Denosumab, cortical bone and bone erosions in rheumatoid arthritis

Changes in bone turnover markers and bone modulators during abatacept treatment

Rheumatoid arthritis (RA) causes bone loss, only partly related to inflammation. The impact of RA treatments on bone metabolism and their ability to mitigate bone loss remains uncertain. The primary goal of our study was to examine the influence of abatacept on serum levels of markers and regulators involved in bone turnover. Secondary objectives included evaluating changes in bone mineral density (BMD), bone health parameters, erosions, and exploring potential correlations among these parameters. We conducted a prospective observational study on patients with active seropositive RA failure to biological disease modifying anti-rheumatic drugs initiating treatment with abatacept. We measured at baseline and after 1, 2, 3, 6, 9 and 12 months: serum bone turnover markers (CTX, P1nP, B-ALP), bone modulators (Dkk-1, sclerostin, vitamin D, PTH, OPG and RANKL), BMD and radiographic parameters (modified Sharp van der Heijde score [mSvdH], bone health index [BHI] and metacarpal index [MCI]). Disease activity and glucocorticoid intake was monitored. 33 patients were enrolled in the study. We found a significant increase in markers of bone formation (B-ALP and P1nP) from baseline to M6 and M12. PTH increased significantly at M6 but not at M12. All other bone markers and modulators did not change. We found a significant decrease in BHI and MCI from baseline to M12 (median difference - 0.17 95% CI - 0.42 to - 0.10, p 0.001 and - 0.09 95% CI - 0.23 to - 0.07, respectively). BMD at femoral neck transitorily decreased at M6 (mean difference - 0.019 g/cm2 95% CI - 0.036 to - 0.001 p 0.04). BMD at total hip, lumbar spine and mSvdH score did not change significantly. P1nP delta at M12 correlated with delta mSvdH. Treatment with abatacept was associated with a significant increase in bone formation markers. The secondary and transient increase in PTH serum levels may be responsible of the transitory bone loss.

Personalized Therapeutic Strategies in the Management of Osteoporosis in Patients with Autoantibody-Positive Rheumatoid Arthritis

Bone mineral density (BMD) reduction and fragility fractures still represent a major source of morbidity in rheumatoid arthritis (RA) patients, despite adequate control of the disease. An increasing number of clinical and experimental evidence supports the role of autoantibodies, especially anti-citrullinated protein antibodies (ACPAs), in causing localized and generalised bone loss in ways that are both dependent on and independent of inflammation and disease activity. The human receptor activator of nuclear factor kappa B and its ligand—the so-called RANK-RANKL pathway—is known to play a key role in promoting osteoclasts’ activation and bone depletion, and RANKL levels were shown to be higher in ACPA-positive early untreated RA patients. Thus, ACPA-positivity can be considered a specific risk factor for systemic and periarticular bone loss. Through the inhibition of the RANK-RANKL system, denosumab is the only antiresorptive drug currently available that exhibits both a systemic anti-osteoporotic activity and a disease-modifying effect when combined with conventional synthetic or biologic disease-modifying anti-rheumatic drugs (DMARDs). Thus, the combination of DMARD and anti-RANKL therapy could be beneficial in the prevention of fragility fractures and structural damage in the subset of RA patients at risk of radiographic progression, as in the presence of ACPAs.

The Emerging Roles of Endocrine Hormones in Different Arthritic Disorders

The relationship between endocrine hormones and the spectrum of rheumatic conditions has long been discussed in the literature, focusing primarily on sexual hormones, such as estrogens, androgens, prolactin (PRL). Estrogens are indeed involved in the pathogenesis of the main inflammatory arthritis thanks to their effects on the immune system, both stimulatory and inhibitory. The PRL system has been discovered in synovial tissue of rheumatoid arthritis (RA) and psoriatic arthritis (PsA), patients and has been propose as a new potential therapeutic target. Besides sexual hormones, in the last years scientific interest about the crosstalk of immune system with other class of hormones has grown. Hormones acting on the bone tissue (i.e. parathyroid hormone, vitamin D) and modulators of the Wnt pathway (i.e. Dickkopf-1) have been demonstrated to play active role in inflammatory arthritis course, defining a new field of research named osteoimmunology. PTH, which is one of the main determinants of Dkkopf-1, plays a crucial role in bone erosions in RA and a correlation between PTH, Trabecular Bone Score (TBS) and disease activity has been found in ankylosing spondylitis (AS). In PSA is under studying the interaction among IL-17 and bone metabolism. The purpose of this review is to discuss and summarize the recent data about the interaction between endocrine hormone and immune system in the main rheumatic disorders, covering in particular the role of bone-related hormones and cytokines. We will describe this relationship from a biochemical, diagnostic and therapeutic perspective, with a particular focus on RA, PsA and AS.

The impact of long-term biologics/target therapy on bone mineral density in rheumatoid arthritis: a propensity score-matched analysis

OBJECTIVES

To investigate changes in BMD in RA patients receiving 3-year biological/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARD) or conventional synthetic DMARD (csDMARD).

METHODS

Patients with RA were recruited from September 2014 until March 2019. Clinical characteristics, BMD and evidence of fragility fractures at enrolment were documented. Participants were treated according to the National Institute for Health and Care Excellence (NICE) guidelines over a 3-year observation period. Repeated BMD was measured at the end of the study period. Participants were grouped into those receiving b/tsDMARD or csDMARD and by propensity score matching (1:2).

RESULTS

A total of 388 participants completed the 3-year follow-up. After propensity score matching, 92 and 184 participants were allocated to the b/tsDMARD (Group I) and csDMARD (Group II), respectively. After 3 years, BMD remained stable at the femoral neck (FN), hip (total) (TH) and lumbar vertebra (L1-4) (P =0.09, 0.15, 0.87) in Group I. However, BMD decreased significantly in Group II (P=0.045, <0.001, 0.004) at corresponding sites. Participants receiving combined b/tsDMARD and anti-osteoporosis therapy experienced a greater BMD preserving effect than other subgroups.

CONCLUSION

Long-term b/tsDMARDs therapy had protective effects on bone loss for patients with RA. Patients receiving concomitant anti-osteoporosis therapy and b/tsDMARDs therapy experienced the greatest BMD preserving effect.

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.

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.

Effects of denosumab on bone mineral density and bone turnover markers in rheumatoid arthritis patients switching from bisphosphonates

Background

To compare the efficacy of 12-month denosumab treatment on bone mineral density (BMD) and bone turnover markers (BTMs) between treatment-naïve osteoporosis patients with rheumatoid arthritis (RA) and those with previous bisphosphonate (BP) therapy.

Methods

A total of 36 RA patients with osteoporosis completed 12-month follow-up. Twenty-five patients were osteoporotic treatment-naïve (naïve group), and 11 patients were previously treated with BPs (switch group) (average 7.9 years). BMD and BTMs were measured before and 6 and 12 months after treatment.

Results

BTM levels were higher in the naïve group at baseline. However, the same level of suppression was achieved at 6 months in both groups. Spine BMD increased significantly in both groups. There was no significant difference in the mean percent changes of BMD of the spine (naïve group: 6.8 ± 0.8, switch group: 5.1 ± 1.5), femoral neck (2.9 ± 1.4, 2.9 ± 1.3), and total hip (1.7 ± 0.9, 1.4 ± 1.1) between these two groups at 12 months.

Conclusions

The effects of denosumab on BMD and BTMs of the switch group after long-term BP treatment are comparable to those of the naïve group in RA patients. Thus, switching BPs to denosumab is one of the useful options to treat osteoporosis with RA.

Impact of switching oral bisphosphonates to denosumab or daily teriparatide on the progression of radiographic joint destruction in patients with biologic-naïve rheumatoid arthritis

In biologic-naïve female RA patients, switching oral BPs to DMAb significantly reduced radiographic joint destruction compared to continuing oral BPs or switching to TPTD at 12 months, which were significantly associated with a decrease of a bone resorption marker at 6 months.

INTRODUCTION

The aim of this study was to clarify the effects of switching oral bisphosphonates (BPs) to denosumab (DMAb) or daily teriparatide (TPTD) on the progression of radiographic joint destruction in patients with biologic-naïve rheumatoid arthritis (RA).

METHODS

A retrospective, case-controlled study involving 90 female RA patients (mean age 68.2 years, 96.7% postmenopausal, disease activity score assessing 28 joints with CRP (DAS28-CRP) 2.4, methotrexate treatment 81.1%, prednisolone treatment 68.9%, and prior BP treatment 44.8 months), who were allocated depending on each patient's and physician's wishes, to (1) the BP-continue group (n = 30), (2) the switch-to-DMAb group (n = 30), or (3) the switch-to-TPTD group (n = 30), was conducted. Patients were retrospectively selected to minimize the difference of possible clinical backgrounds that may affect the joint destruction of RA. The primary endpoint was to clarify the change of the modified total Sharp score (mTSS) from baseline to 12 months.

RESULTS

After 12 months, the mean changes of the modified Sharp erosion score were significantly lower in the switch-to-DMAb group (0.2 ± 0.1; mean ± standard error) than in the switch-to-TPTD group (1.3 ± 0.5; P < 0.05), and mTSS was significantly lower in the switch-to-DMAb group (0.3 ± 0.2) than in the BP-continue group (1.0 ± 0.3; P < 0.05) and the switch-to-TPTD group (1.7 ± 0.6; P < 0.05). The logistic regression analysis showed that mTSS changes were significantly associated with the percent changes of TRACP-5b at 6 months (β = 0.30, 95% CI = 0.002-0.016; P < 0.01).

CONCLUSIONS

Changes of systemic bone turnover induced by switching BPs to DMAb or TPTD may affect not only systemic bone mass, but also local joint destruction, and its clinical relevance should be considered comprehensively.

Effect of treat-to-target strategies on bone erosion progression in early rheumatoid arthritis: An HR-pQCT study

OBJECTIVES

To investigate the efficacy of two tight-control treatment strategies aimed at simplified disease activity score [SDAI] remission (SDAI ≤ 3.3) compared to DAS28 remission (DAS28 < 2.6) on progression of bone erosions in early rheumatoid arthritis (ERA) patients using high-resolution peripheral quantitative computed tomography (HR-pQCT).

METHODS

This was an open-label study in which 80 early RA patients were randomized to receive 1-year of tight-control treatment. Group 1 (n = 37) aimed at SDAI ≤ 3.3 and group 2 (n = 43) aimed at DAS28-CRP < 2.6. The number and size of bone erosions, as well as the bone mineral density (BMD) surrounding bone erosion at the second metacarpophalangeal joint (MCP2), were measured at baseline and 12 months.

RESULTS

After 12 months, images were analyzed in 63 patients. Changes in clinical parameters, number and size of bone erosions as well as the BMD surrounding bone erosion between the two treatment groups were similar. Therefore, a post-hoc analysis including all 63 patients was performed to elucidate the independent predictors of erosion progression and repair. Multivariate analysis revealed that not achieving sustained SDAI remission at month 6, 9 and 12 (p = 0.034) and rheumatoid factor >16U (p = 0.021) were independent predictors associated with an increase in erosion volume. Logistic regression analysis showed that achieving sustained SDAI remission (p = 0.043) was associated with partial erosion repair.

CONCLUSIONS

Although more stringent treatment target did not notably affect clinical treatment outcome and erosion progression at 1 year, achieving sustained SDAI remission was found to be associated with partial erosion repair.

Repair of Bone Erosion in Rheumatoid Arthritis by Denosumab: A High-Resolution Peripheral Quantitative Computed Tomography Study

OBJECTIVE

To compare the bone healing effects of denosumab and alendronate in female rheumatoid arthritis (RA) patients by high-resolution peripheral quantitative computed tomography.

METHODS

This is a post hoc analysis of a randomized controlled trial. Forty patients were randomized in a 1:1 ratio to receive either subcutaneous denosumab (60 mg) once or oral alendronate (70 mg) weekly for 6 months. The size of individual bone erosions and the presence and extent of erosion-associated sclerosis (marginal osteosclerosis) were measured in the second metacarpal head of the nondominant hand at baseline, 3 months, and 6 months.

RESULTS

Forty-two erosions were identified at baseline. After 6 months, the width, depth, and volume of erosion significantly decreased in the denosumab group (-0.23 mm, -0.16 mm, -0.91 mm³ , respectively; all P < 0.01), whereas these parameters significantly increased in the alendronate group (0.19 mm, 0.32 mm, and 1.38 mm³ , respectively; all P < 0.01; between-group differences, P < 0.01 for all). Quantitative analysis showed that the bone mineral density of the erosion margin significantly increased only after treatment by denosumab (19.75 mg/cm³ ; P < 0.05 for denosumab, and -5.44 mg/cm³ ; P = 0.51 for alendronate; P < 0.05 for between-group differences).

CONCLUSION

Inhibition of receptor activator of NF-κB ligand by denosumab can induce partial repair of erosions in patients with RA, while erosions continued to progress in patients treated with alendronate. Combining denosumab with disease-modifying antirheumatic drugs may be considered for RA patients with progressive bone erosions.

Titer-Dependent Effect of Anti-Citrullinated Protein Antibodies On Systemic Bone Mass in Rheumatoid Arthritis Patients

Bone loss in rheumatoid arthritis (RA) is a key feature both local and systemic. Anti-citrullinated protein antibodies (ACPA) have recently been found to directly induce differentiation and activation of osteoclasts and therefore contribute to periarticular bone loss. The aim of this study was to analyze the effect of ACPA on systemic bone mineral density (BMD) in patients with established RA. This is a cross-sectional study with a single-center RA population. BMD was measured with Dual X-ray absorptiometry at lumbar and femoral sites. ACPA were measured by EIA. Multivariate analysis was performed adjusting for the main confounding variables. One hundred twenty-seven RA patients were enrolled. In univariate analysis, ACPA-positive patients showed lower BMD Z-score (SD below the age- and gender-matched mean reference value) at femoral sites (p < 0.01). A negative correlation between ACPA titer and BMD Z-score at all sites was observed (p < 0.01). The multivariate analysis adjusted for the main confounding variables confirmed the negative effect of ACPA at femoral sites (p < 0.05), but not at lumbar spine BMD. No significant effect of rheumatoid factor has been observed. ACPA have a negative titer-dependent effect on BMD at femoral sites, mainly constituted by cortical bone. ACPA-positive patients, especially if at high titer, should undergo bone investigations and be treated with bone protecting agents. Disease-modifying anti-rheumatic drugs lowering ACPA titer might have positive effects on systemic bone mass.

Denosumab: targeting the RANKL pathway to treat rheumatoid arthritis

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic inflammatory disorder characterized by focal pathologic bone resorption due to excessive activity of osteoclasts (OC). Receptor activator of nuclear factor kappa B ligand (RANKL) is essential for the proliferation, differentiation, and survival of OC. Denosumab (DMab) is a humanized monoclonal antibody that binds to RANKL with high affinity and blocks its subsequent association with its receptor RANK on the surface of OC precursors. Area covered: The authors review the molecular and cellular mechanisms underlying therapeutic applications of DMab, provide recent highlights on pharmacology, efficacy and safety of DMab, and discuss the potential of DMab as a novel therapeutic option for the treatment of rheumatoid arthritis. Expert opinion: Clinical results suggest that DMab is efficient both in systemic and articular bone loss in RA with limited side effects. Diminished bone erosion activity was also noted in RA patients on corticosteroids and bisphosphonates. Combination of DMab with an anti-TNF agent was not associated with increased infection rates. Collectively, these data indicate that DMab, in combination with methotrexate and possibly other conventional synthetic Disease Modifying Anti-Rheumatic Drugs (csDMARDs), is an effective, safe and cost-effective option for the treatment of RA.