Proteomics analyses of human plasma reveal triosephosphate isomerase as a potential blood marker of methotrexate resistance in rheumatoid arthritis.

OBJECTIVES: To assess differentially expressed blood proteins between patients with active rheumatoid arthritis (RA) and patients in remission after methotrexate (MTX) treatment, with the aim of identifying a biomarker of methotrexate resistance (MTXR). METHODS: Two populations of RA patients treated with a stable dose of subcutaneous MTX for at least 3 months were constituted according to the DAS28: remission (DAS28 < 2.6; n = 24) and active disease (DAS28 > 3.2; n = 32). The two groups of RA patients were homogeneous regarding their epidemiological characteristics, except for the duration of treatment which was longer in the remission group. After collection of a blood sample, plasma protein digestion was performed, followed by untargeted proteomics analysis. Then, a targeted analysis was performed to confirm the results of the untargeted approach. RESULTS: Untargeted proteomics analysis revealed 8 plasma proteins differentially expressed between the two groups of patients. Among them, triosephosphate isomerase (TPI-1) and glucose-6-phosphate isomerase (GPI), which are main actors of glycolysis, were found down-regulated in the active group. This result was confirmed for TPI-1 in the targeted proteomics analysis. CONCLUSIONS: A first step was achieved in the search for biomarker of MTXR with identification of two actors of glycolysis (TPI-1 and GPI). The next step will be to confirm these results in a larger cohort, including samples from treatment-naive patients, to assess the predictive potential of these protein markers.

The effects of combined amplitude and high-frequency vibration on physically inactive osteopenic postmenopausal women.

Purpose: To evaluate whole-body vibration (WBV) osteogenic potential in physically inactive postmenopausal women using high-frequency and combined amplitude stimuli. Methods: Two-hundred fifty-five physically inactive postmenopausal women (55-75 years) with 10-year major osteoporotic fracture risk (3%-35%) participated in this 18-month study. For the first 12 months, the vibration group experienced progressive 20-min WBV sessions (up to 3 sessions/week) with rest periods (30-60 s) between exercises. Frequencies (30-50 Hz), with low (0.2-0.4 mm) and high (0.6-0.8 mm) amplitude stimuli were delivered via PowerPlate Pro5 platforms producing accelerations of (0.75-7.04 g). The last 6 months for the treatment group were a follow-up period similar to control. Serum bone remodelling markers [C-terminal crosslinked telopeptide of type-1 collagen (CTX), procollagen type-1 N-terminal propeptide (P1NP), bone alkaline phosphatase (BAP) and sclerostin] were measured at fasting. CTX and P1NP were determined by automated chemiluminescence immunoassay, bone alkaline phosphatase (BAP) by automated spectrophotometric immunoassay, and sclerostin by an enzyme-immunoassay. Bone mineral density (BMD) of the whole-body, proximal femur and lumbar vertebrae was measured by dual-energy X-ray absorptiometry (DXA). Bone microarchitecture of the distal non-dominant radius and tibia was measured by high-resolution peripheral quantitative computed tomography (HR-pQCT). Results: Femoral neck (p = 0.520) and spine BMD (p = 0.444) failed to improve after 12 months of WBV. Bone macro and microstructural parameters were not impacted by WBV, as well as estimated failure load at the distal radius (p = 0.354) and tibia (p = 0.813). As expected, most DXA and HR-pQCT parameters displayed age-related degradation in this postmenopausal population. BAP and CTX increased over time in both groups, with CTX more marginally elevated in the vibration group when comparing baseline changes to month-12 (480.80 pmol/L; p = 0.039) and month-18 (492.78 pmol/L; p = 0.075). However, no differences were found when comparing group concentrations only at month-12 (506.35 pmol/L; p = 0.415) and month-18 (518.33 pmol/L; p = 0.480), indicating differences below the threshold of clinical significance. Overall, HR-pQCT, DXA bone parameters and bone turnover markers remained unaffected. Conclusion: Combined amplitude and high-frequency training for one year had no ameliorating effect on DXA and HR-pQCT bone parameters in physically inactive postmenopausal women. Serum analysis did not display any significant improvement in formation and resorption markers and also failed to alter sclerostin concentrations between groups.

Costs of patient management over 18 months following a hip, clinical vertebral, distal forearm, or proximal humerus fragility fracture in France-results from the ICUROS study.

This observational study prospectively assessed direct and indirect costs related to patient management over 18 months following hip, clinical vertebral, humeral, or distal forearm fracture events in France. It appears that their levels were much higher than the previous estimates, raising the burden of osteoporosis-related fractures on public health expenditures. INTRODUCTION: This prospective observational study assessed the costs related to patient management over the 18-month period following the event of a hip, clinical vertebral, humeral, or distal forearm fracture in France. METHODS: Individuals aged ≥ 50 years old with the diagnosis of a fragility fracture in six French University Hospitals were enrolled in the International Costs and Utilities Related to Osteoporotic Fractures Study (ICUROS). All resources used over the defined period and related to fracture and the underlying osteoporosis management were collected by questionnaires at baseline, 4 months, 12 months, and 18 months. Information was collected by direct or phone contact completed by patients' records and interviews of partner, family, and general practitioners. Costs were estimated from a societal perspective, including direct and indirect costs. We implemented recursive partitioning analysis (RPA), a statistical learning algorithm to identify predictors of costs. RESULTS: Four hundred thirty-one patients (mean age 72.5 years; 84.6% women) were evaluated. Among them, 17.6% had a prior fracture in the last 5 years. Approximately half of the whole group lived alone in the community, and 56.8% were from a low- or middle-income category. Over the 18-month period of evaluation, total costs (including initial fracture-related and follow-up ones) were 23 926 €, 14 561 €, and 6 905 € for the hip, clinical vertebral, and distal forearm fracture, respectively. Over a year, costs related to a humeral fracture were 10 319 €. The RPA identified mobility impairment prior to fracture as a predictor of increase in costs related to fracture. CONCLUSIONS: Our study for the first time prospectively assessed total costs related to the four main osteoporotic fractures in France. It appears that their levels were much higher than previous estimates, raising the burden of osteoporosis-related fractures on public health expenditures.

Remaining local subclinical joint inflammation is associated with deteriorated metacarpeal head bone microarchitecture in rheumatoid arthritis patients low disease activity.

OBJECTIVES: Bone alterations at the subchondral level during rheumatoid arthritis (RA) remain under investigation. It remains unknown whether subchondral bone damage might still occur in RA patients in clinical remission, which could then infer suggesting that even minor subclinical inflammatory changes in the joint can induce local bone loss. METHODS: Thirty-two RA patients treated with biological disease-modifying anti-rheumatic drugs (bDMARDs) with low disease activity since at least 6 months and having erosion on the second or third metacarpeal head were enrolled in this pilot cross-sectional study. They were divided in two groups according to local inflammation assessed by Doppler-ultrasound exam surrounding the site of erosion. Cortical and trabecular parameters of the metacarpeal head were then assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT) and compared in both groups. RESULTS: Twenty and twelve RA patients were enrolled in the "Doppler positive erosion" (DE+) group and Doppler negative erosion (DE-) group, respectively. No difference was observed in their clinical or biological RA characteristics. Both cortical density and thickness were similar among groups. Within the trabecular network, while no difference in bone volume was observed, trabecular density as well as trabecular number were decreased (P<0.001 and P<0.05 respectively), whereas trabecular separation and distribution of trabecular separation were increased in DE+ compared to DE- (P<0.05). CONCLUSION: In RA patients in low disease activity under bDMARDs, persistence of local inflammation was associated with alteration of the trabecular compartment. Trabecular density was the most strongly altered parameter and could be a candidate to assess drug effect on periarticular bone damage.

Cortical and Trabecular Bone Microstructure Did Not Recover at Weight-Bearing Skeletal Sites and Progressively Deteriorated at Non-Weight-Bearing Sites During the Year Following International Space Station Missions.

Risk for premature osteoporosis is a major health concern in astronauts and cosmonauts; the reversibility of the bone lost at the weight-bearing bone sites is not established, although it is suspected to take longer than the mission length. The bone three-dimensional structure and strength that could be uniquely affected by weightlessness is currently unknown. Our objective is to evaluate bone mass, microarchitecture, and strength of weight-bearing and non-weight-bearing bone in 13 cosmonauts before and for 12 months after a 4-month to 6-month sojourn in the International Space Station (ISS). Standard and advanced evaluations of trabecular and cortical parameters were performed using high-resolution peripheral quantitative computed tomography. In particular, cortical analyses involved determination of the largest common volume of each successive individual scan to improve the precision of cortical porosity and density measurements. Bone resorption and formation serum markers, and markers reflecting osteocyte activity or periosteal metabolism (sclerostin, periostin) were evaluated. At the tibia, in addition to decreased bone mineral densities at cortical and trabecular compartments, a 4% decrease in cortical thickness and a 15% increase in cortical porosity were observed at landing. Cortical size and density subsequently recovered and serum periostin changes were associated with cortical recovery during the year after landing. However, tibial cortical porosity or trabecular bone failed to recover, resulting in compromised strength. The radius, preserved at landing, unexpectedly developed postflight fragility, from 3 months post-landing onward, particularly in its cortical structure. Remodeling markers, uncoupled in favor of bone resorption at landing, returned to preflight values within 6 months, then declined farther to lower than preflight values. Our findings highlight the need for specific protective measures not only during, but also after spaceflight, because of continuing uncertainties regarding skeletal recovery long after landing. © 2017 American Society for Bone and Mineral Research.