Anti-interferon gamma-inducible protein 16 antibodies: Identification of a novel autoantigen in idiopathic interstitial pneumonia and its clinical characteristics based on a multicenter cohort study.

Autoantibodies are detected in idiopathic interstitial pneumonias (IIPs) without a clear connective tissue disease diagnosis, and their clinical significance is unclear. This study aimed to identify a novel autoantibody in IIPs. We screened 295 IIP patients using a 35S-methionine labeled protein immunoprecipitation assay. Candidate autoantigens were identified via protein array and confirmed by immunoprecipitation. Six sera from 295 IIP patients immunoprecipitated common tetrameric proteins (100 kDa). The protein array identified interferon gamma-inducible protein 16 (IFI16) as the candidate autoantigen. Patients with anti-IFI16 antibodies received immunosuppressants less frequently. Five-year survival rates were 50 %, 69 %, and 63 % (P = 0.60), and acute exacerbation-free rates were 50 %, 96 %, and 84 % (P = 0.15) for patients with anti-IFI16, anti-aminoacyl tRNA antibodies, and others. Anti-IFI16 is a novel autoantibody in IIPs. Patients with this antibody often receive less immunosuppressive therapy and could have a poor prognosis. Further research is needed to refine patient stratification and management.

Comparative effects of biological and targeted synthetic DMARDs on incident chronic kidney disease in patients with rheumatoid arthritis.

OBJECTIVES: The impact of individual biological/targeted synthetic disease-modifying anti-rheumatic drug (b/tsDMARD) on kidney function in patients with rheumatoid arthritis (RA) remains unclear. This study aimed to determine the comparative effects of b/tsDMARDs on chronic kidney disease (CKD) incidence in patients with RA. METHODS: This multicentre cohort study included patients with RA who had baseline estimated glomerular filtration rate (eGFR) of ≥ 60 mL/min/1.73 m2 and started a tumor necrosis factor inhibitor (TNFi), cytotoxic T lymphocyte-associated antigen-4-Ig (CTLA4-Ig), interleukin-6 receptor inhibitor (IL-6Ri), or Janus kinase inhibitor (JAKi) in Japan. Multiple propensity score-based inverse probability weighting (IPW) was used to adjust confounders. The incidence of CKD was compared among b/tsDMARDs using IPW mixed-effect Cox proportional hazards models and linear mixed-effect models with IPW examined trajectories of eGFR. RESULTS: Among 2187 patients with 3068 treatment courses and up to 11 years of follow-up, CKD occurred in 275 cases. Compared with the CTLA4-Ig group, the TNFi group had a significantly lower CKD incidence (hazard ratio [HR] 0.67, 95% confidence interval [CI] 0.46-0.97, p= 0.04), whereas the JAKi group had a significantly higher incidence (HR 2.16, 95% CI 1.23-3.79, p= 0.01). The trajectory of eGFR was significantly greater in the JAKi group than in the CTLA4-Ig group (CTLA4-Ig: -1.28 mL/min/1.73 m2/year, JAKi: -2.29 mL/min/1.73 m2/year, p< 0.001). CONCLUSIONS: TNFi use was associated with reduced CKD incidence, whereas JAKi showed a less protective association for kidney function in patients with RA.

Prediction models incorporating second metacarpal cortical index for osteoporosis in rheumatoid arthritis: Externally validated machine learning models developed using data from the KURAMA cohort.

OBJECTIVE: Osteoporosis and osteopenia are significant concerns in rheumatoid arthritis (RA), predisposing patients to fragility fractures. While dual-energy X-ray absorptiometry (DXA) is the gold standard for bone mineral density (BMD) assessment, simpler screening tools are needed. This study aims to assess the correlation between the second metacarpal cortical index (2MCI) and BMD in RA patients, and to evaluate machine learning (ML) models utilizing 2MCI and clinical parameters for predicting osteoporosis/osteopenia presence and BMD. METHODS: Data from the KURAMA cohort (n = 302) and an external validation cohort (n = 32) were analyzed. BMD in the hip and forearm was obtained using DXA and 2MCI was calculated from plain hand X-ray. ML models were trained to predict osteoporosis/osteopenia presence and BMD using 2MCI and clinical variables and validated using external cohort. RESULTS: 2MCI correlated significantly with hip and forearm BMD. ML models incorporating 2MCI and other clinical parameters showed good performance in predicting osteoporosis/osteopenia presence and BMD. External validation demonstrated the generalizability of the models. CONCLUSION: ML models utilizing 2MCI and clinical parameters show promise for osteoporosis screening in RA patients.

Factors affecting discrepancies in disease activity evaluation between patients and physicians in systemic lupus erythematosus-The importance of symptoms such as fatigue.

OBJECTIVES: There are often discrepancies in the evaluation of disease activity between patients and physicians in systemic lupus erythematosus (SLE). In this study, we examined the factors that affect those evaluations. METHODS: Physician visual analogue scale (Ph-VAS), patient VAS (Pt-VAS), Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2k), glucocorticoid (GC) usage and dose, age, Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index, and three patient-reported outcomes (SLE symptom checklist [SSC], short-form 36 questionnaire [SF-36], and LupusPRO) were obtained from a study performed in 2019 using 225 SLE outpatients of the Kyoto Lupus Cohort at Kyoto University Hospital. Correlations among Ph-VAS, Pt-VAS, or dif (Pt-VAS-Ph-VAS) (Pt-VAS minus Ph-VAS) and other factors were examined. RESULTS: We found a significant discrepancy between Pt-VAS (median 38.0 mm) and Ph-VAS (median 18.7 mm) scores (p < 0.001). SSC score showed a significant correlation with Pt-VAS and dif (Pt-VAS-Ph-VAS) (p < 0.001). Among SSC items, fatigue showed the most significant correlation with dif (Pt-VAS-Ph-VAS). We also showed that higher dif (Pt-VAS-Ph-VAS) was associated with lower quality of life (QOL) evaluated by SF-36 and LupusPRO. CONCLUSIONS: Pt-VAS scores tended to be higher than Ph-VAS scores, and the discrepancy was influenced mainly by fatigue. Higher dif (Pt-VAS-Ph-VAS) was associated with lower patient QOL.

Association of gut commensal translocation with autoantibody production in systemic lupus erythematosus.

OBJECTIVE: Bacterial translocation across the gut barrier has been implicated in the pathogenesis of systemic lupus erythematosus (SLE), though underlying mechanisms remain unclear. This study aimed to investigate the role of translocated bacteria in the context of molecular mimicry by utilizing lupus model mice and blood samples from untreated SLE patients. METHODS: Bacterial translocation was evaluated using nonselective cultured mesenteric lymph nodes (MLNs) from B6SKG mice, a lupus model characterized by impaired TCR signalling and gut dysbiosis. The relationships of detected pathobionts with autoantibody production were examined using in vivo experiments, enzyme-linked immunosorbent assay, immunoblotting, and epitope mapping. RESULTS: Culture-based bacterial profiling in MLNs demonstrated that Lactobacillus murinus was enriched in B6SKG mice with elevated anti-dsDNA IgG levels. Subcutaneous injection of heat-killed L. murinus induced anti-dsDNA IgG production without altering T- or B cell subset composition. Immunoblotting and mass spectrometry analysis identified a peptide ATP-binding cassette (ABC) transporter as a molecular mimicry antigen, with its cross-reactivity in lupus mice confirmed by serological assays and in vivo immunization. The L. murinus ABC transporter exhibited surface epitopes that were cross-reactive with sera from lupus mice and patients. The ABC transporter from R. gnavus, known for its pathogenic role in lupus patients, had a similar epitope sequence to that of the L. murinus ABC transporter and reacted with lupus sera. CONCLUSION: ABC transporters from gut bacteria can serve as cross-reactive antigens that may promote anti-dsDNA antibody production in genetically susceptible mice. These findings underscore the role of commensal-derived molecular mimicry and bacterial translocation in lupus pathogenesis.

Differences in the autoantibody phenotypes and long-term outcomes between juvenile- and adult-idiopathic inflammatory myopathies.

OBJECTIVE: To investigate differences in autoantibodies, clinical features, and long-term outcomes between juvenile-idiopathic inflammatory myopathy (IIM) and adult-IIM METHODS: Autoantibodies, clinical characteristics, and drug-free conditions for a maximum of 20 years were retrospectively analyzed in 320 Japanese IIM patients (juvenile-IIM, n = 34; adult-IIM, n = 286) using the Kyoto University Registry. RESULTS: Autoantibodies observed in juvenile-IIM were anti-TIF1-γ (15 %), anti-MDA-5 (15 %), anti-ARS (9 %), and anti-NXP-2 (6 %). Those observed in adult-IIM were anti-ARS (32 %), anti-MDA-5 (23 %), anti-TIF1-γ (8 %), anti-SRP (8 %), anti-Mi-2 (2 %), and anti-NXP-2 (1 %). The cumulative drug-free condition rate was higher in juvenile-IIM than in adult-IIM up to 20 years (juvenile-IIM vs. adult-IIM, 34 % vs. 18 %, p = 0.0016). Anti-TIF1-γ was associated with lesser muscle symptoms (60 % vs. 90 %), malignancy (0 % vs. 57 %), and glucocorticoid use (40 % vs. 86 %) in juvenile-IIM compared to adult-IIM, while juvenile-IIM more achieved drug-free conditions (60 % vs. 25 %). Both juvenile-IIM and adult-IIM with anti-MDA-5 demonstrated a high frequency of amyopathic dermatomyositis, interstitial lung disease (ILD), and multi-immunosuppressive therapy, with high drug-free conditions (50 % vs. 49 %). Both juvenile-IIM and adult-IIM with anti-ARS showed frequent skin rashes, muscle symptoms, and ILD, frequent need for multi-immunosuppressive therapy, and low drug-free condition rates (0 % vs. 3 %). Both juvenile-IIM and adult-IIM with anti-NXP-2 showed frequent skin rashes and muscle symptoms, low ILD frequency, and frequent use of methotrexate and glucocorticoids, which did not achieve drug-free conditions (0 % vs. 0 %). CONCLUSIONS: Drug-free condition was achieved more frequently in juvenile-IIM patients than adult-IIM patients. Specific autoantibodies were associated with different clinical characteristics and outcomes between juvenile-IIM and adult-IIM.

A Case of Vesiculobullous Dermatomyositis with Anti-NXP-2 Antibody without Malignancy.

Vesiculobullous dermatomyositis (VD) is a rare manifestation of dermatomyositis (DM) and has been suggested to be associated with malignancy. Although the myositis-specific autoantibodies are associated with distinct clinical presentations of DM, those associated with VD remain unclear. Here, we present the case of a 54-year-old man with VD who tested positive for anti-nuclear matrix protein 2 (NXP-2) antibody, one of the DM-specific autoantibodies. Serological and histopathological findings did not support autoimmune blistering disease. Physical and histological findings suggested that the severe edema in combination with the interface dermatitis of DM contributed to blister formation. Although a systemic examination was performed, no evidence of malignancy was found. Following initiation of immunosuppressive therapy, the patient showed significant improvement in both skin lesions and myositis. This case represents the first report of anti-NXP-2-positive VD without malignancy or autoimmune blistering disease. Subcutaneous edema, a characteristic feature of anti-NXP-2-positive DM, could be related to the formation of VD.

Effects of IL-6, JAK, TNF inhibitors, and CTLA4-Ig on knee symptoms in patients with rheumatoid arthritis.

This study aims to identify factors influencing the alleviation of knee joint symptoms in patients with rheumatoid arthritis treated with biologic or target synthetic disease-modifying antirheumatic drugs (b/tsDMARDs). Among 2321 patients who started b/tsDMARDs between 2010 and 2023, we focused on 295 patients who had knee swelling or tenderness at the initiation of b/tsDMARDs and continued b/tsDMARDs at least 3 months, with recorded knee symptoms 6 months later. Symptom relief after 6 months was 78.2% for interleukin 6 (IL-6) inhibitors, 68.6% for Janus kinase (JAK) inhibitors, 65.8% for tumor necrosis factor (TNF) inhibitors, and 57.6% for cytotoxic T lymphocyte-associated antigen-4-Ig (CTLA4-Ig). The initial use of b/tsDMARDs and the use of IL-6 inhibitors in comparison to CTLA4-Ig emerged as a significant factor associated with the improvement of knee joint symptoms. Among 141 patients who underwent knee radiography at baseline and two years later, the deterioration in knee joint radiographs was 7.7% for IL-6 inhibitors, 6.3% for JAK inhibitors, 21.9% for TNF inhibitors, and 25.9% for CTLA4-Ig. The use of IL-6 inhibitors was a significant factor associated with the improvement of knee joint symptoms and the inhibition of joint destruction compared to CTLA4-Ig.

Predictive validity of Lupus Patient-Reported Outcome for damage accrual in patients with systemic lupus erythematosus: the LUNA Registry.

OBJECTIVES: The predictive validity of disease-specific quality of life (QOL) remains unknown in patients with systemic lupus erythematosus (SLE), although disease-specific measures are equally or more responsive to changes than generic QOL. We aimed to examine the predictive validity of the Lupus patient-reported outcome (PRO) for damage accrual. METHODS: Patients with SLE and ≥2 measurements over time were included in Japanese nationwide multicentre registry (LUNA). The Lupus PRO questionnaire contains both health-related (HR) and non-HR-QOL measures. Damage accrual was evaluated using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI). We examined the association between the Lupus-PRO score at baseline and longitudinal SDI scores using mixed-effects models adjusted for prognostic factors. RESULTS: Among 1295 patients, those with higher HR-QOL of Lupus PRO at baseline demonstrated a significantly lower increase in SDI (-0.005/year, 95% confidence interval [CI]: -0.007 to - 0.004, p < 0.001). According to the categorisation of HR-QOL based on tertile, a similar dose-dependent effect of HR-QOL on longitudinal SDI was identified (second vs first tertile category: -0.101/year, 95% CI: -0.172 to - 0.030; third tertile category: -0.211/year, 95% CI: -0.281 to - 0.142). Non-HR-QOL was not significantly associated with the SDI scores. Among the HR-QOL domains, cognition, procreation, and physical health were significantly associated with the total SDI scores over time. HR-QOL was associated with corticosteroid-dependent and -independent SDI scores. CONCLUSION: A higher HR-QOL of Lupus PRO was associated with a lower increase in SDI scores. Our findings imply the importance of disease-specific HR-QOL measurements in assessing prognosis.

Active Rheumatoid Arthritis and Scoliosis: A Mid-Term Cohort Study.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To elucidate the factors related to progression of scoliosis in patients with rheumatoid arthritis (RA) using longitudinal cohort data. SUMMARY OF BACKGROUND DATA: Thirty percent of patients with RA have lumbar scoliosis. However, the effectiveness of current treatment methods in preventing the progression of scoliosis is not well-understood due to a lack of longitudinal studies. METHODS: We enrolled 180 patients with RA who were followed up for over two years, all of whom underwent standing spinal X-rays. These patients were categorized based on their disease activity score-28 with erythrocyte sedimentation rate (DAS28-ESR) into two groups: those in remission (n=76) and those in non-remission (n=104). We evaluated various radiographic measures, including C7 center sacral vertical line (C7-CSVL), pelvic obliquity, major Cobb angle, and curve location. RESULTS: Fifty-three (29.4%) patients presented progression of scoliosis during a mean follow-up period of 4.8 years. Patients in the non-remission showed larger Cobb angle at baseline and final follow-up, compared to those in remission. The annual progression rate of the curve was also greater in the non-remission group (1.04 degree /year), than in the remission group (0.59 degree /year, P=0.001). There was no difference in the incidence of new vertebral fractures. The presence of a baseline cobb angle of 10 degree or more (OR: 3.14; 95% CI: 1.38-7.13; P=0.006), glucocorticoid use (OR: 2.88; 95% CI: 1.18-7.06; P=0.021), and non-remission at baseline (OR: 2.83; 95% CI: 1.25-6.41; P=0.012) were significant risk factors for progression of scoliosis. CONCLUSION: RA disease activity is linked to progression of scoliosis in patients with RA. Patients with RA who present with an initial scoliosis of 10 degrees or greater, require glucocorticoids for treatment and are in non-remission at baseline may be at high risk for scoliosis progression.

Anti-integrin αvß6 antibody in Takayasu arteritis patients with or without ulcerative colitis.

Background: It has been well documented that Takayasu arteritis (TAK) and ulcerative colitis (UC) coexist in the same patients. HLA-B*52 characterizes the co-occurrence, which is one of the common genetic features between these two diseases, indicating shared underlying pathologic mechanisms. Anti-integrin αvß6 antibody (Ab) is present in sera of UC patients in a highly specific manner. We investigated if there were any associations between anti-integrin αvß6 Ab and TAK, considering the risk HLA alleles. Methods: A total of 227 Japanese TAK patients were recruited in the current study and their serum samples were subjected to measurement of anti-integrin αvß6 Ab by ELISA. The clinical information, including the co-occurrence of UC, was collected. The HLA allele carrier status was determined by Luminex or genotype imputation. Results: The information about the presence of UC was available for 165 patients, among which eight (4.84%) patients had UC. Anti-integrin αvß6 antibody was identified in 7 out of 8 TAK subjects with UC (87.5%) while only 5 out of 157 (3.18%) TAK subjects without UC had the antibody (OR 121, p=7.46×10-8). A total of 99 out of 218 (45.4%) patients were HLA-B*52 carriers. There was no significant association between the presence of anti-integrin αvß6 Ab and HLA-B*52 carrier status in those without UC (OR 2.01, 95% CI 0.33-12.4, p = 0.189). Conclusions: The prevalence of anti-integrin αvß6 Ab was high in TAK patients with UC, but not in the absence of concomitant UC. The effect of HLA-B*52 on anti-integrin αvß6 Ab production would be minimal.

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

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

Energy landscape analysis and time-series clustering analysis of patient state multistability related to rheumatoid arthritis drug treatment: The KURAMA cohort study.

Rheumatoid arthritis causes joint inflammation due to immune abnormalities, resulting in joint pain and swelling. In recent years, there have been considerable advancements in the treatment of this disease. However, only approximately 60% of patients achieve remission. Patients with multifactorial diseases shift between states from day to day. Patients may remain in a good or poor state with few or no transitions, or they may switch between states frequently. The visualization of time-dependent state transitions, based on the evaluation axis of stable/unstable states, may provide useful information for achieving rheumatoid arthritis treatment goals. Energy landscape analysis can be used to quantitatively determine the stability/instability of each state in terms of energy. Time-series clustering is another method used to classify transitions into different groups to identify potential patterns within a time-series dataset. The objective of this study was to utilize energy landscape analysis and time-series clustering to evaluate multidimensional time-series data in terms of multistability. We profiled each patient's state transitions during treatment using energy landscape analysis and time-series clustering. Energy landscape analysis divided state transitions into two patterns: "good stability leading to remission" and "poor stability leading to treatment dead-end." The number of patients whose disease status improved increased markedly until approximately 6 months after treatment initiation and then plateaued after 1 year. Time-series clustering grouped patients into three clusters: "toward good stability," "toward poor stability," and "unstable." Patients in the "unstable" cluster are considered to have clinical courses that are difficult to predict; therefore, these patients should be treated with more care. Early disease detection and treatment initiation are important. The evaluation of state multistability enables us to understand a patient's current state in the context of overall state transitions related to rheumatoid arthritis drug treatment and to predict future state transitions.

A preliminary survey of rheumatologists on the management of late-onset rheumatoid arthritis in Japan.

Objectives We investigated the current perspectives regarding the management of late-onset rheumatoid arthritis (LORA) among rheumatologists in clinical practice. Methods This study was performed in October 2021, and included 65 rheumatologists certified by the Japan College of Rheumatology, who were administered questionnaires (including multiple choice and descriptive formulae) regarding the management of LORA. We aggregated and analyzed the responses. Results All 65 rheumatologists responded to the survey; 47 (72%) answered that >50% of newly diagnosed patients were aged ≥65 years, 42 (65%) answered that achievement of remission or low disease activity was the treatment goal, and 40 (62%) considered patient safety to be the highest priority. Most rheumatologists are concerned about the management of conditions other than RA, such as comorbidities, financial constraints, and life circumstances that interfere with standard or recommended treatment implementation. Conclusion This preliminary survey highlighted various rheumatologists' perspectives regarding the management of LORA.

Avacopan's potential to decrease MPO-ANCA titres concurrent with ameliorated activity in ANCA-associated vasculitis.

Avacopan, an orally administered C5a receptor antagonist, is effective in microscopic polyangiitis via the inhibition of neutrophil priming induced by C5a. However, the exact effect of avacopan on the production of myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) is yet to be clearly established. This report presents a microscopic polyangiitis patient without major organ damage where high levels of MPO-ANCA persisted with high-dose steroid therapy and azathioprine, but the addition of avacopan led to a reduction in MPO-ANCA titres. The present case implies that avacopan-mediated inhibition of C5a may lead to a reduction in MPO-ANCA levels, thereby potentially ameliorating the pathophysiology of ANCA-associated vasculitis. Nevertheless, the impact of avacopan on MPO-ANCA production cannot be asserted solely based on this report; therefore, further examination is necessary through subgroup analysis using data from larger-scale studies.

Risk factors for serious infections and infection-related mortality in patients with microscopic polyangiitis: Multicentre REVEAL cohort study.

OBJECTIVE: Infections are a critical concern for patients with microscopic polyangiitis (MPA). This study aimed to identify the risk factors associated with serious infections (SIs) and infection-related mortality in patients with MPA, as well as the effect of glucocorticoid (GC) dose tapering on these outcomes. METHODS: This multicentre, retrospective, and observational study utilised data from a cohort of patients with MPA in Japan [Registry of Vasculitis Patients to Establish REAL World Evidence (REVEAL) cohort]. Patients were categorised based on the occurrence of SIs or infection-related deaths, and various characteristics were compared among the groups. RESULTS: Among 182 patients, 66 (36.2%) experienced 129 SIs and 27 (14.8%) developed infection-related deaths. Advanced age, elevated C-reactive protein (CRP) levels, and higher ratio of the GC dose at 3 months to the initial dose were identified as independent risk factors for SIs. Older age was also associated with infection-related deaths. Furthermore, the cumulative incidence of infection-related deaths was significantly higher in patients with a higher ratio of the GC dose at 24 months to the initial dose. CONCLUSION: Older age, elevated CRP levels, and slower GC dose tapering predispose patients to SIs and infection-related deaths. Strategies, such as rapid GC dose tapering, are anticipated to mitigate the risk of infections.

Low Hounsfield unit values on computed tomography as a potential predictor of vertebral fracture in patients with rheumatoid arthritis: The KURAMA cohort study.

OBJECTIVE: Hounsfield units (HU) measured using computed tomography (CT) have gained considerable attention for the detection of osteoporosis. This study aimed to investigate whether opportunistic CT could predict vertebral fractures in patients with rheumatoid arthritis (RA). METHODS: A total of 233 patients with RA who underwent chest CT were included in this study. The HU values of the anterior 1/3 of the vertebral bodies based on the sagittal plane at T11-L2 after reconstruction were measured. The incidence of vertebral fractures was investigated with respect to the HU value. RESULTS: Vertebral fractures were identified in 32 patients during a mean follow-up period of 3.8 years. In patients who experienced vertebral fractures within 2 years of CT imaging, the HU values of the vertebral bodies (T11-L2) were lower than those in patients who did not experience fractures. Receiver operating characteristic curve analysis identified that a T11 HU value of <125 was a risk factor for vertebral fracture within 2 years. Multivariate analysis showed that a T11 HU value of <125 and the existence of prevalent vertebral fractures were significant risk factors for fracture. CONCLUSION: HU measurements of the anterior 1/3 of the vertebral body are a potential predictor for vertebral fractures in patients with RA.

Myeloid-derived suppressor cell-derived osteoclasts with bone resorption capacity in the joints of arthritic SKG mice.

Background: Myeloid-derived suppressor cells (MDSCs) are heterogeneous immature myeloid cells with immunosuppressive functions. It is known that MDSCs are expanded at inflammatory sites after migrating from bone marrow (BM) or spleen (Sp). In chronic inflammatory diseases such as rheumatoid arthritis (RA), previous reports indicate that MDSCs are increased in BM and Sp, but detailed analysis of MDSCs in inflamed joints is very limited. Objective: The purpose of this study is to characterize the MDSCs in the joints of mice with autoimmune arthritis. Methods: We sorted CD11b+Gr1+ cells from joints (Jo), bone marrow (BM) and spleen (Sp) of SKG mice with zymosan (Zym)-induced arthritis and investigated differentially expressed genes (DEGs) by microarray analysis. Based on the identified DEGs, we assessed the suppressive function of CD11b+Gr1+ cells from each organ and their ability to differentiate into osteoclasts. Results: We identified MDSCs as CD11b+Gr1+ cells by flow cytometry and morphological analysis. Microarray analysis revealed that Jo-CD11b+Gr1+ cells had different characteristics compared with BM-CD11b+Gr1+ cells or Sp-CD11b+Gr1+ cells. Microarray and qPCR analysis showed that Jo-CD11b+Gr1+ cells strongly expressed immunosuppressive DEGs (Pdl1, Arg1, Egr2 and Egr3). Jo-CD11b+Gr1+ cells significantly suppressed CD4+ T cell proliferation and differentiation in vitro, which confirmed Jo-CD11b+Gr1+ cells as MDSCs. Microarray analysis also revealed that Jo-MDSCs strongly expressed DEGs of the NF-κB non-canonical pathway (Nfkb2 and Relb), which is relevant for osteoclast differentiation. In fact, Jo-MDSCs differentiated into osteoclasts in vitro and they had bone resorptive function. In addition, intra-articular injection of Jo-MDSCs promoted bone destruction. Conclusions: Jo-MDSCs possess a potential to differentiate into osteoclasts which promote bone resorption in inflamed joints, while they are immunosuppressive in vitro.

Significant association of HLA-A26 with uveitis and gastrointestinal involvement in patients with Behçet's disease in a multicentre study.

OBJECTIVES: Specific human leukocyte antigen (HLA) haplotypes are associated with Behçet's disease. Because the effects of HLA-A26 and its combination with HLA-B51 on organ involvement in Behçet's disease have not been well demonstrated, we aimed to examine them. METHODS: This multicentre, cross-sectional, observational study enrolled patients with Behçet's disease who visited Kyoto University Hospital between 2018 and 2021 or Kurashiki Central Hospital between 2006 and 2016 (n = 200). Disease severity was evaluated using the Krause score. RESULTS: Uveitis and gastrointestinal involvement were observed in 95/196 and 57/167 patients, respectively. The HLA alleles identified were HLA-B51 (n = 52/106), HLA-A26 (n = 25/88), and HLA-B51 and HLA-A26 (n = 6/88). In patients harbouring HLA-B51, the presence of HLA-A26 was associated with higher frequencies of uveitis (P = .03) and coexistence of uveitis and gastrointestinal involvement (P = .002) and higher Krause scores (P = .02). Furthermore, the presence of HLA-A26 was associated with a higher frequency of uveitis in patients with gastrointestinal involvement (P = .001) and gastrointestinal involvement in patients with uveitis (P = .001). CONCLUSIONS: Since specific HLA haplotypes and their combinations are associated with organ involvement, both HLA-A and HLA-B haplotypes should be confirmed when screening for affected organs.