Comparison of effectiveness of methotrexate in patients with late-onset versus younger-onset rheumatoid arthritis: Real-world data from an inception cohort in Japan (NICER-J).

OBJECTIVE: To compare the effectiveness of methotrexate (MTX) as initial therapy in patients with late-onset and younger-onset rheumatoid arthritis (LORA and YORA). METHODS: Of 114 patients with YORA and 96 patients with LORA, defined as RA occurring at ≥65 years of age, enrolled in a multicentre RA inception cohort study, 71 and 66 patients who had been followed up to 6 months after starting MTX treatment were included in this study. RESULTS: Proportions of patients on MTX treatment at 6 months were 96% and 92% in the YORA and LORA groups, respectively. Despite lower doses of MTX in the LORA group compared with the YORA group, no significant difference was observed in clinical disease activity index scores between the two groups throughout the follow-up period. The proportion of patients in clinical disease activity index remission at 6 months was 35% in both groups. Logistic regression analysis revealed that knee joint involvement and high Health Assessment Questionnaire-Disability Index were significant negative predictors of achieving clinical disease activity index remission at 6 months in the LORA group. CONCLUSION: Observations up to 6 months revealed that the effectiveness of MTX administered based on rheumatologist discretion in patients with LORA is comparable to that in patients with YORA in clinical settings.

Choice of and response to treatment in patients with early-diagnosed rheumatoid arthritis: Real-world data from an inception cohort in Japan (NICER-J).

OBJECTIVE: Various guidelines recommend that patients with early rheumatoid arthritis (RA) try to achieve clinical remission within 6 months, and early therapeutic intervention is important to this end. This study aimed to investigate short-term treatment outcomes of patients with early-diagnosed RA in clinical practice and to examine predictive factors for achieving remission. METHODS: Of the 210 patients enrolled in the multicenter RA inception cohort, 172 patients who were followed up to 6 months after treatment initiation (baseline) were included. Logistic regression analysis was used to examine the impact of baseline characteristics on achievement of Boolean remission at 6 months. RESULTS: Participants (mean age, 62 years) initiated treatment after a mean of 19 days from RA diagnosis. At baseline and 3 and 6 months after treatment initiation, proportions of patients using methotrexate (MTX) were 87.8%, 89.0%, and 88.3%, respectively, and rates of Boolean remission were 1.8%, 27.8%, and 34.5%, respectively. Multivariate analysis revealed that physician global assessment (PhGA) (Odds ratio (OR): 0.84, 95% confidence interval (CI): 0.71-0.99) and glucocorticoid use (OR: 0.26, 95% CI: 0.10-0.65) at baseline were independent factors that predicted Boolean remission at 6 months. CONCLUSION: After a diagnosis of RA, satisfactory therapeutic effects were achieved at 6 months after the initiation of treatment centered on MTX according to the treat to target strategy. PhGA and glucocorticoid use at treatment initiation are useful for predicting the achievement of treatment goals.

Impact of social support on severity of depressive symptoms by remission status in patients with rheumatoid arthritis.

OBJECTIVES: We aimed to examine the psychosocial characteristics of patients with rheumatoid arthritis (RA) by remission status and determine the impacts of social support on severity of depressive symptoms. METHODS: We enrolled RA patients aged 40-79 years who visited university hospitals' outpatient clinics. Severity of depressive symptoms (Beck Depression Inventory-II), physical disability (Health Assessment Questionnaire), and support were evaluated. Furthermore, RA disease activity was evaluated by 28-point Disease Activity Score (DAS28) calculation. The independent impacts of instrumental and emotional social support on depressive symptoms by remission status defined as DAS28 score < 2.6 were estimated by multivariable regression analysis. RESULTS: This study included 360 RA patients. In the remission group, emotional support showed a statistically significant negative impact on depressive symptoms, whereas instrumental support had an extremely limited contribution to severity of depressive symptoms. In the non-remission group, instrumental support showed a negative tendency of impact on severity of depressive symptoms, whereas emotional support had a wide range of influence. CONCLUSIONS: Favourable association between emotional support and depressive symptoms is confirmed only among RA patients in remission status. The influence of emotional support in non-remission patients and that of instrumental support regardless of remission status are inconclusive.

Relationship between disease activity of rheumatoid arthritis and development of locomotive syndrome: A five-year longitudinal cohort study.

OBJECTIVE: This study aimed to longitudinally evaluate the association between rheumatoid arthritis (RA) and locomotive syndrome (LS) in RA patients using the 25-question Geriatric Locomotive Function Scale (GLFS-25). METHODS: Subjects were 58 RA patients (female, 48 (82.8%); mean age, 60.9 ± 10.9 years) who had GLFS-25 scores available for five consecutive years and who did not have LS at baseline (i.e. GLFS-25 < 16 points). Associations between DAS28-CRP and the development of LS were determined using linear regression analysis and receiver operating characteristic (ROC) curve analysis. RESULTS: Subjects were divided into the LS group (n = 15, GLFS-25 ≥ 16 points) and non-LS group (n = 43, GLFS-25 < 16 points) based on GLFS-25 scores at the 5th year of the study period. In the LS group, DAS28-CRP worsened every year. The linear regression model adjusted for age and sex revealed that ΔGLFS-25 increased by 3.80 (95% confidence interval: 1.81-5.79) each time ΔDAS28-CRP increased by 1 (p<.001). Among patients in remission (DAS28-CRP < 2.3), 13.5% had LS. ROC curve analysis yielded a five-year mean DAS28-CRP of 1.99 (sensitivity, 86.7%; specificity, 62.8%) as the cut-off point for the development of LS. CONCLUSION: Tight control of RA disease activity for deeper remission may be needed to prevent the development of LS.

Depression, physical function, and disease activity associated with frailty in patients with rheumatoid arthritis.

OBJECTIVES: To investigate the clinical and psychosocial backgrounds of frailty in rheumatoid arthritis (RA) patients. METHODS: Patients with RA between 40 and 79 years of age who visited university hospitals in an urban area were recruited. Well-validated self-reported questionnaires were used to evaluate patient physical function (Health Assessment Questionnaire, HAQ), depressive symptoms (Beck Depression Inventory-II, BDI-II), and frailty (Kihon Checklist). A 28-point Disease Activity Score (DAS-28) was calculated to evaluate RA disease activity. RESULTS: A total of 375 RA patients, 323 of whom were women, were enrolled (average age: 65.2 ± 9.7 years; average disease duration: 16.6 ± 11.9 years). The prevalence rates of frailty, working-age (40-64 years), young-old (65-74 years), and old-old (≥75 years) patients were 18.5, 28.8, and 36.6%, respectively. Higher age and longer disease duration were associated with frailty. Multivariable logistic regression analysis revealed that HAQ, DAS-28, and BDI-II scores were independently associated with frailty in RA patients. CONCLUSION: Frailty is common, even among working-age RA patients. Physical function, disease activity, and depressive symptoms were independently associated with frailty. A multidisciplinary intervention approach, along with adequate pharmacological therapy, may promote successful aging in patients with RA.

Higher doses of methotrexate associated with discontinuation of oral glucocorticoids after initiation of biological DMARDs: A retrospective observational study based on data from a Japanese multicenter registry study.

OBJECTIVE: Glucocorticoids are important drugs used to treat rheumatoid arthritis. We recommend glucocorticoid discontinuation as soon as possible given the associated side-effects, but many patients continue to take oral glucocorticoids long-term. The present study aimed to explore factors associated with glucocorticoid discontinuation at 52 weeks after initiating biological disease-modifying antirheumatic drugs (bDMARDs). METHODS: Subjects were 564 patients from a Japanese multicenter registry who were administered glucocorticoids and methotrexate (MTX) followed by initiation of the first bDMARD. We examined the status of oral glucocorticoid use at 52 weeks after initiating the first bDMARD. RESULTS: By 52 weeks after bDMARD initiation, 164 patients (29.1%) discontinued glucocorticoids. Multivariable analysis identified age, MTX dose, and glucocorticoid dose as factors independently associated with glucocorticoid discontinuation. After adjusting for baseline characteristics using propensity score matching, among patient groups administered MTX ≤ 8 mg/week and MTX > 8 mg/week, 105 pairs remained. A significantly higher rate of glucocorticoid discontinuation (41.0%) was noted for patients administered MTX > 8 mg/week. CONCLUSION: Our findings suggest that glucocorticoids may be discontinued after initiating bDMARDs. Moreover, higher MTX doses (>8 mg/week) at the time of bDMARD initiation were associated with glucocorticoid discontinuation among patients treated with bDMARDs.

Improvement in matrix metalloproteinase-3 independently predicts low disease activity at 52 weeks in bio-switch rheumatoid arthritis patients treated with abatacept.

OBJECTIVES: To explore predictive factors including MMP-3 for achievement of low disease activity (LDA) at 52 weeks in bio-switch rheumatoid arthritis (RA) patients treated with abatacept, for whom obtaining a good clinical response can be difficult. METHODS: Participants were 423 consecutive patients with RA treated with abatacept who were observed for longer than 52 weeks and registered in the TBCR, a Japanese multicentre registry system. Multivariate logistic regression analysis was used to study factors that predict the achievement of LDA at 52 weeks in bio-naïve (n=234) and bio-switch (n=189) groups. RESULTS: ROC analysis revealed that MMP-3 improvement rates at 12 weeks in bio-switch patients had the highest AUC with a cut-off value of 20.0% for predicting LDA achievement at 52 weeks. Multivariate logistic regression analysis revealed that, in addition to DAS28-CRP at baseline, achieving 20% improvement in MMP-3 levels at 12 weeks was an independent predictive factor (adjusted OR: 4.277, p=0.003) in the bio-switch group, whereas DAS28 was the only predictor in the bio-naïve group. Patients who achieved 20% improvement in MMP-3 levels at 12 weeks had significantly higher achievement rates of LDA at 52 weeks compared to those who did not achieve 20% improvement in the bio-switch group (60.0 vs. 33.3%, p=0.001). CONCLUSIONS: Our findings suggest that improvement in MMP-3 levels is key to predicting the clinical efficacy of abatacept. Closer attention paid not only to major clinical indices, but also changes in MMP-3 levels, could improve our ability to optimise clinical results when treating bio-switch patients.

Characteristics of patients with rheumatoid arthritis undergoing primary total joint replacement: A 14-year trend analysis (2004-2017).

Objectives: To examine time trends in the characteristics of patients with rheumatoid arthritis (RA) undergoing primary total joint replacement (TJR).Methods: Biologics were approved in Japan for use in patients with RA in July 2003. A total of 403 large joints in 282 patients who underwent TJR at our institute between 1 January 2004 and 31 December 2017 were retrospectively examined.Results: A significant decreasing trend was observed in the number of TJRs performed from 2004 to 2017 (p = 0.013). No significant trend was observed in time from RA onset to TJR (p = 0.294). Age at RA onset (p = 0.034) showed a significant increasing trend, and serum C-reactive protein (CRP) levels showed a significant decreasing trend (p < 0.001). Negative CRP (defined as ≤0.3 mg/dl; partial regression coefficient (B) = 2.44, p = 0.016) was independently associated with time from RA onset to TJR as well as age at RA onset and juxta-articular osteophyte formation.Conclusion: The number of TJRs decreased since the approval of biologics in Japan, and changes were observed in the characteristics of patients with RA undergoing TJR. Negative CRP was an independent factor associated with longer time from RA onset to TJR.

Discontinuation of concomitant methotrexate in Japanese patients with rheumatoid arthritis treated with tocilizumab: An interventional study.

Objectives: To evaluate the efficacy and safety of methotrexate (MTX) discontinuation in Japanese rheumatoid arthritis (RA) patients with sustained low disease activity undergoing combination therapy with tocilizumab (TCZ) plus MTX.Methods: This multicenter, open-label, uncontrolled, prospective study included RA patients maintaining low disease activity (Clinical Disease Activity Index (CDAI) ≤10) for ≥12 weeks with TCZ plus MTX. Methotrexate was discontinued following 12 weeks of biweekly administration while continuing TCZ therapy. The primary endpoint was the proportion of patients maintaining low disease activity with no flare at week 36.Results: A total of 49 patients completed 36 weeks of therapy. The proportion of patients maintaining low disease activity at week 36 was 75.5%. The lower limit of the 95% confidence interval exceeded the assumed threshold response rate of 60%, demonstrating the clinical feasibility of MTX discontinuation. The prevalence of gastroesophageal reflux disease, defined as a Frequency Scale for Symptoms of Gastroesophageal reflux disease score ≥8, significantly decreased from week 0 to 12 (27.1-18.4%; p= .025).Conclusion: Discontinuation of concomitant MTX is clinically feasible for maintaining low disease activity, and may be beneficial from the perspective of reducing gastrointestinal symptoms in Japanese RA patients treated with TCZ. Trial registration number: UMIN000021247.

Changes in perioperative C-reactive protein levels in patients with rheumatoid arthritis undergoing total knee arthroplasty in the biologic era.

This study aimed to investigate changes in and factors associated with perioperative serum C-reactive protein (CRP) levels in rheumatoid arthritis (RA) patients undergoing total knee arthroplasty (TKA) in the biologic era. A total of 173 patients (228 knees) with RA underwent elective primary TKA at our institute between January 1, 2006 and December 31, 2018. Of these, 214 cases among 161 patients were examined in this retrospective study after excluding 3cases among 3 patients who developed postoperative complications and 11 cases among 9 patients who were treated with tocilizumab. Factors associated with changes in CRP levels between baseline (preoperative) and day 7 after TKA [ΔCRP (0-7days)] were assessed by multiple regression analysis. Median (interquartile range) CRP levels were 0.69 (0.21, 1.82) mg/dl preoperatively, 5.66 (4.21, 7.61) mg/dl on postoperative day 1, 12.75 (9.79, 16.74) mg/dl on postoperative days 3-4, 3.26 (2.21, 4.85) mg/dl on postoperative day 7, and 0.87 (0.45, 1.81) mg/dl on postoperative day 14. Multivariate regression analysis revealed that body mass index ≥25 [partial regression coefficient (B)=1.03, P=0.012] and use of glucocorticoids (B=-0.86, P=0.017) were independently associated with ΔCRP (0-7days), whereas use of methotrexate and targeted drug modifying antirheumatic drugs and preoperative CRP levels (an objective biomarker of RA activity) were not. In conclusion, serum CRP levels increased rapidly after TKA and peaked on postoperative days 3-4, followed by a return to preoperative levels by postoperative day 14 in patients with RA. Obesity and the use of glucocorticoids were independently associated with changes in CRP levels.

Comparison of the effects of baricitinib and tocilizumab on disease activity in patients with rheumatoid arthritis: a propensity score matching analysis.

OBJECTIVE: This study aimed to compare the effects of baricitinib, a Janus kinase inhibitor, and tocilizumab, a monoclonal anti-interleukin-6 receptor antibody, on disease activity in patients with rheumatoid arthritis (RA), and to investigate the influence of inflammation on improvement in patient global assessment (PGA) of disease activity. METHODS: This study was performed based on data from a multicenter registry, and included 284 and 113 patients treated with tocilizumab and baricitinib, respectively, who were observed for longer than 24 weeks. Propensity score matching was performed to address potential treatment-selection bias. To assess the influence of inflammation on PGA, patients were divided into two groups based on whether or not they achieved improvement in C-reactive protein (CRP, an objective marker of inflammation) at 24 weeks. RESULTS: A total of 48 matched pairs of patients were identified. Compared to treatment with tocilizumab, baricitinib showed a similar improvement in tender and swollen joint count and serum CRP levels, and a significantly greater improvement in PGA at 24 weeks. As a result, the baricitinib group had a significantly higher proportion of patients who achieved Boolean remission at 24 weeks. In subgroups of patients who did not achieve 50% or 70% CRP improvement, significant decreases from baseline to 24 weeks were observed in PGA in patients treated with baricitinib, but not in those treated with tocilizumab. CONCLUSION: Compared to tocilizumab, baricitinib significantly improved PGA despite similar effects on inflammation in patients with RA. Moreover, the influence of inflammation on PGA improvement differed between baricitinib and tocilizumab. Key-points • Baricitinib and tocilizumab had similar effects on inflammation in RA patients. • Baricitinib improved patient global assessment (PGA) more than tocilizumab. • Baricitinib had a higher Boolean remission rate than tocilizumab at 24 weeks. • Influence of inflammation on PGA improvement differed between the two drugs.

Periarticular osteophyte formation protects against total knee arthroplasty in rheumatoid arthritis patients with advanced joint damage.

OBJECTIVE: Periarticular osteophyte formation is observed during the repair of damaged joints in rheumatoid arthritis (RA); however, little is known about its clinical and functional roles. This study aimed to determine the influence of periarticular osteophyte formation on the incidence of total knee arthroplasty (TKA) (a surrogate for long-term outcomes of joint destruction) in patients with RA. METHODS: This retrospective longitudinal study included a total of 130 symptomatic (tender and/or swollen) knee joints in 80 patients starting biologics. Cumulative incidences of TKA were compared according to the presence or absence of osteophyte on plain anteroposterior radiograph (osteophyte (±)) and the extent of advanced joint damage as defined by Larsen's grading system (0-II vs. III-V). RESULTS: Kaplan-Meier estimates showed a significantly lower cumulative incidence of TKA for the osteophyte (+) group (n = 33) compared with the osteophyte (-) group (n = 31) in the Larsen grades III-V group (38 vs. 74% at 10 years, P = 0.010), whereas no significant difference was observed between the osteophyte (+) (n = 11) and osteophyte (-) (n = 55) groups in the Larsen grades 0-II group (9 vs. 10% at 10 years). Multivariate Cox proportional hazards analysis revealed that older age (hazard ratio (HR), 1.04 per 1 year; 95% confidence interval (CI), 1.01-1.08) and osteophyte formation (HR, 0.39; 95% CI, 0.19-0.79) independently predicted TKA in the Larsen grades III-V group, whereas none of the assessed variables predicted TKA in the Larsen grades 0-II group. CONCLUSION: Osteophyte formation reduces the incidence of TKA in patients with RA who have advanced joint damage. Key Points • Older age and Larsen grade were independent predictors of total knee arthroplasty (TKA) in rheumatoid arthritis (RA) patients. • Periarticular osteophyte formation reduced the incidence of TKA in RA patients with Larsen grades III-V.

Predictors for clinical effectiveness of baricitinib in rheumatoid arthritis patients in routine clinical practice: data from a Japanese multicenter registry.

This study aimed to evaluate the short-term effectiveness and safety profiles of baricitinib and explore factors associated with improved short-term effectiveness in patients with rheumatoid arthritis (RA) in clinical settings. A total of 113 consecutive RA patients who had been treated with baricitinib were registered in a Japanese multicenter registry and followed for at least 24 weeks. Mean age was 66.1 years, mean RA disease duration was 14.0 years, 71.1% had a history of use of biologics or JAK inhibitors (targeted DMARDs), and 48.3% and 40.0% were receiving concomitant methotrexate and oral prednisone, respectively. Mean DAS28-CRP significantly decreased from 3.55 at baseline to 2.32 at 24 weeks. At 24 weeks, 68.2% and 64.1% of patients achieved low disease activity (LDA) and moderate or good response, respectively. Multivariate logistic regression analysis revealed that no previous targeted DMARD use and lower DAS28-CRP score at baseline were independently associated with achievement of LDA at 24 weeks. While the effectiveness of baricitinib was similar regardless of whether patients had a history of only one or multiple targeted DMARDs use, patients with previous use of non-TNF inhibitors or JAK inhibitors showed lower rates of improvement in DAS28-CRP. The overall retention rate for baricitinib was 86.5% at 24 weeks, as estimated by Kaplan-Meier analysis. The discontinuation rate due to adverse events was 6.5% at 24 weeks. Baricitinib significantly improved RA disease activity in clinical practice. Baricitinib was significantly more effective when used as a first-line targeted DMARDs.

A retrospective analysis of the relationship between anti-cyclic citrullinated peptide antibody and the effectiveness of abatacept in rheumatoid arthritis patients.

This study aimed to evaluate the effectiveness of abatacept (ABA) by anti-cyclic citrullinated peptide (ACPA) status on disease activity as well as radiographic progression in patients with rheumatoid arthritis (RA) in clinical settings. A retrospective cohort study was conducted using data from a multicenter registry. Data from a total of 553 consecutive RA patients treated with intravenous ABA were included. We primarily compared the status of disease activity (SDAI) and radiographic progression (van der Heijde modified total Sharp score: mTSS) between the ACPA-negative (N = 107) and ACPA-positive (N = 446) groups. 'ACPA positive' was defined as ≥ 13.5 U/mL of anti-CCP antibody. Baseline characteristics between groups were similar. The proportion of patients who achieved low disease activity (LDA; SDAI ≤ 11) at 52 weeks was significantly higher in the ACPA-positive group. Multivariate logistic regression analysis identified ACPA positivity as an independent predictor for achievement of LDA at 52 weeks. Drug retention rate at 52 weeks estimated by the Kaplan-Meier curve was significantly higher in the ACPA-positive group. Achievement rate of structural remission (ΔmTSS ≤ 0.5) at 52 weeks was similar between groups. ABA treatment demonstrated a significantly higher clinical response and higher drug retention rate in ACPA-positive patients. Progression of joint destruction was similar between the ACPA-negative and ACPA-positive groups. Close attention should be paid to joint destruction even in patients showing a favorable response to ABA, especially when the ACPA status is positive.

Predictors of disease flare after discontinuation of concomitant methotrexate in Japanese patients with rheumatoid arthritis treated with tocilizumab.

OBJECTIVE: To investigate predictors of disease flare after methotrexate discontinuation in Japanese rheumatoid arthritis (RA) patients with sustained low disease activity undergoing tocilizumab plus methotrexate combination therapy. METHODS: Participants of this multicenter, open-label, uncontrolled, prospective study were RA patients maintaining low disease activity (Clinical Disease Activity Index [CDAI]≤10) for≥12weeks with tocilizumab plus methotrexate. Methotrexate was discontinued after 12weeks of biweekly administration while continuing tocilizumab therapy. Disease flare was defined as either a CDAI score>10 or intervention with rescue treatments for any reason even if the CDAI score was≤10. The impact of baseline characteristics on disease flare at week 64 (52weeks after methotrexate discontinuation) was assessed with logistic regression models. RESULTS: Efficacy analyses were performed in 49 patients, of whom 15 had a disease flare by week 64. The proportion (95% confidence interval [CI]) of patients who maintained low disease activity without a flare at week 64 was 69.4% (54.6-81.8%). The dosing interval of tocilizumab was longer than that described on the drug label in Japan (i.e., intravenously every 4weeks, or subcutaneously every 2weeks) in 27% and 6% of patients with and without a flare, respectively. Multivariate analysis revealed that male sex (odds ratio [OR]: 18.00, 95% CI: 2.80-115.56) and extended dosing interval of tocilizumab (OR: 12.00, 95% CI: 1.72-83.80) were independent predictors of disease flare. CONCLUSION: Male patients and those receiving tocilizumab at an extended dosing interval are at high risk of disease flare after discontinuation of concomitant methotrexate. TRIAL REGISTRATION NUMBER: jRCTs041180071, UMIN000021247.

Hyaluronan promotes TRPV4-induced chondrogenesis in ATDC5 cells.

Hyaluronan (HA) is an extracellular matrix glycosaminoglycan essential for the homeostasis of cartilage-related tissues. Intracellular adhesion molecule-1 (ICAM-1) and CD44 have been identified as receptors for HA. Recently, transient receptor potential vanilloid 4 (TRPV4) has emerged as a potential research target in several areas of physiology. TRPV4 is a Ca2+-permeable, non-selective cation channel that appears to have mechanosensory or osmosensory roles in several musculoskeletal tissues. HA and TRPV4 play key roles in chondrogenesis; however, it has remained unclear whether they have interactive effects on chondrogenesis and, if so, how do they interact with each other? This study investigated the relationship between HA, its receptors ICAM-1 and CD44, and TRPV4 in the chondrogenic pathway using the ATDC5 cell line. It was found that the presence of HA is required for TRPV4-induced chondrogenesis. Loss of HA suppressed TRPV4-induced expression of the chondrogenic markers, SOX9 and Aggrecan. Moreover, HA affects TRPV4-induced chondrogenic development via each of ICAM-1 and CD44 partially. In conclusion, for the first time, the existence of an interaction between HA, its receptor ICAM-1 and CD44, and TRPV4-activity in chondrogenesis in the ATDC5 cell line was reported. TRPV4 is known to function as a mechanosensory channel in several musculoskeletal tissues. Therefore, findings of this study may suggest the existence of a molecular mechanism that underlies the interactive effects of HA and mechanical loading on joint chondrogenesis.

Relationship between rheumatoid arthritis and locomotive syndrome: validation of the 25-question Geriatric Locomotive Function Scale in patients with rheumatoid arthritis.

This study aimed to understand the clinical state of locomotive syndrome (LS) in patients with rheumatoid arthritis (RA) and to validate the use of the 25-question Geriatric Locomotive Function Scale (GLFS-25) in patients with RA and compare it side-by-side with the Health Assessment Questionnaire-Disability Index (HAQ-DI). Subjects were 159 patients with RA (female, 112 (70.4%); mean age, 66.2 ± 12.0 years) who consecutively visited Yokkaichi Municipal Hospital between June and August 2017. Mean disease duration was 11.4 ± 9.3 years, mean HAQ-DI score was 0.5 ± 0.7 points, and mean GLFS-25 score was 17.8 ± 19.1 points. The correlation between GLFS-25 and HAQ-DI was analyzed using Spearman's rank correlation coefficient. The cut-off point of GLFS-25 corresponding to HAQ-DI≤0.5, which represents functional remission in patients with RA, was calculated by ROC analysis. GLFS-25 and HAQ-DI were positively and strongly correlated (correlation coefficient=0.798). The cut-off point of GLFS-25 corresponding to HAQ-DI≤0.5 was 20 points (sensitivity, 81%; specificity, 90%). Thus, the cut-off point of GLFS-25 corresponding to functional remission is higher than that for developing LS (i.e., 16 points). Moreover, the proportion of patients with LS among those with HAQ-DI ≤0.5 was 17.9%. In conclusion, our findings suggest that some patients with RA in remission may have LS, as well as the need to consider appropriate interventions for such patients.

Inhibition of CD44 intracellular domain production suppresses bovine articular chondrocyte de-differentiation induced by excessive mechanical stress loading.

CD44 fragmentation is enhanced in chondrocytes of osteoarthritis (OA) patients. We hypothesized that mechanical stress-induced enhancement of CD44-intracellular domain (CD44-ICD) production plays an important role in the de-differentiation of chondrocytes and OA. This study aimed to assess the relationship between CD44-ICD and chondrocyte gene expression. Monolayer cultured primary bovine articular chondrocytes (BACs) were subjected to cyclic tensile strain (CTS) loading. ADAM10 inhibitor (GI254023X) and γ-secretase inhibitor (DAPT) were used to inhibit CD44 cleavage. In overexpression experiments, BACs were electroporated with a plasmid encoding CD44-ICD. CTS loading increased the expression of ADAM10 and subsequent CD44 cleavage, while decreasing the expression of SOX9, aggrecan, and type 2 collagen (COL2). Overexpression of CD44-ICD also resulted in decreased expression of these chondrocyte genes. Both GI254023X and DAPT reduced the production of CD44-ICD upon CTS loading, and significantly rescued the reduction of SOX9 expression by CTS loading. Chemical inhibition of CD44-ICD production also rescued aggrecan and COL2 expression following CTS loading. Our findings suggest that CD44-ICD is closely associated with the de-differentiation of chondrocytes. Excessive mechanical stress loading promoted the de-differentiation of BACs by enhancing CD44 cleavage and CD44-ICD production. Suppression of CD44 cleavage has potential as a novel treatment strategy for OA.