EPCR deficiency ameliorates inflammatory arthritis in mice by suppressing the activation and migration of T cells and dendritic cells.

OBJECTIVES: Endothelial protein C receptor (EPCR) is highly expressed in synovial tissues of patients with RA, but the function of this receptor remains unknown in RA. This study investigated the effect of EPCR on the onset and development of inflammatory arthritis and its underlying mechanisms. METHODS: CIA was induced in EPCR gene knockout (KO) and matched wild-type (WT) mice. The onset and development of arthritis was monitored clinically and histologically. T cells, dendritic cells (DCs), EPCR and cytokines from EPCR KO and WT mice, RA patients and healthy controls (HCs) were detected by flow cytometry and ELISA. RESULTS: EPCR KO mice displayed >40% lower arthritis incidence and 50% less disease severity than WT mice. EPCR KO mice also had significantly fewer Th1/Th17 cells in synovial tissues with more DCs in circulation. Lymph nodes and synovial CD4 T cells from EPCR KO mice expressed fewer chemokine receptors CXCR3, CXCR5 and CCR6 than WT mice. In vitro, EPCR KO spleen cells contained fewer Th1 and more Th2 and Th17 cells than WT and, in concordance, blocking EPCR in WT cells stimulated Th2 and Th17 cells. DCs generated from EPCR KO bone marrow were less mature and produced less MMP-9. Circulating T cells from RA patients expressed higher levels of EPCR than HC cells; blocking EPCR stimulated Th2 and Treg cells in vitro. CONCLUSION: Deficiency of EPCR ameliorates arthritis in CIA via inhibition of the activation and migration of pathogenic Th cells and DCs. Targeting EPCR may constitute a novel strategy for future RA treatment.

Association between knee magnetic resonance imaging markers and knee symptoms over 6-9 years in young adults.

OBJECTIVES: To describe associations between MRI markers with knee symptoms in young adults. METHODS: Knee symptoms were assessed using the WOMAC scale during the Childhood Determinants of Adult Health Knee Cartilage study (CDAH-knee; 2008-2010) and at the 6- to 9-year follow-up (CDAH-3; 2014-2019). Knee MRI scans obtained at baseline were assessed for morphological markers (cartilage volume, cartilage thickness, subchondral bone area) and structural abnormalities [cartilage defects and bone marrow lesions (BMLs)]. Univariable and multivariable (age, sex, BMI adjusted) zero-inflated Poisson (ZIP) regression models were used for analysis. RESULTS: The participants' mean age in CDAH-knee and CDAH-3 were 34.95 (s.d. 2.72) and 43.27 (s.d. 3.28) years, with 49% and 48% females, respectively. Cross-sectionally, there was a weak but significant negative association between medial femorotibial compartment (MFTC) [ratio of the mean (RoM) 0.99971084 (95% CI 0.9995525, 0.99986921), P < 0.001], lateral femorotibial compartment (LFTC) [RoM 0.99982602 (95% CI 0.99969915, 0.9999529), P = 0.007] and patellar cartilage volume [RoM 0.99981722 (95% CI 0.99965326, 0.9999811), P = 0.029] with knee symptoms. Similarly, there was a negative association between patellar cartilage volume [RoM 0.99975523 (95% CI 0.99961427, 0.99989621), P = 0.014], MFTC cartilage thickness [RoM 0.72090775 (95% CI 0.59481806, 0.87372596), P = 0.001] and knee symptoms assessed after 6-9 years. The total bone area was negatively associated with knee symptoms at baseline [RoM 0.9210485 (95% CI 0.8939677, 0.9489496), P < 0.001] and 6-9 years [RoM 0.9588811 (95% CI 0.9313379, 0.9872388), P = 0.005]. The cartilage defects and BMLs were associated with greater knee symptoms at baseline and 6-9 years. CONCLUSION: BMLs and cartilage defects were positively associated with knee symptoms, whereas cartilage volume and thickness at MFTC and total bone area were weakly and negatively associated with knee symptoms. These results suggest that the quantitative and semiquantitative MRI markers can be explored as a marker of clinical progression of OA in young adults.

Interpersonal Process of Dyadic Coping in Rheumatoid Arthritis: A Perspective From the Australian Rheumatology Association Database.

OBJECTIVE: Dyadic coping, the process of coping that transpires between couples challenged by one partner's illness, is an important predictor of disease adjustment and patient well-being. However, the extent of dyadic coping in rheumatoid arthritis (RA) remains unclear. This study examines the effect of dyadic coping on psychological distress and relationship quality from the perspectives of both participants with RA and their spouses. METHODS: Participants and their spouses were invited to participate in an online survey study if they were aged ≥ 18 years and had lived together for more than a year. The survey included the Chronic Pain Grade Scale, Dyadic Coping Inventory, Depression Anxiety Stress Scale, and Dyadic Adjustment Scale. Participants and spouses completed the survey independently. The actor-partner interdependence model was used to analyze the dyadic data. RESULTS: One hundred sixty-three couples participated. Our findings showed that participants who reported higher supportive dyadic coping reported lower depression, anxiety, and stress, and higher relationship quality, whereas participants who reported higher negative dyadic coping reported higher depression, anxiety, and stress, and lower relationship quality. Spouses who reported higher supportive dyadic coping reported higher relationship quality, but no effect on depression, anxiety, and stress was observed. In contrast, spouses who reported higher negative dyadic coping reported higher levels of depression, anxiety, and stress, and lower relationship quality. CONCLUSION: Participants' and spouses' perceptions of supportive and negative dyadic coping closely influenced their psychological distress and relationship quality. Further, having a partner with RA also seemed to affect the spouse, especially when there was a negative dyadic coping pattern.

Krill Oil for Knee Osteoarthritis: A Randomized Clinical Trial.

Importance: Knee osteoarthritis is disabling, with few effective treatments. Preliminary evidence suggested that krill oil supplementation improved knee pain, but effects on knee osteoarthritis remain unclear. Objective: To evaluate efficacy of krill oil supplementation, compared with placebo, on knee pain in people with knee osteoarthritis who have significant knee pain and effusion-synovitis. Design, Setting, and Participants: Multicenter, randomized, double-blind, placebo-controlled clinical trial in 5 Australian cities. Participants with clinical knee osteoarthritis, significant knee pain, and effusion-synovitis on magnetic resonance imaging were enrolled from December 2016 to June 2019; final follow-up occurred on February 7, 2020. Interventions: Participants were randomized to 2 g/d of krill oil (n = 130) or matching placebo (n = 132) for 24 weeks. Main Outcomes and Measures: The primary outcome was change in knee pain as assessed by visual analog scale (range, 0-100; 0 indicating least pain; minimum clinically important improvement = 15) over 24 weeks. Results: Of 262 participants randomized (mean age, 61.6 [SD, 9.6] years; 53% women), 222 (85%) completed the trial. Krill oil did not improve knee pain compared with placebo (mean change in VAS score, -19.9 [krill oil] vs -20.2 [placebo]; between-group mean difference, -0.3; 95% CI, -6.9 to 6.4) over 24 weeks. One or more adverse events was reported by 51% in the krill oil group (67/130) and by 54% in the placebo group (71/132). The most common adverse events were musculoskeletal and connective tissue disorders, which occurred 32 times in the krill oil group and 42 times in the placebo group, including knee pain (n = 10 with krill oil; n = 9 with placebo), lower extremity pain (n = 1 with krill oil; n = 5 with placebo), and hip pain (n = 3 with krill oil; n = 2 with placebo). Conclusions and Relevance: Among people with knee osteoarthritis who have significant knee pain and effusion-synovitis on magnetic resonance imaging, 2 g/d of daily krill oil supplementation did not improve knee pain over 24 weeks compared with placebo. These findings do not support krill oil for treating knee pain in this population. Trial Registration: Australian New Zealand Clinical Trials Registry Identifier: ACTRN12616000726459; Universal Trial Number: U1111-1181-7087.

Endothelial Protein C Receptor and 3K3A-Activated Protein C Protect Mice from Allergic Contact Dermatitis in a Contact Hypersensitivity Model.

Endothelial protein C receptor (EPCR) is a receptor for the natural anti-coagulant activated protein C (aPC). It mediates the anti-inflammatory and barrier-protective functions of aPC through the cleavage of protease-activated receptor (PAR)1/2. Allergic contact dermatitis is a common skin disease characterized by inflammation and defective skin barrier. This study investigated the effect of EPCR and 3K3A-aPC on allergic contact dermatitis using a contact hypersensitivity (CHS) model. CHS was induced using 1-Fluoro-2,4-dinitrobenzene in EPCR-deficient (KO) and matched wild-type mice and mice treated with 3K3A-aPC, a mutant form of aPC with diminished anti-coagulant activity. Changes in clinical and histological features, cytokines, and immune cells were examined. EPCRKO mice displayed more severe CHS, with increased immune cell infiltration in the skin and higher levels of inflammatory cytokines and IgE than wild-type mice. EPCR, aPC, and PAR1/2 were expressed by the skin epidermis, with EPCR presenting almost exclusively in the basal layer. EPCRKO increased the epidermal expression of aPC and PAR1, whereas in CHS, their expression was reduced compared to wild-type mice. 3K3A-aPC reduced CHS severity in wild-type and EPCRKO mice by suppressing immune cell infiltration/activation and inflammatory cytokines. In summary, EPCRKO exacerbated CHS, whereas 3K3A-aPC could reduce the severity of CHS in both EPCRKO and wild-type mice.

The association between multimorbidity and osteoporosis investigation and treatment in high-risk fracture patients in Australia: A prospective cohort study.

BACKGROUND: Multimorbidity is common among fracture patients. However, its association with osteoporosis investigation and treatment to prevent future fractures is unclear. This limited knowledge impedes optimal patient care. This study investigated the association between multimorbidity and osteoporosis investigation and treatment in persons at high risk following an osteoporotic fracture. METHODS AND FINDINGS: The Sax Institute's 45 and Up Study is a prospective population-based cohort of 267,153 people in New South Wales, Australia, recruited between 2005 and 2009. This analysis followed up participants until 2017 for a median of 6 years (IQR: 4 to 8). Questionnaire data were linked to hospital admissions (Admitted Patients Data Collection (APDC)), emergency presentations (Emergency Department Data Collection (EDDC)), Pharmaceutical Benefits Scheme (PBS), and Medicare Benefits Schedule (MBS). Data were linked by the Centre for Health Record Linkage and stored in a secured computing environment. Fractures were identified from APDC and EDDC, Charlson Comorbidity Index (CCI) from APDC, Dual-energy X-ray absorptiometry (DXA) investigation from MBS, and osteoporosis treatment from PBS. Out of 25,280 persons with index fracture, 10,540 were classified as high-risk based on 10-year Garvan Fracture Risk (age, sex, weight, prior fracture and falls) threshold ≥20%. The association of CCI with likelihood of investigation and treatment initiation was determined by logistic regression adjusted for education, socioeconomic and lifestyle factors). The high-risk females and males averaged 77 ± 10 and 86 ± 5 years, respectively; >40% had a CCI ≥2. Only 17% of females and 7% of males received a DXA referral, and 22% of females and 14% males received osteoporosis medication following fracture. A higher CCI was associated with a lower probability of being investigated [adjusted OR, females: 0.73 (95% CI, 0.61 to 0.87) and 0.43 (95% CI, 0.30 to 0.62); males: 0.47 (95% CI, 0.33 to 0.68) and 0.52 (0.31 to 0.85) for CCI: 2 to 3, and ≥4 versus 0 to 1, respectively] and of receiving osteoporosis medication [adjusted OR, females: 0.85 (95% CI, 0.74 to 0.98) and 0.78 (95% CI, 0.61 to 0.99); males: 0.75 (95% CI, 0.59 to 0.94) and 0.37 (95% CI, 0.23 to 0.53) for CCI: 2 to 3, and ≥4 versus 0 to 1, respectively]. The cohort is relatively healthy; therefore, the impact of multimorbidity on osteoporosis management may have been underestimated. CONCLUSIONS: Multimorbidity contributed significantly to osteoporosis treatment gap. This suggests that fracture risk is either underestimated or underprioritized in the context of multimorbidity and highlights the need for extra vigilance and improved fracture care in this setting.

Mortality estimates and excess mortality in rheumatoid arthritis.

OBJECTIVES: To determine long-term (20 year) survival in RA patients enrolled in the Australian Rheumatology Association Database (ARAD). METHODS: ARAD patients with RA and data linkage consent who were diagnosed from 1995 onwards were included. Death data were obtained through linkage to the Australian National Death Index. Results were compared with age-, gender- and calendar year-matched Australian population mortality rates. Analysis included both the standardized mortality ratio (SMR) and relative survival models. Restricted mean survival time (RMST) at 20 years was calculated as a measure of life lost. Cause-specific SMRs (CS-SMRs) were estimated for International Classification of Diseases, Tenth Revision cause of death classifications. RESULTS: A total of 1895 RA patients were included; 74% were female, baseline median age 50 years (interquartile range 41-58), with 204 deaths. There was no increase in mortality over the first 10 years of follow up, but at 20 years the SMR was 1.49 (95% CI 1.30, 1.71) and the relative survival was 94% (95% CI 91, 97). The difference between observed (18.41 years) and expected (18.68 years) RMST was 4 months. Respiratory conditions were an important underlying cause of death in RA, primarily attributable to pneumonia [CS-SMR 5.2 (95% CI 2.3, 10.3)] and interstitial lung disease [CS-SMR 7.6 (95% CI 3.0, 14.7)], however, coronary heart disease [CS-SMR 0.82 (95% CI 0.42, 1.4)] and neoplasms [CS-SMR 1.2 (95% CI 0.89, 1.5)] were not. CONCLUSION: Mortality risk in this RA cohort accrues over time and is moderately increased at 20 years of follow-up. Respiratory diseases may have supplanted cardiovascular diseases as a major contributor to this mortality gap.

COVID-19 vaccine hesitancy in inflammatory arthritis patients: serial surveys from a large longitudinal national Australian cohort.

OBJECTIVES: To determine COVID-19 vaccine hesitancy rates in inflammatory arthritis patients and identify factors associated with changing vaccine hesitancy over time. METHODS: This investigation was a prospective cohort study of inflammatory arthritis patients from community and public hospital outpatient rheumatology clinics enrolled in the Australian Rheumatology Association Database (ARAD). Two surveys were conducted, one immediately prior to (pre-pandemic) and another approximately 1 year after the start of the pandemic (follow-up). Coronavirus disease 2019 (COVID-19) vaccine hesitancy was measured at follow-up, and general vaccine hesitancy was inferred pre-pandemic; these were used to identify factors associated with fixed and changing vaccine beliefs, including sources of information and broader beliefs about medication. RESULTS: Of the 594 participants who completed both surveys, 74 (12%) were COVID-19 vaccine hesitant. This was associated with pre-pandemic beliefs about medications being harmful (P < 0.001) and overused (P = 0.002), with stronger beliefs resulting in vaccine hesitancy persistent over two time points (P = 0.008, P = 0.005). For those not vaccine hesitant pre-pandemic, the development of COVID-19 vaccine hesitancy was associated with a lower likelihood of seeking out vaccine information from health-care professionals (P < 0.001). COVID-19 vaccine hesitancy was not associated with new influenza vaccine hesitancy (P = 0.138). CONCLUSION: In this study of vaccine beliefs before and during the COVID-19 pandemic, factors associated with COVID-19 vaccine hesitancy in inflammatory arthritis patients varied, depending on vaccine attitudes immediately prior to the start of the pandemic. Fixed beliefs reflected broader views about medications, while fluid beliefs were highly influenced by whether they sought out information from health-care professionals, including rheumatologists.

Global Burden of Disease Study 2019: an opportunity to understand the growing prevalence and impact of hip, knee, hand and other osteoarthritis in Australia.

BACKGROUND: Understanding population-level trends in osteoarthritis (OA) is critical for planning health services and disease prevention initiatives. AIM: To examine trends in the burden of hip, knee, hand and other OA related conditions in Australia from 1990 to 2019 and consider the OA burden in the context of other common conditions associated with older age. METHODS: Global Burden of Disease Study 2019 data for Australia on OA prevalence, OA-related years lived with disability (YLDs) and OA-related YLDs attributable to high body mass index (BMI) were sourced for 1990-2019. Age-standardised YLD data for ischaemic heart disease, stroke, dementia, type 2 diabetes and chronic obstructive pulmonary disease were obtained for comparison. RESULTS: Overall, 3.20 million Australians were estimated to have OA in 2019, with substantial growth in the prevalence of hip (+171%), knee (+126%), hand (+110%) and other types of OA (+130%) from 1990 to 2019. Age-standardised prevalence rates reflect the contribution of population ageing. Concomitant growth in OA-related YLDs was also evident; knee OA and hand OA demonstrated the highest disease burden in 2019 (59 684 and 41 893 YLDs respectively). The proportion of knee OA burden attributable to high BMI was 36% in 2019. In 2019, age-standardised YLD rates were higher for OA (313 per 100 000 population) than other common conditions (range: 47 per 100 000 (ischaemic heart disease) to 284 per 100 000 (type 2 diabetes)). CONCLUSIONS: OA is an increasingly prevalent, impactful condition with a high non-fatal disease burden relative to other health conditions. Growth in OA populations and OA-related disability underscore the need for enhanced investment in prevention and management.

Patterns of biologic and targeted-synthetic disease-modifying antirheumatic drug use in rheumatoid arthritis in Australia.

OBJECTIVE: The aim of this study was to describe treatment patterns in RA, including the frequency and reasons for switching or stopping biologic and targeted synthetic DMARDs (b/tsDMARDs). METHODS: The reasons for switching or stopping b/tsDMARDs were extracted from the Australian Rheumatology Association Database (ARAD) from 2003 to 2018 for RA participants. Switching patterns for each b/tsDMARD and time on first-, second- and third-line b/tsDMARDs were evaluated using Sankey diagrams and survival methods. RESULTS: A total of 2839 participants were included in the analysis. The first-line b/tsDMARDs were etanercept (n = 1414), adalimumab (n = 1024), infliximab (n = 155), golimumab (n = 98), abatacept (n = 66), certolizumab (n = 38), tocilizumab (n = 21) and tofacitinib (n = 23). Of those starting first-, second- and third-line biologic therapy, 24.0%, 31.8% and 24.4% switched to another b/tsDMARD within 12 months, respectively. Inefficacy or adverse effects were the most common reasons for stopping therapy, irrespective of line of treatment. Compared with first-line etanercept, participants were more likely to stop adalimumab [Hazard ratio (HR) 1.16, 95% CI: 1.04, 1.29] and infliximab (HR 1.77, 95% CI: 1.46, 2.16). No differences were seen for other b/tsDMARDs. For second-line therapies compared with etanercept, the risk of stopping was lower for tocilizumab (HR 0.41, 95% CI: 0.25, 0.70), rituximab (HR 0.51, 95% CI: 0.30, 0.85) and tofacitinib (HR 0.29, 95% CI: 0.15, 0.57). Participants taking rituximab, tocilizumab and tofacitinib were also less likely to stop third-line therapy in comparison with participants taking etanercept. CONCLUSIONS: Switching between b/tsDMARDs was common among ARAD participants with RA, most commonly due to inefficacy or adverse effects. Durability of exposure and reasons for switching varied between b/tsDMARDs.

Association between diet quality in adolescence and adulthood and knee symptoms in adulthood: a 25-year cohort study.

We aimed to describe associations between diet quality in adolescence and adulthood and knee symptoms in adulthood. Two hundred seventy-five participants had adolescent diet measurements, 399 had adult diet measurements and 240 had diet measurements in both time points. Diet quality was assessed by Dietary Guidelines Index (DGI), reflecting adherence to Australian Dietary Guidelines. Knee symptoms were collected using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Data were analysed using zero-inflated negative binomial regressions. The overall adolescent DGI was not associated with adult knee symptoms, although lower intake of discretionary foods (e.g. cream, alcohol, bacon and cake) in adolescence was associated with lower pain (mean ratio (MR) 0·96) and dysfunction (MR 0·94). The overall adult DGI was not associated with knee symptoms; however, limiting saturated fat was associated with lower WOMAC (Pain: MR 0·93; stiffness: MR 0·93; dysfunction: MR 0·91), drinking water was associated with lower stiffness (MR 0·90) and fruit intake was associated with lower dysfunction (MR 0·90). Higher DGI for dairy products in adulthood was associated with higher WOMAC (Pain: MR 1·07; stiffness: MR 1·13; dysfunction: MR 1·11). Additionally, the score increases from adolescence to adulthood were not associated with adult knee symptoms, except for associations between score increase in limiting saturated fat and lower stiffness (MR 0·89) and between score increase in fruit intake and lower dysfunction (MR 0·92). In conclusion, the overall diet quality in adolescence and adulthood was not associated with knee symptoms in adulthood. However, some diet components may affect later knee symptoms.

Rheumatoid arthritis is a preventable disease: 11 ways to reduce your patients' risk.

New evidence shows that up to 40% of rheumatoid arthritis (RA) cases are attributable to exposure to potentially modifiable factors. We can now identify people at higher risk of RA (pre-RA) through their family history, risk factors, autoantibodies and symptoms. Counselling these patients to act to modify factors known to be associated with RA risk could prevent the development of RA, and evidence shows that informing individuals of their risk and of ways to reduce it leads to positive behavioural change and is not harmful. This consumer-focussed narrative review is targeted at primary care providers and physicians to describe 11 changes that can be made, based on current evidence linking potentially modifiable factors to RA risk. These evidence-based recommendations are: (i) cease smoking; (ii) reduce exposure to inhaled silica, dusts and occupational risks; (iii) maintain a healthy weight; (iv) increase leisure time physical activity; (v) maintain good dental hygiene; (vi) maximise breastfeeding if able; (vii) maximise dietary quality and avoid high-salt diets; (viii) consume high levels of omega-3 fatty acids and fish; (ix) reduce consumption of sugar-sweetened soft drinks; (x) consume moderate levels of alcohol; and (xi) remain vitamin D replete.

Prevalence and determinants of physical activity, sedentary behaviour and fatigue five years after total knee replacement.

OBJECTIVE: To determine the prevalence and predictors of physical activity, sedentary behaviour and fatigue five years after total knee replacement surgery. DESIGN: A longitudinal cohort study. SETTING: Community-dwelling adults who had previously undergone total knee replacement. METHODS: Five-year follow-up questionnaire data were obtained from participants previously enrolled in a randomised controlled trial examining rehabilitation after total knee replacement. Main study outcomes at one year did not differ between randomisation groups, hence data were pooled for the present longitudinal analysis. Before and one and five years after surgery, participants completed questionnaires (Active Australia Survey, WOMAC, SF12 v2, demographics and fatigue). RESULTS: 272/422 community-dwelling adults (45-74 years) completed the questionnaires at five years. Excessive sedentary behaviour was evident in 91% of the cohort, predicted by excessive sedentary behaviour and lack of energy at one year. Inadequate physical activity at five years was evident for 59% of the cohort, predicted by higher fatigue and comorbidity scores pre-surgery and inadequate physical activity at one year. Just under half (47%) of the cohort experienced clinically-important fatigue at five years, predicted by clinically-important fatigue before and one year after surgery, lack of sleep before surgery and physical activity one year after surgery. CONCLUSION: Documenting physical activity, sedentary behaviour and fatigue before and one year after knee replacement is important to identify those at risk of longer-term inadequate physical activity, excessive sedentary behaviour and clinically-important fatigue. Interventions to maintain activity and reduce sedentary behaviour are needed to reap the potential health benefits of total knee replacement surgery.

Activated Protein C Protects against Murine Contact Dermatitis by Suppressing Protease-Activated Receptor 2.

Atopic dermatitis (AD) is a chronic inflammatory skin disease associated with excessive inflammation and defective skin barrier function. Activated protein C (APC) is a natural anticoagulant with anti-inflammatory and barrier protective functions. However, the effect of APC on AD and its engagement with protease activated receptor (PAR)1 and PAR2 are unknown. Methods: Contact hypersensitivity (CHS), a model for human AD, was induced in PAR1 knockout (KO), PAR2KO and matched wild type (WT) mice using 2,4-dinitrofluorobenzene (DNFB). Recombinant human APC was administered into these mice as preventative or therapeutic treatment. The effect of APC and PAR1KO or PARKO on CHS was assessed via measurement of ear thickness, skin histologic changes, inflammatory cytokine levels, Th cell phenotypes and keratinocyte function. Results: Compared to WT, PAR2KO but not PAR1KO mice displayed less severe CHS when assessed by ear thickness; PAR1KO CHS skin had less mast cells, lower levels of IFN-γ, IL-4, IL-17 and IL-22, and higher levels of IL-1ß, IL-6 and TGF-ß1, whereas PAR2KO CHS skin only contained lower levels of IL-22 and IgE. Both PAR1KO and PAR2KO spleen cells had less Th1/Th17/Th22/Treg cells. In normal skin, PAR1 was present at the stratum granulosum and spinosum, whereas PAR2 at the upper layers of the epidermis. In CHS, however, the expression of PAR1 and PAR2 were increased and spread to the whole epidermis. In vitro, compared to WT cells, PAR1KO keratinocytes grew much slower, had a lower survival rate and higher para permeability, while PAR2KO cells grew faster, were resistant to apoptosis and para permeability. APC inhibited CHS as a therapeutic but not as a preventative treatment only in WT and PAR1KO mice. APC therapy reduced skin inflammation, suppressed epidermal PAR2 expression, promoted keratinocyte growth, survival, and barrier function in both WT and PAR1KO cells, but not in PAR2KO cells. Conclusions: APC therapy can mitigate CHS. Although APC acts through both PAR1 and PAR2 to regulate Th and mast cells, suppression of clinical disease in mice is achieved mainly via inhibition of PAR2 alone. Thus, APC may confer broad therapeutic benefits as a disease-modifying treatment for AD.

Treating osteoporosis: risks and management.

Osteoporosis, osteopenia and minimal trauma fractures are becoming increasingly common in the ageing population. Fractures cause increases in morbidity and mortality and have a significant financial impact on the healthcare system and society Addressing risk factors for osteoporosis early may prevent or delay the onset of fractures and use of drugs. Calcium and vitamin D supplementation may benefit people with a high risk of deficiency (e.g. institutionalised older people) but may not be required in people without risk factors. Impact and resistance exercises and physical activity can increase bone density and prevent falls Antiresorptive drugs such as bisphosphonates and denosumab remain first-line treatment options for osteoporosis. The ongoing need for bisphosphonates should be assessed after five years and treatment may then be interrupted in some patients. Progressive bone loss will recur slowly. Denosumab therapy should not be interrupted without switching to another therapy, as post-treatment bone loss can progress rapidly. All patients will need ongoing monitoring and most will require some long-term therapy once started Raloxifene may be considered in women who do not tolerate first-line antiresorptive drugs. Romosozumab is a new anabolic treatment for osteoporosis and, together with teriparatide, is subsidised as second-line therapy for individuals with severe disease and multiple fractures. Specialist referral should be considered for patients who sustain fractures while undergoing osteoporosis therapy.

Does weight loss reduce the incidence of total knee and hip replacement for osteoarthritis?-A prospective cohort study among middle-aged and older adults with overweight or obesity.

OBJECTIVE: This study aims to investigate the association between weight change and total knee or hip replacement (TKR or THR) for OA among middle-aged and older adults with overweight or obesity. METHOD: Weight data were collected in 2006-2009 and in 2010 from the 45 and Up Study-a population-based cohort aged ≥45 years in New South Wales, Australia. Participants were included if they had a baseline body mass index (BMI) ≥ 25 kg/m2 and no history of TKR or THR. Weight change was categorised into four groups: >7.5% loss; >5-7.5% loss; stable (≤5% change) and >5% gain. Hospital admission data were linked to identify TKR and THR for OA, and multivariable Cox regression was used to assess risk of TKR and THR. RESULTS: Of 23,916 participants, 2139 lost >7.5% weight, 1655 lost 5-7.5% weight, and 4430 gained >5% weight. Over 5.2 years, 1009 (4.2%) underwent TKR and 483 (2.0%) THR. Compared to weight-stable, weight loss of >7.5% was associated with reduced risk of TKR after adjusting for age, sex, BMI, socioeconomic and lifestyle factors (hazard ratio 0.69, 95%CI 0.54-0.87), but had no association with THR. Weight loss of 5-7.5% was not associated with altered risk of either TKR or THR. Weight gain was associated with increased risk of THR after adjusting for confounders, but not TKR. CONCLUSION: This study suggests that a weight loss target >7.5% is required to reduce the risk of TKR in adults with overweight or obesity. Weight gain should be avoided as it increases the risk of THR.

Towards consensus in defining and handling contextual factors within rheumatology trials: an initial qualitative study from an OMERACT working group.

OBJECTIVES: The Outcome Measures in Rheumatology Initiative established the Contextual Factors Working Group to guide the understanding, identification and handling of contextual factors for clinical trials. In clinical research, different uses of the term 'contextual factors' exist. This study explores the perspectives of researchers (including clinicians) and patients in defining 'contextual factor' and its related terminology, identifying such factors and accounting for them in trials across rheumatology. METHODS: We conducted individual semistructured interviews with researchers (including clinicians) who have experience within the field of contextual factors in clinical trials or other potentially relevant areas, and small focus group interviews with patients with rheumatic conditions. We transcribed the interviews and applied qualitative content analysis. RESULTS: We interviewed 12 researchers and 7 patients. Researcher's and patient's descriptions of contextual factors were categorised into two broad themes, each comprising two contextual factors types. The 'treatment effect' theme focused on factors explaining variations in treatment effects (A) among patients and (B) among studies. The 'outcome measurement' theme focused on factors that explain (C) variations in the measurement result itself (apart from actual changes/differences in the outcome) and (D) variations in the outcome itself (beside treatment of interest). Methods for identifying and handling contextual factors differed among these themes and types. CONCLUSIONS: Two main themes for contextual factors with four types of contextual factors were identified based on input from researchers and patients. This will guide operationalisation of contextual factors. Further research should refine our findings and establish consensus among relevant stakeholders.

Deficiency of protease-activated receptor (PAR) 1 and PAR2 exacerbates collagen-induced arthritis in mice via differing mechanisms.

OBJECTIVES: Protease-activated receptor (PAR) 1 and PAR2 have been implicated in RA, however their exact role is unclear. Here, we detailed the mechanistic impact of these receptors on the onset and development of inflammatory arthritis in murine CIA and antigen-induced arthritis (AIA) models. METHODS: CIA or AIA was induced in PAR1 or PAR2 gene knockout (KO) and matched wild type mice. The onset and development of arthritis was monitored clinically and histologically. Immune cells, cytokines and MMPs were detected by ELISA, zymography, flow cytometry, western blot or immunohistochemistry. RESULTS: In CIA, PAR1KO and PAR2KO exacerbated arthritis, in opposition to their effects in AIA. These deficient mice had high plasma levels of IL-17, IFN-γ, TGF-ß1 and MMP-13, and lower levels of TNF-α; T cells and B cells were higher in both KO spleen and thymus, and myeloid-derived suppressor cells were lower only in PAR1KO spleen, when compared with wild type cells. Th1, Th2 and Th17 cells were lower in PAR1KO spleens cells, whereas Th1 and Th2 cells were lower and Th17 cells higher in both KO thymus cells, when compared with wild type cells. PAR1KO synovial fibroblasts proliferated faster and produced the most abundant MMP-9 amongst three type cells in the control, lipopolysaccharides or TNF stimulated conditions. CONCLUSION: This is the first study demonstrated that deficiency of PAR1 or PAR2 aggravates inflammatory arthritis in CIA. Furthermore, the protective functions of PAR1 and PAR2 in CIA likely occur via differing mechanisms involving immune cell differentiation and cytokines/MMPs.

The association between change in bone marrow lesion size and change in tibiofemoral cartilage volume and knee symptoms.

OBJECTIVE: To describe the association between change in subchondral bone marrow lesions (BMLs) and change in tibiofemoral cartilage volume and knee symptoms in patients with symptomatic knee OA. METHODS: In total, 251 participants (mean 61.7 years, 51% female) were included. Tibiofemoral cartilage volume was measured at baseline and 24 months, and BML size at baseline, 6 and 24 months. Knee pain and function scores were evaluated at baseline, 6 and 24 months. Change in total and compartment-specific BML size was categorized according to the Least Significance Criterion. Linear mixed-effects models were used to evaluate the associations of change in BMLs over 6 and 24 months with change in cartilage volume over 24 months and knee symptoms over 6 and 24 months. RESULTS: Total BML size enlarged in 26% of participants, regressed in 31% and remained stable in 43% over 24 months. Compared with stable BMLs in the same compartment, enlarging BMLs over 24 months were associated with greater cartilage loss (difference: -53.0mm3, 95% CI: -100.0, -6.0), and regressing BMLs were not significantly associated with reduced cartilage loss (difference: 32.4mm3, 95% CI: -8.6, 73.3) over 24 months. Neither enlargement nor regression of total BML size over 6 and 24 months was associated with change in knee pain and function over the same time intervals. CONCLUSIONS: In subjects with symptomatic knee osteoarthritis and BMLs, enlarging BMLs may lead to greater cartilage loss but regressing lesions are not associated with reduced cartilage loss while neither is associated with change in knee symptoms.

Global, regional, and national burden of other musculoskeletal disorders 1990-2017: results from the Global Burden of Disease Study 2017.

OBJECTIVES: To describe the level and trends of point prevalence, deaths and disability-adjusted life years (DALYs) for other musculoskeletal (MSK) disorders, i.e. those not covered by specific estimates generated for RA, OA, low back pain, neck pain and gout, from 1990 to 2017 by age, sex and sociodemographic index. METHODS: Publicly available modelled estimates from the Global Burden of Disease (GBD) 2017 study were extracted and reported as counts and age-standardized rates per 100 000 population for 195 countries and territories between 1990 and 2017. RESULTS: Globally, the age-standardized point prevalence estimates and deaths rates of other MSK disorders in 2017 were 4151.1 and 1.0 per 100 000. This was an increase of 3.4% and 7.2%, respectively. The age-standardized DALY rate in 2017 was 380.2, an increase of 3.4%. The point prevalence estimate was higher among females and increased with age. This peaked in the 65-69 year age group for both females and males in 2017, followed by a decreasing trend for both sexes. At the national level, the highest age-standardized point prevalence estimates in 2017 were seen in Bangladesh, India and Nepal. The largest increases in age-standardized point prevalence estimates were observed in Romania, Croatia and Armenia. CONCLUSION: The burden of other MSK disorders is proven to be substantial and increasing worldwide, with a notable intercountry variation. Data pertaining to specific diseases within this overarching category are required for future GBD MSK estimates. This would enable policymakers to better allocate resources and provide interventions appropriately.