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Autoimmune diseases are often accompanied by acute exacerbation. However, the mechanism underlying systemic lupus erythematosus (SLE) flares remains unclear. We investigated whether short-term enteric Toll-like receptor 7 (TLR7) stimulation can exacerbate SLE using B6SKG mice, which spontaneously develop SLE due to a mutation in the zeta‒chain‒associated protein kinase 70 (Zap70) gene. Imiquimod (IMQ) or phosphate-buffered saline (PBS) were orally administered on B6WT and B6SKG mice every other day for 2 weeks. SLE exacerbation was assessed via fluorescent immunohistochemical staining of glomeruli for IgG and C3, hematoxylin and eosin staining of kidneys, and enzyme-linked immunosorbent assay for antinuclear antibody (ANA). Flow cytometry was used to evaluate germinal center B cells (GCBs), plasma cells, follicular helper T cells (Tfhs), regulatory T cells (Tregs), effector T cells (Th1s and Th17s), plasmacytoid dendritic cells (pDCs), conventional dendritic cells (cDCs), and macrophages (Mφs) in spleens. Oral administration of IMQ every other day for 2 weeks resulted in exacerbation of splenomegaly, increased IgG and C3 deposition in glomeruli, and increased ANA production in the B6SKG IMQ (SKG-IMQ) group compared to the B6SKG PBS (SKG-PBS) group; the percentages of GCBs, plasma cells, Tfhs, Th1s, pDCs, and Mφs were also increased in the SKG-IMQ group. Splenomegaly, IgG, and C3 deposition in glomeruli, and the percentages of GCBs, plasma cells, Tfhs, and Th1s were enhanced in SKG-IMQ mice compared with B6SKG mice topically treated with IMQ (SKG-ear-IMQ). Oral TLR7 stimulation in a Zap70 genetic mutation background can cause acute exacerbations of SLE. Key Points • The mechanism of SLE flares is not well understood. • We have created a model that causes short-term SLE exacerbations in mice with a genetic background. • IMQ administered orally causes more SLE in mice than transdermally.

Biologics are structurally heterogeneous and can undergo biotransformation in the body. Etanercept (ETN) is a fusion protein composed of a soluble tumor necrosis factor (TNF) receptor and the Fc portion of human immunoglobulin G1. The N-terminus of ETN has a putative sequence cleaved by dipeptidyl peptidase-4 (DPP-4). The purpose of this study was to investigate the biotransformation of ETN in humans and mice and evaluate its effects on functional properties.An analytical method using liquid chromatography-mass spectrometry (LC-MS/MS) was established. The N-terminal heterogeneity of ETN was assessed in the serum of patients with rheumatoid arthritis or mice receiving ETN. The in vitro N-terminal truncation was explored using recombinant DPP-4. The binding affinity to TNF-α or TNF-β was investigated using an in-house enzyme-linked immunosorbent assay.In the formulations, about 90% of ETN had an intact N-terminus, while the N-terminal truncated form was most abundant in the serum of the patients with rheumatoid arthritis and mice. Recombinant human DPP-4 cleaved two amino acids from the N-terminus of ETN in vitro. Sitagliptin, a DPP-4 inhibitor, inhibited N-terminal truncation both in vivo and in vitro. However, N-terminal truncation did not affect the binding ability to TNF-α or TNF-β and the pharmacokinetics of ETN. ETN biosimilars exhibited similar characteristics to the reference product in vivo and in vitro.ETN undergoes N-terminal truncation in the body, and DPP-4 cleaves exogenous ETN via N-terminal proteolysis. The application of an MS-based assay will detect novel biotransformation of therapeutic proteins.

Objective To investigate the associations of disease duration and anti-cyclic citrullinated peptide antibody (ACPA) status with the effectiveness of abatacept in biologic-naïve patients with rheumatoid arthritis (RA) Methods We performed post-hoc analyses of the ORIGAMI study of biologic-naïve RA patients aged ≥20 years with moderate disease activity who were prescribed abatacept. Changes in Simplified Disease Activity Index (SDAI) and Japanese Health Assessment Questionnaire (J-HAQ) at 4, 24, and 52 weeks of treatment were analysed in patients divided according to ACPA serostatus (positive/negative), disease duration ( Results SDAI scores decreased from baseline in all groups. SDAI scores trended to decrease more in the ACPA-positive group and disease duration Conclusion These results suggest that starting abatacept within 1 year of diagnosis was associated with greater effectiveness of abatacept in biologic-naïve patients with RA and moderate disease activity.

Objectives: The incidence of remdesivir-induced renal dysfunction has not been investigated until now. The present study explored the clinical factors and laboratory data that predict remdesivir-induced renal dysfunction. The subjects were COVID-19 patients and we determined the endpoint as dialysis or death within 29 days. Background status parameters included (1) estimated glomerular filtration rate < 30 ml/min/1.73 m2, (2) serum creatinine (SCr) ratios to baseline > 1.5, (3) SCr ratios to upper limits > 1.5, (4) alanine aminotransferase ratios to upper limits > 5, (5) administration days, (6) sex, (7) age, (8) height, (9) weight, (10) dexamethasone use, and (11) SARS-CoV-2 vaccination. Results: In a total of 490 patients, a multivariate analysis showed that status (2) (odds ratio [OR] 8.342, 95% confidence interval [CI] 1.589-43.788, P=0.012) and status (7) (OR 7.620, CI 1.181-49.169, P=0.033) at 72 years or more were significant factors for remdesivir-induced renal dysfunction. To monitor renal function after remdesivir administration in COVID-19 patients, SCr ratios to baseline may work better than those to the upper limits.

Background Patients with rheumatoid arthritis (RA) are prone to muscle atrophy due to inflammatory cytokines and corticosteroid use and immobility due to joint pain and deformity. Although resistance training is effective and safe in reversing muscle atrophy in RA, some patients are unable to perform a conventional high-load exercise program due to disease-related limitations. This study aims to examine the efficacy of individualized exercise therapy on physical function in elderly patients with RA who are at a high risk for sarcopenia. Methods This study is a single-center, parallel-group, two-arm, healthcare provider- and outcome assessor-blinded, superiority randomized controlled trial with a 1:1 allocation ratio. A total of 160 participants with RA between 60 and 85 years of age with a positive screening test for sarcopenia will be included. The intervention group will receive nutritional guidance and a four-month individualized exercise program in addition to the usual treatment. The control group will receive nutritional guidance in addition to the usual care. The primary endpoint will be physical function assessed using the Short Physical Performance Battery (SPPB) at 4 months. The data on outcome measures will be collected at baseline and at the two- and four-month follow-ups. Linear mixed-effects models for repeated measures will be conducted using the modified intention-to-treat analysis population. Discussion This study will provide evidence on whether a personalized exercise program can improve physical function and quality of life in elderly patients with RA. Some limitations include limited generalizability due to the single-center study and lack of blinding of the patients to the intervention assignment because of the nature of the exercise. Physical therapists may use this knowledge in their daily practice to improve RA treatment. Tailored exercise may enhance the health outcomes of the RA population and contribute to a reduction in healthcare costs. Trial registration The study protocol was retrospectively registered at the University hospital Medical Information Network-Clinical Trial Repository (UMIN-CTR) (registration number: UMIN000044930, https://www.umin.ac.jp/ctr/index-j.htm) on January 4, 2022.

Objectives Although the SLE Disease Activity Score (SLE-DAS) and its definitions to classify disease activity have been recently developed to overcome the drawbacks of the SLE Disease Activity Index 2000 (SLEDAI-2K), the performance of the SLE-DAS for patient-reported outcomes (PROs) has not been fully examined. We aimed to compare SLE-DAS with SLEDAI-2K and validate the classifications of disease activity based on SLE-DAS in terms of PROs. Methods We assessed generic quality of life (QoL) using the Medical Outcome Survey 36-Item Short-Form Health Survey (SF-36), disease-specific QoL using the lupus patient-reported outcome tool (LupusPRO), burden of symptoms using the SLE Symptom Checklist (SSC), patient global assessment (PtGA) and physician global assessment (PhGA). Results Of the 335 patients with SLE, the magnitudes of the mean absolute error, root mean square error, Akaike information criterion, and Bayesian information criterion were comparable for most PROs between the SLE-DAS and SLEDAI-2K. In contrast, SLEDAI-2K had a higher predictive value for health-related QoL of LupusPRO and PtGA than SLE-DAS. Low disease activity, Boolean and index-based remission and categories of disease activity (remission, mild and moderate/severe activity) were significantly associated with health-related QoL in LupusPRO, SSC and PhGA, but not SF-36 or PtGA. Conclusion No clear differences were identified in the use of the SLE-DAS over the SLEDAI-2K in assessing PROs in patients with SLE. The classification of disease activity based on the SLE-DAS was validated against several PROs. SLE-DAS and its categories of disease activity effectively explain some of the PROs.

Due to the poor prognosis of pancreatic cancer, novel diagnostic modalities for early diagnosis and new therapeutic strategy are urgently needed. Recently, microRNA-21 (miR-21) was reported to be strongly overexpressed in pancreatic cancer as well as in other solid cancers. We investigated the functional roles of miR-21, which have not been fully elucidated in pancreatic cancer. miR-21 expression was assessed in pancreatic cancer cell lines (14 cancer cell lines, primary cultures of normal pancreatic epithelial cells and fibroblasts, and a human normal pancreatic ductal epithelial cell line) and pancreatic tissue samples (25 cancer tissues and 25 normal tissues) by quantitative real-time reverse transcription-PCR amplification. Moreover, we investigated the proliferation, invasion, and chemoresistance of pancreatic cancer cells transfected with miR-21 precursor or inhibitor. miR-21 was markedly overexpressed in pancreatic cancer cells compared with nonmalignant cells, and miR-21 in cancer tissues was much higher than in nonmalignant tissues. The cancer cells transfected with the miR-21 precursor showed significantly increased proliferation, Matrigel invasion, and chemoresistance for gemcitabine compared with the control cells. In contrast, inhibition of miR-21 decreased proliferation, Matrigel invasion, and chemoresistance for gemcitabine. Moreover, miR-21 positively correlated with the mRNA expression of invasion-related genes, matrix metalloproteinase-2 and -9, and vascular endothelial growth factor. These data suggest that miR-21 expression is increased in pancreatic cancer cells and that miR-21 contributes to the cell proliferation, invasion, and chemoresistance of pancreatic cancer.[Mol Cancer Ther 2009;8(5):1067–74]

Supplementary Table from MicroRNA-21 modulates biological functions of pancreatic cancer cells including their proliferation, invasion, and chemoresistance

Supplementary Figure Legends from MicroRNA-21 modulates biological functions of pancreatic cancer cells including their proliferation, invasion, and chemoresistance

Supplementary Fig. from MicroRNA-21 modulates biological functions of pancreatic cancer cells including their proliferation, invasion, and chemoresistance

PDF file - 211K, Supplementary Figure 2: Representative photographs showing histological evaluation of Sirius red positive area on subcutaneous pancreatic cancer mouse models.

PDF file - 75K, Supplementary Table 1: Primers used for quantitative RT-PCR.

PDF file - 141K, Supplementary Figure 1: A and B. Expression analysis of α-SMA, glial fibrillary acidic protein (GFAP), and cytokeratin 19 in human PSCs isolated from pancreatic ductal adenocarcinoma.

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PDF file - 1482K, Supplementary Figure 3: A. Representative photographs showing histological evaluation of desmoplastic activity on orthotopic pancreatic cancer mouse models. B. Evaluation of the PCNA index (%). C. Representative photographs showing nodules of liver metastasis on the surface of the liver.

Pancreatic stellate cells (PSC), which are implicated in desmoplasia in pancreatic cancer, enhance the malignancy of cancer cells and confer resistance to established treatments. We investigated whether the antifibrotic agent pirfenidone can suppress desmoplasia and exert antitumor effects against pancreatic cancer. Primary PSCs were established from pancreatic cancer tissue obtained during surgery. In vitro, pirfenidone inhibited the proliferation, invasiveness, and migration of PSCs in a dose-dependent manner. Although supernatants of untreated PSCs increased the proliferation, invasiveness, and migration of pancreatic cancer cells (PCC), supernatants of pirfenidone-treated PSCs decreased these effects. Exposure to PCC supernatant increased the production of platelet-derived growth factor-A, hepatic growth factor, collagen type I, fibronectin, and periostin in PSCs, which was significantly reduced by pirfenidone. Mice were subcutaneously implanted with PCCs (SUIT-2 cells) and PSCs into the right flank and PCCs alone into the left flank. Oral administration of pirfenidone to these mice significantly reduced tumor growth of co-implanted PCCs and PSCs, but not of PCCs alone. Pirfenidone also decreased the proliferation of PSCs and the deposition of collagen type I and periostin in tumors. In mice with orthotopic tumors consisting of PCCs co-implanted with PSCs, pirfenidone suppressed tumor growth, reduced the number of peritoneal disseminated nodules, and reduced the incidence of liver metastasis. Pirfenidone in combination with gemcitabine more effectively suppressed orthotopic tumor growth compared with pirfenidone or gemcitabine alone. In conclusion, our findings indicate that pirfenidone is a promising antitumor agent for pancreatic cancer, owing to its suppression of desmoplasia through regulating PSCs. Cancer Res; 73(7); 2345–56. ©2013 AACR.

Background Anti-citrullinated protein/peptide antibodies (ACPAs) are present in patients at onset and have important pathogenic roles during the course of rheumatoid arthritis (RA). The characteristics of several molecules recognized by ACPA have been studied in RA, but the positivity rate of autoantibodies against each antigen is not high, and the pathogenic mechanism of each antibody is not fully understood. We investigated the role of anti-citrullinated osteopontin (anti-cit-OPN) antibodies in RA pathogenesis. Methods Enzyme-linked immunosorbent assays on RA patients’ sera were used to detect autoantibodies against OPN. Fibroblast-like synoviocytes (FLS) isolated from RA patients were used to test the binding activity and inflammatory response of OPN mediated by anti-cit-OPN antibodies, and their effect was tested using an inflammatory arthritis mouse model immunized with cit-OPN. Anti-cit-OPN antibody positivity and clinical characteristics were investigated in the patients as well. Results Using sera from 224 RA patients, anti-cit-OPN antibodies were positive in approximately 44% of RA patients, while approximately 78% of patients were positive for the cyclic citrullinated peptide (CCP2) assay. IgG from patients with anti-cit-OPN antibody increased the binding activity of OPN to FLSs, which further increased matrix metalloproteinase and interleukin-6 production in TNF-stimulated FLSs. Mice immunized with cit-OPN antibodies experienced severe arthritis. Anti-cit-OPN antibodies in RA patients decreased the drug survival rate of tumor necrosis factor (TNF) inhibitors, while it did not decrease that of CTLA4-Ig. Conclusions Anti-cit-OPN antibodies were detected in patients with RA. IgG from patients with anti-cit-OPN antibodies aggravated RA, and anti-cit-OPN antibody was a marker of reduced the survival rate of TNF inhibitors in RA patients.

Rheumatoid factor (RF) binds to the fragment crystallizable (Fc) portion of immunoglobulin. It could bind to the Fc portion of anti-TNF inhibitors (TNFi) and attenuate the clinical efficacy. We tried to determine whether the therapeutic efficacy of TNFi with Fc might be lower than that of TNFi without Fc in rheumatoid arthritis (RA) patients with high titres of RF. The Kansai Consortium for Well-being of Rheumatic Disease Patients (ANSWER) cohort is an observational multi-center registry of patients with RA in the Kansai district of Japan. RA patients treated with TNFi were included and divided into two groups based on the structural characteristics between TNFi with Fc (infliximab, adalimumab, golimumab, and etanercept) and TNFi without Fc (certolizumab pegol). Patients were classified into 4 groups according to RF titre quartiles. The sequential disease activity score in 28 joints using erythrocyte sedimentation rate (DAS28-ESR) was compared by Mann-Whitney U test between TNFi with and without Fc in each RF titre group. Multiple linear regression analysis was used to analyze the effect of TNFi without Fc for the change of DAS28-ESR adjusted after potential confounders. A total of 705 RA patients were classified into four groups (RF

The mature form of sterol regulatory element-binding protein (SREBP)1 is a transcription factor involved in lipid synthesis, which participates in toll like receptor 4-triggered inflammatory pathways during the resolution phase of inflammation in macrophages. SREBP1 has thus attracted interest as a candidate target molecule for ameliorating inflammation. Fatostatin is a small molecule that inhibits the maturation and function of SREBP, and its role in regulating inflammation is poorly understood. To evaluate the anti-inflammatory effect of fatostatin, we compared body weight, footpad and hock dimensions, and arthritis scores between K/BxN serum-induced arthritis mice treated with fatostatin and those treated with dimethyl sulfoxide as the vehicle control. We performed hematoxylin and eosin staining of joints of distal paws to assess tissue inflammation. Moreover, inflammatory cytokine production levels and cell viability were measured in lipopolysaccharide-responsive human embryonic kidney 293 cells (293/hTLR4A-MD2-CD14 cells) after fatostatin administration. In K/BxN serum-induced arthritis mice, fatostatin treatment significantly reduced the arthritis scores and hyperplasia. In vitro analysis revealed that fatostatin significantly inhibited the secretion of inflammatory cytokines from cells activated with lipopolysaccharide, without affecting cell viability. This is the first study to demonstrate that fatostatin is an anti-inflammatory agent that modulates the processing of lipid transcription factors without affecting cell viability. Accordingly, the study reveals the potential of anti-inflammatory therapeutics that link lipid regulation and inflammation.

Objective The aim of this study was to investigate association of autoantibodies with scleroderma renal crisis (SRC) among Japanese patients. Methods The clinical characteristics and mortality of 330 patients with sytemic screlosis (SSc) at Kyoto University Hospital were retrospectively analysed, focusing on possible association with anti-topoisomerase I (anti-topo I), anti-centromere (ACA), anti-RNA polymerase III (RNAPIII) and/or anti-U1-RNP. Logistic regression analyses were performed to reveal any association of these autoantibodies with the development and mortality of SRC. Results SRC was observed in 24 out of 330 SSc patients, including patients with anti-topo I (n = 12/24, 50%), anti-RNAPIII (n = 7/24, 29%), anti-U1-RNP (n = 5/24, 21%) and ACA (n = 3/24, 13%). Anti-U1-RNP [odds ratio (95% CI), 3.63 (1.11, 10.2)], anti-topo I [3.22 (1.37, 7.57)] and anti-RNAPIII (3.29 [1.16, 8.70]) were associated with the development of SRC. Furthermore, anti-topo I [6.00 (1.11, 41.1)] was associated with 1-year mortality of SRC. The 1-year survival rate after the onset of SRC among all patients and among those positive for anti-topo I was 54% and 33%, respectively. In contrast, the survival rate in patients negative for anti-topo I was 75%, of which the survival rate of patients positive for anti-RNAPIII and ACA was 83% and 100%, respectively. Conclusion Specific SSc-related autoantibodies were associated with the morbidity and mortality of SRC.

Objectives Osteoporosis and compression fractures of the lumbar spine are some of the major adverse effects of glucocorticoid therapy in patients with systemic lupus erythematosus (SLE). This study examined the association between bone mineral density, bone turnover markers, presence of vertebral fractures, and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index in SLE patients. Methods This was a cross-sectional study of 246 outpatients with SLE at the Kyoto University Hospital. Lumbar and femoral bone mineral density was measured with dual-energy X-ray absorptiometry, and the presence of vertebral fractures was determined using X-ray, computed tomography, or magnetic resonance imaging. Results On multiple regression analysis, both high lumbar and femoral T-scores were associated with the concomitant use of hydroxychloroquine (P = .018 and P = .037, respectively), no use of bisphosphonate or denosumab (P = .004 and P = .038, respectively), high body mass index (P Conclusion Vertebral fracture was associated with SLE-associated organ damage, and serum bone-specific alkaline phosphatase level is a potentially useful marker for osteoporosis monitoring in SLE patients.

Objective We previously reported that RF recognized the IgG heavy chain (IgGH)/RA-susceptible HLA class II molecule complex. In the present study, we investigated the molecular mechanisms underlying HLA binding to and the RF recognition of IgGH. Methods We synthesized various types of IgGH segments, including VH, CH1, CH2 and CH3, and transfected them with or without HLA class II molecules into the Human Embryonic Kidney 293T cell line. IgGH single domains linked with the HLA-Cw3 peptide, which binds to the binding groove of the HLA class II molecule, were also synthesized. The expression of IgGH domains on the cell surface and their recognition by RF were examined using flow cytometry. Results Flag-tagged IgGH segments containing CH1 (CH1, VH-CH1, CH1-CH2, VH-CH1-CH2, CH1-CH2-CH3 and VH-CH1-CH2-CH3) were clearly presented on the cell surface by HLA-DR4, while segments without the CH1 domain were expressed at a low level, and the CH3 single domain was only weakly detected on the cell surface, even with HLA-DR4. We then transfected IgGH single domains linked to the Cw3 peptide together with HLA-DR4 and showed that RF-containing sera from RA patients only recognized the CH3 domain and none of the other single domains. When various segments without the Cw3 peptide were transfected with HLA-DR4, only the CH1-CH2-CH3 segment and full-length IgGH were detected by the sera of RA patients. Conclusion The CH1 domain of IgGH binds to the RA-susceptible HLA-DR molecule and is expressed on the cell surface. RF specifically recognizes the CH3 domain of the IgGH/HLA-DR4 complex.

Aim This study aimed to assess the relationship between pain catastrophizing and achievement of 28-joint Disease Activity Score-defined remission of rheumatoid arthritis (RA), considering the presence or absence of systemic inflammation, and to evaluate associated factors for pain catastrophizing. Method This cross-sectional study included 421 RA outpatients. The relationship between pain catastrophizing and remission was analyzed by adjusting several confounding factors. Univariable and multivariable analyses were performed to determine the relationship between pain catastrophizing and RA-related factors, comorbidities, and lifestyle habits. Results The prevalence of pain catastrophizing was 26%. Pain catastrophizing was negatively associated with remission (odds ratio 0.62, 95% confidence interval 0.38-1.00, P = .048). A multinomial logistic analysis showed that the presence of pain catastrophizing was an independent factor that was negatively correlated with the achievement of remission in the absence of systemic inflammation (odds ratio 0.51, 95% confidence interval 0.28-0.93, P = .029). Factors associated with elevated ratings on the Pain Catastrophizing Scale were a history of falls within the past year, a Health Assessment Questionnaire score >0.5, and smoking habit. Further, patients' subjective symptoms, including patient global assessment minus evaluator global assessment values ≥20 and high tender joint count minus swollen joint counts, were associated with elevated pain catastrophizing. Conclusion Pain catastrophizing is a major obstacle to achieving remission in RA patients with normal C-reactive protein levels. Advanced physical disability, smoking habit, and history of falls were associated with pain catastrophizing, in addition to patients' subjective symptoms.

Neuroendocrine neoplasms (NENs) are rare neoplasms that occur in various organs and present with diverse clinical manifestations. Pathological classification is important in the diagnosis of NENs. Treatment strategies must be selected according to the status of differentiation and malignancy by accurately determining whether the neoplasm is functioning or nonfunctioning, degree of disease progression, and presence of metastasis. The newly revised Clinical Practice Guidelines for Gastroenteropancreatic Neuroendocrine Neoplasms (GEP-NENs) comprises 5 chapters—diagnosis, pathology, surgical treatment, medical and multidisciplinary treatment, and multiple endocrine neoplasia type 1 (MEN1)/von Hippel–Lindau (VHL) disease—and includes 51 clinical questions and 19 columns. These guidelines aim to provide direction and practical clinical content for the management of GEP-NEN preferentially based on clinically useful reports. These revised guidelines also refer to the new concept of “neuroendocrine tumor” (NET) grade 3, which is based on the 2017 and 2019 WHO criteria; this includes health insurance coverage of somatostatin receptor scintigraphy for NEN, everolimus for lung and gastrointestinal NET, and lanreotide for GEP-NET. The guidelines also newly refer to the diagnosis, treatment, and surveillance of NEN associated with VHL disease and MEN1. The accuracy of these guidelines has been improved by examining and adopting new evidence obtained after the first edition was published. Supplementary Information The online version contains supplementary material available at 10.1007/s00535-021-01827-7.

Objectives The present study aimed to clarify comprehensive relationships among the clinical variables of systemic lupus erythematosus (SLE). Methods We retrospectively surveyed 32 clinical variables in 581 patients and conducted comprehensive association studies among SLE clinical phenotypes. A univariate analysis of all possible combinations was performed, and the results of phenotypic correlations were reduced into two dimensions. We also created a regression formula using L1 regularisation (LASSO) to calculate the probability of exhibiting each phenotype. Results The univariate analysis identified 26 correlations, including multiple phenotypes with low complement. Some unpredicted correlations were identified, including fever and the anti-Sm antibody (odds ratio; OR = 2.3, p = 1.6 × 10–5) or thrombocytopenia and psychosis (OR = 3.7, p = 3.2 × 10–5). The multivariate analysis accurately estimated the probability of exhibiting each phenotype (area under the curve > 0.7) in 10 out of 20 phenotypes. Conclusions The present results show the phenotypic architecture of SLE and represent a model for estimating the probability of exhibiting each phenotype. They also offer insights into the pathology of SLE and estimating the probability of the onset of new phenotypes in clinical practice.

Objectives Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by localized and generalized bone loss. The risk of fractures is doubled in patients with RA. Denosumab, an anti-RANKL monoclonal antibody, is used for those with osteoporosis at high risk fracture and it has inhibitory effect of progressive bone erosion in patients with RA. While the increase in bone mineral density by denosumab has been reported in patients with RA, preventive effect of fracture by denosumab remains unknown. This study aimed to evaluate the efficacy of denosumab in treating clinical fracture risk in patients with RA. Methods Patients with RA who received denosumab treatment between 2013 and 2019 were retrospectively evaluated using the ANSWER (Kansai Consortium for the Well-Being of Rheumatic Disease Patients) cohort data. Fracture rates were evaluated between 0 and 6 months (reference period) versus > 6 months (post-reference period) of denosumab use. Results A total of 873 patients with RA received denosumab, and their characteristics were as follows: 88% females, mean age 68 years, and average disease duration 14.5 years. The hazard rates of all clinical fractures were 0.69 (per 100 person-years) in the reference period and 0.35 in the post-reference period, indicating a 49.2% decrease (p = 0.03). Conclusions Denosumab suppresses the risk of clinical fractures in patients with RA.

Neutropenia is a common adverse event of tocilizumab (TCZ) in rheumatoid arthritis (RA) patients; however, the association between the decrease in neutrophil counts and the TCZ clinical efficacy remains inconclusive. This study aimed to examine whether TCZ-induced neutrophil decrease at 1 month predicts clinical remission within 1 year. We reviewed medical records of RA patients initiating TCZ between May 2011 and September 2019 in our hospital. The Clinical Disease Activity Index (CDAI) was evaluated at baseline (before initiating TCZ) and 1, 3, 6, and 12 months after administration. Clinical remission was defined when CDAI decreased ≤ 2.8. The ratio of neutrophil counts 1 month after initiating TCZ to those at baseline (neutrophil ratio) was also calculated. Among 255 TCZ-treated patients, 169 with valid CDAI and neutrophil counts were enrolled (with median age of 60 years and 79% females). Rheumatoid factor and anti-cyclic citrullinated peptide antibody were positive in 75% and 83%, respectively, and 56% of the patients had concomitant methotrexate (median dose: 8 mg/week). Multivariate logistic regression analysis suggested baseline CDAI (odds ratio (OR) 0.96, p = 0.045), concomitant PSL (OR 0.42, p = 0.030), and the neutrophil ratio (OR 0.19, p = 0.011) as predictors of CDAI remission. Neutrophil ratio ≤ 0.8 was associated with achieving remission (Fisher's exact test, p = 0.02) with no apparent increase of severe infection. More than 20% reduction of neutrophil count 1 month after initiating TCZ predicts clinical remission within 1 year at an early treatment phase.

Background: To see how the COVID-19 pandemic influenced the 3-year use of parenteral antimicrobials, we attempted a historical control study. Main body: Materials were the electronic medical record on the use of a total of 33 antimicrobials. We compared antimicrobial use density (AUD) of pre-pandemic 1 year (PreY), the first pandemic year (Pan1Y), and the second pandemic year (Pan2Y). Our antimicrobial team monitored all in-patients and COVID-19 patients underwent clinical pathways with antivirals. Results: showed that in a total of 20,013 patients (7,534, 6,146, and 6,333 for PreY, Pan1Y, and Pan2Y), sepsis-3 was diagnosed in 152, 132, and 283 patients while Clostridioides difficile toxin tests were positive in 17, 5, and 7 patients, respectively. Among patients with COVID-19 (N=622) at a median age of 58 (range, 1-99), 11 (1.8%) died; parenteral antimicrobials were given in 59 patients (9.5%) preceded by bacteriological tests in 48 (81.4%). Comparing before and during the pandemic, parametric analyses showed that the means of total AUD decreased from 16.767 (PreY) to 15.62 (Pan1Y+Pan2Y) (P=0.034). Likewise, the means of carbapenems’ AUD showed decrease from 0.773 (PreY) to 0.462 (Pan1Y) but increase into 0.777 (Pan2Y) (P=0.001).The non-parametric comparison between COVID-19 and other wards showed that the medians of AUD in the COVID-19 wards were significantly (PConclusion: The COVID-19 pandemic stewardship decreased the total AUD and may have contributed to decrease ESBL-producing microbes and C. difficile infection. The burden of sepsis-3 may have fluctuated the carbapenems’ use.

Background: Established assessment tools for patients with rheumatoid arthritis (RA), including disease activity scores (DASs), disease activity indices (DAIs), visual analog scales (VASs), and health assessment questionnaires (HAQs), are widely used. However, comparative associations between joint involvement and disease status assessment tools have rarely been investigated.Methods: We included a dataset of 4016 patients from a large RA cohort from 2012 to 2019. The tenderness and swelling of each joint were counted as a symptom, with 70 and 68 affected joints throughout the body, respectively. The relative contribution of various joints to the disease status assessment tools, VAS scores, and functional disability indexes was analyzed using multiple regression analysis.Results: Upper extremity joints contributed more than the lower extremity joints, except the knee, toward disease assessment. Additionally, larger joints contributed more than the smaller joints overall, but the metacarpophalangeal and proximal interphalangeal joints made significant contributions to DASs and DAIs. Further, the ankle played a minor but important role in most assessment tools, especially in HAQs.Conclusions: Larger joints and the joints in the upper extremity contribute more to disease status, VAS score, and functional disability. However, each joint makes a unique contribution to these assessment tools.

Background: Corrected QT (QTc) prolongation is a frequently observed ECG abnormality in patients with rheumatoid arthritis (RA). Objectives: We aimed to investigate the association between disease activity and QTc interval in patients with RA. Methods: Data were obtained from the Kyoto University Rheumatoid Arthritis Management Alliance population-based RA cohort. We used a linear model to compare the association between QTc interval and RA-related parameters, including patient characteristics and disease activity assessed using the visual analog scale, C-reactive protein level, erythrocyte sedimentation rate (ESR), disease activity score 28-joint count using erythrocyte sedimentation rate (DAS28-ESR), simplified disease activity index (SDAI), clinical disease activity index (CDAI), and health assessment questionnaire (HAQ) score. We also constructed multivariate linear regression models to adjust for confounding effects. Results: The mean QTc interval of 340 patients (mean age: 64.7 ± 12.3 years, female: 289 [85%]) with ECG data was 420.0 ± 18.4, and the mean disease activity indices were: DAS28-ESR, 2.7 ± 1.1 points; CDAI, 5.0 ± 5.2 points; SDAI, 5.4 ± 5.7 points; and HAQ, 0.61 ± 0.71 points. Linear correlations were observed between the QTc interval and all parameters for disease activity in the univariate analysis. The three multivariate linear regression models using age, sex, HAQ score, and disease activity indices (CDAI, SDAI, or DAS28-ESR) were significantly associated with the QTc interval (P = 0.0002, 0.0002, 0.0004, respectively). Conclusions: Disease activity is significantly associated with the QTc interval in patients with RA. Attention should be given to ECG abnormalities in patients with RA and progressive disease activity.

OBJECTIVES: Numerous case reports have referred to new onset or flare of SLE after SARS-CoV-2 messenger RNA (mRNA) vaccines. Several observational studies showed that the short-term flare rate of SLE after SARS-CoV-2 vaccination is low. However, well-controlled clinical surveys are unavailable and the medium-term impact of the SARS-CoV-2 mRNA vaccines against the flare of SLE is uncertain. Therefore, we aimed to analyse the association between vaccination and medium-term subjective and objective disease activities of SLE and flares using matched pair methods. METHODS: Altogether, 150 patients with SLE from the Kyoto Lupus Cohort were included. Patients who received two doses of the SARS-CoV-2 mRNA vaccines were 1:1 matched with unvaccinated patients based on the first vaccination date. The outcome measures were the SLE Disease Activity Index-2000 (SLEDAI-2K), the Japanese version of the SLE Symptom Checklist Questionnaire (SSC-J) and the Safety of Estrogens in Lupus Erythematosus National Assessment-SLEDAI flare index at 30, 60 and 90 days after vaccination. RESULTS: SLEDAI-2K levels were not significantly different in vaccinated and unvaccinated patients with SLE at 30, 60 and 90 days after the second vaccination (adjusted estimate (95% CI): 30 days: -0.46 (-1.48 to 0.56), p=0.39; 60 days: 0.38 (-0.64 to 1.40), p=0.47; 90 days: 0.40 (-0.54 to 1.34), p=0.41). Similar results were observed in the SSC-J score (adjusted estimate (95% CI), 30 days: 0.05 (-1.46 to 1.56), p=0.95; 60 days: -0.63 (-2.08 to 0.82), p=0.40; 90 days: 0.27 (-1.04 to 1.58), p=0.69) and flare index (adjusted OR (95% CI), 30 days: 0.81 (0.36 to 1.85), p=0.62; 60 days: 1.13 (0.50 to 2.54), p=0.77; 90 days: 0.85 (0.32 to 2.26), p=0.74). CONCLUSION: SARS-CoV-2 vaccination did not significantly influence the medium-term subjective and objective disease activities or flares of SLE until 90 days after the second vaccination., 全身性エリテマトーデスへのコロナワクチンの影響を分析 --中期的な疾患活動性と再燃への影響について--. 京都大学プレスリリース. 2022-10-25.

Objective The systemic lupus erythematosus (SLE) symptom checklist (SSC) is a patient-reported outcome measure consisting of 38 queries. We translated SSC into Japanese and attempted to validate its usefulness for evaluating the quality of life (QOL) of SLE patients and identify factors that affect QOL. Methods Data from the Medical Outcomes Study Short-form 36 questionnaire (SF-36), Japanese LupusPRO, the Japanese version of the SSC (SSC-J) questionnaire, SLEDAI-2k, and the physician global assessment (PGA) were obtained on the same day from 226 SLE outpatients of the Kyoto Lupus cohort at Kyoto University Hospital. Relationships between the total scores or each item of SSC-J and SF-36, Japanese LupusPRO, SLEDAI-2k, or PGA were analyzed by Spearman’s rank test. Results The total scores of SSC-J correlated with the scores of SF-36 and Japanese LupusPRO. In each item of SSC-J, all 38 items correlated with the physical component summary and mental component summary of SF-36 as well as the Health-Related QOL (HRQOL) scores of Japanese LupusPRO, but not with the non-HRQOL of LupusPRO. SSC-J scores correlated with age, PGA, and corticosteroid doses, but not with SLEDAI-2k. Conclusions SSC-J is suitable as a disease-specific QOL assessment tool for SLE.

Objective To investigate clinical characteristics and time course of lymphoproliferative disorders (LPDs) in rheumatoid arthritis (RA) patients after methotrexate (MTX) discontinuation, in those who achieved spontaneous regression (SR). Methods We retrospectively reviewed clinical data from RA patients with LPDs obtained from eight institutions between 2000 and 2017 and compared clinical and pathological findings between SR and non-SR groups. Results Among 232 RA patients with LPDs, 216 were treated with MTX at the onset of LPD and 144 (66.7%) achieved SR after MTX discontinuation. Higher MTX doses, high titers of anti-CCP antibodies (>13.5 U/mL), and lower LDH and soluble IL-2 receptor levels were associated with SR. Lymphocyte count was decreased at LPD onset and increased at 2 weeks after MTX discontinuation in the SR group. Epstein–Barr virus-positive mucocutaneous ulcer, reactive lymphoid hyperplasia and unclassifiable B-cell lymphoma, were more frequent in the SR than in the non-SR group. In multivariable analysis, diffuse large B-cell lymphomas was an independent predictive factor for non-SR. In the patients with SR, 73.9% achieved partial or complete regression as early as 2 weeks after MTX discontinuation. Conclusion SR and non-SR in RA patients with LPDs after MTX discontinuation were associated with certain clinical characteristics.

Objectives To clarify factors affecting 5-year survival rates and relapse rates after spontaneous regression (SR) of lymphoproliferative disorders (LPDs) in patients with rheumatoid arthritis (RA). Methods This retrospective longitudinal study comprised 232 patients with RA diagnosed with LPDs between January 2000 and March 2017 at eight hospitals in Japan. The Kaplan-Meier method was used to analyze survival and the Cox proportional hazard model was applied to identify predictive factors. Results Among all patients, 1-, 2- and 5-year overall survival rates were 89.5%, 86.1%, and 78.2%, respectively. Multivariable analysis revealed four 5-year survival risk factors assessed at diagnosis: age above 70 years (p = .002), deep lymphadenopathy and/or more than one extranodal lesion (p = .008), Eastern Cooperative Oncology Group/Zubrod performance status of 2–4 (p = .004), and classic Hodgkin lymphoma (CHL) histology (p = .047). Among 143 patients who achieved SR, 2- and 5-year relapse rates were 14.2% and 24.9%, respectively. CHL histology (p = .003) and serum soluble interleukin-2 receptor levels exceeding 2000 IU/L (p = .014) were associated with post-SR relapse-free survival. Blood lymphocyte counts were significantly lower at relapse than at 3–6 months prior (p Conclusion Assessment of the above risk factors and routine inspection of blood lymphocyte counts could aid in the care management of LPDs in RA.

Rheumatoid arthritis (RA) is an autoimmune disease that can cause damage to the joints, cartilage and bone. There is no cure but early diagnosis can help mitigate damage. Sometimes RA is particularly difficult to treat, for example when the disease took a long time to be diagnosed. Associate Professor Masao Tanaka, Graduate School of Medicine, Kyoto University, Japan, leads a team of researchers working to improve understanding of the causes of poor response to treatment in RA with a long morbidity. The goal is to restore patients' therapeutic responsiveness, thereby improving outcomes. A previous focus for Tanaka was on a protein called FSTL1. He is now exploring DIP2 as a binding molecule for FSTL1. Other important mechanisms Tanaka is exploring are DNA methylation and the mechanisms of carnitine, which has been found to decrease a variety of activation signalling by inhibiting ceramide production in T cells. He and the team are exploring the involvement of these mechanisms in DIP2. In his most recent investigations, Tanaka is exploring DIP2C as a novel regulator for epithelial-mesenchymal transition of RA synovium and a potential therapeutic target. He is focusing on molecules that are expressed in the cells in joints, making the work directly applicable to RA. The team is carrying out a cohort study called KURAMA (Kyoto University Rheumatoid Arthritis Management Alliance) that involves around 2,000 outpatients with RA. Ultimately, Tanaka hopes to identify a reproducible combination of patient conditions and therapeutic interventions that achieve better treatment results for RA patients.

Objectives To identify the optimal treatment for rheumatoid arthritis (RA) after the regression of lymphoproliferative disorders (LPDs). Methods The subjects were 232 patients with RA who developed LPD between 2000 and 2017 at seven hospitals participating in the LPD-WG study. Kaplan-Meier and Cox proportional regression analyses were performed to determine the factors associated with the rate of LPD relapse and the retention of biological disease-modifying antirheumatic drugs (bDMARDs). Results Treatment for RA was resumed in 138 patients after spontaneous regression of LPD after the discontinuation of methotrexate and in 52 patients after chemotherapy for LPD (persistent-LPD). LPD relapses occurred in 23 patients. Not DMARDs use but Hodgkin’s lymphoma was identified as a risk factor for LPD relapse. In 88 RA patients treated with bDMARDs [tocilizumab, 39 patients; abatacept 20 patients; tumor necrosis factor inhibitor, 29 patients], the one-year retention rate was 67.8%. The risk factors for discontinuation of bDMARDs were persistent-LPD, non-diffuse large B-cell lymphomas (non-DLBCL), and a high clinical disease activity index (CDAI). Tocilizumab showed the highest retention rate among bDMARDs, particularly in DLBCL. Conclusion Although any bDMARD could be used in patients after LPD regression, effectiveness and risk for relapse should be carefully assessed for each LPD subtype.

In this study, we computationally assess the effects of the distributed fibre orientation in the periodontal ligament (PDL) on mechanical responses of the tooth-PDL complex. An idealised axial-symmetric geometry of a tooth-PDL complex was constructed. The fibre orientation in the PDL was modelled as a trigonometric function based on anatomical knowledge, and the PDL was modelled as a transversely isotropic hyperelastic material dependent on fibre orientations. Parametric studies of the fibre orientation on the mechanical responses of the tooth-PDL complex were conducted. Obtained results showed that the anatomically consistent fibre orientation functions as a supporting structure against not only vertical but also horizontal loads.

Background Sotrovimab has been developed to neutralize SARS-CoV-2 which remained effective at the advent of B.1 lineage of the Omicron variant. To investigate post-infusion clinical events and their risk factors, we performed a retrospective study.Methods Subjects were a consecutive series of inpatients with COVID-19 undergoing an infusion of sotrovimab in our institute. In accordance with previous clinical trials, we included patients at risk but permitted SARS-CoV-2 vaccinees. For statistical analyses, we reviewed background factors of demographics, imaging, and laboratory findings for the outcome of post-infusion events such as temperature over 38 degrees Celsius (Temp38) and pulse oximetry below 94%.Results Of a total of 136 patients, the median follow-up was 47 days. Among 110 fully vaccinated patients (80.9%) for SARS-CoV-2, 2-time vaccinees accounted for 88 while 3-time vaccinees were 22. Three patients (2.2%) showed worsening of COVID-19; one developed hypoxia and two died. For the outcome of Temp38 (N=41), multivariate analysis showed that factors at risk were younger age (2) (OR 8.657, 95% CI 1.030 – 72.786, P=0.047) and pulse oximetry (

Background Sotrovimab neutralizing SARS-CoV-2 remained effective at the advent of B.1 lineage of the Omicron variant in outpatients. Primarily for hospitalized patients, however, the Japanese government regulated to administer this antibody agent. As this regulation enabled close monitoring in inpatients to investigate post-infusion adverse events (AEs) and efficacy, we attempted a retrospective study while the Omicron BA.1 lineage was dominant regionally. Methods Subjects were inpatients with COVID-19 who received infusion of sotrovimab in our institute. In line with previous clinical trials, we included patients at risk of COVID-19 worsening and SARS-CoV-2 vaccinees, who were hospitalized as directed by the government. For statistical analyses, we reviewed background factors of demographics, imaging, and laboratory findings for the outcome infusion-related reactions including post-infusion pyrexia over 38 degrees Celsius and/or pulse oximetry below 94%. Results In a total of 139 patients, the follow-up period had a median of 200 days (range, 154–248 days). Among 119 patients (85.6%) fully vaccinated for SARS-CoV-2, 86 (61.9% of all) underwent 2 doses while 33 (23.7% of all) received 3 doses. For the outcome of pyrexia and/or dyspnea (N = 40, 28.8%), multivariate analysis showed that significant risk factors were pre-infusion lowered oximetry below 96.5% (Odds Ratio [OR] 0.344, 95% Confidence Interval [CI] 0.139–0.851, P = 0.021) and pre-infusion temperature more than 36.7 degrees Celsius (OR 4.056, 95% CI 1.696–9.701, P = 0.002). Infusion-related reactions included vomiting immediately after infusion, chill/shivering, dizziness, rash, pruritus, pyrexia, and dyspnea. The number of patients with any of these events was 44 (31.6%). Three patients (2.2%) showed worsening of COVID-19; one developed hypoxia and two died. Limitations for this study included no genome typing whether BA.1 or BA.2 lineage of the Omicron variant but the local epidemiology indicated the prevalence of BA.1. Another was sotrovimab administration for inpatients that allow precise detection of post-infusion events, confounding previous exacerbation definition including hospitalization. Conclusions For 24 h after infusion of sotrovimab, COVID-19 patients showing pre-infusion lowered oximetry below 96.5% and/or temperature more than 36.7 degrees Celsius may have temperature elevation or dyspnea, warranting close monitoring for these risk factors.

The factors influencing long-term responses to a tumor necrosis factor inhibitor (TNFi) in rheumatoid arthritis (RA) patients currently remain unknown. Therefore, we herein conducted a multi-omics analysis of TNFi responses in a Japanese RA cohort. Blood samples were collected from 27 biological disease-modifying antirheumatic drug (DMARD)-naive RA patients at the initiation of and after three months of treatment with TNFi. Treatment responses were evaluated at one year. Differences in gene expression levels in peripheral blood mononuclear cells (PBMCs), plasma protein levels, drug concentrations, and the presence/absence of anti-drug antibodies were investigated, and a cell phenotypic analysis of PBMCs was performed using flow cytometry. After one year of treatment, thirteen patients achieved clinical remission (responders), while the others did not or switched to other biologics (non-responders). Differentially expressed genes related to treatment responses were enriched for the interferon (IFN) pathway. The expression of type I IFN signaling-related genes was higher in non-responders than in responders before and after treatment (P = 0.03, 0.005, respectively). The expression of type II IFN signaling-related genes did not significantly differ before treatment; however, it increased in non-responders and decreased in responders, with a significant difference being observed after three months of treatment (P = 1.2×10-3). The total number of lymphocytes and C-X-C Motif Chemokine Ligand 10 (CXCL10) protein levels were associated with the type I IFN signature (P = 6.7×10-7, 6.4×10-3, respectively). Hepatocyte growth factor (HGF) protein levels before treatment predicted fold increases in type II IFN (P = 0.03). These IFN signature-related indices (the number of lymphocytes, CXCL10, and HGF) significantly differed between responders and non-responders (P = 0.01, 0.01, and 0.04, respectively). A single-cell analysis revealed that the type I IFN signature was more highly enriched in monocytes than in other cell types. A deconvolution analysis of bulk-RNA sequence data identified CD4+ and CD8+ T cells as the main sources of the type II IFN signature in non-responders. Collectively, the present results demonstrated that the dynamics of the type I and II IFN pathways affected long-term responses to TNFi, providing information on its biological background and potential for clinical applications.

We report a case of 68-year-old man with stable polymyositis complicated with primary hepatic lymphoma (PHL) as other iatrogenic immunodeficiency-related lymphoproliferative disorders (OIIA-LPD). Multiple liver masses were diagnosed as diffuse large B-cell lymphoma (DLBCL) by biopsy. The LPD was associated with Epstein-Barr virus (EBV) reactivation, because EBV-DNA was detected in peripheral blood, and EBV antigen was detected in the tumour. He presented with high fever, cytopenia and hyperferritinemia, suggesting hemophagocytosis. Only discontinuation of methotrexate and tacrolimus resulted in a dramatic regression of the liver masses and improvement of fever and cytopenia. We review six cases of OIIA-LPD localised in the liver. All cases were DLBCL; 4/6 cases (67%) were positive for EBV staining, and 2/6 cases (33%) were improved after the discontinuation of immunosuppressants. Screening for EBV in blood and liver tumour is important, when a patient in immunosuppressive status presented with liver masses.

Otani T., Kobayashi Y., Tanaka M.. Computational study of kinematics of the anterior cruciate ligament double-bundle structure during passive knee flexion–extension. Medical Engineering and Physics, 83, 56-63. https://doi.org/10.1016/j.medengphy.2020.07.015., The anterior cruciate ligament (ACL) comprises an anteromedial bundle (AMB) and posterolateral bundle (PLB). Cadaver studies showed that this double-bundle structure exhibits reciprocal function during passive knee flexion–extension, with the PLB taut in knee extension and the AMB taut in knee flexion. In vivo measurements indicated that straight-line lengths of both bundles decrease with increasing knee-flexion angle (KFA). To interpret these seemingly conflicting facts, we developed a computational ACL model simulating the kinematics of the double-bundle structure during passive knee flexion–extension. Tibial and femoral shapes were reconstructed from computed-tomography images of a cadaver knee and used to construct an idealized model of an ACL including its bundles at the tibiofemoral joint. The ACL deformations at various KFAs were computed by finite element analysis. Results showed that the PLB was stretched in knee extension (KFA = 0∘) and slackened with increasing KFA. The AMB was stretched in knee extension (KFA = 0∘) and remained stretched on the medial side when the knee flexed (KFA = 90∘), but its straight-line length decreased with increasing KFA. These findings are consistent with cadaver and in vivo experimental results and highlight the usefulness of a computational approach for understanding ACL functional anatomy.

Bone structure can change by remodeling to adapt to mechanical status. Such change can result in bone affecting the long-term stability of the stem. The objective of this study was to propose a method to evaluate mechanical adaptation for preoperative planning of total hip arthroplasty. Finite element models of preoperative planning were examined in two ways: bone remodeling simulation and initial mechanical status of femur. A mathematical model of remodeling for long-term changes of bone was developed assuming that bone resorption/formation could be distinguished by strain magnitude of bone. Also, initial compatibility between stem and bone was set with four strain levels based on mechanostat theory. The results of bone remodeling simulation were shown average equivalent stress change was mainly observed in Gruen zone 1 and zone 7 where stress shielding or bone resorption could occur. The proportion of this value was the smallest in the first choice of the stem by a specialist surgeon. Also, these are showed same tendency with evaluation of initial strain distribution results that Gruen zone 1 and 7. Initial strain distribution after total hip arthroplasty was correlated with the long-term change of bone structures after total hip arthroplasty. Bone structure changes around prostheses occur due to changes in the mechanical environment, and this is correlated with strain distribution of immediate post-operative model. Findings of this study suggest that biomechanical indices might be useful for exploring difference in long-term fitting among different surgical plans.

Hypoxia occurs in tumors, infections, and sites of inflammation, such as in the affected joints of patients with rheumatoid arthritis (RA). It alleviates inflammatory responses and increases bone resorption in inflammatory arthritis by enhancing osteoclastogenesis. The mechanism by which the hypoxia response is linked to osteoclastogenesis and inflammatory bone resorption is unclear. This study was undertaken to evaluate whether the protein lysine-specific demethylase 1 (LSD1) metabolically integrates inflammatory osteoclastogenesis and bone resorption in a state of inflammatory arthritis.LSD1-specific inhibitors and gene silencing with small interfering RNAs were used to inhibit the expression of LSD1 in human osteoclast precursor cells derived from CD14-positive monocytes, with subsequent assessment by RNA-sequencing analysis. In experimental mouse models of arthritis, inflammatory osteolysis, or osteoporosis, features of accelerated bone loss and inflammatory osteolysis were analyzed. Furthermore, in blood samples from patients with RA, cis-acting expression quantitative trait loci (cis-eQTL) were analyzed for association with the expression of hypoxia-inducible factor 1α (HIF-1α), and associations between HIF-1α allelic variants and extent of bone erosion were evaluated.In human osteoclast precursor cells, RANKL induced the expression of LSD1 in a mechanistic target of rapamycin-dependent manner. Expression of LSD1 was higher in synovium from RA patients than in synovium from osteoarthritis patients. Inhibition of LSD1 in human osteoclast precursors suppressed osteoclast differentiation. Results of transcriptome analysis identified several LSD1-mediated hypoxia and cell-cycle pathways as key genetic pathways involved in human osteoclastogenesis. Furthermore, HIF-1α protein, which is rapidly degraded by the proteasome in a normoxic environment, was found to be expressed in RANKL-stimulated osteoclast precursor cells. Induction of LSD1 by RANKL stabilized the expression of HIF-1α protein, thereby promoting glycolysis, in conjunction with up-regulation of the transcription factor E2F1. Analyses of cis-eQTL revealed that higher HIF-1α expression was associated with increased bone erosion in patients with RA. Inhibition of LSD1 decreased pathologic bone resorption in mice, both in models of accelerated osteoporosis and models of arthritis and inflammatory osteolysis.LSD1 metabolically regulates osteoclastogenesis in an energy-demanding inflammatory environment. These findings provide potential new therapeutic strategies targeting osteoclasts in the management of inflammatory arthritis, including in patients with RA.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic joint inflammation and destruction. The affected synovium becomes the basis of the inflammatory milieu by recruiting immune cells including T cells, B cells, monocytes, macrophages and granulocytes etc., and activates osteoclasts leading to joint destruction and dysfunction. If this inflammatory environment can be restored, destructive arthritis in RA can be prevented. With the introduction of molecular-targeted agents (MTAs) at the beginning of this century, RA has become a controllable disease. Nevertheless, effective drugs including MTAs require continuous administration. This is because they are still unable to eliminate the cause of the disease. Patients with refractory RA often show a decreased response to treatment over time, suggesting that there underlie the irreversible traits of cytokine dysregulation. For the treatment aiming a closer-to-cure condition, it is necessary to find new approach to restore such traits. The RA synovium has two abnormalities: morphological and functional ones. The first is the loss of the single-cell-layer structure surrounding the joint cavity followed by abnormal proliferation to form a tumor-like tissue called pannus which is comparable to epithelial-mesenchymal transition (EMT), and the second is the autonomous activation of inflammation-related genes due to epigenetic changes in DNA and the decrease in immune regulatory response due to metabolic changes, etc. Especially, these functional abnormalities seem to be associated with traits of cytokine dysregulation in RA synovium. Recent chromatin immunoprecipitation sequencing analysis with synovial fibroblasts has shown that EMT-like changes are linked to changes in cytokine production. In RA, compared to osteoarthritis, non-autoimmune joint disease, there were activating histone modifications at the IL-6 locus. Intriguingly, such activation changes were observed also in the loci of EMT marker genes, SNAI1 and COL1A1. These epigenetic changes in the RA synovium seem to be related to irreversible, fixed traits that continue the inflammatory response. Candidate targets of the trait-restoring therapy for RA include molecules involved in epigenetic plasticity that can restore irreversible changes toward inflammatory nature in the RA synovium.