Safety of Janus kinase inhibitors compared to biological DMARDs in patients with rheumatoid arthritis and renal impairment: the ANSWER cohort study.

Data on the safety of Janus kinase inhibitors (JAKis) in patients with renal impairment are lacking. This study aimed to investigate the safety of JAKis compared to biological (b) DMARDs in patients with rheumatoid arthritis (RA) and renal impairment. We used a multi-centre observational registry of patients with RA in Japan (the ANSWER cohort). We assessed the drug retention rates of b/targeted synthetic DMARDs with different modes of action (tumour necrosis factor inhibitors (TNFis), immunoglobulins fused with cytotoxic T-lymphocyte antigen (CTLA-4-Ig), interleukin-6 receptor inhibitors (IL-6Ris), and JAKis) in patients with RA stratified by pre-treatment estimated glomerular filtration rate (eGFR) levels. The time to discontinuation of bDMARDs or JAKis was analysed using a multivariate Cox proportional hazards model This study included 3775 patients, who were classified into three groups (the normal group (eGFR ≥ 60 mL/min/1.73 m2): 2893 patients; CKDa group (eGFR 45-60 mL/min/1.73 m2): 551; and CKDb group (eGFR < 45 mL/min/1.73 m2): 331). In the CKDb group, the 12-month drug retention rate due to adverse events (AE) was the lowest in patients treated with JAKi (TNFi: 93.1%; IL-6Ri: 94.1%; CTLA-4-Ig: 92.3%; JAKi: 75.1%). In the normal and CKDa groups, drug retention rates due to AE were similar among patients treated with bDMARDs and JAKi. In contrast, drug retention rates due to inefficacy were similar between bDMARDs and JAKis in all groups. In the Cox-proportional model, in the CKDb group, TNFi, IL-6Ri, and CTLA-4-Ig showed lower incidence of drug discontinuation due to AE than JAKis (TNFi: hazard ratio = 0.23 (95% confidence interval 0.09-0.61), IL-6Ri: 0.34 (0.14-0.81), CTLA-4-Ig: 0.36 (0.15-0.89)). JAKis showed the lowest drug retention due to AE in patients with moderate-to-severe and severe renal impairment (eGFR < 45 mL/min/1.73 m2). Physicians should pay more attention to renal function when using JAKis than when using bDMARDs.

Predictive factors and treatment outcomes associated with difficult-to-treat rheumatoid arthritis conditions: the ANSWER cohort study.

OBJECTIVES: To investigate the predictive factors for difficult-to-treat rheumatoid arthritis (D2T RA) and assess the efficacy of biological disease-modifying antirheumatic drugs (bDMARDs) and Janus kinase inhibitors (JAKi). METHODS: Retrospective analysis was conducted on data from the ANSWER cohort comprising 3,623 RA patients treated with bDMARDs or JAKi in Japan. Multivariate Cox proportional hazards modelling was used to analyse the hazard ratios (HRs) for treatment retention. RESULTS: Of these, 450 (12.4%) met the first two criteria of EULAR D2T RA definition (defined as D2T RA in this study). Factors contributing to D2T RA included age over 75 (compared to those under 65, HR = 0.46, 95% CI: 0.31 to 0.69), higher rheumatoid factor (RF) titres (HR = 1.005, 95% CI: 1.00 to 1.01), higher clinical disease activity index (HR = 1.02, 95% CI: 1.01 to 1.03), lower methotrexate dosage (HR = 0.97, 95% CI: 0.95 to 0.99), and comorbidities like hypertension (HR = 1.53, 95% CI: 1.2 to 1.95) and diabetes (HR = 1.37, 95% CI: 1.09 to 1.73). Anti-interleukin 6 receptor antibodies (aIL-6R, HR = 0.53, 95% CI: 0.37 to 0.75) and JAKi (HR = 0.64, 95% CI: 0.46 to 0.90) were associated with fewer discontinuations due to ineffectiveness compared to tumour necrosis factor inhibitors. Oral glucocorticoids usage (HR = 1.65, 95% CI: 1.11 to 2.47) was linked to increased discontinuation due to toxic adverse events. CONCLUSION: Younger onset, higher RF titres, and comorbidities predicted D2T RA development. For managing D2T RA, aIL-6R and JAKi exhibited superior drug retention.

Iguratimod suppresses sclerostin and receptor activator of NF-κB ligand production via the extracellular signal-regulated kinase/early growth response protein 1/tumor necrosis factor alpha pathway in osteocytes and ameliorates disuse osteoporosis in mice.

Disuse osteoporosis is a prevalent complication among patients afflicted with rheumatoid arthritis (RA). Although reports have shown that the antirheumatic drug iguratimod (IGU) ameliorates osteoporosis in RA patients, details regarding its effects on osteocytes remain unclear. The current study examined the effects of IGU on osteocytes using a mouse model of disuse-induced osteoporosis, the pathology of which crucially involves osteocytes. A reduction in distal femur bone mass was achieved after 3 weeks of hindlimb unloading in mice, which was subsequently reversed by intraperitoneal IGU treatment (30 mg/kg; five times per week). Histology revealed that hindlimb-unloaded (HLU) mice had significantly increased osteoclast number and sclerostin-positive osteocyte rates, which were suppressed by IGU treatment. Moreover, HLU mice exhibited a significant decrease in osteocalcin-positive cells, which was attenuated by IGU treatment. In vitro, IGU suppressed the gene expression of receptor activator of NF-κB ligand (RANKL) and sclerostin in MLO-Y4 and Saos-2 cells, which inhibited osteoclast differentiation of mouse bone marrow cells in cocultures. Although IGU did not affect the nuclear translocation or transcriptional activity of NF-κB, RNA sequencing revealed that IGU downregulated the expression of early growth response protein 1 (EGR1) in osteocytes. HLU mice showed significantly increased EGR1- and tumor necrosis factor alpha (TNFα)-positive osteocyte rates, which were decreased by IGU treatment. EGR1 overexpression enhanced the gene expression of TNFα, RANKL, and sclerostin in osteocytes, which was suppressed by IGU. Contrarily, small interfering RNA-mediated suppression of EGR1 downregulated RANKL and sclerostin gene expression. These findings indicate that IGU inhibits the expression of EGR1, which may downregulate TNFα and consequently RANKL and sclerostin in osteocytes. These mechanisms suggest that IGU could potentially be used as a treatment option for disuse osteoporosis by targeting osteocytes.

An investigation of the differential therapeutic effects of romosozumab on postmenopausal osteoporosis patients with or without rheumatoid arthritis complications: a case-control study.

The impact of ROMO on the width of anabolic windows and the increase in BMD was reduced in the RA group compared to the non-RA group, and this reduction was associated with correlations to RA-related factors. PURPOSE: To investigate the effects of romosozumab (ROMO) in postmenopausal osteoporosis, with and without comorbid rheumatoid arthritis (RA). METHODS: In this retrospective, case-controlled, multicenter study, 171 postmenopausal patients who did not receive oral glucocorticoid, comprising 59 in the RA group and 121 in the non-RA group, received uninterrupted ROMO treatment for 12 months. Propensity score matching was employed to ensure comparability in clinical backgrounds, resulting in 41 patients in each group. Baseline characteristics were as follows: overall (mean age, 76.3 years; T-score of lumbar spine (LS), - 3.0; 45.1% were treatment-naive for osteoporosis); RA group (anti-cyclic citrullinated peptide antibody (ACPA) positivity, 80.5%; titer, 206.2 U/ml; clinical disease activity index (CDAI), 13.6; health assessment questionnaire disability index (HAQ-DI), 0.9). Bone mineral density (BMD) and serum bone turnover markers were monitored over a 12-month period. RESULTS: The rate of increase in the bone formation marker, PINP, and the rates of decrease in the bone resorption marker, TRACP-5b, exhibited a trend toward smaller changes in the RA group compared to the non-RA group, implying a smaller anabolic window. After 12 months, the RA group displayed lower BMD increases in the LS (9.1% vs. 12.6%; P = 0.013) and total hip (2.4% vs. 4.8%; P = 0.025) compared to the non-RA group. Multiple regression analysis in the all RA group (n = 59) for the association between RA-specific factors and 12-month BMD changes revealed negative correlations between ACPA titer and LS BMD and between HAQ-DI and femoral neck BMD. CONCLUSIONS: The efficacy of ROMO may be attenuated by RA-related factors.

Reverse V-shaped osteotomy for ankylosing rocker-bottom foot deformity in patients with rheumatoid arthritis. A report of 3 cases.

This study evaluated reverse V-shaped osteotomy for ankylosing rocker-bottom foot deformity in patients with rheumatoid arthritis. We experienced 3 feet: rheumatoid rocker-bottom deformities with painful and/or infectious bony prominence towards the bottom of the foot, treated with a reverse V-shaped osteotomy in the mid-hindfoot. In all three cases, significant correction was achieved with restoration of the medial longitudinal arch, and improvement in clinical scores was confirmed. Reverse V-shaped osteotomy has the potential to be a useful and definitive procedure for ankylosing rocker-bottom deformity in patients with rheumatoid arthritis.

Early full weight-bearing and gait exercise after cemented total ankle arthroplasty with modified antero-lateral approach.

BACKGROUND: According to the conventional postoperative procedure after total ankle arthroplasty (TAA) against end-stage osteoarthritis (OA) and rheumatoid arthritis (RA), mobilization and weight-bearing is currently started after completion of wound healing. Recently, early mobilization for dorsiflexion after TAA with modified antero-lateral approach was reported to be feasible and safe. To investigate the further possibility of expediting rehabilitation, this study evaluated the feasibility and safety of early full weight-bearing and gait exercise after cemented TAA utilizing a modified antero-lateral approach. MATERIALS AND METHODS: This retrospective, observational study investigated 23 consecutive ankles (OA: 14 ankles, RA: 9 ankles) that had received cemented TAA with a modified antero-lateral approach. These ankles were divided into three groups [1. conventional postoperative protocol: 8 ankles, 2. early dorsiflexion protocol: 7 ankles, 3. early dorsiflexion+full weight-bearing protocol: 8 ankles]. In group 3, after early dorsiflexion mobilization (day 3), full weight-bearing/gait exercise was started from 7 days after surgery (10 days after if malleolar osteotomy was added). Postoperative wound complications were observed and recorded. Number of days for hospitalization was also evaluated. Range of motion (ROM) of dorsiflexion/plantar flexion was measured. Patients also completed a self-administered foot evaluation questionnaire (SAFE-Q) and the scale of Japanese Society for Surgery of the Foot (JSSF) ankle/hindfoot score preoperatively and at final follow-up. RESULTS: No postoperative complications related to wound healing were observed even after early full weight-bearing and gait exercise. Days for hospitalization was significantly shortened in early full weight-bearing and gait exercise group (group 3) from 35-38 days to 24 days. ROM for both dorsiflexion and plantar flexion significantly increased in group 3, furthermore all indices of SAFE-Q score also showed stronger significant improvement in group 3. JSSF score improved significantly after TAA in all groups. CONCLUSION: Within this small number of cases, early full weight-bearing and gait exercise from 7 days after cemented TAA was feasible and safe with the modified antero-lateral approach. Combination of early dorsiflexion mobilization and weight-bearing/gait exercise contributed to shortening the hospitalization day, and improving ROM for both dorsiflexion and plantar flexion after surgery. Innovations in postoperative procedures for rehabilitation after TAA can be expected.

Anti-NF-κB peptide derived from nuclear acidic protein attenuates ovariectomy-induced osteoporosis in mice.

NF-κB is a transcription factor that is activated with aging. It plays a key role in the development of osteoporosis by promoting osteoclast differentiation and inhibiting osteoblast differentiation. In this study, we developed a small anti-NF-κB peptide called 6A-8R from a nuclear acidic protein (also known as macromolecular translocation inhibitor II, Zn2+-binding protein, or parathymosin) that inhibits transcriptional activity of NF-κB without altering its nuclear translocation and binding to DNA. Intraperitoneal injection of 6A-8R attenuated ovariectomy-induced osteoporosis in mice by inhibiting osteoclast differentiation, promoting osteoblast differentiation, and inhibiting sclerostin production by osteocytes in vivo with no apparent side effects. Conversely, in vitro, 6A-8R inhibited osteoclast differentiation by inhibiting NF-κB transcriptional activity, promoted osteoblast differentiation by promoting Smad1 phosphorylation, and inhibited sclerostin expression in osteocytes by inhibiting myocyte enhancer factors 2C and 2D. These findings suggest that 6A-8R has the potential to be an antiosteoporotic therapeutic agent with uncoupling properties.

Real-world comparative study of the efficacy of Janus kinase inhibitors in patients with rheumatoid arthritis: the ANSWER cohort study.

OBJECTIVE: This multicentre, retrospective study compared the efficacy and safety of tofacitinib, baricitinib, peficitinib and upadacitinib in real-world clinical settings after minimizing selection bias and adjusting the confounding patient characteristics. METHOD: The 622 patients were selected from the ANSWER cohort database and treated with tofacitinib (TOF), baricitinib (BAR), peficitinib (PEF) or upadacitinib (UPA). The patient's background was matched using propensity score-based inverse probability of treatment weighting (IPTW) among four treatment groups. The values of Clinical Disease Activity Index (CDAI), C-reactive protein (CRP), and modified Health Assessment Questionnaire (mHAQ) after drug initiation and the remission or low disease activity (LDA) rates of CDAI at 6 months after drug initiation were compared among the four groups. Further, the predictive factor for TOF and BAR efficacy was analysed. RESULTS: The retention and discontinuation rates until 6 months after drug initiations were not significantly different among the four JAK inhibitors treatment groups. Mean CDAI value, CDAI remission rate, and CDAI-LDA rate at 6 months after drug initiation were not significantly different among treatment groups. Baseline CDAI (TOFA: OR 1.09, P < 0.001; BARI: OR 1.07, P < 0.001), baseline CRP (TOFA: OR 1.32, P = 0.049), baseline glucocorticoid dose (BARI: OR 1.18, 95% CI 1.01-1.38, P = 0.035), a number of previous biological or targeted synthetic disease-modifying antirheumatic drugs (biological/targeted synthetic DMARDs) (BARI: OR 1.36, P = 0.004) were predictive factors for resistance to CDAI-LDA achievement to JAK inhibitor treatment. CONCLUSION: The efficacy and safety of TOF, BAR, PEF and UPA were not significantly different for the treatment of patients with rheumatoid arthritis.

Angioleiomyoma mimicking a swollen bursa on first metatarsophalangeal joint accompanying with hallux valgus deformity.

We present a case of a patient who underwent a modified scarf osteotomy and tumour excision based on a preoperative diagnosis of hallux valgus deformity and accompanying bursitis. Subsequent histopathological examination revealed that the tumour was an angioleiomyoma. While tumours around the first metatarsophalangeal (MTP) joint are typically associated with gouty nodules, infections, or swollen bursa (bursitis) in patients with hallux valgus deformity, the occurrence of soft tissue tumours in this area is rare. Moreover, angioleiomyoma is an even rarer form of soft tissue tumour and is seldom suspected prior to resection. To our knowledge, there have been no reports of angioleiomyoma arising in the first MTP joint. However, it is important to consider the possibility of an atypical tumour in cases where soft tissue masses are present, even in patients with hallux valgus deformity, and to perform at least imaging tests such as ultrasound and magnetic resonance imaging before surgery. This prospect should always be kept in mind.

Drug retention of biologics and Janus kinase inhibitors in patients with rheumatoid arthritis: the ANSWER cohort study.

OBJECTIVES: This multicentre retrospective study in Japan aimed to assess the retention of biological disease-modifying antirheumatic drugs and Janus kinase inhibitors (JAKi), and to clarify the factors affecting their retention in a real-world cohort of patients with rheumatoid arthritis. METHODS: The study included 6666 treatment courses (bDMARD-naïve or JAKi-naïve cases, 55.4%; tumour necrosis factor inhibitors (TNFi) = 3577; anti-interleukin-6 receptor antibodies (aIL-6R) = 1497; cytotoxic T lymphocyte-associated antigen-4-Ig (CTLA4-Ig) = 1139; JAKi=453 cases). The reasons for discontinuation were divided into four categories (ineffectiveness, toxic adverse events, non-toxic reasons and remission); multivariate Cox proportional hazards modelling by potential confounders was used to analyse the HRs of treatment discontinuation. RESULTS: TNFi (HR=1.93, 95% CI: 1.69 to 2.19), CTLA4-Ig (HR=1.42, 95% CI: 1.20 to 1.67) and JAKi (HR=1.29, 95% CI: 1.03 to 1.63) showed a higher discontinuation rate due to ineffectiveness than aIL-6R. TNFi (HR=1.28, 95% CI: 1.05 to 1.56) and aIL-6R (HR=1.27, 95% CI: 1.03 to 1.57) showed a higher discontinuation rate due to toxic adverse events than CTLA4-Ig. Concomitant use of oral glucocorticoids (GCs) at baseline was associated with higher discontinuation rate due to ineffectiveness in TNFi (HR=1.24, 95% CI: 1.09 to 1.41), as well as toxic adverse events in JAKi (HR=2.30, 95% CI: 1.23 to 4.28) and TNFi (HR=1.29, 95%CI: 1.07 to 1.55). CONCLUSIONS: TNFi (HR=1.52, 95% CI: 1.37 to 1.68) and CTLA4-Ig (HR=1.14, 95% CI: 1.00 to 1.30) showed a higher overall drug discontinuation rate, excluding non-toxicity and remission, than aIL-6R.

Basic fibroblast growth factor promotes meniscus regeneration through the cultivation of synovial mesenchymal stem cells via the CXCL6-CXCR2 pathway.

OBJECTIVE: To investigate the efficacy of basic fibroblast growth factor (bFGF) in promoting meniscus regeneration by cultivating synovial mesenchymal stem cells (SMSCs) and to validate the underlying mechanisms. METHODS: Human SMSCs were collected from patients with osteoarthritis. Eight-week-old nude rats underwent hemi-meniscectomy, and SMSCs in pellet form, either with or without bFGF (1.0 × 106 cells per pellet), were implanted at the site of meniscus defects. Rats were divided into the control (no transplantation), FGF (-) (pellet without bFGF), and FGF (+) (pellet with bFGF) groups. Different examinations, including assessment of the regenerated meniscus area, histological scoring of the regenerated meniscus and cartilage, meniscus indentation test, and immunohistochemistry analysis, were performed at 4 and 8 weeks after surgery. RESULTS: Transplanted SMSCs adhered to the regenerative meniscus. Compared with the control group, the FGF (+) group had larger regenerated meniscus areas, superior histological scores of the meniscus and cartilage, and better meniscus mechanical properties. RNA sequencing of SMSCs revealed that the gene expression of chemokines that bind to CXCR2 was upregulated by bFGF. Furthermore, conditioned medium derived from SMSCs cultivated with bFGF exhibited enhanced cell migration, proliferation, and chondrogenic differentiation, which were specifically inhibited by CXCR2 or CXCL6 inhibitors. CONCLUSION: SMSCs cultured with bFGF promoted the expression of CXCL6. This mechanism may enhance cell migration, proliferation, and chondrogenic differentiation, thereby resulting in superior meniscus regeneration and cartilage preservation.

Early Resection of the Tibialis Anterior Tendon for Tendon Exposure After Total Ankle Arthroplasty to Prevent Deep Infection: A Report of Three Cases in Patients With Rheumatoid Arthritis.

Exposure of the tibialis anterior (TA) tendon with wound dehiscence after total ankle arthroplasty (TAA) with the anterior approach is a problematic complication, especially in rheumatoid arthritis (RA) patients. Once the TA tendon is exposed, the duration of wound healing is prolonged, and it could be a risk factor for deep infection. Thus, early resection of the TA tendon was evaluated for tendon exposure with wound dehiscence after TAA in RA patients. In this case report, three rheumatoid ankles that showed wound dehiscence with exposure of the TA tendon after TAA with the anterior approach are presented. Early resection of the TA tendon and debridement under local anesthesia were performed within two days after wound dehiscence. In all cases, wound healing was completed within two weeks after the treatment. Drop foot was not seen in any patients, and there was no difference between the pre and postoperative (1 year after TAA) range of dorsiflexion. Muscle strength for ankle dorsiflexion was also maintained. In conclusion, early resection of the TA tendon appears to be a useful option for undesirable tendon exposure with wound dehiscence to prevent deep infection and prolonged wound healing after total ankle arthroplasty in RA patients.

Early mobilization of dorsiflexion from 3 days after cemented total ankle arthroplasty with modified antero-lateral approach.

BACKGROUND: According to the conventional postoperative procedure after total ankle arthroplasty (TAA), mobilization is currently started after completion of wound healing. To investigate the possibility of expediting rehabilitation, this study evaluated the feasibility and safety of early mobilization of dorsiflexion after cemented TAA utilizing a modified antero-lateral approach. MATERIALS AND METHODS: This retrospective, observational study investigated 14 consecutive ankles that had received cemented TAA. Mobilization of dorsiflexion was started from 3 days after surgery. Postoperative wound complications including blister formation, eschar formation, wound dehiscence, peri-incisional decreased sensation were observed and recorded. Range of motion (ROM) of dorsiflexion/plantar flexion was measured. Patients also completed a self-administered foot evaluation questionnaire (SAFE-Q) and the scale of Japanese Society for Surgery of the Foot (JSSF) ankle/hindfoot score preoperatively and at final follow-up. RESULTS: No postoperative complications related to wound healing were observed. ROM for dorsiflexion, SAFE-Q score, and JSSF score improved significantly after TAA. CONCLUSION: Within this small number of cases, early mobilization of dorsiflexion from 3 days after cemented TAA was feasible and safe with the modified antero-lateral approach. Innovations in postoperative procedures for rehabilitation after TAA can be expected.

Modified scarf osteotomy with capsular interposition as salvage for resection or silicone implant arthroplasty in patients with rheumatoid arthritis. A report of three cases.

This study investigated modified scarf osteotomy as a salvage procedure after resection arthroplasty or silicone implant arthroplasty to preserve mobility of the first metatarsophalangeal (MTP) joint after hallux valgus surgery in patients with rheumatoid arthritis (RA). We investigated three feet with rheumatoid forefoot deformities that showed recurrence of forefoot deformity or breakage of the implant after resection or silicone implant arthroplasty in the first MTP joint. All feet were treated using modified scarf osteotomy with capsular interposition. All cases achieved obvious correction after modified scarf osteotomy despite resection of the first MTP joint and consequently showed both radiographic and clinical improvements. Modified scarf osteotomy offers potential as a definitive salvage procedure after resection arthroplasty or silicone implant arthroplasty for forefoot deformity in patients with RA, because the procedure can realign the first MTP joint obviously with preservation of the range of motion. Concomitant medial capsular interposition into the newly formed first MTP joint is also recommended where possible, to protect the edges of the proximal basal phalanx and distal first metatarsal and also to smoothen the motion of newly formed first MTP joint.

Add-on effectiveness of methotrexate or iguratimod in patients with rheumatoid arthritis exhibiting an inadequate response to Janus kinase inhibitors: The ANSWER cohort study.

OBJECTIVES: This multicenter, retrospective study evaluated the effectiveness of add-on methotrexate (MTX) or iguratimod (IGU) in patients with rheumatoid arthritis exhibiting an inadequate response to Janus kinase inhibitors (JAKis). METHODS: Forty-five patients were treated with new additional MTX (n = 22) or IGU (n = 23) and followed for 6 months. Patients' background is as follows: age, 59.2 years; disease activity score of 28 joints with C-reactive protein (DAS28-CRP), 3.4; clinical disease activity index, 15.7; biological disease-modifying antirheumatic drug (DMARD)-switched cases, 77.8%; first JAKi cases, 95.6%; and JAKi treatment: tofacitinib (n = 25), baricitinib (n = 17), upadacitinib (n = 2), and peficitinib (n = 1) for 9.6 months. RESULTS: Thirty-five patients continued the combination therapy for 6 months without a significant change in concomitant glucocorticoid or other conventional synthetic DMARDs. DAS28-CRP (MTX, 3.6 to 2.6, p < 0.05; IGU, 3.3 to 2.1, p < 0.001) and clinical disease activity index (MTX, 16.7 to 8.8, p < 0.05; IGU, 14.6 to 6.5, p < 0.01) improved significantly from baseline. Using the 2019 European League Against Rheumatism criteria, 45.4% (MTX) and 39.1% (IGU) achieved moderate or good response and 40.9% (MTX) and 39.1% (IGU) achieved American College of Rheumatology 20% improvement criteria. CONCLUSIONS: Adding MTX or IGU to inadequate responders of JAKi can be considered as a complementary treatment.

Semaphorin 4D induces articular cartilage destruction and inflammation in joints by transcriptionally reprogramming chondrocytes.

Proinflammatory cytokines play critical roles in the pathogenesis of joint diseases. Using a mass spectrometry-based cloning approach, we identified Semaphorin 4D (Sema4D) as an inflammatory cytokine that directly promoted cartilage destruction. Sema4d-deficient mice showed less cartilage destruction than wild-type mice in a model of rheumatoid arthritis. Sema4D induced a proinflammatory response in mouse articular chondrocytes characterized by the induction of proteolytic enzymes that degrade cartilage, such as matrix metalloproteinases (MMPs) and aggrecanases. The activation of Mmp13 and Mmp3 expression in articular chondrocytes by Sema4D did not depend on RhoA, a GTPase that mediates Sema4D-induced cytoskeletal rearrangements. Instead, it required NF-κB signaling and Ras-MEK-Erk1/2 signaling downstream of the receptors Plexin-B2 and c-Met and depended on the transcription factors IκBζ and C/EBPδ. Genetic and pharmacological blockade of these Sema4D signaling pathways inhibited MMP induction in chondrocytes and cartilage destruction in femoral head organ culture. Our results reveal a mechanism by which Sema4D signaling promotes cartilage destruction.

A novel anti-TNF-α drug ozoralizumab rapidly distributes to inflamed joint tissues in a mouse model of collagen induced arthritis.

In clinical studies, the next-generation anti-tumor necrosis factor-alpha (TNF-α) single domain antibody ozoralizumab showed high clinical efficacy shortly after the subcutaneous injection. To elucidate the mechanism underlying the rapid onset of the effects of ozoralizumab, we compared the biodistribution kinetics of ozoralizumab and adalimumab after subcutaneous injection in an animal model of arthritis. Alexa Fluor 680-labeled ozoralizumab and adalimumab were administered by subcutaneous injection once (2 mg/kg) at five weeks after induction of collagen-induced arthritis (CIA) in an animal arthritis model. The time-course of changes in the fluorescence intensities of the two compounds in the paws and serum were evaluated. The paws of the CIA mice were harvested at four and eight hours after the injection for fluorescence microscopy. Biofluorescence imaging revealed better distribution of ozoralizumab to the joint tissues than of adalimumab, as early as at four hours after the injection. Fluorescence microscopy revealed a greater fluorescence intensity of ozoralizumab in the joint tissues than that of adalimumab at eight hours after the injection. Ozoralizumab showed a significantly higher absorption rate constant as compared with adalimumab. These results indicate that ozoralizumab enters the systemic circulation more rapidly and is distributed to the target tissues earlier and at higher levels than conventional IgG antibodies. Our investigation provides new insight into the mechanism underlying the rapid onset of the effects of ozoralizumab in clinical practice.

Improvement of Knee Alignment and Function After Corrective Surgery for Hindfoot Deformity: A Report of 3 Cases.

CASE: Marked varus or valgus hindfoot deformities in 3 patients with ankle osteoarthritis or rheumatoid arthritis were treated by corrective surgery using total ankle arthroplasty or distal tibia oblique osteotomy. All cases achieved not only sufficient correction and satisfactory clinical/radiographic hindfoot improvement but also improvements in both knee alignment and function. CONCLUSION: Corrective surgery for hindfoot deformity can potentially change or improve ipsilateral knee alignment and function, representing an unexpected benefit of hindfoot realignment.

Characteristics of Intermetatarsal Angle Between the Second and Fifth Metatarsals (M2-M5A) in the Rheumatoid Foot.

BACKGROUND: Increasing of intermetatarsal angle between the first and second metatarsals (M1-M2A) has been reported as a risk factor for recurrence of hallux valgus (HV) deformity, on the other hand, increasing of intermetatarsal angle between the second and fifth metatarsals (M2-M5A) has been reported as a risk factor for resubluxation of the metatarsophalangeal (MTP) joint of the lesser toe after rheumatoid forefoot surgery. In this study, parameters related to increasing M2-M5A were investigated, as compared with M1-M2A and M1-M5A. METHODS: Radiographic parameters including M1-M2A, M1-M5A, and M2-M5A were retrospectively evaluated for 119 lower limbs from 68 patients with rheumatoid arthritis (RA). To clarify the clinical importance of these intermetatarsal angles, relationships with results from the timed up-and-go (TUG) test were also investigated. RESULTS: M1-M5A showed no correlation with mid-hind foot parameters, whereas M1-M2A and M2-M5A correlated with valgus/varus parameters. An increased M1-M2A was associated with lateral shift of the loading axis in the tibial plafond, whereas an increased M2-M5A was associated with medial shift, but M1-M5A showed no associations. M2-M5A/M1-M2A was significantly lower (1.7) in the normal TUG group than in the delayed TUG group (2.8) (p=0.045). CONCLUSIONS: Different patterns of spread are seen for the forefoot. One has a predominantly increased M1-M2A with lateral shift of the loading point in the tibial plafond, whereas the other has a predominantly increased M2-M5A with medial shift of the loading point in the tibial plafond. M2-M5A also should be calculated, and M2-M5A/M1-M2A might be meaningful in understanding physical mobility in RA patients.