Randomised trial of genetic testing and targeted intervention to prevent the development and progression of Paget's disease of bone.

INTRODUCTION: Paget's disease of bone (PDB) frequently presents at an advanced stage with irreversible skeletal damage. Clinical outcomes might be improved by earlier diagnosis and prophylactic treatment. METHODS: We randomised 222 individuals at increased risk of PDB because of pathogenic SQSTM1 variants to receive 5 mg zoledronic acid (ZA) or placebo. The primary outcome was new bone lesions assessed by radionuclide bone scan. Secondary outcomes included change in existing lesions, biochemical markers of bone turnover and skeletal events related to PDB. RESULTS: The median duration of follow-up was 84 months (range 0-127) and 180 participants (81%) completed the study. At baseline, 9 (8.1%) of the ZA group had PDB lesions vs 12 (10.8%) of the placebo group. Two of the placebo group developed new lesions versus none in the ZA group (OR 0.41, 95% CI 0.00 to 3.43, p=0.25). Eight of the placebo group had a poor outcome (lesions which were new, unchanged or progressing) compared with none of the ZA group (OR 0.08, 95% CI 0.00 to 0.42, p=0.003). At the study end, 1 participant in the ZA group had lesions compared with 11 in the placebo group. Biochemical markers of bone turnover were significantly reduced in the ZA group. One participant allocated to placebo required rescue therapy with ZA because of symptomatic disease. The number and severity of adverse events did not differ between groups. CONCLUSIONS: Genetic testing for pathogenic SQSTM1 variants coupled with intervention with ZA is well tolerated and has favourable effects on the progression of early PDB. TRIAL REGISTRATION NUMBER: ISRCTN11616770.

Paranasal sinus occupancy assessed from magnetic resonance images-associations with clinical indicators in patients with systemic lupus erythematosus.

OBJECTIVES: Nasal, paranasal sinus and mucosal disorders are common symptoms in autoimmune rheumatic diseases. Soft tissue changes and fluid accumulation in the osteomeatal complexes and paranasal sinuses manifest as opaqueness on radiological images which can be assessed using visual scoring and computational methods on CT scans, but their results do not always correlate. Using MRI, we investigate the applicability of different image analysis methods in SLE. METHODS: We assessed paranasal sinus opaqueness on MRI from 51 SLE patients, using three visual scoring systems and expert-delineated computational volumes, and examined their association with markers of disease activity, inflammation, endothelial dysfunction and common small vessel disease (SVD) indicators, adjusting for age and sex-at-birth. RESULTS: The average paranasal sinus volume occupation was 4.55 (6.47%) [median (interquartile range) = 0.67 (0.25-2.65) ml], mainly in the maxillary and ethmoid sinuses. It was highly correlated with Lund-Mackay (LM) scores modified at 50% opaqueness cut-off (Spearman's ρ: 0.71 maxillary and 0.618 ethmoids, P < 0.001 in all), and with more granular variations of the LM system. The modified LM scores were associated with SVD scores (0: B = 5.078, s.e. = 1.69, P = 0.0026; 2: B = -0.066, s.e. = 0.023, P = 0.0045) and disease activity (anti-dsDNA: B = 4.59, s.e. = 2.22, P = 0.045; SLEDAI 3-7: 2.86 < B < 4.30; 1.38 < s.e. < 1.63; 0.0083 ≤ P ≤ 0.0375). Computationally derived percent opaqueness yielded similar results. CONCLUSION: In patients with SLE, MRI computational assessment of sinuses opaqueness and LM scores modified at a 50% cut-off may be useful tools in understanding the relationships among paranasal sinus occupancy, disease activity and SVD markers.

Osteogenesis Imperfecta: Skeletal and Non-skeletal Challenges in Adulthood.

Osteogenesis imperfecta (OI) is a Mendelian connective tissue disorder associated with increased bone fragility and other clinical manifestations most commonly due to abnormalities in production, structure, or post-translational modification of type I collagen. Until recently, most research in OI has focused on the pediatric population and much less attention has been directed at the effects of OI in the adult population. This is a narrative review of the literature focusing on the skeletal as well as non-skeletal manifestations in adults with OI that may affect the aging individual. We found evidence to suggest that OI is a systemic disease which involves not only the skeleton, but also the cardiopulmonary and gastrointestinal system, soft tissues, tendons, muscle, and joints, hearing, eyesight, dental health, and women's health in OI and potentially adds negative affect to health-related quality of life. We aim to guide clinicians as well as draw attention to obvious knowledge gaps and the need for further research in adult OI.

Ubiquitin-protein ligase Ubr5 cooperates with hedgehog signalling to promote skeletal tissue homeostasis.

Mammalian Hedgehog (HH) signalling pathway plays an essential role in tissue homeostasis and its deregulation is linked to rheumatological disorders. UBR5 is the mammalian homologue of the E3 ubiquitin-protein ligase Hyd, a negative regulator of the Hh-pathway in Drosophila. To investigate a possible role of UBR5 in regulation of the musculoskeletal system through modulation of mammalian HH signaling, we created a mouse model for specific loss of Ubr5 function in limb bud mesenchyme. Our findings revealed a role for UBR5 in maintaining cartilage homeostasis and suppressing metaplasia. Ubr5 loss of function resulted in progressive and dramatic articular cartilage degradation, enlarged, abnormally shaped sesamoid bones and extensive heterotopic tissue metaplasia linked to calcification of tendons and ossification of synovium. Genetic suppression of smoothened (Smo), a key mediator of HH signalling, dramatically enhanced the Ubr5 mutant phenotype. Analysis of HH signalling in both mouse and cell model systems revealed that loss of Ubr5 stimulated canonical HH-signalling while also increasing PKA activity. In addition, human osteoarthritic samples revealed similar correlations between UBR5 expression, canonical HH signalling and PKA activity markers. Our studies identified a crucial function for the Ubr5 gene in the maintenance of skeletal tissue homeostasis and an unexpected mode of regulation of the HH signalling pathway.

Genome-wide association study identifies genetic variants which predict the response of bone mineral density to teriparatide therapy.

OBJECTIVES: Teriparatide (TPTD) is an effective treatment for osteoporosis but the individual response to therapy is variable for reasons that are unclear. This study aimed to determine whether the response to TPTD might be influenced by genetic factors. METHODS: We searched for predictors of the response of bone mineral density (BMD) to TPTD using a two-stage genome-wide association study in 437 patients with osteoporosis from three referral centres. Demographic and clinical data including the response of BMD to treatment at the lumbar spine and hip were extracted from the medical records of each participant. RESULTS: Allelic variation at rs6430612 on chromosome 2, close to the CXCR4 gene was associated with the response of spine BMD to TPTD at a genome wide significant level (p=9.2×10-9 beta=-0.35 (-0.47 to -0.23)). The increase in BMD was almost twice as great in AA homozygotes at rs6430612 as compared with GG homozygotes with intermediate values in heterozygotes. The same variant was also associated with response of femoral neck and total hip BMD (p=0.007). An additional locus on chromosome 19 tagged by rs73056959 was associated with the response of femoral neck BMD to TPTD (p=3.5×10-9, beta=-1.61 (-2.14 to -1.07)). CONCLUSIONS: Genetic factors influence the response to TPTD at the lumbar spine and hip with a magnitude of effect that is clinically relevant. Further studies are required to identify the causal genetic variants and underlying mechanisms as well as to explore how genetic testing for these variants might be implemented in clinical practice.

Cost-effectiveness of cognitive behavioural and personalized exercise interventions for reducing fatigue in inflammatory rheumatic diseases.

OBJECTIVES: To estimate the cost-effectiveness of a cognitive behavioural approach (CBA) or a personalized exercise programme (PEP), alongside usual care (UC), in patients with inflammatory rheumatic diseases who report chronic, moderate to severe fatigue. METHODS: A within-trial cost-utility analysis was conducted using individual patient data collected within a multicentre, three-arm randomized controlled trial over a 56-week period. The primary economic analysis was conducted from the UK National Health Service (NHS) perspective. Uncertainty was explored using cost-effectiveness acceptability curves and sensitivity analysis. RESULTS: Complete-case analysis showed that, compared with UC, both PEP and CBA were more expensive [adjusted mean cost difference: PEP £569 (95% CI: £464, £665); CBA £845 (95% CI: £717, £993)] and, in the case of PEP, significantly more effective [adjusted mean quality-adjusted life year (QALY) difference: PEP 0.043 (95% CI: 0.019, 0.068); CBA 0.001 (95% CI: -0.022, 0.022)]. These led to an incremental cost-effectiveness ratio (ICER) of £13 159 for PEP vs UC, and £793 777 for CBA vs UC. Non-parametric bootstrapping showed that, at a threshold value of £20 000 per QALY gained, PEP had a probability of 88% of being cost-effective. In multiple imputation analysis, PEP was associated with significant incremental costs of £428 (95% CI: £324, £511) and a non-significant QALY gain of 0.016 (95% CI: -0.003, 0.035), leading to an ICER of £26 822 vs UC. The estimates from sensitivity analyses were consistent with these results. CONCLUSION: The addition of a PEP alongside UC is likely to provide a cost-effective use of health care resources.

Probiotics Inhibit Cartilage Damage and Progression of Osteoarthritis in Mice.

Increasing interest has focussed on the possible role of alterations in the microbiome in the pathogenesis of metabolic disease, inflammatory disease, and osteoporosis. Here we examined the role of the microbiome in a preclinical model of osteoarthritis in mice subjected to destabilisation of medical meniscus (DMM). The intestinal microbiome was depleted by broad-spectrum antibiotics from 1 week before birth until the age of 6 weeks when mice were subjected reconstitution of the microbiome with faecal microbial transplant (FMT) followed by the administration of a mixture of probiotic strains Lacticaseibacillus paracasei 8700:2, Lactiplantibacillus plantarum HEAL9 and L. plantarum HEAL19 or vehicle. All mice were subjected to DMM at the age of 8 weeks. The severity of osteoarthritis was evaluated by histological analysis and effects on subchondral bone were investigated by microCT analyses. The combination of FMT and probiotics significantly inhibited cartilage damage at the medial femoral condyle such that the OARSI score was 4.64 ± 0.32 (mean ± sem) in the FMT and probiotic group compared with 6.48 ± 0.53 in the FMT and vehicle group (p = 0.007). MicroCT analysis of epiphyseal bone from the femoral condyle showed that the probiotic group had higher BV/TV, increased Tb.Th, and moderately thicker subchondral bone plates than the control group. There was no difference between groups in joint inflammation or in serum concentrations of inflammatory cytokines and chemokines. We conclude that treatment with probiotics following FMT in mice where the microbiome has been depleted inhibits DMM-induced cartilage damage and impacts on the structure of subchondral bone particularly at the femoral condyle. While further studies are required to elucidate the mechanism of action, our research suggests that these probiotics may represent a novel intervention for the treatment of osteoarthritis.

Clinical Features, Incidence and Treatment Outcome in Pregnancy-Associated Osteoporosis: A Single-Centre Experience over Two Decades.

Pregnancy-associated osteoporosis (PAO) is a rare syndrome which typically presents with vertebral fractures during pregnancy or lactation. The medical records of sixteen patients with PAO who presented to a specialist clinic at the Western General Hospital in Edinburgh over a 20-year period were reviewed to evaluate the mode of presentation, potential risk factors and response to treatment. The most common presentation was back pain occurring in 13/16 (81.2%) individuals due to multiple vertebral fractures. The diagnosis was usually made postpartum and in 12/16 individuals (75.0%), PAO presented during the woman's first pregnancy. Medicines which could have contributed to the development of PAO included thromboprophylaxis therapies in 8 subjects (50.0%), inhaled or injected corticosteroids in 5 (31.3%), anticonvulsants in 2 (12.5%) and a LHRH agonist in 1 (6.3%). Five individuals reported a family history of osteoporosis, and two pregnancies were complicated by hyperemesis gravidarum. Treatments administered included calcium and vitamin D supplements, bisphosphonates and teriparatide. Bone mineral density increased following the diagnosis in all cases, regardless of treatment given. One patient had further fracture during follow-up, but four patients had subsequent pregnancies without fractures. We estimated that in this locality, the incidence of PAO was 6.8/100,000 pregnancies with a point prevalence of 4.1 per 100,000 women. This case series indicates the importance of family history of osteoporosis and thromboprophylaxis drugs as risk factors for PAO while also demonstrating that the reductions in bone density tend to reverse with time, irrespective of the treatment given.

Outcomes following Total Hip and Knee Arthroplasty in Patients Who Have Paget's Disease of Bone: A Systematic Review.

BACKGROUND: Patients who have Paget's Disease more frequently require total hip arthroplasty (THA) and total knee arthroplasty (TKA) than matched controls. However, controversy remains regarding their outcome. We aimed to evaluate the literature regarding outcomes following THA and TKA in patients who have Paget's Disease. METHODS: MEDLINE, EMBASE and Cochrane databases were searched for all articles evaluating outcomes following THA and TKA in patients who have Paget's Disease. Quality of included studies was assessed using the Newcastle-Ottawa Scale. RESULTS: A total of 19 articles (published between 1976 and 2022) were included, comprising 58,695 patients (48,766 controls and 10,018 patients who have Pagets Disease), from 209 potentially relevant titles. Patients with Paget's Disease have a pooled mortality of 32.5% at a mean of 7.8 years (range, 0.1 to 20) following THA and 31.0% at a mean of 8.5 years (range, 2 to 20) following TKA, with a pooled revision rate of 4.4% at 7.2 years (range, 0 to 20) following THA and 2.2% at 7.4 years (range, 2 to 20) following TKA. Renal and respiratory complications, as well as heterotopic ossification and surgical-site infection were the most common post-operative complications. CONCLUSION: There is marked heterogeneity in outcome reporting of studies assessing arthroplasty in patients who have Paget's Disease, with studies of low to moderate quality. Patients with Paget's Disease undergoing THA and TKA appear to have similar implant longevity as their unaffected counterparts. However, they appear to have an increased risk of medical and surgical complications and may have a higher mortality risk from their procedure.

Effect of Denosumab or Alendronic Acid on the Progression of Aortic Stenosis: A Double-Blind Randomized Controlled Trial.

BACKGROUND: Valvular calcification is central to the pathogenesis and progression of aortic stenosis, with preclinical and observational studies suggesting that bone turnover and osteoblastic differentiation of valvular interstitial cells are important contributory mechanisms. We aimed to establish whether inhibition of these pathways with denosumab or alendronic acid could reduce disease progression in aortic stenosis. METHODS: In a single-center, parallel group, double-blind randomized controlled trial, patients >50 years of age with calcific aortic stenosis (peak aortic jet velocity >2.5 m/s) were randomized 2:1:2:1 to denosumab (60 mg every 6 months), placebo injection, alendronic acid (70 mg once weekly), or placebo capsule. Participants underwent serial assessments with Doppler echocardiography, computed tomography aortic valve calcium scoring, and 18F-sodium fluoride positron emission tomography and computed tomography. The primary end point was the calculated 24-month change in aortic valve calcium score. RESULTS: A total of 150 patients (mean age, 72±8 years; 21% women) with calcific aortic stenosis (peak aortic jet velocity, 3.36 m/s [2.93-3.82 m/s]; aortic valve calcium score, 1152 AU [655-2065 AU]) were randomized and received the allocated trial intervention: denosumab (n=49), alendronic acid (n=51), and placebo (injection n=25, capsule n=25; pooled for analysis). Serum C-terminal telopeptide, a measure of bone turnover, halved from baseline to 6 months with denosumab (0.23 [0.18-0.33 µg/L] to 0.11 µg/L [0.08-0.17 µg/L]) and alendronic acid (0.20 [0.14-0.28 µg/L] to 0.09 µg/L [0.08-0.13 µg/L]) but was unchanged with placebo (0.23 [0.17-0.30 µg/L] to 0.26 µg/L [0.16-0.31 µg/L]). There were no differences in 24-month change in aortic valve calcium score between denosumab and placebo (343 [198-804 AU] versus 354 AU [76-675 AU]; P=0.41) or alendronic acid and placebo (326 [138-813 AU] versus 354 AU [76-675 AU]; P=0.49). Similarly, there were no differences in change in peak aortic jet velocity or 18F-sodium fluoride aortic valve uptake. CONCLUSIONS: Neither denosumab nor alendronic acid affected progression of aortic valve calcification in patients with calcific aortic stenosis. Alternative pathways and mechanisms need to be explored to identify disease-modifying therapies for the growing population of patients with this potentially fatal condition. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02132026.

Communicating Absolute Fracture Risk Reduction and the Acceptance of Treatment for Osteoporosis.

Healthcare professionals frequently communicate the benefits of treatments as a relative risk reduction (RRR) in the likelihood of an event occurring. Here we evaluated whether presenting the benefits of osteoporosis treatment as a RRR in fractures compared with an absolute risk reduction (ARR) changed the patient's attitudes towards accepting treatment. We surveyed 160 individuals attending a specialised osteoporosis clinic for face-to-face consultations between May 2018 and Jan 2021. They were presented with information on RRR for the treatment being considered followed by ARR and after each question were asked about how likely they would be to start treatment on a 5-point scale (1 = very likely, 5 = very unlikely). Participants were less likely to accept treatment when it was presented as ARR (mean score 2.02 vs. 2.67, p < 0.001, 95% CI for difference - 0.82 vs - 0.47) and thirty-eight participants (23.7%) declined treatment with knowledge of their ARR when they would have accepted the same treatment based on the RRR. Individuals who declined treatment had a lower 5-year risk of fracture than those who accepted treatment (9.0 vs. 12.5%, p < 0.001, 95% CI - 5.0 to - 1.6) and as fracture risk decreased, the participant was less likely to accept treatment (Spearman r - 0.32, 95% CI - 0.46 to - 0.17, p ≤ 0.001). Whilst presentation of data as ARR more accurately reflects individual benefit and helps facilitate shared decision-making, clinicians should be aware that this will lead to a proportion of patients with lower fracture risk declining treatment for osteoporosis.

Role of the Microbiome in Regulating Bone Metabolism and Susceptibility to Osteoporosis.

The human microbiota functions at the interface between diet, medication-use, lifestyle, host immune development and health. It is therefore closely aligned with many of the recognised modifiable factors that influence bone mass accrual in the young, and bone maintenance and skeletal decline in older populations. While understanding of the relationship between micro-organisms and bone health is still in its infancy, two decades of broader microbiome research and discovery supports a role of the human gut microbiome in the regulation of bone metabolism and pathogenesis of osteoporosis as well as its prevention and treatment. Pre-clinical research has demonstrated biological interactions between the microbiome and bone metabolism. Furthermore, observational studies and randomized clinical trials have indicated that therapeutic manipulation of the microbiota by oral administration of probiotics may influence bone turnover and prevent bone loss in humans. In this paper, we summarize the content, discussion and conclusions of a workshop held by the Osteoporosis and Bone Research Academy of the Royal Osteoporosis Society in October, 2020. We provide a detailed review of the literature examining the relationship between the microbiota and bone health in animal models and in humans, as well as formulating the agenda for key research priorities required to advance this field. We also underscore the potential pitfalls in this research field that should be avoided and provide methodological recommendations to facilitate bridging the gap from promising concept to a potential cause and intervention target for osteoporosis.

Efficacy of Burosumab in Adults with X-linked Hypophosphatemia (XLH): A Post Hoc Subgroup Analysis of a Randomized Double-Blind Placebo-Controlled Phase 3 Study.

The anti-fibroblast growth factor 23 monoclonal antibody burosumab corrects hypophosphatemia in adults with X-linked hypophosphatemia (XLH) and improves pain, stiffness, physical function, and fatigue. This post hoc subgroup analysis used data from the 24-week placebo-controlled period of a phase 3 study in 134 adults with XLH (ClinicalTrials.gov NCT02526160), to assess whether the benefits of burosumab are evident in 14 clinically relevant subgroups defined by baseline demographic and functional criteria, including sex, Brief Pain Inventory-short form (BPI-SF) Average And Worst Pain, region, race, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC®) Stiffness, Physical Function and Pain domains and total score, use of opioid/other pain medication, active fractures/pseudo-fractures, and 6-min walk test distance. There were no statistically significant interactions between any of the subgroups and treatment arm for any endpoint. Higher proportions of subjects achieved mean serum phosphate concentration above the lower limit of normal (the primary endpoint) with burosumab than with placebo in all subgroups. For the key secondary endpoints (WOMAC Stiffness and Physical Function; BPI-SF Worst Pain) individual subgroup categories showed improvements with burosumab relative to placebo. For additional efficacy endpoints, burosumab was favored in some subgroups but differences were not significant and confidence intervals were wide. For some endpoints the treatment effect is small at 24 weeks in all subjects. This subgroup analysis shows that burosumab was largely superior to placebo across endpoints in the 14 clinically relevant subgroup variables at 24 weeks and is likely to benefit all symptomatic adults with active XLH.

Life-Course Genome-wide Association Study Meta-analysis of Total Body BMD and Assessment of Age-Specific Effects.

Bone mineral density (BMD) assessed by DXA is used to evaluate bone health. In children, total body (TB) measurements are commonly used; in older individuals, BMD at the lumbar spine (LS) and femoral neck (FN) is used to diagnose osteoporosis. To date, genetic variants in more than 60 loci have been identified as associated with BMD. To investigate the genetic determinants of TB-BMD variation along the life course and test for age-specific effects, we performed a meta-analysis of 30 genome-wide association studies (GWASs) of TB-BMD including 66,628 individuals overall and divided across five age strata, each spanning 15 years. We identified variants associated with TB-BMD at 80 loci, of which 36 have not been previously identified; overall, they explain approximately 10% of the TB-BMD variance when combining all age groups and influence the risk of fracture. Pathway and enrichment analysis of the association signals showed clustering within gene sets implicated in the regulation of cell growth and SMAD proteins, overexpressed in the musculoskeletal system, and enriched in enhancer and promoter regions. These findings reveal TB-BMD as a relevant trait for genetic studies of osteoporosis, enabling the identification of variants and pathways influencing different bone compartments. Only variants in ESR1 and close proximity to RANKL showed a clear effect dependency on age. This most likely indicates that the majority of genetic variants identified influence BMD early in life and that their effect can be captured throughout the life course.

Long-term cardiovascular safety of febuxostat compared with allopurinol in patients with gout (FAST): a multicentre, prospective, randomised, open-label, non-inferiority trial.

BACKGROUND: Febuxostat and allopurinol are urate-lowering therapies used to treat patients with gout. Following concerns about the cardiovascular safety of febuxostat, the European Medicines Agency recommended a post-licensing study assessing the cardiovascular safety of febuxostat compared with allopurinol. METHODS: We did a prospective, randomised, open-label, blinded-endpoint, non-inferiority trial of febuxostat versus allopurinol in patients with gout in the UK, Denmark, and Sweden. Eligible patients were 60 years or older, already receiving allopurinol, and had at least one additional cardiovascular risk factor. Those who had myocardial infarction or stroke in the previous 6 months or who had severe congestive heart failure or severe renal impairment were excluded. After a lead-in phase in which allopurinol dose was optimised towards achieving a serum urate concentration of less than 0·357 mmol/L (<6 mg/dL), patients were randomly assigned (1:1, with stratification according to previous cardiovascular events) to continue allopurinol (at the optimised dose) or start febuxostat at 80 mg/day, increasing to 120 mg/day if necessary to achieve the target serum urate concentration. The primary outcome was a composite of hospitalisation for non-fatal myocardial infarction or biomarker-positive acute coronary syndrome; non-fatal stroke; or cardiovascular death. The hazard ratio (HR) for febuxostat versus allopurinol in a Cox proportional hazards model (adjusted for the stratification variable and country) was assessed for non-inferiority (HR limit 1·3) in an on-treatment analysis. This study is registered with the EU Clinical Trials Register (EudraCT 2011-001883-23) and ISRCTN (ISRCTN72443728) and is now closed. FINDINGS: From Dec 20, 2011, to Jan 26, 2018, 6128 patients (mean age 71·0 years [SD 6·4], 5225 [85·3%] men, 903 [14·7%] women, 2046 [33·4%] with previous cardiovascular disease) were enrolled and randomly allocated to receive allopurinol (n=3065) or febuxostat (n=3063). By the study end date (Dec 31, 2019), 189 (6·2%) patients in the febuxostat group and 169 (5·5%) in the allopurinol group withdrew from all follow-up. Median follow-up time was 1467 days (IQR 1029-2052) and median on-treatment follow-up was 1324 days (IQR 870-1919). For incidence of the primary endpoint, on-treatment, febuxostat (172 patients [1·72 events per 100 patient-years]) was non-inferior to allopurinol (241 patients [2·05 events per 100 patient-years]; adjusted HR 0·85 [95% CI 0·70-1·03], p<0·0001). In the febuxostat group, 222 (7·2%) of 3063 patients died and 1720 (57·3%) of 3001 in the safety analysis set had at least one serious adverse event (with 23 events in 19 [0·6%] patients related to treatment). In the allopurinol group, 263 (8·6%) of 3065 patients died and 1812 (59·4%) of 3050 had one or more serious adverse events (with five events in five [0·2%] patients related to treatment). Randomised therapy was discontinued in 973 (32·4%) patients in the febuxostat group and 503 (16·5%) patients in the allopurinol group. INTERPRETATION: Febuxostat is non-inferior to allopurinol therapy with respect to the primary cardiovascular endpoint, and its long-term use is not associated with an increased risk of death or serious adverse events compared with allopurinol. FUNDING: Menarini, Ipsen, and Teijin Pharma Ltd.

Proton Pump Inhibitors Inhibit PHOSPHO1 Activity and Matrix Mineralisation In Vitro.

Proton pump inhibitors (PPIs) have been associated with an increased risk of fragility fractures in pharmaco-epidemiological studies. The mechanism is unclear, but it has been speculated that by neutralising gastric acid, they may reduce intestinal calcium absorption, causing secondary hyperparathyroidism and bone loss. Here we investigated that hypothesis that the skeletal effects of PPI might be mediated by inhibitory effects on the bone-specific phosphatase PHOSPHO1. We found that the all PPIs tested inhibited the activity of PHOSPHO1 with IC50 ranging between 0.73 µM for esomeprazole to 19.27 µM for pantoprazole. In contrast, these PPIs did not inhibit TNAP activity. We also found that mineralisation of bone matrix in primary osteoblast cultures was inhibited by several PPIs in a concentration dependent manner. In contrast, the histamine-2 receptor antagonists (H2RA) nizatidine, famotidine, cimetidine and ranitidine had no inhibitory effects on PHOSPHO1 activity. Our experiments show for the first time that PPIs inhibit PHOSPHO1 activity and matrix mineralisation in vitro revealing a potential mechanism by which these widely used drugs are associated with the risk of fractures.

Pattern of SQSTM1 Gene Variants in a Hungarian Cohort of Paget's Disease of Bone.

Paget's disease of bone (PDB) is characterized by focal or multifocal increase in bone turnover. One of the most well-established candidate genes for susceptibility to PDB is Sequestosome 1 (SQSTM1). Mutations in SQSTM1 have been documented among Western-European, British and American patients with PDB. However, there is no information on SQSTM1 mutation status in PDB patients from the Central- and Eastern-European regions. In this study, we conducted a mutation screening for SQSTM1 gene variants in 82 PDB patients and 100 control participants in Hungary. Mutations of SQSTM1 were detected in 18 PDB patients (21.95%); associations between genotype and clinical characteristics were also analyzed. Altogether, six different exonic alterations, including two types of UTR variants in the SQSTM1 gene, were observed in our PDB patients. Similarly, to previous genetic studies on Paget's disease, our most commonly detected variant was the c.1175C > T (p.Pro392Leu) in nine cases (four in monostotic and five in polyostotic form). We have surveyed the germline SQSTM1 variant distribution among Hungarian patients with PDB. We also highlighted that the pattern of the analyzed disease-associated pathophysiological parameters could partially discriminate PDB patients with normal or mutant SQSTM1 genotype. However, our findings also underline and strengthen that not solely SQSTM1 stands in the background of the complex PDB etiology.

Targeted Inactivation of Rin3 Increases Trabecular Bone Mass by Reducing Bone Resorption and Favouring Bone Formation.

Common genetic variants at the RIN3 locus on chromosome 14q32 predispose to Paget's disease of bone (PDB) but the mechanisms by which they do so are unknown. Here, we analysed the skeletal phenotype of female mice with targeted inactivation of the mouse Rin3 gene (Rin3-/-) as compared with wild-type littermates. The Rin3-/- mice had higher trabecular bone volume (BV/TV%) compared with wild type. Mean ± standard deviation values at the distal femur at 8 weeks were 9.0 ± 2.5 vs. 7.0 ± 1.5 (p = 0.002) and at 52 weeks were 15.8 ± 9.5 vs. 8.5 ± 4.2 (p = 0.002). No differences were observed in femoral cortical bone parameters with the exception of marrow diameter which was significantly smaller in 52-week-old Rin3-/- mice compared to wild type: (0.43 mm ± 0.1 vs. 0.57 mm ± 0.2 (p = 0.001). Bone histomorphometry showed a lower osteoclast surface / bone surface (Oc.S/BS%) at 8 weeks in Rin3-/- mice compared to wild type (24.1 ± 4.7 vs. 29.7 ± 6.6; p = 0.025) but there were no significant differences in markers of bone formation at this time. At 52 weeks, Oc.S/BS did not differ between genotypes but single labelled perimeter (SL.Pm/B.Pm (%)) was significantly higher in Rin3-/- mice (24.4 ± 6.4 vs. 16.5 ± 3.8, p = 0.003). We conclude that Rin3 negatively regulates trabecular bone mass in mice by inhibiting osteoclastic bone resorption and favouring bone formation. Our observations also suggest that the variants that predispose to PDB in humans probably do so by causing a gain-in-function of RIN3.

Brain network reorganisation and spatial lesion distribution in systemic lupus erythematosus.

OBJECTIVE: This work investigates network organisation of brain structural connectivity in systemic lupus erythematosus (SLE) relative to healthy controls and its putative association with lesion distribution and disease indicators. METHODS: White matter hyperintensity (WMH) segmentation and connectomics were performed in 47 patients with SLE and 47 healthy age-matched controls from structural and diffusion MRI data. Network nodes were divided into hierarchical tiers based on numbers of connections. Results were compared between patients and controls to assess for differences in brain network organisation. Voxel-based analyses of the spatial distribution of WMH in relation to network measures and SLE disease indicators were conducted. RESULTS: Despite inter-individual differences in brain network organization observed across the study sample, the connectome networks of SLE patients had larger proportion of connections in the peripheral nodes. SLE patients had statistically larger numbers of links in their networks with generally larger fractional anisotropy weights (i.e. a measure of white matter integrity) and less tendency to aggregate than those of healthy controls. The voxels exhibiting connectomic differences were coincident with WMH clusters, particularly the left hemisphere's intersection between the anterior limb of the internal and external capsules. Moreover, these voxels also associated more strongly with disease indicators. CONCLUSION: Our results indicate network differences reflective of compensatory reorganization of the neural circuits, reflecting adaptive or extended neuroplasticity in SLE.

Genetic Determinants of Paget's Disease of Bone.

PURPOSE OF REVIEW: To provide an overview of the role of genes and loci that predispose to Paget's disease of bone and related disorders. RECENT FINDINGS: Studies over the past ten years have seen major advances in knowledge on the role of genetic factors in Paget's disease of bone (PDB). Genome wide association studies have identified six loci that predispose to the disease whereas family based studies have identified a further eight genes that cause PDB. This brings the total number of genes and loci implicated in PDB to fourteen. Emerging evidence has shown that a number of these genes also predispose to multisystem proteinopathy syndromes where PDB is accompanied by neurodegeneration and myopathy due to the accumulation of abnormal protein aggregates, emphasising the importance of defects in autophagy in the pathogenesis of PDB. Genetic factors play a key role in the pathogenesis of PDB and the studies in this area have identified several genes previously not suspected to play a role in bone metabolism. Genetic testing coupled to targeted therapeutic intervention is being explored as a way of halting disease progression and improving outcome before irreversible skeletal damage has occurred.