Early Rheumatoid Arthritis Patients at Presentation Are Changing: A 24-Year Study of the Early Undifferentiated PolyArthritis (EUPA) Cohort.

OBJECTIVE: To analyze changes in baseline characteristics of very early rheumatoid arthritis (RA) over 24 years in the Early Undifferentiated PolyArthritis (EUPA) cohort. METHODS: Consecutive recent-onset polyarthritis patients fulfilling RA classification criteria recruited in EUPA were assessed at baseline. Three successive periods were defined: prior to the general availability of biologics (1998-2004; 245 patients), prior to the implantation of the 2010 classification criteria (2005-2010; 266 patients), and the most recent decade (2011-2022; 329 patients). RESULTS: At baseline, demographics, BMI, swollen and tender joint counts, proportion fulfilling 2010 ACR/EULAR criteria, Modified Health Assessment Questionnaire, shared epitope status, patient-reported outcomes except pain and Patient Evaluation of Disease Activity remained stable over the 3 periods. Despite a marked decrease in active smoking (22.2 to 12.1%), prevalence of cardiovascular comorbidities and prior cancer increased. While duration of symptoms increased from 2.9 to 4.1 months, seropositivity (53.9 to 42.2%), and CRP began decreasing in the 2005-2010 period. A large decrease in Erosive status (Sharp-van der Heijde erosion score ≥5; 18.3 to 9.4%) was only observed after 2011; this decrease occurred mostly in seronegative patients. DMARD use prior to inclusion remained low and stable (25.7%), but oral corticosteroids increased (18.0 to 33.4%). CONCLUSION: Baseline characteristics of RA patients evolved since 2005 towards less seropositivity and lower blood inflammation but with more comorbidities. Milder erosive damage at baseline became evident only since 2011, mostly in seronegative patients. These changes at baseline, before any intervention, suggest ongoing secular trends that may favorably impact early RA patients' outcomes.

Depressive symptoms predict future simple disease activity index scores and simple disease activity index remission in a prospective cohort of patients with early inflammatory polyarthritis.

OBJECTIVE: To determine whether depressive symptoms assessed in treated patients with early inflammatory polyarthritis (EPA) influence disease activity during follow-up. METHODS: Consecutively recruited EPA patients were actively treated to remission. Simple disease activity index (SDAI) and Center for Epidemiologic Studies Depression Scale (CES-D) scores were calculated at inclusion and up to 42 months into disease. SDAI scores were log-transformed to compute univariate and multivariate linear regressions. Parametric interval-censored Kaplan-Meier and survival regressions using Weibull distribution were used to assess time to and predictors of SDAI remission. RESULTS: A total of 275 EPA patients were recruited at a median of 4 months into disease. In multivariate linear regression models, accounting for baseline demographic, clinical, serological and functional variables and 12-month inflammation markers, CES-D scores at 12 months into disease were correlated (r(2) = 0.14) with subsequent SDAI scores. Patients with 12-month high CES-D (≥19; suggestive of depression) had a lower proportion of SDAI remission (31.3% vs 84.3%; P < 0.001) and reached SDAI remission less rapidly [hazard ratio = 0.25 (95% CI 0.12, 0.53); P < 0.001]. CONCLUSION: Each follow-up SDAI correlated significantly with 12-month depressive symptoms, a median of 7 months after initiation of treatment. CES-D scores suggestive of depression at 12 months were strongly correlated with delay and failure to reach remission later on. Depressive symptoms in treated EPA patients represent important clinical issues with long-term association with disease activity. Interventions to alleviate persistent depressive symptoms in treated EPA warrant careful evaluation of their potential to improve disease remission rates.

Monocytes from patients with osteoarthritis display increased osteoclastogenesis and bone resorption: the In Vitro Osteoclast Differentiation in Arthritis study.

OBJECTIVE: To compare the osteoclastogenic capacity of peripheral blood mononuclear cells (PBMCs) from patients with osteoarthritis (OA) to that of PBMCs from self-reported normal individuals. METHODS: PBMCs from 140 patients with OA and 45 healthy donors were assayed for CD14+ expression and induced to differentiate into osteoclasts over 3 weeks in vitro. We assessed the number of osteoclasts, their resorptive activity, osteoclast apoptosis, and expression of the following cytokine receptors: RANK, interleukin-1 receptor type I (IL-1RI), and IL-1RII. A ridge logistic regression classifier was developed to discriminate OA patients from controls. RESULTS: PBMCs from OA patients gave rise to more osteoclasts that resorbed more bone surface than did PBMCs from controls. The number of CD14+ precursors was comparable in both groups, but there was less apoptosis in osteoclasts obtained from OA patients. Although no correlation was found between osteoclastogenic capacity and clinical or radiographic scores, levels of IL-1RI were significantly lower in cultures from patients with OA than in cultures from controls. Osteoclast apoptosis and expression levels of IL-1RI and IL-1RII were used to build a multivariate predictive model for OA. CONCLUSION: During 3 weeks of culture under identical conditions, monocytes from patients with OA display enhanced capacity to generate osteoclasts compared to cells from controls. Enhanced osteoclastogenesis is accompanied by increased resorptive activity, reduced osteoclast apoptosis, and diminished IL-1RI expression. These findings support the possibility that generalized changes in bone metabolism affecting osteoclasts participate in the pathophysiology of OA.

Work-Related Issues and Physical and Psychological Burden in Canadian Patients With Axial Spondyloarthritis: Results From the International Map of Axial Spondyloarthritis.

OBJECTIVE: To identify factors associated with work-related issues in Canadian patients with axial spondyloarthritis. METHODS: Data from 542 Canadian patients who participated in the International Map of Axial Spondyloarthritis online survey were analyzed. Participants who were employed, unemployed, or on short-term disability were included in this analysis. Regression analysis was used to study the association between work-related issues, disease activity (Bath Ankylosing Spondylitis Disease Activity Index [BASDAI]), and psychological distress (12-item General Health Questionnaire [GHQ-12]). RESULTS: The mean age of surveyed participants was 44.3 (SD 13.9) years, 81% were university educated, and 52.6% employed. A substantial proportion had high disease activity (BASDAI ≥ 4, 72.1%) and psychological distress (GHQ-12 ≥ 3, 53.1%); 81% had work-related issues. This study analyzed responses from a subset of participants who were either employed, unemployed, or on short-term disability (n = 339). Ninety percent of this subset reported at least 1 work-related issue in the year before questionnaire completion, with the most frequent being absenteeism (49.3%) and missing work for healthcare provider visits (42.5%). Factoring in disability benefits eliminated the association between work-related issues and disease activity for all variables except fatigue (r = 0.217; P = 0.03) and discomfort (r = 0.196; P = 0.047). Difficulty fulfilling working hours (ß 2.342, 95% CI 1.413-3.272) and effect on professional advancement (ß 1.426, 95% CI 0.355-2.497) were associated with psychological distress. In the presence of disability benefits, only the effect on professional advancement remained (ß 2.304, 95% CI 0.082-4.527). CONCLUSION: Work-related issues are associated with worse patient-reported outcomes, both physical and psychological.

Impending radiographic erosive progression over the following year in a cohort of consecutive patients with inflammatory polyarthritis: prediction by serum biomarkers.

BACKGROUND/PURPOSE: To evaluate biomarkers as predictors of impending erosion progression. METHODS: Variables were measured at baseline and annually up to 5 years in patients with recent-onset polyarthritis treated to zero swollen joints. Erosive status was defined as ≥5 Units in Sharp/van der Heijde Erosion Score; Rapid Erosive Progression (REP) was defined as an increase ≥5 Units in Erosion Scores between consecutive visits. Generalised estimating equations (GEEs) evaluated the effect on REP of positive anticyclic citrullinated peptides (ACPAs) and/or rheumatoid factor (RF), C-reactive protein ˃8.0 mg/L (High-CRP) and 14-3-3η protein ≥0.50 ng/mL (High-14-3-3η), alone and in combinations. RESULTS: Out of 2155 evaluations in 749 consecutive patients, REP occurred after 186 (8.6%) visits, including 13 (2.2%) in patients recruited since 2010. Only 18/537 (3.4%; 6/411 (1.5%) in non-erosive vs 12/126 (9.5%) in patients already erosive) visits without any positive biomarker were followed by REP; at least one biomarker was positive prior to REP in 168/186 (90.3%) visits. Being positive for all four biomarkers conferred a positive predictive value (PPV) of 30.0% (RR 21.8) in patients non-erosive at the visit versus 35.5% (RR 3.07) in those already erosive. High-14-3-3η increased REP only in visits with High-CRP (eg, RR 2.5 to 3.9 when ACPA also positive) and in patients with non-erosive status (eg, RR from 4.3 to 9.4 when also High-CRP). CONCLUSIONS: Adding High-14-3-3η to positive antibodies and CRP improves prediction of impending REP. Although REP is becoming rarer, signatures of biomarkers might help to adapt treatment strategies in at-risk individuals, even those already erosive.

Assessing bone impairment in ankylosing spondylitis (AS) using the trabecular bone score (TBS) and high-resolution peripheral quantitative computed tomography (HR-pQCT).

OBJECTIVES: To compare bone quality using the trabecular bone score (TBS) and bone microarchitecture in the distal tibia using high-resolution peripheral quantitative computed tomography (HR-pQCT) in ankylosing spondylitis (AS) patients and healthy controls (HC). METHODS: Areal bone mineral density (aBMD) and TBS (TBS iNsight software) were evaluated using DXA (Hologic, QDR 4500); while volumetric bone mineral density (vBMD) and bone microarchitecture were analyzed in the distal tibia using HR-pQCT (Scanco) in 73 male patients with AS and 52 age-matched HC. RESULTS: AS patients were a mean 41.6 ±â€¯7.9 years old and had a mean disease duration of 16.4 ±â€¯8.6 y, with a mean mSASSS 25.6 ±â€¯16.4. No difference was observed in lumbar spine aBMD in AS patients and HC (p = 0.112), but total hip BMD (p = 0.011) and TBS (p < 0.001) were lower in AS patients. In the distal tibia, reduced trabecular volumetric density [Tb.vBMD (p < 0.006)] and structural alterations - trabecular thickness (Tb.Th), p = 0.044 and trabecular separation (Tb.Sp), p = 0.039 - were observed in AS patients relative to controls. Further analysis comparing TBS < 1.310 and TBS ≥ 1.310 in AS patients revealed a higher mean body mass index [BMI] (p = 0.010), lower tibia cortical vBMD [Ct.vBMD] (p = 0.007), lower tibia cortical thickness [Ct.Th]: (p = 0.048) in the former group. On logistic regression analysis, BMI (OR = 1.27; 95%IC = 1.08-1.50, p = 0.005), (VF 4.65; 1.13-19.1, p = 0.033) and tibial Ct.vBMD (0.98; 0.97-1.00, p = 0.007) were associated with a lower TBS (<1.310). CONCLUSIONS: The present study demonstrates that TBS and HR-pQCT imaging are important technologies evaluating bone impairment in AS patients. Moreover, in these patients vertebral fractures were associated with lower TBS.

The inducible nitric-oxide synthase modulates endothelin-1-dependent release of prostacyclin and inhibition of platelet aggregation ex vivo in the mouse.

Nitric oxide and other reactive oxygen species generated by nitric-oxide synthases (NOS) modulate, among several other cellular responses, the production of eicosanoids and platelet aggregation. The roles of specific NOS in these two phenomena remain to be determined. Thus, the present study assessed whether inducible NOS (iNOS) and endothelial NOS (eNOS) modulate in a similar manner the production of eicosanoids and platelet aggregation. Mice knocked out for eNOS (eNOS-/-) or iNOS (iNOS-/-) and their wild-type (WT) congeners were used to analyze agonist-induced increases in plasma levels of eicosanoids as well as inhibition of platelet aggregation ex vivo. Systemically administered endothelin-1 (ET-1) triggered an increase in plasma levels of 6-keto prostaglandin F(1alpha) (6-keto PGF(1alpha)) in WT and eNOS-/- but not in iNOS-/- mice. ET-1 (0.01-1 nmol/kg) also induced a dose-dependent inhibition of platelet aggregation in WT and eNOS-/- but not in iNOS-/- mice. Another agonist, bradykinin (10 nmol/kg), triggered the release of 6-keto PGF(1alpha) and inhibited platelet aggregation in all strains of mice studied. In addition, ADP-induced platelet aggregation in vitro was similarly reduced by iloprost (100 nM) in iNOS-/- mice and WT congeners. In another series of experiments, ET-1 (0.1 nmol/kg) significantly increased 8-isoprostane plasma levels in WT but not in iNOS-/- mice. Finally, a 3-week treatment with anti-oxidants inhibited the capacity of ET-1 to significantly increase plasma 6-keto PGF(1alpha) in WT mice. We show for the first time that iNOS is involved in the control of ET-1-induced prostacyclin release and related inhibition of platelet aggregation in the murine model.

Differential regulation of the signaling and trafficking of the two prostaglandin D2 receptors, prostanoid DP receptor and CRTH2.

Prostaglandin D2 (PGD2) exerts its actions on two G protein-coupled receptors, the prostanoid DP receptor and CRTH2 (chemoattractant homologous receptor expressed on TH2 cells). Here, we characterize the regulation of the signaling and trafficking of the prostanoid DP receptor and CRTH2. Time-course and dose-response curves showed that both receptors expressed in HEK293 cells internalized maximally after 2 h of stimulation with 1 microM PGD2. Co-expression of the G protein-coupled receptor kinases GRK2, GRK5 or GRK6 increased agonist-induced internalization of CRTH2, while only GRK2 had an effect on the internalization of the prostanoid DP receptor. Protein kinase C (PKC) activation stimulated the internalization of both receptors. Interestingly, only PGD2-induced internalization of CRTH2, and not of prostanoid DP receptor, was decreased by inhibition of PKC or protein kinase A (PKA). Our data also indicate that CRTH2 is subjected to basal phosphorylation by PKA, which appears to be involved in CRTH2 internalization. Prostanoid DP receptor internalization was promoted by co-expression of arrestin-2 and -3, while the internalization of CRTH2 was increased by co-expression of arrestin-3 only. The detection of prostanoid DP receptor and CRTH2 internalization was reduced by the co-expression of Rab4 and Rab11, respectively, suggesting differential regulation of receptor recycling. Moreover, immunofluorescence microscopy experiments showed that the prostanoid DP receptor specifically co-localized with Rab4, and CRTH2 with Rab11. The signaling of the prostanoid DP receptor was regulated by GRK2 overexpression, while that of CRTH2 was modulated by overexpression of GRK2, -5 and -6. Our results show a differential regulation of the prostanoid DP receptor and CRTH2, two receptors for PGD2.

Serum levels of 14-3-3η protein supplement C-reactive protein and rheumatoid arthritis-associated antibodies to predict clinical and radiographic outcomes in a prospective cohort of patients with recent-onset inflammatory polyarthritis.

BACKGROUND: Age, C-Reactive Protein (CRP) and autoantibodies (Abs) are associated with worse prognosis in patients with recent-onset inflammatory polyarthritis (EPA). Serum 14-3-3η protein is a joint-derived biomarker that up-regulates cytokines and enzymes that perpetuate local and systemic inflammation and may contribute to joint damage. Our objective was to evaluate, over a 5-year prospective period of observation, the additional prognostic potential of serum 14-3-3η protein in EPA patients. METHODS: Clinical variables, serum and radiographs (scored according to the Sharp/van der Heijde (SvH) method) were collected serially. Relationships between serum 14-3-3η protein and other biomarkers were computed with Spearman correlations. Outcomes were Simple Disease Activity Index (SDAI) scores and joint damage progression: ΔSvH for SvH score and ΔErosion for its Erosive component. The additional predictive contribution of 14-3-3η was defined using generalized estimating equations (GEE) and generalized linear mixed models (GLMM). RESULTS: Among 331 patients, baseline 14-3-3η was ≥0.19 and ≥0.50 ng/ml in 153 (46.2 %) and 119 (36.0 %), respectively; CRP was >8.0 mg/L in 207 (62.5 %), and at least one Ab (Rheumatoid Factor, anti-CCP2 or anti-Sa/citrullinated vimentin) was positive in 170 (51.5 %). Elevated 14-3-3η levels moderately correlated with positive Abs, but not with elevated CRP. Baseline 14-3-3η ≥0.19 ng/ml was associated with more radiographic progression over 5 years. The optimal levels of baseline 14-3-3η to predict radiographic progression was defined by ROC curves at 0.50 ng/ml. Levels of 14-3-3η ≥0.50 ng/ml at baseline were associated with lower likelihoods of ever reaching SDAI remission (RR 0.79 (95 % CI 0.64-0.98), p = 0.03) and higher subsequent progression of Total and Erosion SvH scores. Elevated levels of 14-3-3η during follow-up also predicted higher subsequent progression, even in patients in SDAI remission. Decreases of 14-3-3η levels by at least 0.76 ng/ml and reversion to negative during follow-up associated with less subsequent radiographic progression. In multivariate models, elevated 14-3-3η interacted with positive Abs, elevated CRP and older age to predict subsequent radiographic progression. CONCLUSIONS: Levels of 14-3-3η protein ≥0.50 ng/ml predict poorer clinical and radiographic outcomes in EPA, both at baseline and after initiation of treatment, even in SDAI remitters. 14-3-3η, CRP, age and Abs represent independent predictors of subsequent joint damage. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT00512239 . Registered August 6, 2007.

Chondroitin sulfate efficacy versus celecoxib on knee osteoarthritis structural changes using magnetic resonance imaging: a 2-year multicentre exploratory study.

BACKGROUND: In osteoarthritis (OA) treatment, although chondroitin sulfate (CS) was found in a number of studies using radiography to have a structure-modifying effect, to date CS use is still under debate. A clinical study using quantitative magnetic resonance imaging (qMRI) is therefore of the utmost importance. Here we report data from a 24-month, randomised, double-blind, double-dummy, controlled, comparative exploratory study of knee OA. The primary endpoint was to determine the effect of CS 1200 mg/day versus celecoxib 200 mg/day on cartilage volume loss (CVL) in the lateral compartment over time as measured by qMRI. Secondary endpoints included assessment of the OA structural changes and signs and symptoms of OA. METHODS: qMRI was performed at baseline and at 12 and 24 months. CVL, bone marrow lesion size, and synovial thickness were evaluated using qMRI. The primary statistical analysis was carried out on the modified intention-to-treat (mITT) population (n = 138) using chi-squared, Fisher's exact, Wilcoxon Mann-Whitney, and Student's t tests and analysis of covariance. Analyses were also conducted on the according-to-protocol (ATP; n = 120) population. RESULTS: In the adjusted mITT analysis, compared with celecoxib treatment, patients treated with CS had a significant reduced CVL at 24 months in the medial compartment (celecoxib -8.1 % ± 4.2, CS -6.3 % ± 3.2; p = 0.018) and medial condyle (-7.7 % ± 4.7, -5.5 % ± 3.9; p = 0.008); no significant effect was seen in the lateral compartment. In the ATP population, CS reduced CVL in the medial compartment at 12 months (celecoxib -5.6 % ± 3.0, CS -4.5 % ± 2.6; p = 0.049) and 24 months (celecoxib -8.4 % ± 4.2, CS -6.6 % ± 3.3; p = 0.021), and in the medial condyle at 24 months (celocoxib -8.1 % ± 4.7, CS -5.7 % ± 4.0; p = 0.010). A trend towards a statistically reduced synovial thickness (celecoxib +17.96 ± 33.73 mm, CS -0.66 ± 22.72 mm; p = 0.076) in the medial suprapatellar bursa was observed in CS patients. Both groups experienced a marked reduction in the incidence of patients with joint swelling/effusion and in symptoms over time. Data showed similar good safety profiles including cardiovascular adverse events for both drugs. CONCLUSION: This study demonstrated, for the first time in a 2-year randomised controlled trial using qMRI, the superiority of CS over celecoxib at reducing CVL in knee OA patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT01354145 . Registered 13 May 2011.

Production of prostaglandin D(2) by human osteoblasts and modulation of osteoprotegerin, RANKL, and cellular migration by DP and CRTH2 receptors.

UNLABELLED: Human osteoblasts produce PGD(2), which acts on the DP receptor to decrease osteoprotegerin production and on the CRTH2 receptor to decrease RANKL expression and to induce osteoblast chemotaxis. These results indicate that activation of CRTH2 may lead to an anabolic response in bone. INTRODUCTION: Whereas the actions of prostaglandin (PG)E(2) as a modulator of bone and osteoblast function are relatively well characterized, little is known about PGD(2) and bone metabolism. The objectives of this study were to determine if human osteoblasts can produce PGD(2), which prostaglandin D(2) synthases are implicated in this synthesis, to identify the PGD(2) receptors (DP and CRTH2) on these cells and to characterize the biological effects resulting from their activation. MATERIALS AND METHODS: RT-PCR analysis and immunohistochemistry were used to detect PGD(2) receptor and synthases in cultured human osteoblasts. Immunohistochemistry was used to identify the synthases and receptors in human bone tissue. Intracellular cAMP and calcium levels were determined to verify receptor activation. The cells were stimulated with PGD(2) or the specific agonists BW 245C (DP) and DK-PGD(2) (CRTH2), and the resulting effects on osteoprotegerin (OPG) secretion, RANKL expression, and chemotaxis were determined. Osteoblast production of PGD(2) was evaluated by measuring PGD(2) in the culture supernatants after stimulation with interleukin (IL)-1, TNF-alpha, PTH, vascular endothelial growth factor (VEGF), and insulin-like growth factor I (IGF-I). RESULTS: Human osteoblasts in culture generated PGD(2) when stimulated. Both osteoblasts in culture and in situ present the lipocalin-type PGD(2) synthase only. Both DP and CRTH2 receptors were present in human osteoblasts in culture and in situ. Stimulation of DP resulted in an increase in cAMP, whereas CRTH2 increased the intracellular calcium level. OPG production was reduced by 60% after DP receptor stimulation, whereas CRTH2 receptor stimulation decreased RANKL expression on human osteoblasts. As reported for other cell types, CRTH2 was a potent inducer of chemotaxis for human osteoblasts in culture. CONCLUSIONS: Human osteoblasts in culture produce PGD(2) under biologically relevant stimuli through the lipocalin-type PGD(2) synthase (L-PGDS) pathway. As an autacoid, PGD(2) can act on DP and CRTH2 receptors, both present on these cells. Specific activation of CRTH2 could lead directly and indirectly to an anabolic response in bone.

Role of extracellular cysteine residues in dimerization/oligomerization of the human prostacyclin receptor.

Prostacyclin activation of prostanoid IP receptors may result in pain sensation, inflammatory responses, inhibition of platelet aggregation, and vasodilation in vascular tissue. The prostanoid IP receptor is a G-protein-coupled receptor. In the present study, we investigated the determinants responsible, at least in part, for the prostacyclin receptor (IP) dimerization/oligomerization. Using co-immunoprecipitation of differentially tagged IP expressed in COS-7 cells, we demonstrate that IP can form dimers and oligomers. Treatment of IP-expressing cells with the stable agonist carbaprostacyclin failed to alter the ratios of oligomeric/dimeric/monomeric forms of the receptor, suggesting that IP dimerization/oligomerization is an agonist-independent process. The reducing agents dithiothreitol and 2-mercaptoethanol were highly efficient in converting the receptor from its oligomeric form to the monomeric state, indicating the involvement of disulfide bonds in IP oligomerization. Immunoblotting of the osteoblastic MG-63 cell line lysates with an anti-IP specific antibody revealed the presence of endogenous IP oligomers which were converted to dimers and monomers upon treatment with dithiothreitol. Individual substitutions of the four extracellular IP Cys residues (Cys(5), Cys(92), Cys(165) and Cys(170)) for Ser resulted in greatly decreased receptor protein expression in COS-7 cells. The C92-170S double mutant showed receptor protein expression level similar to the individual mutants. However, expression of the C92-165S and C165-170S mutants was drastically reduced, suggesting that there was formation of disulfide bonds between Cys(5) and Cys(165), and between Cys(92) and Cys(170). The Cys receptor mutants showed altered oligomer/dimer/monomer ratios. Dimerization/oligomerization likely occurs intracellularly since these Cys receptor mutants could still form dimers/oligomers despite their lack of expression at the cell surface.

Secreted phospholipase A2 type II is present in Paget's disease of bone and modulates osteoclastogenesis, apoptosis and bone resorption of human osteoclasts independently of its catalytic activity in vitro.

OBJECTIVES: To study the role of secreted phospholipase A2 (sPLA2) in the pathophysiology of human osteoclasts (OCs). METHODS: Immunohistochemistry and sPLA2 inhibitors were to determine the localization of sPLA2 and its role in OCs biology. RESULTS: sPLA2 is expressed by OCs from healthy fetal bone and OCs from Paget's disease but not in normal bone. Inhibition of sPLA2 greatly reduces in vitro osteoclastogenesis. DISCUSSION: The decrease in OCs formed could be attributed to a decline in the viability of CD14(+) OC precursors as well as a reduced viability of mature OCs. Inhibition of sPLA2 strongly decreases bone resorption by OCs independently of actin cytoskeleton remodeling, probably also by reducing OCs viability. CONCLUSION: High amounts of this enzyme are present in fetal and Pagetic bone samples. Inhibition of sPLA2in vitro decreases osteoclastogenesis and OC activity and might constitute an interesting pharmacologic target for diseases with high bone turnover.

Cytosolic phospholipase A2 and eicosanoids modulate life, death and function of human osteoclasts in vitro.

INTRODUCTION: Eicosanoids are important in bone physiology but the specific function of phopholipase enzymes has not been determined in osteoclasts. The objective of this is study was to determine the presence of cPLA2 in human in vitro-differentiated osteoclasts as well as osteoclasts in situ from bone biopsies. MATERIALS AND METHODS: Osteoclastogenesis, apoptosis, bone resorption and the modulation of actin cytoskeleton assays were performed on osteoclasts differentiated in vitro. Immunohistochemistry was done in differentiated osteoclasts as well as on bone biopsies. RESULTS: Human osteoclasts from normal, fetal, osteoarthritic, osteoporotic and Pagetic bone biopsies express cPLA2 and stimulation with RANKL increases cPLA2 phosphorylation in vitro. Inhibition of cPLA2 increased osteoclastogenesis and decreased apoptosis but decreased the capacity of osteoclasts to generate actin rings and to resorb bone. DISCUSSION AND CONCLUSIONS: These results suggest that cPLA2 modulates osteoclast functions and could be a useful target in bone diseases with hyperactivated osteoclasts.

Prostaglandin D(2) induces apoptosis of human osteoclasts through ERK1/2 and Akt signaling pathways.

In a recent study we have shown that prostaglandin D2 (PGD2) induces human osteoclast (OC) apoptosis through the activation of the chemoattractant receptor homologous molecule expressed on T-helper type 2 cell (CRTH2) receptor and the intrinsic apoptotic pathway. However, the molecular mechanisms underlying this response remain elusive. The objective of this study is to investigate the intracellular signaling pathways mediating PGD2-induced OC apoptosis. OCs were generated by in vitro differentiation of human peripheral blood mononuclear cells (PBMCs), and then treated with or without the selective inhibitors of mitogen-activated protein kinase-extracellular signal-regulated kinase (ERK) kinase, (MEK)-1/2, phosphatidylinositol3-kinase (PI3K) and NF-κB/IκB kinase-2 (IKK2) prior to the treatments of PGD2 as well as its agonists and antagonists. Fluorogenic substrate assay and immunoblotting were performed to determine the caspase-3 activity and key proteins involved in Akt, ERK1/2 and NF-κB signaling pathways. Treatments with both PGD2 and a CRTH2 agonist decreased ERK1/2 (Thr202/Tyr204) and Akt (Ser473) phosphorylation, whereas both treatments increased ß-arrestin-1 phosphorylation (Ser412) in the presence of naproxen, which was used to eliminate endogenous prostaglandin production. In the absence of naproxen, treatment with a CRTH2 antagonist increased both ERK1/2 and Akt phosphorylations, and reduced the phosphorylation of ß-arrestin-1. Treatment of OCs with a selective MEK-1/2 inhibitor increased caspase-3 activity and OC apoptosis induced by both PGD2 and a CRTH2 agonist. Moreover, a CRTH2 antagonist diminished the selective MEK-1/2 inhibitor-induced increase in caspase-3 activity in the presence of endogenous prostaglandins. In addition, treatment of OCs with a selective PI3K inhibitor decreased ERK1/2 (Thr202/Tyr204) phosphorylation caused by PGD2, whereas increased ERK1/2 (Thr202/Tyr204) phosphorylation by a CRTH2 antagonist was attenuated with a PI3K inhibitor treatment. The DP receptor was not implicated in any of the parameters evaluated. Treatment of OCs with PGD2 as well as its receptor agonists and antagonists did not alter the phosphorylation of RelA/p65 (Ser536). Moreover, the caspase-3 activity was not altered in OCs treated with a selective IKK2/NF-κB inhibitor. In conclusion, endogenous or exogenous PGD2 induces CRTH2-dependent apoptosis in human differentiated OCs; ß-arrestin-1, ERK1/2, and Akt, but not IKK2/NF-κB are probably implicated in the signaling pathways of this receptor in the model studied.

Serum C-X-C motif chemokine 13 is elevated in early and established rheumatoid arthritis and correlates with rheumatoid factor levels.

INTRODUCTION: We hypothesized that serum levels of C-X-C motif chemokine 13 (CXCL13), a B-cell chemokine, would delineate a subset of rheumatoid arthritis (RA) patients characterized by increased humoral immunity. METHODS: Serum from patients with established RA (the Dartmouth RA Cohort) was analyzed for CXCL13, rheumatoid factor (RF) levels, anticitrullinated peptide/protein antibody (ACPA) and total immunoglobulin G (IgG); other parameters were obtained by chart review. A confirmatory analysis was performed using samples from the Sherbrooke Early Undifferentiated PolyArthritis (EUPA) Cohort. The Wilcoxon rank-sum test, a t-test and Spearman's correlation analysis were utilized to determine relationships between variables. RESULTS: In both the Dartmouth and Sherbrooke cohorts, CXCL13 levels were selectively increased in seropositive relative to seronegative RA patients (P = 0.0002 and P < 0.0001 for the respective cohorts), with a strong correlation to both immunoglobulin M (IgM) and IgA RF levels (P < 0.0001). There was a weaker relationship to ACPA titers (P = 0.03 and P = 0.006, respectively) and total IgG (P = 0.02 and P = 0.14, respectively). No relationship was seen with regard to age, sex, shared epitope status or inclusion high-sensitivity C-reactive protein (hsCRP) in either cohort or regarding the presence of baseline erosions in the Sherbrooke Cohort, whereas a modest relationship with Disease Activity Score in 28 joints CRP (DAS28-CRP) was seen in the Dartmouth cohort but not the Sherbrooke cohort. CONCLUSION: Using both established and early RA cohorts, marked elevations of serum CXCL13 levels resided nearly completely within the seropositive population. CXCL13 levels exhibited a strong relationship with RF, whereas the association with clinical parameters (age, sex, DAS28-CRP and erosions) or other serologic markers (ACPA and IgG) was either much weaker or absent. Elevated serum CXCL13 levels may identify a subset of seropositive RA patients whose disease is shaped by or responsive to RF production.

Predictors of pain for patients with early inflammatory polyarthritis.

OBJECTIVE: To identify predictors of pain at 1 year in patients with early inflammatory polyarthritis (EIP). METHODS: Using a prospective design, patients were examined by a rheumatologist and completed questionnaires at baseline and at 1 year after symptom onset. Separate regression analyses were run for pain intensity, sensory pain, and affective pain. Age and sex were adjusted in cross-sectional and longitudinal analyses; baseline potential predictors consisted of measures for corresponding pain values and disease activity, depression, coping scores, medication use, rheumatoid arthritis criteria being met, and duration of symptoms. RESULTS: A total of 211 patients were enrolled in the study (mean ± SD age 58.8 ± 14.2 years, 63% women). There were significant improvements at 1 year for disease activity, instrumental coping, emotional coping, depression, and all 3 pain measures. At baseline, disease activity and depression were positively associated with all types of pain; in addition, instrumental coping was positively associated with sensory pain and palliative coping was positively associated with affective pain. At 1 year, pain intensity was predicted by baseline pain intensity, duration of symptoms, use of disease-modifying antirheumatic drugs (DMARDs), and emotional coping. Sensory pain was predicted by baseline sensory pain and DMARD use. Affective pain was predicted by baseline affective pain, DMARD use, and emotional coping. CONCLUSION: The majority of treated EIP patients can expect improvements in clinical and psychosocial variables over the first year of their illness. Emotional coping at baseline may contribute to pain in the future, and therefore it may be useful for patients to learn other means of dealing with this chronic disease.

Prostaglandin D2 induces apoptosis of human osteoclasts by activating the CRTH2 receptor and the intrinsic apoptosis pathway.

Prostaglandin D(2) (PGD(2)) is a lipid mediator synthesized from arachidonic acid that directly activates two specific receptors, the D-type prostanoid (DP) receptor and chemoattractant receptor homologous molecule expressed on T-helper type 2 cells (CRTH2). PGD(2) can affect bone metabolism by influencing both osteoblast and osteoclast (OC) functions, both cells involved in bone remodeling and in in vivo fracture repair as well. The objective of the present study was to determine the effects of PGD(2), acting through its two specific receptors, on human OC apoptosis. Human OCs were differentiated in vitro from peripheral blood mononuclear cells in the presence of receptor activator for nuclear factor κB ligand (RANKL) and macrophage-colony stimulating factor (M-CSF), and treated with PGD(2), its specific agonists and antagonists. Treatment with PGD(2) for 24hours in the presence of naproxen (10µM) to inhibit endogenous prostaglandin production increased the percentage of apoptotic OCs in a dose-dependent manner, as did the specific CRTH2 agonist compound DK-PGD(2) but not the DP agonist compound BW 245C. In the absence of naproxen, the CRTH2 antagonist compound CAY 10471 reduced OC apoptosis rate but the DP antagonist BW A868C had no effect. The induction of PGD(2)-CRTH2 dependent apoptosis was associated with the activation of caspase-9, but not caspase-8, leading to caspase-3 cleavage. These data show that PGD(2) induces human OC apoptosis through activation of CRTH2 and the apoptosis intrinsic pathway.

Utility and feasibility of musculoskeletal ultrasonography (MSK US) in rheumatology practice in Canada: needs assessment.

The utility of musculoskeletal ultrasound (MSK US) is being extensively explored and evaluated amongst European rheumatologists. However, utilization of MSK US by rheumatologists in Canada is much less common. This study aimed to evaluate the current use of MSK US in Canadian rheumatology practice, to determine beliefs and attitudes towards MSK US, and to determine factors that may encourage or limit its use. A 13-question needs assessment questionnaire was developed. All Canadian rheumatologists were invited via e-mail to participate in the survey. The overall response rate was 156/470 (33%). Fifty-one percent of participants used MSK US in their clinical practice. Lack of training appeared to be the main obstacle to its current use. Eighty-three percent believed that MSK US should be performed by rheumatologists and expressed a willingness to learn the technique. Skills offering greatest clinical utility were the assessment of inflammatory arthritis in small joints (i.e., hands (metacarpophalyngeal and proximal interphalangeal joints), wrists, feet (metatarsophalyngeal), shoulders, and ankles. Limited available time, equipment costs, and difficulties with billing were the main obstacles to MSK US utilization in the clinical setting. There is a great level of interest in learning and applying MSK US in Canadian rheumatology practice. The balance between added clinical value and lack of remuneration, equipment associated costs, and time to complete training is the major limiting factor influencing rheumatologists' willingness to take on MSK US. Training programs must be relevant to rheumatologists' needs before MSK US will be adopted into routine clinical practice in Canada.

Increased concentrations of prostaglandin D2 during post-fracture bone remodeling.

OBJECTIVE: To test the hypothesis that increased concentrations of prostaglandin D(2) (PGD(2)) correlate with bone remodeling. Studies using isolated bone cells indicate that PGD(2) may be implicated in the regulation of bone homeostasis, with a positive influence on bone anabolism. We studied patients with traumatic fractures and age- and sex-matched healthy controls as an in vivo model of increased bone remodeling. METHODS: Thirty-five patients with bone fracture and matched controls were recruited. Urine and sera samples were collected. Urinary 11ss-PGF(2alpha), a PGD(2) metabolite, and PGE(2) metabolites (PGEM), serum lipocalin-type PGD(2) synthase (L-PGDS), bone alkaline phosphatase (bone ALP), and crosslinked C-telopeptides of type I collagen (CTX) were measured. RESULTS: At 5-6 weeks post-fracture, 11ss-PGF(2alpha), L-PGDS, bone ALP, and CTX were significantly increased in the fracture patients compared to controls. PGEM levels were not different between groups. Levels of 11ss-PGF(2alpha) and bone ALP were positively correlated, suggesting that PGD(2) may be implicated in fracture repair. CONCLUSION: These results support our working hypothesis that PGD(2) could be implicated in the control of bone anabolism in humans.