Evaluation of an operation support system using the femoral anterior tangent line to determine intraoperative femoral component rotation in total knee arthroplasty.

BACKGROUND: The femoral anterior tangent (FAT) line refers to a line parallel to the anterior surface of the distal femur in the axial plane. This study aimed to evaluate the effectiveness of a new operation support system which uses the FAT line to set the femoral component rotational alignment in total knee arthroplasty (TKA). METHODS: A total of 170 consecutive knees in 139 patients undergoing primary TKA with the JIGEN (Jig Engaged Three-dimensional (3D) Pre-Operative Planning Software for TKA) operation support system was examined. The JIGEN system creates 3D models of bones using computed tomography data, allowing for surgical simulations such as positioning of implants while calculating positions of the intramedullary alignment rod (IM rod) and surgical jig. We retrospectively analyzed the FAT line angle relative to the surgical epicondylar axis (SEA) on the axis plane perpendicular to the IM rod and evaluated the accuracy of the femoral component alignment after TKA with the 3D measurement system. RESULTS: The FAT line was 9.6° ± 3.7° (range, 1.4°-20.4°) internally rotated relative to the SEA. The average absolute error was 1.4° ± 1.1° in the coronal plane, 2.0° ± 1.5° in the sagittal plane, and 1.6° ± 1.3° in the axial plane. The femoral component outliers (i.e., >3° away from the goal alignment) were 7.7% in the coronal plane, 20.6% in the sagittal plane, and 10.3% in the axial plane. CONCLUSIONS: Our findings suggest that the FAT line is a reliable and reproducibly identifiable axis for the accurate determination of proper rotational alignment in TKA. An operation support system which uses the FAT line for determining intraoperative femoral component rotation can effectively achieve highly accurate positioning of the femoral component in TKA.

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.

Clinical effectiveness and long-term retention of abatacept in elderly rheumatoid arthritis patients: Results from a multicenter registry system.

Objective: To study the clinical effectiveness and long-term retention rate of abatacept (ABA) in elderly rheumatoid arthritis (RA) patients in daily clinical practice.Methods: A retrospective cohort study was performed using data from a multicenter registry. Our study population comprised 500 consecutive RA patients treated with ABA. We compared clinical effectiveness and ABA retention rates between the Young (≤62 years), Middle (62 to 72 years), and Elderly (≥72 years) groups. We also performed separate examinations to identify predictive factors for ABA discontinuation in those with versus those without concomitant methotrexate (MTX) treatment.Results: Mean age was 52.7 years in the Young group, 67.7 years in the Middle group, and 78.1 years in the Elderly group. No significant group-dependent differences were found in mean DAS28 score, categorical distribution of DAS28, and EULAR response rate across the 52 weeks. The ABA retention rates at three years as determined by the Kaplan-Meier method were similar in all three groups. Patient age was not a significant predictor of ABA discontinuation due to adverse events in patients with concomitant MTX; however, it was found to be a significant predictor for those who did not use MTX (Cox hazard model).Conclusion: ABA would be a reasonable treatment option for elderly RA patients from the viewpoints of both clinical effectiveness and long-term retention. However, physicians should watch carefully for any serious adverse reactions in elderly RA patients with intolerance to MTX.

Predictors of biologic discontinuation due to insufficient response in patients with rheumatoid arthritis who achieved clinical remission with biologic treatment: A multicenter observational cohort study.

OBJECTIVE: This study aimed to investigate predictors of biologic discontinuation due to insufficient response as a surrogate for relapse in patients with rheumatoid arthritis (RA) who achieved clinical remission with biologic treatment. METHODS: This study was performed based on data from a multicenter registry, and included 404 patients who achieved clinical remission within the first year of treatment with their first biologic. Cumulative retention rate of the first biologic was estimated using Kaplan-Meier curves, and the impact of patient characteristics on biologic discontinuation was assessed with Cox proportional hazards models. RESULTS: During follow-up, 50 patients discontinued their first biologic due to insufficient response. Overall discontinuation rates due to insufficient response after achieving remission were 6%, 11%, and 19% at 1, 2, and 5 years, respectively. Multivariate analysis revealed that concomitant glucocorticoids at achieving remission [hazard ratio (HR): 3.80, 95% confidence interval (CI): 1.89-7.64)] and a higher level of C-reactive protein (CRP) at achieving remission (HR: 1.47 per 1 mg/dL, 95% CI: 1.09-1.99) independently predict discontinuation due to insufficient response after achieving remission. CONCLUSION: Patients with RA who achieved remission with concomitant glucocorticoid treatment and a higher level of CRP are at high risk of subsequent biologic discontinuation due to insufficient response.

LRP4 third ß-propeller domain mutations cause novel congenital myasthenia by compromising agrin-mediated MuSK signaling in a position-specific manner.

Congenital myasthenic syndromes (CMS) are heterogeneous disorders in which the safety margin of neuromuscular transmission is compromised by one or more specific mechanisms. Using Sanger and exome sequencing in a CMS patient, we identified two heteroallelic mutations, p.Glu1233Lys and p.Arg1277His, in LRP4 coding for the postsynaptic low-density lipoprotein receptor-related protein 4. LRP4, expressed on the surface of the postsynaptic membrane of the neuromuscular junction, is a receptor for neurally secreted agrin, and LRP4 bound by agrin activates MuSK. Activated MuSK in concert with Dok-7 stimulates rapsyn to concentrate and anchor AChR on the postsynaptic membrane and interacts with other proteins implicated in the assembly and maintenance of the neuromuscular junction. LRP4 also functions as an inhibitor of Wnt/beta-catenin signaling. The identified mutations in LRP4 are located at the edge of its 3rd beta-propeller domain and decrease binding affinity of LRP4 for both MuSK and agrin. Mutations in the LRP4 3rd beta-propeller domain were previously reported to impair Wnt signaling and cause bone diseases including Cenani-Lenz syndactyly syndrome and sclerosteosis-2. By analyzing naturally occurring and artificially introduced mutations in the LRP4 3rd beta-propeller domain, we show that the edge of the domain regulates the MuSK signaling whereas its central cavity governs Wnt signaling. We conclude that LRP4 is a new CMS disease gene and that the 3rd beta propeller domain of LRP4 mediates the two signaling pathways in a position-specific manner.

Disease activity early in treatment as a predictor of future low disease activity in RA patients treated with iguratimod.

OBJECTIVES: This retrospective observational study aimed to examine the efficacy of iguratimod with and without concomitant methotrexate (MTX) and to estimate the adequate observational period for predicting low disease activity (LDA) achievement at 24 weeks in patients with rheumatoid arthritis (RA). METHODS: All patients treated with iguratimod were registered in a Japanese multicenter registry. Multivariate analyses were performed to identify predictive factors for LDA achievement at 24 weeks. Receiver operating characteristic (ROC) curve analyses were performed to estimate the association of 28-joint disease activity score based on erythrocyte sedimentation rate (DAS28-ESR) at each time point with achievement of LDA at 24 weeks and determine a cut-off for DAS28-ESR. RESULTS: A total of 123 patients were treated with iguratimod with (n = 65) or without (n = 58) MTX. Iguratimod therapy resulted in significant clinical improvement in both groups. Multivariate analysis revealed that DAS28-ESR at each time point was an independent significant predictor of LDA achievement at 24 weeks. Cut-off values of DAS28-ESR at 12 weeks based on ROC curves were 3.2 and 3.6 in patients with and without MTX, respectively. CONCLUSIONS: Iguratimod was effective in RA patients in clinical practice. Our results suggest that 12 weeks may be a sufficient period to judge the medium-term efficacy of iguratimod in patients treated with and without MTX.

Importance of methotrexate therapy concomitant with tocilizumab treatment in achieving better clinical outcomes for rheumatoid arthritis patients with high disease activity: an observational cohort study.

OBJECTIVE: The purpose of this study was to identify the effects of concomitant use of MTX and baseline characteristics for remission in the treatment of RA with tocilizumab (TCZ) in daily clinical practice. METHODS: A total of 240 RA patients who received TCZ were selected from the multicentre Tsurumai Biologics Communication Registry. Predictive baseline factors for remission [28-item DAS (DAS28) < 2.6] at 52 weeks were determined by logistic regression analysis. To confirm whether the associations varied by the level of baseline disease activity, we also assessed the model including the interaction term (each baseline variable × DAS28). RESULTS: In total, 49.3% of the study participants used MTX with TCZ. Even after controlling for the baseline DAS28, shorter disease duration (≤3 year) [odds ratio (OR) 3.58 (95% CI 1.81, 7.07)], less structural damage [Steinbroker stage ≤II, OR 2.33 (95% CI 1.32, 4.12)] and concomitant prednisolone use [OR 0.38 (95% CI 0.21, 0.68)] showed significant predictive values for remission. Concomitant MTX use failed to show a significant association with remission, whereas a significant interaction was observed among concomitant MTX use × DAS28 (P = 0.006). In patients with high baseline disease activity (DAS28 > 5.1), concomitant MTX use was associated with increased odds for remission [adjusted OR for all baseline variables 2.54 (95% CI 1.11, 5.83)], while no association was indicated between them in patients with low to moderate baseline disease activity (DAS28 ≤ 5.1). CONCLUSION: Concomitant MTX use is an important component of TCZ treatment for RA patients with high disease activity.

Concomitant methotrexate and tacrolimus augment the clinical response to abatacept in patients with rheumatoid arthritis with a prior history of biological DMARD use.

This observational retrospective study examined whether abatacept efficacy could be augmented with concomitant methotrexate (MTX) or tacrolimus (TAC) in patients with rheumatoid arthritis (RA) who experienced failure with prior biological disease-modifying antirheumatic drugs (DMARDs) and in whom favorable therapeutic efficacy is difficult to achieve. All patients with a prior biological DMARD history who were treated with abatacept for 52 weeks and registered in a Japanese multicentre registry were included. Clinical efficacy and safety of abatacept according to the concomitant drug used, i.e., none (ABT-mono), MTX (ABT-MTX), and TAC (ABT-TAC), were compared. A greater mean percent change of DAS28-ESR was observed in the ABT-TAC group compared with the ABT-mono group at weeks 12 (-20.5 vs. -5.4 %, p = 0.035) and 24 (-25.0 vs. -11.0 %, p = 0.036). ABT-MTX and ABT-TAC groups had a significantly higher proportion of patients who achieved low disease activity (LDA) within 52 weeks compared with the respective baselines, while no significant change was observed in the ABT-mono group. A higher proportion of patients in the ABT-TAC group achieved EULAR moderate response compared with the ABT-mono group at week 52 (66.7 vs. 35.0 %, p = 0.025). Multivariate logistic regression analysis revealed that concomitant TAC use was independently associated with the achievement of LDA and EULAR response at 52 weeks, while concomitant MTX use was not. Concomitant TAC use may offer a suitable option for RA patients treated with abatacept after prior biological DMARD failure, likely because both abatacept and TAC affect T cell activation.

Drug retention rates of second biologic agents after switching from tumor necrosis factor inhibitors for rheumatoid arthritis in Japanese patients on low-dose methotrexate or without methotrexate.

OBJECTIVES: The purpose of this study was to explore drug retention rates of second biologic agents after switching from tumor necrosis factor inhibitors (TNFi) in clinical practice in patients with rheumatoid arthritis (RA) on low-dose methotrexate (MTX) or without MTX. METHODS: A total of 169 RA patients who had been withdrawn from first-course TNFi therapy and received a different TNFi or tocilizumab (TCZ) as a second biologic agent were selected from the Tsurumai Biologics Communication Registry, an observational cohort database. Retention rates of second biologic treatment were compared by the type of first TNFi and second biologic agents. RESULTS: Eighty-six patients received first-course infliximab (IFX) or adalimumab (ADA) therapy, and 83 patients received first-course etanercept (ETN) therapy. The former group had a significantly higher retention rate (IFX, 81.1%; ADA, 83.3%) of the second biologic therapy compared to the latter (56.6%, p < 0.001, log-rank test). Drug retention rates of the second biologic agent after switching from IFX/ADA were significantly higher with ETN (90.0%) and TCZ (94.7%) than with ADA/IFX (59.3%). Drug retention rates of the second biologic agent after switching from ETN were significantly higher with TCZ (75.9%) than with ADA/IFX (46.3%). The differences were significant even after adjusting for baseline clinical variables using the Cox proportional hazards model. CONCLUSIONS: Drug retention rates of IFX and ADA after switching from the first TNFi were significantly lower compared to those of ETN and TCZ in patients on low-dose MTX or without MTX.

LRP4 induces extracellular matrix productions and facilitates chondrocyte differentiation.

Endochondral ossification is an essential step for skeletal development, which requires chondrocyte differentiation in growth cartilage. The low-density lipoprotein receptor-related protein 4 (LRP4), a member of LDLR family, is an inhibitor for Wnt signaling, but its roles in chondrocyte differentiation remain to be investigated. Here we found by laser capture microdissection that LRP4 expression was induced during chondrocyte differentiation in growth plate. In order to address the roles, we overexpressed recombinant human LRP4 or knocked down endogenous LRP4 by lentivirus in mouse ATDC5 chondrocyte cells. We found that LRP4 induced gene expressions of extracellular matrix proteins of type II collagen (Col2a1), aggrecan (Acan), and type X collagen (Col10a1), as well as production of total proteoglycans in ATDC5 cells, whereas LRP4 knockdown had opposite effects. Interestingly, LRP4-knockdown reduced mRNA expression of Sox9, a master regulator for chondrogenesis, as well as Dkk1, an extracellular Wnt inhibitor. Analysis of Wnt signaling revealed that LRP4 blocked the Wnt/ß-catenin signaling activity in ATDC5 cells. Finally, the reduction of these extracellular matrix productions by LRP4-knockdown was rescued by a ß-catenin/TCF inhibitor, suggesting that LRP4 is an important regulator for extracellular matrix productions and chondrocyte differentiation by suppressing Wnt/ß-catenin signaling.

Orchid Mycorrhizal Association of Cultivated Dendrobium Hybrid and Their Role in Seed Germination and Seedling Growth.

Orchids are crucial for the horticulture industry. Mycorrhizal fungi benefit crops by improving nutrition, plant growth, and disease resistance. However, the mycorrhizal association of horticultural hybrid orchids is poorly understood. To address this, we investigated mycorrhizal colonization in the entire root system and assessed the mycorrhizal community using a Dendrobium cultivar, D. Stardust 'Firebird', obtained from three nurseries. Additionally, we isolated and tested mycorrhizal fungi in symbiotic culture to assess their role in the seed germination and growth of Dendrobium species. All plants were colonized by mycorrhizal fungi, with a higher colonization rate in mature than in juvenile plants. Molecular identification of mycorrhizal fungi by Sanger and high-throughput sequencing revealed that the cultivar was associated with a phylogenetically diverse group of fungi, including mycorrhizal fungi from Tulasnellaceae, and several wood-decaying fungi. The Tulasnellaceae isolates significantly enhanced the seed germination of three Dendrobium species and increased the survival rate and growth of asymbiotic seedlings of D. moniliforme. This study is the first comprehensive examination of mycorrhizal associations in horticultural orchid hybrids, providing valuable insights for commercial production.

A review of tocilizumab treatment in 122 rheumatoid arthritis patients included in the Tsurumai Biologics Communication Registry (TBCR) Study.

OBJECTIVES: Biologics have transformed the treatment of rheumatoid arthritis. Clinical remission is now the goal. We sought to verify whether the administration of tocilizumab-a biologic-can help to achieve current treatment goals. METHODS: Using data from the Tsurumai Biologics Communication Registry for 122 patients treated with tocilizumab, we evaluated changes in DAS28-ESR at 12 months after initiation, and also evaluated remission rates defined using conventional and new Boolean-based remission criteria. We divided 50 patients who had received tocilizumab as a first-line treatment into two groups [disease duration at baseline of 12 months or less (≤12 M) and more than 12 months (>12 M)]. RESULTS: At 12 months after initiation, there was no difference in DAS28-ESR, and remission rates based on the conventional criterion were also comparable (50 % in both groups). However, under the new criterion, remission was 50.0 % in the ≤12 M group against 12.5 % in the >12 M group (p = 0.0181). Among the individual components of the new remission criterion, the small proportion of patients in the >12 M group with a patient global assessment (PtGA) of ≤1 had a particularly strong influence on the remission rate for that group, but this component was not as important for the ≤12 M group. CONCLUSIONS: When used as a first-line biological drug for patients with early-stage RA (≤12 M), tocilizumab appears to provide high rates of remission under the Boolean-based remission criterion, which were strongly affected by the PtGA.

Monitoring C-reactive protein levels to predict favourable clinical outcomes from tocilizumab treatment in patients with rheumatoid arthritis.

OBJECTIVES: The inflammatory cytokine interleukin-6 (IL-6) directly stimulates C-reactive protein (CRP) expression. The present study aimed to examine how clinical treatment outcomes of rheumatoid arthritis (RA) with tocilizumab (TCZ), a humanised monoclonal anti-IL-6 receptor antibody, are related to CRP levels monitored for 52 weeks. METHODS: One hundred and twenty-two RA patients who underwent TCZ treatment between May 2008 and September 2009 were registered in the Tsurumai Biologics Communication Registry. Data were collected at initiation of treatment (baseline) and over 52 weeks for Disease Activity Score 28-ESR (DAS28-ESR), Boolean core measurements, serum CRP levels and matrix metalloproteinase-3 levels. To compare clinical results, patients were divided into three groups based on treatment time required to achieve normal CRP levels. RESULTS: Multivariate analysis using the Cox proportional-hazards regression model found that higher CRP levels at baseline was a significant and independent factor in predicting normal CRP levels over 52 weeks (hazard ratio 0.86 per 1 mg/dL). In contrast, disease duration, concomitant methotrexate use and previous tumour necrosis factor inhibitor failure were not significant factors. Patients with normal CRP levels at 12 weeks of TCZ treatment achieved better clinical outcomes, including remission based on DAS28-ESR criteria, compared to patients with elevated CRP levels at 12 weeks. CONCLUSIONS: Adequate suppression of pathological IL-6 signalling during TCZ treatment improves clinical outcomes and can be monitored with serum CRP levels, a readily available biomarker in clinical practice.

Femoral Valgus Correction Angle for the Intramedullary Alignment Rod Is Strongly Associated with Femoral Lateral Bowing in Japanese Patients with Varus Knee Osteoarthritis Undergoing Total Knee Arthroplasty.

Background: This study aimed to investigate factors, such as differences in femoral shape, that could affect the femoral valgus correction angle (VCA) for the intramedullary alignment rod (IM rod) by using a three-dimensional (3D) measurement system in patients with varus knee osteoarthritis undergoing total knee arthroplasty (TKA). Methods: A total of 305 knees in 233 Japanese patients with varus knee osteoarthritis who underwent primary TKA by using Jig Engaged 3D Pre-Operative Planning Software for the TKA operation support system was examined. We retrospectively analysed factors, such as the shape of the proximal, middle, and distal femur in the coronal plane, all of which could affect the VCA for the IM rod, by multiple linear regression analyses. Results: The VCA for the IM rod was 5.9° ± 1.6° (range: 1.7° to 10.7°), and the femoral lateral bowing angle (FBA) was 3.5° ± 3.2°. Major factors independently associated with the VCA for the IM rod were the FBA (ß: 0.75), femoral offset (ß: 0.38), and the medial angle between the mechanical femoral axis and the line that connects the distal margins of the medial and lateral femoral condyles (ß: -0.16). The model was created by stepwise multiple linear regression (F = 266.6, p < 0.001, and estimated effect size = 4.4) explained 85% of the variance in the VCA for the IM rod (R 2 = 0.85). Conclusions: The VCA for the IM rod was most strongly associated with femoral lateral bowing in patients with varus knee osteoarthritis undergoing TKA. Our findings suggest that preoperatively measuring the VCA for the IM rod in patients with femoral lateral bowing by using a 3D measurement system could be useful for accurate coronal alignment of the femoral component in TKA.

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.

Influence of methotrexate on gastrointestinal symptoms in patients with rheumatoid arthritis.

AIM: This study aimed to determine the influence of methotrexate (MTX) on gastrointestinal (GI) symptoms in patients with rheumatoid arthritis (RA). METHODS: This cross-sectional study examined 529 consecutive patients with RA receiving oral MTX in our department between April 1 and September 30, 2017. GI symptoms were evaluated by the Gastrointestinal Symptom Rating Scale (GSRS); a score of ≥2 was considered "symptomatic." Prevalence of GI symptoms was compared between patients receiving ≤8 mg/wk (low-dose) vs >8 mg/wk (high-dose) of MTX. RESULTS: Of our study population, 313 (59%) received low-dose MTX at a median (interquartile range) dose of 6 (6-8) mg/wk, whereas 216 (41%) received high-dose MTX at a median dose of 12 (10-12) mg/wk. Relative to the low-dose MTX group, the high-dose MTX group exhibited a higher prevalence of reflux (32% vs 24%, P = 0.043) and abdominal pain (28% vs 18%, P = 0.007). There was no significant group-dependent difference in the prevalence of indigestion, diarrhea or constipation. Multivariate logistic regression analysis revealed that high-dose MTX (>8 mg/wk) was independently associated with reflux (odds ratio [OR]: 1.62, 95% confidence interval [CI]: 1.07-2.43) and abdominal pain (OR: 1.60, 95% CI: 1.04-2.43), and that the ORs for reflux and abdominal pain among those receiving high-dose MTX (>8 mg/wk) were similar to those using nonsteroidal anti-inflammatory drugs. CONCLUSION: High-dose MTX is independently associated with the prevalence of upper GI symptoms in Japanese patients with RA.

Computed tomography evaluation of the periacetabular gap of a porous tantalum acetabular component.

The periacetabular gap is an inherent consequence of the peripheral rim press-fit of the porous tantalum acetabular component. The circumference of the prosthesis is clearly depicted with computed tomography (CT) images that have been optimised to reduce metal artefacts. This case report highlights the utility of single-energy metal artefact reduction (SEMAR) for CT evaluation of the periacetabular gap by comparing CT images with and without SEMAR. A 70-year-old woman with a 5-year history of rheumatoid arthritis underwent total hip arthroplasty with a porous tantalum modular acetabular component. A periacetabular gap was suspected by plain radiography 2 weeks postoperatively. The metal artefacts rendered evaluation of the circumference of the acetabular component difficult in CT images acquired without SEMAR. In contrast, there were fewer metal artefacts, and a periacetabular gap (depth of 6.5 mm in DeLee and Charnley zone 2) was clearly depicted in CT images with SEMAR 2 weeks postoperatively. The porous surface of the acetabular component was in contact with the anterior and posterior rims of the acetabulum. Gap filling with bone and bone ingrowth into the porous surface were observed on CT images with SEMAR 24 weeks postoperatively. In conclusion, SEMAR reduces metal artefacts and improves CT image quality around the circumference of the acetabular component. The periacetabular gap and its filling with bone are clearly depicted in CT images with SEMAR, but not without SEMAR.

Association between chest computed tomography findings and respiratory adverse events in rheumatoid arthritis patients undergoing long-term biological therapy.

OBJECTIVE: This study aimed to assess the association between chest computed tomography (CT) findings and incidence of respiratory adverse events (RAEs), and to detect risk factors for RAEs, in RA patients treated with long-term biological therapy. METHODS: Clinical and radiological data of 332 RA patients who were treated with biological disease-modifying antirheumatic drugs were collected. CT data were assessed by an experienced radiologist. Patients were categorized into the interstitial lung disease (ILD) group (n = 29), airway disease (AD) group (n = 76), co-existing ILD and AD (Co-existing) group (n = 6), and the group without detectable change (WDC, n = 221) based on CT findings and scores. The incidence of RAEs was calculated for each group, and risk factors for RAEs from CT findings were explored. RESULTS: We identified 41 RAEs, including acute onset or exacerbation of ILD (ILD events, n = 15), respiratory tract infection events (infection events, n = 21), and other events (n = 6). Cumulative incidences of ILD events were 20.2, 3.75, 47.2, and 1.94 (/1000 patient-years: PY) in the ILD, AD, Co-existing, and WDC groups, respectively, and those of infection events were 11.3, 17.6, 23.6, and 2.39 (/1000PY), respectively. Severity, as assessed by CT scores, was correlated with the incidence of RAEs. Risk factors for ILD events were reticular and honeycomb changes, and those for infection events were consolidation, bronchial wall thickening, bronchiectasis, bronchiolitis, air trapping, and atelectasis after adjusting for background factors. CONCLUSION: Our findings highlight particular CT findings that are associated with RAEs in RA patients undergoing long-term biological therapy.