMD expressed as g/cm² and body composition modifications over 18 months with RTX treatment of 20 postmenopausal RA patients.

Results

After eighteen months of therapy with RTX, a statistically significant increase in vertebral (L1–L4) BMD and the stability of femoral BMD were documented.

Conclusions

Rituximab is associated with an improvement of vertebral and preservation of femoral BMD, suggesting a bone-sparing effect due to B cell depletion. Furthermore, patients displayed a redistribution of fat masses toward the hip region.

Causal risk and protective factors in rheumatoid arthritis: A genetic update

The characterization of risk and protective factors in complex diseases such as rheumatoid arthritis (RA) has evolved from epidemiological studies, which test association, to the use of Mendelian randomization approaches, which test direct relationships. Indeed, direct associations with the mucosal origin of RA are retrieved with periodontal disease (Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans predominantly), interstitial lung involvement, tobacco smoking and air pollutants. Next, factors directly associated with an acquired immune response include genetic factors (HLA DRB1, PTPN22), capacity to produce anti-modified protein antibodies (AMPA), and relatives with a history of autoimmune diseases. Finally, factors can be also classified according to their direct capacity to interfere with the IL-6/CRP/sIL-IL6R proinflammatory pathway as risk factor (body fat, cardiometabolic factors, type 2 diabetes, depressive syndrome) or either as protective factors by controlling of sIL-6R levels (higher education level, and intelligence). Although some co-founders have been characterized (e.g. vitamin D, physical activity, cancer) the direct association with sex-discrepancy, pregnancy, and infections among other factors remains to be better explored.

Comparative Risk of Nonvertebral Fractures Among Patients With Rheumatoid Arthritis Treated With Biologic or Targeted Synthetic Disease-Modifying Antirheumatic Drugs

OBJECTIVE

The objective of this study was to compare the incidence rate of nonvertebral osteoporotic fractures (NVFs) in patients with rheumatoid arthritis (RA) initiating one of the nine biologic or targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs).

METHODS

We analyzed claims data from Optum (2008 to March 2019), Medicare, and MarketScan (2008-2017) to identify adults with RA who newly initiated b/tsDMARDs. Adalimumab was the most frequently used and was thus selected as a reference. The primary outcome was a composite of incident NVFs, including hip, humerus, pelvis, and wrist fractures, based on validated algorithms. We adjusted for greater than 70 potential confounders in each database through propensity score-based inverse probability treatment weighting. Follow-up time started the day after cohort entry until the first occurrence of one of the following: outcome, treatment discontinuation, switching, nursing home admission, death, disenrollment, or end of study period. For each drug comparison, weighted Cox proportional hazards models estimated the hazard ratios (HRs) and 95% confidence intervals (CIs). Secondary analyses were conducted in patients switching from a tumor necrosis factor inhibitor to a different b/tsDMARD.

RESULTS

A total of 134,693 b/tsDMARD initiators were identified across three databases. The adjusted HRs showed similar risk of composite NVFs in all b/tsDMARD exposures compared with adalimumab: abatacept, HR 1.03 (95% CI 0.82-1.30); certolizumab, HR 1.08 (95% CI 0.79-1.49); etanercept, HR 1.12 (95% CI 0.89-1.40); golimumab, HR 0.91 (95% CI 0.59-1.39); infliximab, HR 1.03 (95% CI 0.84-1.28); rituximab, HR 1.07 (95% CI 0.74-1.55); tocilizumab, HR 1.24 (95% CI 0.71-2.17); and tofacitinib, HR 1.07 (95% CI 0.69-1.64). Secondary analyses showed similar results.

CONCLUSION

This multidatabase cohort study found no differences in the risk of NVFs across individual b/tsDMARDs for RA, which provides reassurance to physicians prescribing b/tsDMARDs, especially to patients at high risk of developing NVFs.

Methotrexate osteopathy: five cases and systematic literature review

INTRODUCTION

Methotrexate (MTX)-related osteopathy is rare, defined by the triad of pain, osteoporosis, and "atypical fractures" when it was first described in the 1970s in children treated with high doses MTX for acute leukemia. Since then, several cases have been reported in patients treated with low-dose MTX for inflammatory diseases.

METHODS

A systematic research of cases of MTX-related osteopathy was performed in records of Rheumatology Department of Rennes University Hospital. Data collection focused on demographic data, corticosteroid doses, MTX doses and intake method, cumulative doses, year of diagnosis, fracture location, bone densitometry value, and osteoporosis treatment if necessary. A literature review was also conducted to identify other cases in literature and try to understand the pathophysiological mechanisms of this rare entity.

RESULTS

We report 5 cases identified between 2011 and 2019, which represents the largest cohort described excluding oncology cases. Fracture locations were atypical for osteoporotic fractures. All patients improved in the following months with MTX withdrawal. All patients except one were treated with antiresorptives (bisphosphonates, denosumab). Two patients, treated with bisphosphonates, had a recurrence of fracture, once again of atypical location. Twenty-five cases were collected in literature with similar clinical presentation. The cellular studies that investigated the bone toxicity of MTX mainly showed a decrease in the number of osteoblasts, osteocytes, and chondrocytes in the growth plate and an increase in the number and activity of osteoclasts. In vitro, consequences of mechanical stimulation on human trabecular bone cells in the presence of MTX showed an alteration in mechano-transduction, with membrane hyperpolarization, acting on the integrin pathway. In contrast with our report, the cases described in the literature were not consistently associated with a decrease in bone mineral density (BMD).

CONCLUSION

MTX osteopathy while rare must be known by the rheumatologist, especially when using this treatment for inflammatory conditions. The mechanisms are still poorly understood, raising the question of a possible remnant effect of MTX on osteo-forming bone cells, potentially dose-dependent. Methotrexate (MTX) osteopathy, described as a clinical triad, pain, osteoporosis, and atypical stress fractures, while rare, must be known by the rheumatologist. Our cohort of 5 cases represent the largest series of the literature. Pathophysiological studies raised the question of a dose-dependent remnant effect of MTX on osteo-forming bone cells.

Osteoporosis in Inflammatory Arthritides: New Perspective on Pathogenesis and Treatment

Osteoporosis is a skeletal disorder characterized by impaired bone strength and increased risk of fragility fracture and is among the most relevant comorbidities of rheumatic diseases. The purpose of the present review is to discuss the pathogenesis of local and systemic bone involvement in inflammatory arthritides, especially Rheumatoid Arthritis, Psoriatic Arthritis, and Spondyloarthritides, as well as the effect of anti-rheumatic treatments and anti-osteoporotic medication on bone health and fracture incidence, including recent data on novel therapeutic perspective.

Bone phenotypes in rheumatology - there is more to bone than just bone

Osteoarthritis, rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis, all have one clear common denominator; an altered turnover of bone. However, this may be more complex than a simple change in bone matrix and mineral turnover. While these diseases share a common tissue axis, their manifestations in the area of pathology are highly diverse, ranging from sclerosis to erosion of bone in different regions. The management of these diseases will benefit from a deeper understanding of the local versus systemic effects, the relation to the equilibrium of the bone balance (i.e., bone formation versus bone resorption), and the physiological and pathophysiological phenotypes of the cells involved (e.g., osteoblasts, osteoclasts, osteocytes and chondrocytes). For example, the process of endochondral bone formation in chondrocytes occurs exists during skeletal development and healthy conditions, but also in pathological conditions. This review focuses on the complex molecular and cellular taxonomy of bone in the context of rheumatological diseases that alter bone matrix composition and maintenance, giving rise to different bone turnover phenotypes, and how biomarkers (biochemical markers) can be applied to potentially describe specific bone phenotypic tissue profiles.

Osteoporosis in Rheumatoid Arthritis: Dangerous Liaisons

Osteoporosis has been classically considered a comorbidity of rheumatoid arthritis (RA). However, recent advances in the pathogenesis of osteoporosis in RA have shown a close interplay between cells of the immune system and those involved in bone remodeling, introducing new actors into the classic route in which osteoclast activation is related to the RANK/RANKL/OPG pathway. In fact, the inflammatory state in early stages of RA, mediated by interleukin (IL)-1, IL-6, IL-8 and tumor necrosis factor (TNF)-α has the ability to activate and differentiate osteoclasts not only through their relationship with RANKL, but also through the Wnt/DKK1/sclerostin pathway, leading to bone loss. The role of synovial fibroblasts and activated T lymphocytes in the expression of the RANKL system and its connection to bone destruction is also depicted. In addition, autoantibodies such as rheumatoid factor and anti-citrullinated protein antibodies are other pathogenic mechanisms for the development of bone erosions and systemic osteoporosis in RA, even before the onset of arthritis. The aim of this review is to unravel the relationship between different factors involved in the development of osteoporosis in RA patients, both the classic factors and the most novel, based on the relationship of autoantibodies with bone remodeling. Furthermore, we propose that bone mineral density measured by different techniques may be helpful as a biomarker of severity in early arthritis patients.

Tocilizumab Was Effective in Repairing the Large Geode in a Patient with Rheumatoid Arthritis

Rheumatoid arthritis is characterized by multiple chronic arthritis subsequently inducing joint destruction. Although subchondral geode is a well-known feature of high-disease activity, a large geode is rare. Moreover, the treatment effect of biologic agents in the repair of large geode has not been reported. The present report shows the significant effect of interleukin-6 receptor blocker, tocilizumab, in repairing the large geode in the left humeral lateral epicondyle. This case implies that tocilizumab might be an effective treatment in patients with rheumatoid arthritis even with large geode.

Understanding the Role of Interleukin-6 (IL-6) in the Joint and Beyond: A Comprehensive Review of IL-6 Inhibition for the Management of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, debilitating autoimmune disorder involving inflammation and progressive destruction of the joints, affecting up to 1% of the population. The majority of patients with RA have one or more comorbid conditions, the most common being cardiovascular disease, osteoporosis, and depression, the presence of which are associated with poorer clinical outcomes and lower health-related quality of life. RA pathogenesis is driven by a complex network of proinflammatory cells and cytokines, and of these, interleukin-6 (IL-6) plays a key role in the chronic inflammation associated with RA. Through cell signaling that can be initiated by both membrane-bound and soluble forms of its receptor, IL-6 acts both locally to promote joint inflammation and destruction, and in the circulation to mediate extra-articular manifestations of RA, including pain, fatigue, morning stiffness, anemia, and weight loss. This narrative review describes the role of IL-6 in the pathogenesis of RA, its comorbidities, and extra-articular systemic manifestations, and examines the effects of the IL-6 receptor inhibitors sarilumab and tocilizumab on clinical endpoints of RA, patient-reported outcomes, and common comorbidities and extra-articular manifestations.

Osteoporosis in patients with rheumatoid arthritis: an update in epidemiology, pathogenesis, and fracture prevention

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic disabling disease characterized by a symmetrical articular involvement due to ongoing joint inflammation, if left insufficiently treated. Local and generalized bone loss is one of the main extra-articular complications of RA and leads to an increased risk for fragility fractures, which further impair functional ability, quality of life, and life expectancy. Therefore, there is an urgent need for good fracture risk management in the vulnerable RA patient.

AREAS COVERED

The authors review: the epidemiology and pathophysiology (i.e. risk factors) of osteoporosis (OP), fracture, and vertebral fracture risk assessment, the effects of anti-rheumatic drugs on bone loss, pharmacological treatment of OP in RA including both bisphosphonates (BP) and newer drugs including anti-resorptives and osteoanabolic treatment options.

EXPERT OPINION

Patients with active RA have elevated bone resorption and local bone loss. Moreover, these patients are at increased risk for generalized bone loss, vertebral and non-vertebral fractures. Since general risk factors (such as low BMI, fall risk) and RA-related factors play a role, optimal fracture prevention in RA patients is based on optimal diagnostics based on both of these factors, and on the use of adequate non-medical and medical treatment options.

Acute Effects of Glucocorticoid Treatment, TNFα or IL-6R Blockade on Bone Turnover Markers and Wnt Inhibitors in Early Rheumatoid Arthritis: A Pilot Study

Tumor Necrosis Factor (TNF)-α and Interleukin (IL)-6 play a fundamental role in bone loss in rheumatoid arthritis (RA), partly due to the inhibition of the Wnt canonical pathway. The aim of our study was to investigate the short-term effects of three different treatments on Wnt inhibitors (Dkk-1 and sclerostin) and on bone turnover markers (BTMs): N-propeptide of type I collagen (PINP) and C-terminal telopeptide of type I collagen (β-CTX-I). We performed a retrospective analysis of prospectively collected data. We enrolled women affected by early RA (< 12 months) with active disease (DAS28 ≥ 2.6) despite a 6-month treatment with methotrexate (10-15 mg/week), who then started certolizumab pegol, tocilizumab, or methyl-prednisolone (8 mg/daily). Patients were divided into three groups according to the treatment. Blood samples were collected at baseline, week 1, and week 4. We selected 14 patients treated with certolizumab pegol, 14 patients with tocilizumab, and 20 patients with methyl-prednisolone. No difference between any of the tested parameters was found at baseline. β-CTX-I, Dkk-1, and sclerostin decreased after 1 week of treatment with certolizumab pegol (- 27% ± 21.5, - 50% ± 13.2, and - 30% ± 30.4, respectively, p < 0.05). Methyl-prednisolone induced similar changes, albeit less marked, on β-CTX-I and Wnt inhibitors, with a decrease in PINP (- 16.1% ± 16.5, p < 0.05). Tocilizumab did not significantly affect BTMs or Wnt inhibitors. No significant changes were found for PTH and 25OHD. In the first four weeks of treatment, TNFα inhibition showed strong effects on BTMs and Wnt inhibitors, differently from IL-6 blockade. Glucocorticoids induced similar changes; nonetheless, they showed undesired effects on bone formation.

Pharmacological Management of Osteoporosis in Rheumatoid Arthritis Patients: A Review of the Literature and Practical Guide

Rheumatoid arthritis (RA) is a chronic disabling disease that is associated with increased localized and generalized osteoporosis (OP). Previous studies estimated that approximately one-third of the RA population experience bone loss. Moreover, RA patients suffer from a doubled fracture incidence depending on several clinical factors, such as disease severity, age, glucocorticoid (GC) use, and immobility. As OP fractures are related to impaired quality of life and increased mortality rates, OP has an enormous impact on global health status. Therefore, there is an urgent need for a holistic approach in daily clinical practice. In other words, both OP- and RA-related factors should be taken into account in treatment guidelines for OP in RA. First, to determine the actual fracture risk, dual-energy X-ray absorptiometry (DXA), including vertebral fracture assessment (VFA) and calculation of the 10-year fracture risk with FRAX^®, should be performed. In case of high fracture risk, calcium and vitamin D should be supplemented alongside anti-osteoporotic treatment. Importantly, RA treatment should be optimal, aiming at low disease activity or remission. Moreover, GC treatment should be at the lowest possible dose. In this way, good fracture risk management will lead to fracture risk reduction in RA patients. This review provides a practical guide for clinicians regarding pharmacological treatment options in RA patients with OP, taking into account both osteoporotic-related factors and factors related to RA.

Drugs Causing Bone Loss

Drugs may cause bone loss by lowering sex steroid levels (e.g., aromatase inhibitors in breast cancer, GnRH agonists in prostate cancer, or depot medroxyprogestone acetate - DMPA), interfere with vitamin D levels (liver inducing anti-epileptic drugs), or directly by toxic effects on bone cells (chemotherapy, phenytoin, or thiazolidinedions, which diverts mesenchymal stem cells from forming osteoblasts to forming adipocytes). However, besides effects on the mineralized matrix, interactions with collagen and other parts of the unmineralized matrix may decrease bone biomechanical competence in a manner that may not correlate with bone mineral density (BMD) measured by dual energy absorptiometry (DXA).Some drugs and drug classes may decrease BMD like the thiazolidinediones and consequently increase fracture risk. Other drugs such as glucocorticoids may decrease BMD, and thus increase fracture risk. However, glucocorticoids may also interfere with the unmineralized matrix leading to an increase in fracture risk, not mirrored in BMD changes. Some drugs such as selective serotonin reuptake inhibitors (SSRI), paracetamol, and non-steroidal anti-inflammatory drugs (NSAIDs) may not per se be associated with bone loss, but fracture risk may be increased, possibly stemming from an increased risk of falls stemming from effects on postural balance mediated by effects on the central nervous system or cardiovascular system.This paper performs a systematic review of drugs inducing bone loss or associated with fracture risk. The chapter is organized by the Anatomical Therapeutic Chemical (ATC) classification.

Rapid suppression of bone formation marker in response to sleep restriction and circadian disruption in men

We describe the time course of bone formation marker (P1NP) decline in men exposed to ~ 3 weeks of sleep restriction with concurrent circadian disruption. P1NP declined within 10 days and remained lower with ongoing exposure. These data suggest even brief exposure to sleep and circadian disruptions may disrupt bone metabolism.

INTRODUCTION

A serum bone formation marker (procollagen type 1 N-terminal, P1NP) was lower after ~ 3 weeks of sleep restriction combined with circadian disruption. We now describe the time course of decline.

METHODS

The ~ 3-week protocol included two segments: "baseline," ≥ 10-h sleep opportunity/day × 5 days; "forced desynchrony" (FD), recurring 28 h day (circadian disruption) with sleep restriction (~ 5.6-h sleep per 24 h). Fasted plasma P1NP was measured throughout the protocol in nine men (20-59 years old). We tested the hypothesis that PINP would steadily decline across the FD intervention because the magnitude of sleep loss and circadian misalignment accrued as the protocol progressed. A piecewise linear regression model was used to estimate the slope (β) as ΔP1NP per 24 h with a change point mid-protocol to estimate the initial vs. prolonged effects of FD exposure.

RESULTS

Plasma P1NP levels declined significantly within the first 10 days of FD ([Formula: see text] = - 1.33 μg/L per 24 h, p < 0.0001) and remained lower than baseline with prolonged exposure out to 3 weeks ([Formula: see text] = - 0.18 μg/L per 24 h, p = 0.67). As previously reported, levels of a bone resorption marker (C-telopeptide (CTX)) were unchanged.

CONCLUSION

Sleep restriction with concurrent circadian disruption induced a relatively rapid decline in P1NP (despite no change in CTX) and levels remained lower with ongoing exposure. These data suggest (1) even brief sleep restriction and circadian disruption can adversely affect bone metabolism, and (2) there is no P1NP recovery with ongoing exposure that, taken together, could lead to lower bone density over time.

Osteoporosis in Rheumatic Diseases

Osteoporosis is a chronic disease characterized by an increased risk of fragility fracture. Patients affected by rheumatic diseases are at greater risk of developing osteoporosis. The purpose of the present review is to discuss the pathogenesis, epidemiology, and treatment of osteoporosis in patients affected by rheumatic diseases with special focus for rheumatoid arthritis, psoriatic arthritis, spondyloarthritis, systemic lupus erythematosus, systemic sclerosis, vasculitides, Sjogren syndrome, and crystal-induced arthritis.

Association between levels of synovial anti-citrullinated peptide antibodies and neutrophil response in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is characterized by the presence of anti-citrullinated peptide antibodies (ACPAs) and neutrophils infiltrating the synovial fluid (SF) of the affected joints. The aim of this work was to analyze whether the presence of ACPAs in SF is associated with neutrophil infiltration and with their phenotype in the inflamed joints of RA patients. We found that in the presence of ACPAs, the number of synovial neutrophils correlated with severe disease activity. The SF were divided according to synovial ACPA levels in negative- (<25 U/mL), low- (25-200 U/mL) and high level (˃200 U/mL; ACPA^high ). We observed that IL-6, IL-17, and IL-8 were significantly elevated in ACPA^high SF and that IL-8 levels correlated positively with neutrophil counts and with worse clinical manifestations. Additionally, in vitro incubation of neutrophils with ACPA^high SF resulted in an increased ROS production and extracellular DNA release compared to neutrophils incubated with ACPA-negative SF. These exacerbated effector functions were associated with a fraction of ICAM-1-positive neutrophils, which were induced by ACPA^high SF. Likewise, in in vivo, we could also detect this subset among neutrophils present in ACPA^high SF. In conclusion, the data presented here shed light on the role of SF-ACPAs as inductors of a proinflammatory profile in neutrophils.

Osteoporosis in Rheumatic Diseases: Anti-rheumatic Drugs and the Skeleton

Osteoporosis in rheumatic diseases is a very well-known complication. Systemic inflammation results in both generalized and localized bone loss and erosions. Recently, increased knowledge of inflammatory process in rheumatic diseases has resulted in the development of potent inhibitors of the cytokines, the biologic DMARDs. These treatments reduce systemic inflammation and have some effect on the generalized and localized bone loss. Progression of bone erosion was slowed by TNF, IL-6 and IL-1 inhibitors, a JAK inhibitor, a CTLA4 agonist, and rituximab. Effects on bone mineral density varied between the biological DMARDs. Medications that are approved for the treatment of osteoporosis have been evaluated to prevent bone loss in rheumatic disease patients, including denosumab, cathepsin K, bisphosphonates, anti-sclerostin antibodies and parathyroid hormone (hPTH 1-34), and have some efficacy in both the prevention of systemic bone loss and reducing localized bone erosions. This article reviews the effects of biologic DMARDs on bone mass and erosions in patients with rheumatic diseases and trials of anti-osteoporotic medications in animal models and patients with rheumatic diseases.