Effectiveness of intravenous methylprednisolone pulse in patients with severe microscopic polyangiitis and granulomatosis with polyangiitis.

OBJECTIVES: To evaluate the effectiveness and safety of two different intravenous methylprednisolone (IVMP) pulse doses in patients with severe microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA). METHODS: We emulated a target trial using observational data from the nationwide registry in Japan. Patients with severe glomerulonephritis or diffuse alveolar haemorrhage were selected and pseudo-randomised into three groups using propensity score-based overlap weighting as follows: non-IVMP, IVMP 0.5 g/day, and IVMP 1.0 g/day. The primary outcome was all-cause death, and the secondary outcomes were composite all-cause death and kidney failure, severe relapse, and serious infection from 2 to 48 weeks after treatment initiation. To estimate the treatment effects, the Cox proportional hazard model and Fine-Gray subdistribution hazard model were used. RESULTS: In this emulated target trial, of 201 eligible patients (MPA, 175; GPA, 26), 6 (2.8%) died, 4 (2.0%) had kidney failure, 11 (5.3%) had severe relapse, and 40 (19.8%) had severe infections. Hazard ratios (HR) for IVMP 0.5 g/day and IVMP 1.0 g/day pulse groups compared with non-IVMP pulse were as follows: all-cause death = 0.46 (95% confidence interval [95%CI]: 0.07-2.81) and 0.07 (95%CI: 0.01-0.41); all-cause death/kidney failure = 1.18 (95%CI: 0.26-5.31) and 0.59 (95%CI: 0.08-4.52); subdistribution HRs for severe relapse = 1.26 (95%CI: 0.12-13.70) and 3.36 (95%CI: 0.49-23.29); and serious infection = 1.88 (95%CI: 0.76-4.65) and 0.94 (95%CI: 0.28-3.13). CONCLUSIONS: IVMP 1.0 g/day pulse may improve 48-week mortality in patients with severe MPA/GPA.

Association between early immunophenotypic changes and therapeutic response of belimumab in patients with systemic lupus erythematosus.

Belimumab is a therapeutic medication that inhibits the B-cell-activating factor (BAFF) used for systemic lupus erythematosus (SLE); however, the response sometimes varies among individuals, even when patients are stratified based on general clinical characteristics. Therefore, we focused on immunological phenotypic changes with belimumab, investigated their association with subsequent clinical courses, and sought to identify relevant immunological indicators to stratify patients who would benefit from belimumab. We assessed changes in B and T cell phenotypes, as well as BAFF-related factors, such as levels of BAFF and a proliferation-inducing ligand, and expression of three BAFF receptors: BAFF receptor (BAFF-R), B-cell maturation antigen (BCMA), transmembrane activator and cyclophilin ligand interactor (TACI), in 19 patients with SLE who were treated with belimumab before and 3 months after treatment. First, to visualize patterns in complex and diverse data, we summarized B cell changes such as subsets and BAFF receptor expressions into two axes, the first and second principal components (PC1 and PC2), and characterized broad phenotypic changes by cluster analysis. Next, we evaluated whether the B cell changes represented by PC1 and PC2 were associated with other concurrent phenotypic changes, baseline factors, and treatment response at 6 months. We found that lower PC2, indicating increased BAFF-R expression and decreased percentage of naïve B cells, was associated with a subsequent therapeutic response at 6 months (odds ratio 5.3, 95% confidence interval 1.2-24, p = .031). Furthermore, higher percentages of effector memory CD3+CD4+ T cells at baseline were associated with lower PC2 and therapeutic response. Further analysis revealed that increased PC1, as reflected by increased BCMA and TACI expression and an increase in the percentage of class-switched memory B cells, was associated with both T and B cell activation. Although belimumab is a B-cell targeted therapy, it can also influence T-cell phenotypes. Thus, early B cell changes could be used to predict treatment response, and their changes could be predicted from baseline T cell phenotypes, indicating the importance of B and T cell interactions.

Non-drug and surgical treatment algorithm and recommendations for the 2020 update of the Japan College of Rheumatology clinical practice guidelines for the management of rheumatoid arthritis-secondary publication.

OBJECTIVES: The aim of this study was to update the Japan College of Rheumatology (JCR) clinical practice guidelines (CPGs) for the management of rheumatoid arthritis (RA) and prepare an algorithm for non-drug and surgical treatments. This article is a digest version of the guidelines. METHODS: The Japanese Ministry of Health, Labour and Welfare's research group, in collaboration with the JCR, used the Grading of Recommendations, Assessment, Development, and Evaluation method to update the 2014 JCR CPG for RA. The consensus was formed by CPG panel members. RESULTS: We raised 19 clinical questions regarding non-drug and surgical treatments for RA and developed recommendations. The treatments included exercise therapy; occupational therapy; joint injection of corticosteroids; and orthopaedic surgeries including cervical spine surgery, wrist and foot arthroplasty, ankle arthrodesis, and replacement arthroplasty of the shoulder, elbow, finger, hip, knee, and ankle. Recommendations regarding the risks of surgery and perioperative discontinuation of medications have also been developed. Based on these recommendations, we created an original algorithm for the non-drug and surgical treatment of RA. CONCLUSIONS: These recommendations are expected to serve rheumatologists, health care professionals, and patients with RA as tools for shared decision-making to treat residual limb joint symptoms and functional impairment.

Drug treatment algorithm and recommendations from the 2020 update of the Japan College of Rheumatology clinical practice guidelines for the management of rheumatoid arthritis-secondary publication.

OBJECTIVE: The aim of this study was to update the Japan College of Rheumatology (JCR) clinical practice guidelines (CPG) for the management of rheumatoid arthritis (RA; JCR CPG for RA) according to recent changes in the medical environment in Japan. This article is a digest version of the guidance. METHODS: We used the Grading of Recommendations, Assessment, Development, and Evaluation method to update the 2014 JCR CPG for RA. A consensus was formed by CPG panel members. RESULTS: We identified 36 important clinical questions regarding drug treatment and developed corresponding recommendations for RA. The recommendations included the following RA medications: non-steroidal anti-inflammatory drugs, corticosteroids, conventional synthetic disease-modifying antirheumatic drugs, biological disease-modifying antirheumatic drugs, anti-receptor activator for nuclear factor-κB ligand antibodies, and Janus kinase inhibitors, as well as the tapering and discontinuation of these medications. Recommendations regarding the efficacy and safety of treatments in the elderly and patients with comorbidities were also developed. Finally, we used these recommendations to create an original algorithm for drug treatment for RA based on the Treat-to-Target approach. CONCLUSION: The 2020 JCR CPG for RA provides a useful tool for rheumatologists, health care professionals, and patients with RA, enabling shared decision-making in a variety of clinical situations.

Optimal Dose of Intravenous Cyclophosphamide during remission induction therapy in ANCA-associated vasculitis: a retrospective cohort study of J-CANVAS.

OBJECTIVES: To identify the optimal dose of intravenous cyclophosphamide (IVCY) for induction therapy for anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV). METHODS: We retrospectively assessed patients with AAV who received IVCY every 2-3 weeks during the remission induction phase. The associations of the IVCY dose with infection-free survival and relapse-free survival were analysed using a Cox regression model. We compared patients in three categories: very low-dose (VLD), low-dose (LD), and conventional dose (CD) (<7.5 mg/kg, 7.5-12.5 mg/kg, and >12.5 mg/kg, respectively). The non-linear association between IVCY dose and the outcomes were also evaluated. RESULTS: Of the 80 patients (median age 72 years), 12, 42, and 26 underwent the VLD, LD, and CD regimens, respectively, of whom 4, 3, and 7 developed infection or died. The adjusted hazard ratios for infection or death were 4.3 (95% confidence interval (CI) 0.94-19.8) for VLD and 5.1 (95% CI 1.21-21.3) for CD, compared with LD. We found the hazard ratio for infection or death increased when the initial IVCY dose exceeded 9 mg/kg. Relapse-free survival did not differ clearly. CONCLUSION: Low-dose IVCY (7.5-12.5 mg/kg) may result in fewer infections and similar relapse rates compared with the conventional regimen (>12.5 mg/kg).

Risk of adrenal insufficiency in patients with polymyalgia rheumatica versus patients with rheumatoid arthritis: A cross-sectional study.

OBJECTIVE: To determine whether patients with polymyalgia rheumatica (PMR) are more susceptible to glucocorticoid-induced adrenal insufficiency, one of the barriers to glucocorticoid tapering strategies, compared to patients with rheumatoid arthritis (RA). METHODS: This cross-sectional study included PMR and RA patients who underwent adrenocorticotropic hormone (ACTH) tests to assess adrenal function. The eligibility criteria were as follows: previous use of prednisolone (PSL) ≥ 5 mg/day, use of PSL for six consecutive months before ACTH test, and current use of PSL at 5 mg/day or less. The association between disease type (PMR vs. RA) and insufficient adrenal response was assessed using logistic regression models. RESULTS: Twenty-six of 34 (76.5%) patients with PMR and 13 of 37 (35.1%) patients with RA had insufficient adrenal response. Compared to patients with RA, patients with PMR were more likely to have insufficient adrenal response, even after adjusting for age, sex, and PSL dose (adjusted odds ratio, 6.75; 95% confidence interval, 1.78-25.60). CONCLUSION: Patients with PMR have a higher risk of glucocorticoid-induced adrenal insufficiency than patients with RA. Assessing the adrenal function in patients with PMR will contribute to establishing a more appropriate glucocorticoid reduction strategy.

Does exercise therapy improve patient-reported outcomes in rheumatoid arthritis? A systematic review and meta-analysis for the update of the 2020 JCR guidelines for the management of rheumatoid arthritis.

OBJECTIVES: This study aimed to evaluate the impact of exercise therapy on patient-reported outcomes (PROs) in rheumatoid arthritis (RA) as part of the process of updating the 2020 Japanese guidelines for the management of RA according to the Grading of Recommendations, Assessment, Development, and Evaluation system. METHODS: We searched PubMed, Japana Centra Revuo Medicina Web, and the Cochrane Library (from 2009 to 2018) to identify articles that evaluated PROs of exercise therapy and RA disease activity. RESULTS: A total of 662 articles were identified, including nine RCTs, and meta-analyses were performed on six RCTs on systemic exercise therapy and three RCTs on upper extremity exercise therapy. Analyzed exercise therapies were diverse, differing in target population, intervention method, and duration. Significant improvements were observed in the Health Assessment Questionnaire Disability Index (mean difference -0.35, 95% confidence interval (CI): -0.60 to -0.10), pain (standardized mean difference -2.04, 95% CI: -3.77 to -0.32), and SF-36. For upper extremity exercise therapy, significant improvements in PROs (Disabilities of the Arm, Shoulder, and Hand Questionnaire, Michigan Hand Outcome Questionnaire) were observed. CONCLUSION: Exercise therapy in RA treatment improves patient subjective assessment of pain, physical function, and quality of life.

Systematic review and meta-analysis of biosimilar for the treatment of rheumatoid arthritis informing the 2020 update of the Japan College of Rheumatology clinical practice guidelines for the management of rheumatoid arthritis.

OBJECTIVES: To evaluate the efficacy and safety of biosimilars compared with reference biological disease modifying antirheumatic drugs (bDMARDs) in patients with rheumatoid arthritis (RA) as a part of the process of developing the 2020 update of the Japan College of Rheumatology guidelines for the management of RA. METHODS: PubMed, Cochrane Library, and Japan Centra Revuo Medicina were searched for articles to conduct a systematic review (SR). The quality of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation system. RESULTS: Twenty randomized controlled trials were included (biosimilars of infliximab, etanercept, and adalimumab). A meta-analysis revealed that the risk ratios (RRs) and 95% confidence intervals (CIs) of achieving the American College of Rheumatology 50% response (ACR50) at week 24 and serious adverse events (SAEs) for biosimilars compared with the reference bDMARDs were 1.04 (0.98-1.10) and 0.84 (0.61-1.18), respectively. The RRs of achieving ACR50 and SAEs at week 24 were respectively 0.93 (0.69-1.26) and 2.15 (0.55-8.35) in the patients who switched to biosimilars from the reference bDMARDs and 0.92 (0.76-1.12) and 1.41 (0.32-6.15) in those who continued the reference bDMARDs. CONCLUSION: Biosimilars and reference bDMARDs were equally useful for the management of RA.

Patient satisfaction with total joint replacement surgery for rheumatoid arthritis: a questionnaire survey for the 2020 update of the Japan college of rheumatology clinical practice guidelines.

OBJECTIVE: This study aimed to evaluate satisfaction with total joint replacement (TJR) surgery among patients with rheumatoid arthritis (RA). METHODS: We mailed questionnaires to randomly selected members of the Japan Rheumatism Friendship Association, stratified by age and prefecture, throughout Japan. The questionnaire collected demographic and clinical characteristics as well as patients' satisfaction with TJR and their current therapy. RESULTS: Of the 1156 patients who returned the questionnaire, 339 (29.3%) responded that they had had TJR of any type. The mean age was 66.6 years, and 94.4% were women. The mean time period from the hip and knee TJR was 14-15 years. Over half of the patients who had had TJR were satisfied with the results, especially those who had had hip (89.6%) and knee TJR (87.3%), who reported a high level of satisfaction. Multivariable linear regression analysis revealed that, in patients with knee TJR, satisfaction with current therapy was significantly related to whether they were satisfied with the results of the surgery. CONCLUSION: Most patients with RA who had undergone TJR were satisfied with the results even after a long period of time, and their level of satisfaction was associated with their satisfaction with current therapy.

Systematic review for the treatment of older rheumatoid arthritis patients informing the 2020 update of the Japan College of Rheumatology clinical practice guidelines for the management of rheumatoid arthritis.

OBJECTIVES: To provide an evidence base for clinical practice guidelines (CPG) for the management of rheumatoid arthritis (RA) in older adults. METHODS: PubMed, Cochrane library, and Japan Centra Revuo Medicina databases were searched for articles published between 1990 and 2019. Quality of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation system, with some modifications. RESULTS: Among 702 identified articles, there were 5 post-hoc analyses of randomized controlled trials and 10 observational studies. Meta-analysis of the former yielded a mean difference of the van der Heijde-modified total Sharp score of -2.79 (95% confidence interval [CI] - 3.74 to -1.84) for treatment with tumor necrosis factor inhibitors. The risk ratio (RR) for the American College of Rheumatology 50% response rate, and for serious adverse events was 2.83 (95%CI 1.90-4.21) and 1.32 (95%CI 0.53-3.31), respectively, for Janus kinase inhibitors. Meta-analysis of the observational studies yielded an RR for disease activity score-28 remission and serious infections of 0.76 (95%CI 0.64-0.91) and 1.92 (95%CI 1.31-2.81) for older-versus-younger patients receiving biological disease-modifying antirheumatic drugs, respectively. CONCLUSION: This systematic review provides the necessary evidence for developing CPG for the management of RA in older adults.

Patients' perspectives of rheumatoid arthritis treatment: a questionnaire survey for the 2020 update of the Japan college of rheumatology clinical practice guidelines.

OBJECTIVES: This study aimed to evaluate patients' opinions regarding their rheumatoid arthritis (RA) therapy and to reflect the patients' perspectives in the 2020 update of the Japan College of Rheumatology clinical practice guidelines. METHODS: A self-administered questionnaire was mailed to 1600 members of the Japan Rheumatology Friendship Association, who were randomly selected by age and prefecture. RESULTS: A total of 1156 patients returned the questionnaire (response rate, 72.3%; mean age, 63.0 ± 11.9 years). Those who reported having discussed their treatment goals with their doctors (450 respondents, 38.9%) were more likely to be satisfied with their current medical care (odds ratio, 7.13; 95% CI 4.72-10.8) compared with those who had not discussed their goals nor had them explained (287 respondents, 24.8%). The benefits exceeded the adverse effects for all pharmacotherapy (methotrexate, corticosteroids, conventional synthetic antirheumatic drugs, biological agents, Janus kinase inhibitor, and anti-RANKL antibodies). However, while 74.2% of the respondents using biological agents perceived that 'the favorable aspects outweighed the unfavorable aspects,' most of those taking anti-RANKL antibodies (69.2%) felt uncertain. CONCLUSIONS: The questionnaire successfully collected information regarding patients' perceptions regarding their therapy. Further implementation of treat-to-target is necessary in Japan to improve patient satisfaction.

Comprehensive risk analysis of postoperative complications in patients with rheumatoid arthritis for the 2020 update of the Japan College of Rheumatology clinical practice guidelines for the management of rheumatoid arthritis.

OBJECTIVES: To examine the risk factors of surgical site infection (SSI), delayed wound healing, and death after orthopedic surgery in patients with rheumatoid arthritis (RA). METHODS: We identified articles indexed in the Cochrane Library, PubMed, and Japan Centra Revuo Medicina Web published from 2013 to 2019 and other articles. Articles fulfilling the predefined inclusion criteria were reviewed systematically and their quality was appraised according to the Grading of Recommendations Assessment, Development, and Evaluation system with some modifications. RESULTS: After inclusion and exclusion by full-text review, 29 articles were analyzed. Use of biological disease modifying antirheumatic drugs was a risk factor of SSI (risk ratio 1.66, 95% confidence interval 1.25-2.19), but not of delayed wound healing. RA itself was a risk factor of SSI, and oral glucocorticoid use was a risk factor of SSI in three of the four studies analyzed and of postoperative death. Age, male sex, comorbidities such as diabetes mellitus and chronic obstructive pulmonary disease, surgical factors such as foot/ankle and spine surgery and longer operative time were risk factors of those postoperative complications. CONCLUSION: Patients with those factors should be dealt with appropriate cautions to strike a risk-benefit balance of orthopedic surgeries.

CG223, a novel BET inhibitor, exerts TGF-ß1-mediated antifibrotic effects in a murine model of bleomycin-induced pulmonary fibrosis.

Pulmonary fibrosis is a progressive disease with poor prognosis and limited therapeutic options. In this study, we evaluated the potential therapeutic effects of CG223, a novel inhibitor of bromodomain and extra-terminal motif (BET) proteins, on pulmonary fibrosis by focusing on the transforming growth factor-ß1 (TGF-ß1) pathway. In a murine model of bleomycin-induced pulmonary fibrosis, CG223 attenuated fibrosis while reducing the infiltration of inflammatory cells into the lungs. Fibroblasts expressing BRD4, a member of the BET protein family, were enriched in the tissue regions corresponding to bleomycin-induced fibrotic lesions. Additionally, pulmonary fibroblasts isolated from bleomycin-instilled mice showed a significantly increased association of BRD4 with the promoters of two pro-fibrotic genes linked to the entry into the TGF-ß1 autocrine/paracrine loop, thrombospondin 1 (Thbs1) and integrin ß3 (Itgb3), as well as with the promoter of a myofibroblast marker gene, actin alpha 2 (Acta2). Subsequent in vitro studies with murine primary lung fibroblasts showed that the mRNA induction of Thbs1, Itgb3, and Acta2 by TGF-ß1 can be inhibited by CG223 in a dose-dependent manner. Taken together, CG223-induced BRD4 inhibition suppressed lung fibrogenesis by affecting multiple genes, including those involved in the triggering of the TGF-ß1 autocrine/paracrine loop.

Risk factors for cytomegalovirus disease with cytomegalovirus re-activation in patients with rheumatic disease.

Objective: To assess risk factors for cytomegalovirus (CMV) disease with CMV re-activation in patients with rheumatic disease.Methods: The clinical data of consecutive patients with rheumatic disease who experienced CMV re-activation were examined. We evaluated the difference in various baseline factors at the first detection of CMV pp65 antigenemia on the development of CMV disease using logistic regression models. The changes of laboratory data in the 4 weeks before CMV re-activation were also assessed.Results: We identified 80 patients (median age [interquartile range] = 65.0 years [51.5-74.0]) with CMV re-activation. Oral candidiasis, serum albumin ≤30 g/L, and CMV pp65-positive cell count >5.6/105 polymorphonuclear leukocyte cells were found to be associated with CMV disease (odds ratio [OR] [95% CI] = 9.99 [2.02-49.50], 11.4 [1.94-67.40] and 6.80 [1.63-28.30], respectively). Moreover, decreases in serum albumin level and blood lymphocyte count in the 4 weeks before CMV re-activation also predicted CMV disease (OR [95% CI] = 2.02 [1.07-3.8] and 1.96 [1.09-3.54], respectively).Conclusion: In CMV re-activation patients with rheumatic disease, the presence of oral candidiasis, high CMV pp65 positive cell count, and hypoalbuminemia are possible risk factors for CMV disease.

Association between preexisting lung involvements and the risk of diffuse alveolar hemorrhage in patients with microscopic polyangiitis: A multi-center retrospective cohort study.

Objectives: To identify the factors associated with the risk of diffuse alveolar hemorrhage (DAH) in patients with microscopic polyangiitis (MPA), focusing on other preexisting lung involvements such as interstitial lung disease (ILD) and airway disease.Methods: In this retrospective cohort study, we analyzed consecutive patients with myeloperoxidase-antineutrophil cytoplasmic antibody-positive MPA who had undergone chest computed tomography (CT) before starting treatment between 2006 and 2016. Patients who already had DAH at initial CT imaging were excluded. CT images were evaluated for the presence of ILD and airway disease. The association between preexisting lung involvements and the development of DAH was assessed using logistic regression models adjusted for various clinical characteristics.Results: We identified 113 patients (median age 72 years; median follow-up duration 39 months), and 27 (24%) of them developed DAH during the follow-up. Airway disease was identified in 41 (36%) patients and was independently associated with the development of DAH (adjusted odds ratio 6.86, 95% confidence interval 1.85-25.4). However, ILD identified in 45 (40%) patients was not associated with DAH.Conclusion: Our findings suggest that DAH in MPA occurs frequently in patients with airway disease. Attention to preexisting airway disease may help predict the development of DAH.

Effectiveness and safety of chronic hepatitis C treatment with direct-acting antivirals in patients with rheumatic diseases: A case-series.

Objectives: To assess the effectiveness and safety of interferon-free direct-acting antiviral (DAA) therapy for patients with concomitant hepatitis C virus (HCV) infection and rheumatic diseases (RDs), including rheumatoid arthritis (RA).Methods: This was a single-center observational case-series study conducted in Japan from 2014 to 2018. The primary endpoint was the sustained virological response (SVR) rate 24 weeks after the end of therapy (EoT24). We also evaluated hepatological and rheumatological outcomes and adverse events.Results: Of the 2314 patients with RDs, 18 received DAA therapy (RA = 11, other RDs = 7). The SVR rate for the initial DAA therapy was 89% (16/18). The remaining two achieved SVR with secondary DAA therapy. Along with HCV elimination, hepatological parameters improved significantly from baseline to EoT24. During the study period, no patients newly developed cirrhosis or HCC after HCV elimination. Several patients showed improvement in RDs activity. In RA patients, the simplified disease activity index decreased significantly from baseline to EoT24 (median [interquartile range]: 11.53 [5.14-14.89] vs. 4.06 [2.08-9.05], respectively). On-treatment adverse events were minimal, while two patients experienced tuberculosis reactivation after EoT.Conclusion: DAA therapy was effective and safe, providing hepatological and rheumatological benefits in HCV-infected patients with RDs. Immune reconstitution following HCV elimination should be noted.

Utility of Coagulation Markers for the Prediction of Rapidly Progressive Interstitial Lung Disease in Patients with Dermatomyositis.

We aimed to evaluate the utility of coagulation markers for the prediction of rapidly progressive interstitial lung disease (RP-ILD) in patients with dermatomyositis (DM). In this retrospective study, 29 patients with DM-associated ILD were analyzed. The number of patients with RP-ILD was 15 (52%). The baseline clinical and demographic data and laboratory markers were analyzed to identify predictive factors for RP-ILD.The univariate logistic regression analysis demonstrated that in addition to well-known laboratory markers, such as serum ferritin, KL-6, and lymphocyte counts, a prolonged activated partial thromboplastin time (aPTT) ratio at the time of DM-associated ILD diagnosis was useful for predicting RP-ILD. Moreover, the logistic regression model and receiver operating characteristic curve analysis showed that combinations of the aPTT ratio and well-known laboratory markers were significantly effective in predicting RP-ILD. This study suggested that an association between RP-ILD and the coagulation system exists.

Roles of high-mobility group box 1 and thrombin in murine pulmonary fibrosis and the therapeutic potential of thrombomodulin.

Cross talk between inflammation and coagulation plays important roles in acute or subacute progressive pulmonary fibrosis characterized by diffuse alveolar damage. Thrombomodulin is a physiological inhibitor of high-mobility group box 1 (HMGB1), and thrombin and may be effective for this condition. This study investigated the roles of HMGB1 and thrombin in the pathophysiology of bleomycin-induced pulmonary fibrosis and the efficacy of recombinant human soluble thrombomodulin (rhTM). Pulmonary fibrosis was induced in wild-type C57BL/6 mice by intratracheal instillation of bleomycin. We first assessed HMGB1, thrombin, transforming growth factor (TGF)-ß1, and α-smooth muscle actin (SMA) levels in bronchoalveolar lavage fluid and lung tissue sections over time. Expression of HMGB1 and thrombin was elevated before that of TGF-ß1 and α-SMA and remained high during the fibrotic phase after bleomycin instillation. We next examined whether in vitro stimulation with HMGB1 and thrombin induced expression of TGF-ß1 and α-SMA in cultured alveolar macrophages and lung fibroblasts, respectively, by performing quantitative PCR, enzyme-linked immunosorbent assay, Western blot, and immunofluorescence analyses. HMGB1 and thrombin stimulation induced TGF-ß1 production by alveolar macrophages, and thrombin stimulation also induced α-SMA expression in lung fibroblasts. Finally, we evaluated the effect of rhTM on bleomycin-induced pulmonary fibrosis. Compared with the vehicle control, both early and late-phase administration of rhTM suppressed the fibrotic process. Our results suggest that HMGB1 and thrombin were involved in the pathophysiology of pulmonary fibrosis via production of profibrotic proteins and that rhTM attenuated bleomycin-induced pulmonary fibrosis. rhTM may be a therapeutic option for acute or subacute pulmonary fibrosis.

Role of allograft inflammatory factor-1 in bleomycin-induced lung fibrosis.

Allograft inflammatory factor-1 (AIF-1) is a protein expressed by macrophages infiltrating the area around the coronary arteries in a rat ectopic cardiac allograft model. We previously reported that AIF-1 is associated with the pathogenesis of rheumatoid arthritis and skin fibrosis in sclerodermatous graft-versus-host disease mice. Here, we used an animal model of bleomycin-induced lung fibrosis to analyze the expression of AIF-1 and examine its function in lung fibrosis. The results showed that AIF-1 was expressed on lung tissues, specifically macrophages, from mice with bleomycin-induced lung fibrosis. Recombinant AIF-1 increased the production of TGF-ß which plays crucial roles in the mechanism of fibrosis by mouse macrophage cell line RAW264.7. Recombinant AIF-1 also increased both the proliferation and migration of lung fibroblasts compared with control group. These results suggest that AIF-1 plays an important role in the mechanism underlying lung fibrosis, and may provide an attractive new therapeutic target.

Inhibition of osteoclastogenesis by osteoblast-like cells genetically engineered to produce interleukin-10.

Bone destruction at inflamed joints is an important complication associated with rheumatoid arthritis (RA). Interleukin-10 (IL-10) may suppress not only inflammation but also induction of osteoclasts that play key roles in the bone destruction. If IL-10-producing osteoblast-like cells are induced from patient somatic cells and transplanted back into the destructive bone lesion, such therapy may promote bone remodeling by the cooperative effects of IL-10 and osteoblasts. We transduced mouse fibroblasts with genes for IL-10 and Runx2 that is a crucial transcription factor for osteoblast differentiation. The IL-10-producing induced osteoblast-like cells (IL-10-iOBs) strongly expressed osteoblast-specific genes and massively produced bone matrix that were mineralized by calcium phosphate in vitro and in vivo. Culture supernatant of IL-10-iOBs significantly suppressed induction of osteoclast from RANKL-stimulated Raw264.7 cells as well as LPS-induced production of inflammatory cytokine by macrophages. The IL-10-iOBs may be applicable to novel cell-based therapy against bone destruction associated with RA.