Biologic therapies and bone loss in rheumatoid arthritis

Biologic treatment in comparison to methotrexate has positive effect on trabecular bone score in rheumatoid arthritis patients: 1-year follow-up

INTRODUCTION

Biologic treatment may influence activity of rheumatoid arthritis (RA), as well as areal bone mineral density (aBMD). Decreased aBMD explains the fracture risk in RA patients only partially. The trabecular bone score (TBS), novel texture parameter reflects degradation of trabecular bone and therefore could be used as a further parameter to predict the risk of fragility fracture.

OBJECTIVE

To compare the effects of biological disease-modifying antirheumatic drugs (bDMARDs) and conventional synthetic (cs) DMARDs (methotrexate) on aBMD and TBS in patients suffering from active RA.

METHODS

A 12 month prospective trial was performed in 105 active RA patients. The cohort was divided into two groups: group 1 (n = 84, mean age 54 yrs) treated with bDMARDs and group 2 (n = 21, mean age 53 yrs) treated with csDMARDs. The mean daily dose of prednisone at baseline was 6.2 and 6.6 mg (NS) between group 1 and 2, respectively. Patients with anti-osteoporotic treatment were not included. All patients received calcium (600 mg) and cholecalciferol (800IU). Lumbar spine (LS) and FN aBMD (by DXA, Hologic) were measured at baseline and after 1 year of treatment. TBS was generated using TBS Insight software (Medimaps, Switzerland).

RESULTS

Treatment with bDMARDS led to decrease in mean prednisone dose and to increase of 1.7% (p < 0.05) in TBS and OC levels of 26% (p < 0.001) but not on aBMD and CTX after treatment. The greatest TBS increase (2.7%, p < 0.05) was observed in premenopausal females within group 1. No effect of csDMARDS on measured parameters was observed.

CONCLUSION

Treatment of patients suffering from active RA with bDMARDs in comparison to csDMARDS led to increase of TBS, with greater increment of TBS in premenopausal women, despite no change in aBMD.

Tissue engineered bone mimetics to study bone disorders ex vivo: Role of bioinspired materials

Recent advances in materials development and tissue engineering has resulted in a substantial number of bioinspired materials that recapitulate cardinal features of bone extracellular matrix (ECM) such as dynamic inorganic and organic environment(s), hierarchical organization, and topographical features. Bone mimicking materials, as defined by its self-explanatory term, are developed based on the current understandings of the natural bone ECM during development, remodeling, and fracture repair. Compared to conventional plastic cultures, biomaterials that resemble some aspects of the native environment could elicit a more natural molecular and cellular response relevant to the bone tissue. Although current bioinspired materials are mainly developed to assist tissue repair or engineer bone tissues, such materials could nevertheless be applied to model various skeletal diseases in vitro. This review summarizes the use of bioinspired materials for bone tissue engineering, and their potential to model diseases of bone development and remodeling ex vivo. We largely focus on biomaterials, designed to re-create different aspects of the chemical and physical cues of native bone ECM. Employing these bone-inspired materials and tissue engineered bone surrogates to study bone diseases has tremendous potential and will provide a closer portrayal of disease progression and maintenance, both at the cellular and tissue level. We also briefly touch upon the application of patient-derived stem cells and introduce emerging technologies such as organ-on-chip in disease modeling. Faithful recapitulation of disease pathologies will not only offer novel insights into diseases, but also lead to enabling technologies for drug discovery and new approaches for cell-based therapies.

Inhibition of periarticular bone loss is associated with clinical remission and ACR70-Response in rheumatoid arthritis

The aim of this study, based on a post hoc analysis of the data set used in the RAPID 1 trial, focuses on the associations between metacarpal bone mineral density, as estimated by digital X-ray radiogrammetry (DXR), and clinical remission as well as ACR70-Response in rheumatoid arthritis (RA) patients treated with certolizumab pegol (CZP). The trial evaluates a total of 345 RA patients treated with methotrexate versus CZP 200 mg versus CZP 400 mg. All patients underwent X-rays of the hand at baseline and week 52 as well as computerized calculations of bone mineral density (BMD) by DXR. Clinical remission was defined as DAS28 < 2.6. ACR70-Response was also evaluated. The radiological assessment of disease progression was estimated using the modified total Sharp Score. The mean difference for DAS28 was observed for patients treated with CZP 400 mg (median: - 3.53, minimum: - 6.77; maximum: + 0.48) and CZP 200 mg (median: - 3.13, minimum: - 6.37; maximum: - 0.52) compared to the methotrexate group (median - 2.41, minimum: - 4.76; maximum: + 0.31). The DXR-BMD showed a minor bone loss for the treatment groups undergoing therapy with CZP 200 mg (median: - 0.009 g/cm², minimum: - 0.059 g/cm²; maximum: + 0.095 g/cm²) and CZP 400 mg (median: - 0.008 g/cm², minimum: - 0.064 g/cm²; maximum: + 0.080 g/cm²). The methotrexate group presented an advanced periarticular metacarpal bone loss as measured by DXR-BMD (median: - 0.024 g/cm², minimum: - 0.102 g/cm²; maximum: + 0.057 g/cm²). In the case of clinical remission and ACR70-Response, no significant change of the DXR-BMD was observed for both CZP groups. The study highlights that patients treated with CZP show a less accentuated periarticular bone loss as estimated by DXR in comparison to patients with methotrexate plus placebo. In addition, patients with clinical remission and ACR70-Response revealed no periarticular demineralisation.

Referral pattern for DXA scanning in a tertiary care centre from southern India

Referral patterns for bone mineral density testing by dual energy X-ray absorptiometry (DXA) scanning are seldom studied. In our study, the overall proportion of referrals from specialties remained low. This highlights the need for adequate utilisation of DXA by specialties treating subjects at risk for osteoporosis.

PURPOSE/OBJECTIVES

The knowledge of referral patterns for DXA scanning (dual energy X-ray absorptiometry) for bone mineral density (BMD) measurement is relevant in a developing country like India. We studied the referral source and clinical and densitometric profile of patients referred for DXA scanning at a south Indian tertiary care centre.

METHODS

We conducted a cross-sectional study over 3 months and included subjects referred during this period for BMD assessment (lumbar spine and femoral neck) by DXA scan. Details regarding referring departments and reasons for referral were collected. The number of patients seen in individual departments was obtained during the study period and respective proportions of patients referred were calculated.

RESULTS

Of the 1932 subjects included in the study, we observed a definite female preponderance (90.2%), with a mean (SD) age of 51.6 (13.3) years. The greatest number of referrals came from the departments of rheumatology (37%; n = 724) and endocrinology (20%; n = 382). Overall, 36% were referred for inflammatory arthritis or systemic inflammatory disorders (n = 696) and 34% for postmenopausal state screening (n = 657). In relation to the individual outpatient strength, the departments who referred the highest proportion of their patients were rheumatology (6.8%), endocrinology (1.76%) and geriatrics (1.05%). A diagnosis of osteoporosis at any one site was made in 41% (448 of 1107) and the BMD was below the expected range for age in 37% (304 of 825) of the referrals.

CONCLUSION

Most referrals for DXA scanning were from rheumatology. Among the referred patients, about two fifth had osteoporosis and over one third had BMD below expected range for age. Although referrals by rheumatology were relatively higher, overall referrals from all departments remained low. This underscores the need for adequate utilisation of DXA by specialties treating subjects at risk for osteoporosis.

The multi-biomarker disease activity score tracks response to rituximab treatment in rheumatoid arthritis patients: a post hoc analysis of three cohort studies

BACKGROUND

A multi-biomarker disease activity (MBDA) score has been validated as an objective measure of disease activity in rheumatoid arthritis (RA) and shown to track response to treatment with several disease-modifying anti-rheumatic drugs (DMARDs). The objective of this study was to evaluate the ability of the MBDA score to track response to treatment with rituximab.

METHODS

Data were used from 57 RA patients from three cohorts treated with rituximab 1000 mg and methylprednisolone 100 mg at days 1 and 15. The MBDA score was assessed in serum samples obtained at baseline and 6 months. Spearman's rank correlation coefficients were calculated for baseline values, 6-month values, and change from baseline to 6 months (∆), between MBDA score and the following measures: disease activity score assessing 28 joints (DAS28) using erythrocyte sedimentation rate (ESR) or high-sensitivity C-reactive protein (hsCRP), ESR, (hs)CRP, swollen and tender joint counts assessing 28 joints (SJC28, TJC28), patient visual analogue scale for general health (VAS-GH), health assessment questionnaire (HAQ), and radiographic progression over 12 months using Sharp/van der Heijde score (SHS), as well as six bone turnover markers. Additionally, multivariable linear regression analyses were performed using these measures as dependent variable and the MBDA score as independent variable, with adjustment for relevant confounders. The association between ∆MBDA score and European League Against Rheumatism (EULAR) response at 6 months was assessed with adjustment for relevant confounders.

RESULTS

At baseline, the median MBDA score and DAS28-ESR were 54.0 (IQR 44.3-70.0) and 6.3 (IQR 5.4-7.1), respectively. MBDA scores correlated significantly with DAS28-ESR, DAS28-hsCRP, ESR and (hs)CRP at baseline and 6 months. ∆MBDA score correlated significantly with changes in these measures. ∆MBDA score was associated with EULAR good or moderate response (adjusted OR = 0.89, 95% CI = 0.81-0.98, p = 0.02). Neither baseline MBDA score nor ΔMBDA score correlated statistically significantly with ∆SHS (n = 11) or change in bone turnover markers (n = 23), although ∆SHS ≥ 5 was observed in 5 (56%) of nine patients with high MBDA scores.

CONCLUSIONS

We have shown, for the first time, that the MBDA score tracked disease activity in RA patients treated with rituximab and that change in MBDA score reflected the degree of treatment response.

Association Between Osteoporosis and Age-Related Macular Degeneration: The Korea National Health and Nutrition Examination Survey

Purpose

Previous studies have reported a possible link between low bone mineral density and AMD. The aim of the present study was to investigate the association between osteoporosis and AMD in a South Korean cohort.

Methods

This cross-sectional, nationwide study included 3496 women and 2789 men who had participated in the Korean National Health and Nutrition Examination Survey from 2008 to 2011. All retinal photographs were graded using an international classification and grading system. Osteoporosis was assessed using dual-energy x-ray absorptiometry. Multivariate logistic regression analysis was performed to examine the relationship between osteoporosis and AMD after adjustment for potential confounders, including age, the body mass index, dietary calcium intake, and the serum vitamin D level. The odds ratios (OR) for other aging-related eye diseases, including cataract, open-angle glaucoma, and diabetic retinopathy, were analyzed in accordance with the presence of osteoporosis.

Results

Multivariate regression analysis revealed that osteoporosis was significantly associated with all types of AMD (early and late: OR, 1.31; P = 0.017) and early AMD (OR, 1.36; P = 0.007) in women. Late AMD was not associated with osteoporosis (OR, 0.84; P = 0.670). In men, osteoporosis was not associated with any type of AMD. In women, the status of osteoporosis in the femoral neck showed a linear relationship with AMD (P = 0.004). Although osteoporosis was associated with AMD in women, it showed no association with other age-related eye diseases; this suggested a disease-specific association.

Conclusions

Our findings suggest that osteoporosis plays a role in AMD development in postmenopausal women.

The renin-angiotensin system in the synovium promotes periarticular osteopenia in a rat model of collagen-induced arthritis

Periarticular osteopenia is the most specific hallmark of rheumatoid arthritis (RA). The renin-angiotensin system (RAS) in the synovium has been found to participate in the pathogenic process of RA. This study examined whether and how RAS regulates periarticular osteopenia in RA. The synovial tissues from patients with RA and osteoarthritis (OA) were prepared. Female Sprague-Dawley rats were treated with either saline, bovine type II collagen (CII) to induce arthritis (CIA), or CII combined with perindopril, an inhibitor of angiotensin-converting enzyme (ACE). Expressions of RAS components, including AT1R, AT2R and ACE, in human and rat synovial tissues were detected. Bone mass of rat joints was examined. Levels of RANKL, OPG and DKK-1 in rat synovium and expressions of TRAF6 and β-catenin in rat bone were examined. The results showed that AT1R, AT2R and ACE in human and rat synovium were up-regulated, but the increased ACE in rat synovial tissues was abrogated by perindopril. While CIA rats displayed increased bone resorption and decreased bone formation, perindopril treatment almost completely abrogated the RAS-mediated osteopenia, indicating that inhibition of ACE reduced the joint damages in rats. The expressions of RANKL and DKK-1 increased in CIA rats as compared with those in the control; TRAF6 was up-regulated and β-catenin was down-regulated in the bone tissues of CIA rats. The changes were then reversed by the use of perindopril. Our findings demonstrate that RAS in the synovium promotes periarticular osteopenia by increasing bone resorption and decreasing bone formation through modulating the RANKL/RANK/TRAF6 and Wnt/β-catenin pathways.

Personalization of biologic therapy in patients with rheumatoid arthritis: less frequently accounted choice-driving variables

Objective

To propose appropriate statements that drive the choice of biologic therapies in patients with rheumatoid arthritis (RA), factoring in their impact on the following issues: anti-drug antibody (ADAb) formation, suspicion and management of infections, lupus-like syndrome (LLS), effects on bone mass and sexual sphere, and relationship between RA and periodontal disease (PD).

Methods

An overview of existing evidence was undertaken by an expert panel on behalf of the Italian board for the TAilored BIOlogic therapy (ITABIO). Data were extracted from controlled trials, national registries, national health care databases, post-marketing surveys, and, when required by the paucity of controlled studies, from open-label clinical series. Anti-tumor necrosis factor (anti-TNF) and non-anti-TNF-targeted biologics approved for RA were investigated.

Results

ADAb formation is chiefly associated with anti-TNFs, and it is reduced by combination therapy with methotrexate. To date, ADAb titration is not advisable for clinical practice, and, in case of anti-TNF secondary failure, a non-anti-TNF biologic is indicated. LLS is observed in anti-TNF receivers and, in most cases, resolves without anti-TNF withdrawal. A non-anti-TNF biologic is advisable in patients experiencing LLS. Non-anti-TNFs demonstrated a low or absent infection risk and are preferable in patients with comorbidities. Due to their positive effects on bone mass, anti-TNFs are indicated in women at osteoporosis risk, whereas non-anti-TNF have been poorly investigated. The emerging evidence of the relationship between RA and PD and the effects on anti-TNF efficacy should lead clinicians to consider the periodontal status in RA patients. Anti-TNFs may exert a positive effect on fertility and sexuality, and clinicians should explore these aspects in RA patients.

Conclusion

The optimization of biologic therapies by taking into proper account the above issues would improve patient outcomes.

Dose adjustments and discontinuation in TNF inhibitors treated patients: when and how. A systematic review of literature

Objectives

To review the available evidence concerning the possibility of discontinuing and/or tapering the dosage of TNF inhibitors (TNFi) in RA patients experiencing clinical remission or low disease activity.

Methods

A systematic review of the literature concerning the low dosage and discontinuation of TNFi in disease-controlled RA patients was performed by evaluation of reports published in indexed international journals (Medline via PubMed, EMBASE), in the time frame from 8 April 2013 to 15 January 2016.

Results

We analysed the literature evaluating the efficacy and the safety of two different strategies using TNFi, decreasing dosage or discontinuation, in patients experiencing clinical remission or low disease activity. After the analysis of online databases, 25 references were considered potentially relevant and 16 references were selected. The majority of data concerned etanercept and adalimumab. Results suggested the induction of stable clinical remission or low disease activity by using TNFi followed by a dosage tapering and/or discontinuation of such drugs may be associated with the maintenance of a good clinical response in a subset of patients affected by early disease.

Conclusion

RA patients treated early with TNFi and achieving their therapeutic clinical targets seem to maintain their clinical response after tapering or discontinuing TNFi. These data may allow physicians a more dynamic and tailored management of RA patients.

Blood-induced bone loss in murine hemophilic arthropathy is prevented by blocking the iRhom2/ADAM17/TNF-α pathway

Hemophilic arthropathy (HA) is a debilitating degenerative joint disease that is a major manifestation of the bleeding disorder hemophilia A. HA typically begins with hemophilic synovitis that resembles inflammatory arthritides, such as rheumatoid arthritis, and frequently results in bone loss in patients. A major cause of rheumatoid arthritis is inappropriate release of the proinflammatory cytokine tumor necrosis factor-α (TNF-α) by the TNF-α convertase (TACE; also referred to as ADAM17) and its regulator, iRhom2. Therefore, we hypothesized that iRhom2/ADAM17-dependent shedding of TNF-α also has a pivotal role in mediating HA. Here, we show that addition of blood or its components to macrophages activates iRhom2/ADAM17-dependent TNF-α shedding, providing the premise to study the activation of this pathway by blood in the joint in vivo. For this, we turned to hemophilic FVIII-deficient mice (F8-/- mice), which develop a hemarthrosis following needle puncture injury with synovial inflammation and significant osteopenia adjacent to the affected joint. We found that needle puncture-induced bleeding leads to increased TNF-α levels in the affected joint of F8-/- mice. Moreover, inactivation of TNF-α or iRhom2 in F8-/- mice reduced the osteopenia and synovial inflammation that develops in this mouse model for HA. Taken together, our results suggest that blood entering the joint activates the iRhom2/ADAM17/TNF-α pathway, thereby contributing to osteopenia and synovitis in mice. Therefore, this proinflammatory signaling pathway could emerge as an attractive new target to prevent osteoporosis and joint damage in HA patients.

Soluble Tumor Necrosis Factor Alpha Receptor 1, Bone Resorption, and Bone Mineral Density in the Year Following Hip Fractures: The Baltimore Hip Studies

Although inflammation is known to influence bone turnover and bone mineral density (BMD), less is known about role of soluble tumor necrosis factor alpha receptor 1 (sTNFα-R1) in changes in bone turnover and BMD in the year after hip fracture. We studied 245 persons (117 men and 128 women) from the Baltimore Hip Studies. Bone turnover markers of resorption (carboxy-terminal type I collagen cross-links [CTX-I]) and formation (amino-terminal propeptide type I collagen [P1NP]), BMD of the contralateral hip, and sTNFα-R1 were measured within 15 days of hospitalization and 2, 6, and 12 months later. Latent class growth modeling was used to determine sTNFα-R1 trajectories. Weighted generalized estimating equations were used to examine the association of sTNFα-R1 trajectories with serum levels of CTX-I and P1NP and BMD; standardized beta coefficients (βˆ) are reported. Higher baseline sTNFα-R1 was significantly associated with a greater rate of CTX-I change (βˆ = 0.26, p = 0.004). Four distinct sTNFα-R1 trajectories were identified. The two groups with higher sTNFα-R1 levels during the year following fracture had faster increasing levels of CTX-I compared to the group with lowest sTNFα-R1 levels (men: group 3: βˆ = 0.76, p = 0.02; group 4: βˆ = 1.4, p < 0.001; women: group 3; βˆ = 0.67, p = 0.02; group 4: βˆ = 1.3, p = 0.004). Men in the highest sTNFα-R1 group had a greater decline in BMD compared to the lowest sTNFα-R1 group (2-month βˆ = -0.01, p = 0.01; 6-month: βˆ = -0.09, p = 0.001; 12-months: βˆ = -0.1, p < 0.001). An increasing rate of CTX-I was associated with a steeper decline in total hip BMD in those within higher sTNFα-R1 trajectory groups (p < 0.001). CTX-I was significantly increased with sTNFα-R1 in both sexes. CTX-I and the highest sTNFα-R1 trajectory were significantly associated with declines in total hip BMD in men. Interventions that reduce systemic inflammation should be explored to reduce bone resorption and prevent a decline in BMD after hip fracture. © 2018 American Society for Bone and Mineral Research.

Effects of once-monthly minodronate versus risedronate in osteoporosis patients with rheumatoid arthritis: a 12-month randomized head-to-head comparison

A head-to-head comparison of once-monthly oral bisphosphonates minodronate (MIN) and risedronate (RIS) in patients with rheumatoid arthritis (RA) demonstrated that MIN has the same effect as RIS on increase in bone mineral density (BMD) and a stronger effect on inhibition of bone resorption than RIS, suggesting that MIN is a promising treatment option for osteoporosis patients with RA.

INTRODUCTION

To evaluate the effect of once-monthly oral MIN in patients with RA, a prospective, randomized, open-label, head-to-head comparison with once-monthly oral RIS was conducted.

METHODS

A total of 83 patients with RA were randomly assigned to either once-monthly oral MIN 50 mg (n = 42) or once-monthly oral RIS 75 mg (n = 41). Serial BMD and bone turnover markers were measured and compared between the treatment groups.

RESULTS

BMD (lumbar spine, total hip, femoral neck) increased significantly after 12 months of treatment with MIN (3.8, 2.0, and 2.2%, respectively, P < 0.05) and RIS (3.6, 1.9, and 1.9%, respectively, P < 0.05). There were no significant differences between the treatment groups. Percent changes of bone turnover markers from baseline to 12 months in the MIN group were significantly greater than those in the RIS group (TRACP-5b: - 36.3 vs - 19.3%, P < 0.05; NTX: - 27.1 vs - 17.3%, P < 0.05; BAP: -30.2 vs -19.4%, P < 0.05).

CONCLUSIONS

The present study of RA patients demonstrated that MIN has the same effect as RIS on increase in BMD and a stronger effect on inhibition of bone resorption than RIS. The results suggest that MIN is a promising treatment option for osteoporosis patients with RA.

Male patients with rheumatoid arthritis have an increased risk of osteoporosis: Frequency and risk factors

Most previous research investigating osteoporosis in rheumatoid arthritis (RA) has focused on female patients and there is a lack of data regarding clinical characteristics of osteoporosis in male patients with RA.The aim of this study was to compare the frequency of osteoporosis between male patients with RA and healthy patients, and to identify the risk factors for osteoporosis and low bone mineral density (BMD) in male patients with RA.We conducted a retrospective, cross-sectional study including 76 South Korean male patients with RA aged over 50 years and 76 age-matched male healthy individuals. BMD was measured at the lumbar spine (L1-4) and left hip (femoral neck and total hip) using dual energy X-ray absorptiometry. Osteoporosis was defined as a T-score of ≤ -2.5 according to the World Health Organization (WHO) classification.The frequency of osteoporosis at either the spine or the hip among male patients with RA was significantly higher than that among controls (22.4% vs 10.5%, P = .049) and RA patients had a significantly lower total hip BMD than healthy individuals (0.92 ± 0.14 vs 0.96 ± 0.1 g/cm, P = .027). For male RA patients, the mean 28-joint Disease Activity Scores using erythrocyte sedimentation rate (DAS28-ESR) and body mass index (BMI) were 3.28 and 22 kg/m, respectively. In multivariable logistic regression models, BMI ≤ 22 kg/m (odds ratio = 3.43, P = .043) and DAS28-ESR > 3.2 (odds ratio = 3.85, P = .032) were independent risk factors for osteoporosis at either site in male patients with RA.Our data demonstrate that male patients with RA had a 2.1 times higher risk for osteoporosis compared with healthy individuals. This suggests that appropriate management of osteoporosis in patients with RA is crucial not only for postmenopausal women but also for men aged over 50 years, especially those with low BMI and higher disease activity.

Osteoimmunology: Effects of Standard Orthopaedic Interventions on Inflammatory Response and Early Fracture Healing

Achieving fracture union is highly dependent on the initial inflammatory phase of fracture healing, which is influenced by both the local and systemic inflammatory environments. The rapidly emerging field of osteoimmunology involves the study of the interactions between the immune system and the skeletal system. Recent research has advanced the current state of knowledge regarding the effects of the surrounding soft-tissue injury, fracture hematoma, and the method of fracture fixation on the inflammatory phase of fracture healing. Acute systemic inflammation, as seen in patients with polytrauma, and chronic systemic inflammation, as seen in patients with diabetes or rheumatoid arthritis, affects the inflammatory phase of fracture healing. The use of NSAIDs can influence early fracture healing. Understanding the effects of standard orthopaedic interventions on the local and systemic inflammatory responses and early fracture healing is important for optimizing fracture union.

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.

Effects of denosumab on bone metabolism and bone mineral density with anti-TNF inhibitors, tocilizumab, or abatacept in osteoporosis with rheumatoid arthritis

Introduction

The aim of this 18-month retrospective study was to evaluate the differences in outcomes of denosumab with tumor necrosis factor (TNF) inhibitors (TNFis), tocilizumab (TCZ), or abatacept (ABT) treatment in osteoporosis (OP) patients with rheumatoid arthritis (RA).

Patients and methods

Patients were divided into TNFis-treated (TNF group; 44 cases), TCZ-treated (TCZ group; 8 cases), or ABT-treated (ABT group; 14 cases) groups. We measured serum bone-specific alkaline phosphatase (BAP) and tartrate-resistant acid phosphatase 5b (TRACP-5b) at baseline and every 3 months for 18 months and assessed bone mineral density (BMD) of the lumbar 1–4 vertebrae (L-BMD) and total hip BMD (H-BMD) at baseline and every 6 months for 18 months.

Results

There were no significant differences in the percent changes in BAP, TRACP-5b, or L-BMD among the groups. The percent change in H-BMD was significantly increased in the TCZ group at 12 months or at 12 and 18 months, compared with that in the ABT group or TNF group, respectively. The percent change in L-BMD was significantly increased at 12 months in the TCZ and TNF groups, and at 18 months in all the 3 groups compared with pretreatment levels, whereas the percent change in H-BMD was significantly higher at 6, 12, and 18 months in the TCZ group, at 12 and 18 months in the TNF group, and at 18 months in the ABT group, compared with pretreatment levels.

Conclusion

Our findings suggest that TCZ might be more useful than TNF or ABT in light of the observed H-BMD increases with denosumab therapy for OP patients with RA.

Micro-structural bone changes in early rheumatoid arthritis persist over 1-year despite use of disease modifying anti-rheumatic drug therapy

Background

We used High Resolution – peripheral Quantitative CT (HR-pQCT) imaging to examine peri-articular bone quality in early rheumatoid arthritis (RA) and explore whether bone quality improved over 12-months in individuals receiving care consistent with practice guidelines.

Methods

A 1-year longitudinal cohort study (Baseline and 12-months) evaluating individuals with early RA compared to age/sex-matched peers. Personal demographic and health and lifestyle information were collected for all. Whereas, active joint count (AJC₂₈), functional limitation, and RA medications were also collected for RA participants. HR-pQCT imaging analyses quantified bone density and microstructure in the Metacarpal Head (MH) and Ultra-Ultra-Distal (UUD) radius at baseline and 12-months. Analyses included a General Linear Modelling repeated measures analyses examined main effects for disease, time, and interaction on bone quality.

Results

Participants (n = 60, 30 RA/30 NRA); 80% female, mean age 53 (varying from 21 to 74 years). At baseline, RA participants were on average 7.7 months since diagnosis, presenting with few active joints (AJC₂₈: 30% none, remaining 70% Median 4 active joints) and minimal self-reported functional limitation (mHAQ-DI_0–3: 0.56). At baseline, 29 of 30 RA participants had received one or more non-biologic disease-modifying anti-rheumatic drugs (DMARD);13 in combination with glucocorticoid and 1 in combination with a biologic medication. One participant only received glucocorticoid medication. Four RA participants withdrew leaving 26 pairs (n = 52) at 12-months; 23 pairs (n = 46) with UUD and 22 pairs (n = 44) with MH baseline and 12-month images to compare. Notable RA/NRA differences (p < 0.05) in bone quality at all three sites included lower trabecular bone density and volume, more rod-like trabeculae, and larger and more variable spaces between trabeculae; fewer trabeculae at the UUD and MH2 sites; and lower cortical bone density and volume in the MH sites. Rate of change over 12-months did not differ between RA/NRA participants which meant there was also no improvement over the year in RA bone quality.

Conclusions

Early changes in peri-articular bone density and microstructure seen in RA are consistent with changes more commonly seen in aging bone and are slow or resistant to recover despite well controlled inflammatory joint symptoms with early DMARD therapy.

Electronic supplementary material

The online version of this article (10.1186/s12891-017-1888-3) contains supplementary material, which is available to authorized users.

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

Rheumatoid arthritis (RA) is associated with a high risk of osteoporosis and fracture. Interleukin (IL)-6 inhibitors may suppress osteoclast activation. Anticitrullinated protein antibody (ACPA) titers are inversely associated with bone mineral density (BMD). However, the differential effect of ACPA on bone turnover marker (BTM) and BMD changes after IL-6 inhibition remains unclear. This prospective study recruited patients with active RA with inadequate response to methotrexate or biologics. BMD was measured before and after 2-year tocilizumab (TCZ) treatment. Serum osteocalcin, N-terminal propeptide of type I collagen (P1NP), and C-terminal cross-linking telopeptide of type I collagen (CTX) levels were assessed at the baseline and after treatment. We enrolled 76 patients with RA (89.5% women, age: 57.2 ± 13.3 years) receiving TCZ. The 28-joint disease activity score was negatively correlated with BMD and T-scores of the lumbar spine and bilateral femoral neck. ACPA-positive patients had lower lumbar spine and femoral neck T-scores. After 2-year TCZ treatment, CTX levels significantly decreased (0.32 ± 0.21 vs. 0.26 ± 0.17, p = 0.038). Femoral neck BMD increased significantly (0.71 ± 0.22 vs. 0.69 ± 0.55, p = 0.008). Decreased CTX levels and improved BMD were observed only in ACPA-positive patients. After treatment, femoral neck BMD significantly increased only in patients receiving a glucocorticoid dose of ≥5 mg/day. Two-year TCZ treatment reduced bone resorption and increased femoral BMD in ACPA-positive patients. The net effects of glucocorticoids and IL-6 inhibition on BMD imply that strict inflammation control might affect bone metabolism.

Skeletal complications of rheumatoid arthritis

Rheumatoid arthritis (RA) is associated with local and systemic inflammation that induces many changes in the skeletal health. Locally, periarticular bone loss and juxta-articular bone erosions may occur while joint ankylosis, generalized bone loss, osteoporosis, and fractures may develop secondary to inflammation. The aim of this narrative review is to summarize the clinical evidence for abnormal skeletal health in RA, the effects of disease modifying anti-rheumatic drugs (DMARDS) on bone health, and the effects of drugs for the prevention or treatment of osteoporosis in the RA population.

New Molecules Modulating Bone Metabolism – New Perspectives in the Treatment of Osteoporosis

In this review the authors outline traditional antiresorptive pharmaceuticals, such as bisphosphonates, monoclonal antibodies against RANKL, SERMs, as well as a drug with an anabolic effect on the skeleton, parathormone. However, there is also a focus on non-traditional strategies used in therapy for osteolytic diseases. The newest antiosteoporotic pharmaceuticals increase osteoblast differentiation via BMP signaling (harmine), or stimulate osteogenic differentiation of mesenchymal stem cells through Wnt/β-catenin (icarrin, isoflavonoid caviunin, or sulfasalazine). A certain promise in the treatment of osteoporosis is shown by molecules targeting non-coding microRNAs (which are critical for osteoclastogenesis) or those stimulating osteoblast activity via epigenetic mechanisms. Vitamin D metabolites have specific antiosteoporotic potencies, modulating the skeleton not only via mineralization, but markedly also through the direct effects on the bone microstructure.

MicroRNA-433-3p promotes osteoblast differentiation through targeting DKK1 expression

Dickkopf-1 (DKK1) is a powerful antagonist of canonical WNT signaling pathway, and is regarded as a biomarker for osteoporosis. Its expression is highly correlated with bone mass and osteoblasts maturation. In this study, mouse primary bone marrow cells and osteoblast cell lines were used. Luciferase reporter assay and western blotting methods were employed to validate if miRNA-433-3p epigenetically regulated DKK1 translation. Rat bone marrow derived osteoblasts were infected with lentivirus vector in which miR-433-3p was constructed. The authors constructed lentivirus mediated miRNA-433-3p stable expression and examined the alkaline phosphatase (ALP) activity and mineral deposition level in vitro. In situ hybridization method was used to observe miR-433-3p in primary osteoblasts. We built up an OVX rat model to mimic postmenopausal osteoporosis, and found aberrant circulating miR-433-3p and miR-106b, which were not reported previously. Results showed that miR-433-3p potentially regulated DKK1 mRNA, Furthermore, the correlation of serum DKK1 with circulating miR-433-3p level was significant (r = 0.7520, p = 0.046). In the luciferase reporter assay, we found that miR-433-3p siRNA decreased luminescence signal, indicating direct regulation of miR-433-3p on DKK1 mRNA. When the miR-433-3p binding site in DKK1 3’UTR was mutant, such reduction was prohibited. Western blotting result validated that miR-433-3p inhibited over 90% of DKK1 protein expression. Similarly, the change of protein expression was not observed in mutant group. The stable expression of lentivirus mediated miR-433-3p increased ALP activity and mineralization both in human and rat derived immortalized cells. We found that primary osteoblasts had higher miR-433-3p level compared with immortal cells through real-time PCR, as well as in situ hybridization experiment. Conclusively, our findings further emphasized the vital role of miR-433-3p in DKK1/WNT/β-catenin pathway through decreasing DKK1 expression and inducing osteoblasts differentiation.

Late conversion from tacrolimus to a belatacept-based immuno-suppression regime in kidney transplant recipients improves renal function, acid-base derangement and mineral-bone metabolism

BACKGROUND

Calcineurin inhibitor (CNI)-induced nephrotoxicity and chronic graft dysfunction with deteriorating glomerular filtration rate (GFR) are common problems of kidney transplant recipients. The aim of this study was to analyze the role of belatacept as a rescue therapy in these patients.

METHODS

In this retrospective, observational study we investigated 20 patients (10 females, 10 males) who were switched from a CNI (tacrolimus) to a belatacept-based immunosuppression because of CNI intolerance or marginal transplant function. Patient follow-up was 12 months.

RESULTS

Patients were converted to belatacept in mean 28.8 months after transplantation. Reasons for conversion were CNI intolerance (14 patients) or marginal transplant function (6 patients). Mean estimated GFR (eGFR) before conversion was 22.2 ± 9.4 ml/min at baseline and improved significantly to 28.3 ± 10.1 ml/min at 4 weeks and to 32.1 ± 12.6 ml/min at 12 months after conversion. Serum bicarbonate significantly increased from 24.4 ± 3.2 mmol/l at baseline to 28.7 ± 2.6 mmol/l after 12 months. Conversion to belatacept decreased parathyroid hormone and phosphate concentrations significantly, whereas albumin levels significantly increased. In 6 cases an acute rejection preceded clinically relevant CNI toxicity; only two patients suffered from an acute rejection after conversion. Belatacept was well tolerated and there was no increase in infectious or malignant side effects.

CONCLUSION

A late conversion from a tacrolimus-based immunosuppression to belatacept is safe, effective and significantly improves renal function in kidney transplant recipients. Additionally, the conversion to belatacept has a beneficial impact on acid-base balance, mineral-bone and protein metabolism, independently of eGFR.