Headache in systemic lupus erythematosus: The LUNA registry cross-sectional study.

OBJECTIVES: This study investigated the clinically relevant factors for headaches in patients with systemic lupus erythematosus (SLE) using a registry from a Japanese multicenter cohort. METHODS: This cross-sectional study analysed the clinical information of patients with SLE who experienced headache episodes using the Migraine Disability Assessment (MIDAS) questionnaire. Significant findings in the comparisons between patients with headache (HA patients) and those without headache (non-HA patients) and in the comparisons depending on the grades of headache-induced disability in daily life based on the MIDAS scores were evaluated. Multivariate logistic regression analyses were performed to identify the relevant factors for headache. RESULTS: We analyzed 369 patients (median age, 45 years; female, 90.8%), including 113 HA patients who were significantly younger than non-HA patients (p < .005). HA patients had significantly higher frequencies of photosensitivity, rashes, and mucosal ulcers than non-HA patients (p < .05). Age and photosensitivity were significantly associated with headache (odds ratio (OR) 0.93, 95% confidence interval (CI) 0.95-0.99; OR 2.11, 95% CI 1.29-3.49, respectively). In the HA patients, hypocomplementemia was significantly associated with a disability of more than mild grade (OR 2.89, 95% CI 1.14-7.74), while rash was significantly observed in those presenting with moderate and severe disability. CONCLUSION: This study suggests that photosensitivity is a relevant manifestation of headache in patients with SLE. Persistent hypocomplementemia can contribute to headache-induced disability in daily life, whereas a rash may be a dominant manifestation in patients presenting with moderate/severe headache-induced disability.

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.

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.

Seasonal Effects on Relapse of Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: A Retrospective Multicenter Cohort Study in Japan (J-CANVAS).

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a type of systemic vasculitis characterized by autoantibody development against the neutrophil proteins leukocyte proteinase 3 (PR3)-ANCA and myeloperoxidase (MPO)-ANCA. We previously reported that newly developed AAV in Japan was influenced by seasonal variations and that AAV was less frequently observed in autumn.1.

Improvement of active salivary gland ultrasonography findings in Sjögren's syndrome in response to short-term glucocorticoid treatment: A case report and review of the literature.

Salivary gland ultrasonography is a non-invasive imaging technique that helps in the diagnosis and assessment of disease activity in Sjögren's syndrome. However, it remains unclear whether the salivary gland ultrasonography findings are reversible in response to treatment. We present a case of a woman in her 20s who presented with parotid swelling and pain lasting for three months. The patient was diagnosed with anti-SS-A antibody-positive Sjögren's syndrome with active sialadenitis, and short-term glucocorticoid treatment resulted in resolution of clinical symptoms and improvement of salivary gland ultrasonography findings by the Outcome Measures in Rheumatology Clinical Trials scoring system. Notably, the anechoic/hypoechoic foci and vascular signals in the parotid and submandibular glands were reduced after treatment. Furthermore, peak systolic blood flow velocity of the facial artery entering the submandibular gland was decreased. Our case highlights that the findings of "inflammatory" structural changes and vascularization on salivary gland ultrasonography, including the Outcome Measures in Rheumatology Clinical Trials scoring system, reflect the disease active of Sjögren's syndrome and are reversible with treatment. Salivary gland ultrasonography has the potential to be a useful tool for monitoring treatment response and stratifying patients by disease activity in Sjögren's syndrome, therefore further research is needed on the relationship of salivary gland ultrasonography findings with the pathophysiological mechanisms of sialadenitis and long-term clinical outcomes.

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).

Seasonal Influence on Development of Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: A Retrospective Cohort Study Conducted at Multiple Institutions in Japan (J-CANVAS).

OBJECTIVE: To clarify seasonal and other environmental effects on the onset of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). METHODS: We enrolled patients with new-onset eosinophilic granulomatosis with polyangiitis (EGPA), microscopic polyangiitis (MPA), and granulomatosis with polyangiitis (GPA) registered in the database of a Japanese multicenter cohort study. We investigated the relationship between environmental factors and clinical characteristics. Seasons were divided into 4 (spring, summer, autumn, and winter), and the seasonal differences in AAV onset were analyzed using Pearson chi-square test, with an expected probability of 25% for each season. RESULTS: A total of 454 patients were enrolled, with a mean age of 70.9 years and a female proportion of 55.5%. Overall, 74, 291, and 89 patients were classified as having EGPA, MPA, and GPA, respectively. Positivity for myeloperoxidase (MPO)-ANCA and proteinase 3 (PR3)-ANCA was observed in 355 and 46 patients, respectively. Overall, the seasonality of AAV onset significantly deviated from the expected 25% for each season (P = 0.001), and its onset was less frequently observed in autumn. In ANCA serotypes, seasonality was significant in patients with MPO-ANCA (P < 0.001), but not in those with PR3-ANCA (P = 0.97). Additionally, rural residency of patients with AAV was associated with PR3-ANCA positivity and biopsy-proven pulmonary vasculitis. CONCLUSION: The onset of AAV was influenced by seasonal variations and was less frequently observed in autumn. In contrast, the occurrence of PR3-ANCA was triggered, not by season, but by rural residency.

Association between hypogammaglobulinaemia and severe infections during induction therapy in ANCA-associated vasculitis: from J-CANVAS study.

OBJECTIVES: To investigate the association between decreased serum IgG levels caused by remission-induction immunosuppressive therapy of antineutrophil cytoplasmic antibody-associated vasculitis (AAV) and the development of severe infections. METHODS: We conducted a retrospective cohort study of patients with new-onset or severe relapsing AAV enrolled in the J-CANVAS registry, which was established at 24 referral sites in Japan. The minimum serum IgG levels up to 24 weeks and the incidence of severe infection up to 48 weeks after treatment initiation were evaluated. After multiple imputations for all explanatory variables, we performed the multivariate analysis using a Fine-Gray model to assess the association between low IgG (the minimum IgG levels <500 mg/dl) and severe infections. In addition, the association was expressed as a restricted cubic spline (RCS) and analysed by treatment subgroups. RESULTS: Of 657 included patients (microscopic polyangiitis, 392; granulomatosis with polyangiitis, 139; eosinophilic granulomatosis with polyangiitis, 126), 111 (16.9%) developed severe infections. The minimum serum IgG levels were measured in 510 patients, of whom 77 (15.1%) had low IgG. After multiple imputations, the confounder-adjusted hazard ratio of low IgG for the incidence of severe infections was 1.75 (95% confidence interval: 1.03-3.00). The RCS revealed a U-shaped association between serum IgG levels and the incidence of severe infection with serum IgG 946 mg/dl as the lowest point. Subgroup analysis showed no obvious heterogeneity between treatment regimens. CONCLUSION: Regardless of treatment regimens, low IgG after remission-induction treatment was associated with the development of severe infections up to 48 weeks after treatment initiation.

Number of Attending Physicians and Accumulated Organ Damage in Patients with Systemic Lupus Erythematosus: LUNA Registry Cross-Sectional Study.

INTRODUCTION: Patients with systemic lupus erythematosus (SLE) frequently change attending physicians. The number of changes in attending physicians is related to the accumulated organ damage in patients with diabetes mellitus and inflammatory bowel disease, although similar results are not known for patients with SLE. This study investigated whether the number of attending physicians after the onset of SLE is associated with organ damage. METHODS: Patients with SLE were enrolled in a multicenter registry of 14 institutions (the Lupus Registry of Nationwide Institutions). Patients with a disease duration of 6 months to 10 years were included. Exposure was defined as the number of attending physicians. The primary outcome was the Systemic Lupus International Collaborating Clinics/American College of Rheumatology damage index (SDI). The secondary outcomes were corticosteroid- and non-corticosteroid-related damage. Multiple logistic regression analysis was used to estimate the association between the number of attending physicians and SDI, adjusting for potential confounders, including age, sex, disease duration, number of hospitalizations due to SLE, disease activity at diagnosis, and emotional health. RESULTS: Of the 702 patients, 86.5% were women (median age 46 years, interquartile range 35-58). The disease duration was 7.3 years (4.3-11.3), the number of hospitalizations due to SLE was 1 (1-3), the number of attending physicians was 3 (2-4), and SDI was 0 points (0-1). The number of attending physicians was significantly associated with SDI [odds ratio (OR) 1.14, 95% confidence interval (CI) 1.03-1.26]. In the secondary outcome, the number of attending physicians was significantly associated with corticosteroid-related damage (OR 1.22, 95% CI 1.09-1.38). The number of attending physicians was not significantly associated with non-corticosteroid-related damage (OR 1.08, 95% CI 0.99-1.19). CONCLUSIONS: This study showed that SDI could increase as the number of attending physicians increases. The impact of changing attending physicians warrants greater attention for SLE and other diseases.

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.

Systematic review and meta-analysis for 2023 clinical practice guidelines of the Japan Research Committee of the Ministry of Health, Labour, and Welfare for Intractable Vasculitis for the management of ANCA-associated vasculitis.

OBJECTIVES: The objective of this study is to provide evidence for the revision of clinical practice guidelines for the management of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis by the Japan Research Committee for Intractable Vasculitis. METHODS: PubMed, CENTRAL, and the Japan Medical Abstracts Society databases were searched for articles published between 2015 and 2020 to update the systematic review for existing clinical questions, while PubMed, CENTRAL, EMBASE, and the Japan Medical Abstracts Society were searched for articles published between 2000 and 2020 to conduct a systematic review for newly developed clinical questions. The certainty of evidence was assessed with the GRADE approach. RESULTS: For remission induction, when used in conjunction with cyclophosphamide or rituximab, reduced-dose glucocorticoid lowered the risk of serious adverse events compared to standard-dose glucocorticoid. Avacopan improved sustained remission at 12 months compared to high-dose glucocorticoid. Addition of plasma exchange to remission induction therapy did not reduce the risk of death, end-stage kidney disease, or relapse. For remission maintenance, rituximab reduced the risk of relapse compared to azathioprine. Long-term rituximab or azathioprine reduced the risk of relapse compared to short-term rituximab or azathioprine, respectively. CONCLUSIONS: This systematic review provided evidence required to develop the 2023 clinical practice guideline for the management of ANCA-associated vasculitis.

Late-onset rheumatoid arthritis registry study, LORIS study: study protocol and design.

BACKGROUND: Although drug treatment strategies for rheumatoid arthritis (RA) are relatively well established, there is a paucity of evidence on the treatment in older patients. The purpose of this study is to build a registry for late-onset RA (LORA), which is expected to increase rapidly worldwide. In addition, we aim to propose optimal treatment strategies according to the patient background including frailty, thereby contributing to improving the quality of treatment and daily living in patients with RA. METHODS/DESIGN: The LORIS (Late-onset Rheumatoid Arthritis Registry) Study is a prospective nation-wide multicenter observational study of patients with LORA. The inclusion criteria were patients aged ≥ 65 years at onset, meeting 2010 ACR/EULAR classification criteria for RA, and starting either any disease-modifying antirheumatic drugs (DMARDs) in a DMARD-naïve patient or the first biologic/targeted synthetic DMARDs during the study period. Enrollment was started on 11 January, 2022 and will be closed on 31 December, 2023. Patients will undergo a comprehensive baseline assessment including clinical data, medication, cognitive and physical function, psychosocial factors, and frailty. Data will be collected at baseline, Month 3, 6, 12, 18, 24, 36, and summarized descriptively. The factors associated with adverse events and achieving remission will be determined. DISCUSSION: A multi-disciplinary panel including patients, rheumatologists, and geriatric specialists will discuss the results and build a consensus regarding the treatment goals of LORA. We expect to provide a broad range of information for evidence-based shared decision making in the treatment of LORA. STUDY REGISTRATION: Registered at the UMIN registry (UMIN000046086) on 1 January 2022.

Latent trajectory modelling of pulmonary artery pressure in systemic sclerosis: a retrospective cohort study.

OBJECTIVES: To visualise the trajectories of pulmonary arterial pressure (PAP) in systemic sclerosis (SSc) and identify the clinical phenotypes for each trajectory, by applying latent trajectory modelling for PAP repeatedly estimated by echocardiography. METHODS: This was a multicentre, retrospective cohort study conducted at four referral hospitals in Kyoto, Japan. Patients with SSc who were treated at study sites between 2008 and 2021 and who had at least three echocardiographic measurements of systolic PAP (sPAP) were included. A group-based trajectory model was applied to the change in sPAP over time, and patients were classified into distinct subgroups that followed similar trajectories. Pulmonary hypertension (PH)-free survival was compared for each trajectory. Multinomial logistic regression analysis was performed for baseline clinical characteristics associated with trajectory assignment. RESULTS: A total of 236 patients with 1097 sPAP measurements were included. We identified five trajectories: rapid progression (n=9, 3.8%), early elevation (n=30, 12.7%), middle elevation (n=54, 22.9%), late elevation (n=24, 10.2%) and low stable (n=119, 50.4%). The trajectories, in the listed order, showed progressively earlier elevation of sPAP and shorter PH-free survival. In the multinomial logistic regression analysis with the low stable as a reference, cardiac involvement was associated with rapid progression, diffuse cutaneous SSc was associated with early elevation and anti-centromere antibody was associated with middle elevation; older age of onset was associated with all three of these trajectories. CONCLUSION: The pattern of changes in PAP over time in SSc can be classified into five trajectories with distinctly different clinical characteristics and outcomes.

Hypertrophic pachymeningitis in ANCA-associated vasculitis: a cross-sectional and multi-institutional study in Japan (J-CANVAS).

BACKGROUND: This study investigated the characteristics of hypertrophic pachymeningitis (HP) in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), using information from a multicenter study in Japan. METHODS: We analyzed the clinical information of 663 Asian patients with AAV (total AAV), including 558 patients with newly diagnosed AAV and 105 with relapsed AAV. Clinical findings were compared between patients with and without HP. To elucidate the relevant manifestations for HP development, multivariable logistic regression analyses were additionally performed. RESULTS: Of the patients with AAV (mean age, 70.2 ± 13.5 years), HP was noted in 30 (4.52%), including 20 (3.58%) with newly diagnosed AAV and 10 (9.52%) with relapsed AAV. Granulomatosis with polyangiitis (GPA) was classified in 50% of patients with HP. A higher prevalence of GPA was significantly observed in patients with HP than in those without HP in total AAV and newly diagnosed AAV (p < 0.001). In newly diagnosed AAV, serum proteinase 3 (PR3)-ANCA positivity was significantly higher in patients with HP than in those without HP (p = 0.030). Patients with HP significantly had ear, nose, and throat (ENT) (odds ratio [OR] 1.48, 95% confidence interval [CI] 1.03-2.14, p = 0.033) and mucous membrane/eye manifestations (OR 5.99, 95% CI 2.59-13.86, p < 0.0001) in total AAV. Moreover, they significantly had conductive hearing loss (OR 11.6, 95% CI 4.51-29.57, p < 0.0001) and sudden visual loss (OR 20.9, 95% CI 5.24-85.03, p < 0.0001). CONCLUSION: GPA was predominantly observed in patients with HP. Furthermore, in newly diagnosed AAV, patients with HP showed significantly higher PR3-ANCA positivity than those without HP. The ear and eye manifestations may be implicated in HP development.

Effectiveness and safety of allergen immunotherapy in patients with allergic rhinitis complicated by rheumatic autoimmune diseases: a case series study.

BACKGROUND: Allergen immunotherapy (AIT) is the only treatment that has modified the natural history of allergic diseases. However, since its overall effect on the immune system has not been elucidated, AIT is either absolutely or relatively contraindicated in patients with rheumatic autoimmune diseases (RADs). Therefore, there have been no long-term observations of patients with RADs receiving AIT; thus, the effectiveness and safety of AIT in these patients remain unclear. METHODS: This was a single-center retrospective observational study. RAD patients receiving AIT for allergic rhinitis at our institution were selected. Changes in the activity of RAD patients were investigated for 2 years from baseline, including those who discontinued AIT. The effectiveness of AIT was also investigated using the Japan Allergic Rhinitis Standard Quality of Life Questionnaire. RESULTS: Thirteen patients with RADs were enrolled in the study. All patients received sublingual immunotherapy, of which four discontinued AIT owing to adverse events. Among all patients, the symptoms of RADs in three patients worsened during the observation period; however, none of them were causally related to AIT. Most of the adverse events associated with AIT were mild, in which only one patient required drug intervention due to worsening rhinitis symptoms. In the nine patients who were able to continue AIT, their eye and nasal symptom scores showed a significant improvement from 1.67 (1.5-2.0) at baseline to 0.67 (0-1.17) in the 2nd year of treatment (p = 0.0141). CONCLUSIONS: AIT is a safe and effective treatment modality for patients with allergic rhinitis complicated by RADs.

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.

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.

Exposure to particulate matter upregulates ACE2 and TMPRSS2 expression in the murine lung.

Coronavirus disease (COVID-19) is currently a serious global issue. Epidemiological studies have identified air pollutants, including particulate matter (PM), as a risk factor for COVID-19 infection and severity of illness, in addition to numerous factors such as pre-existing conditions, aging and smoking. However, the mechanisms by which air pollution is involved in the manifestation and/or progression of COVID-19 is still unknown. In this study, we used a mouse model exposed to crude PM, collected by the cyclone method, to evaluate the pulmonary expression of angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine type 2 (TMPRSS2), the two molecules required for the entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into host cells. Multiplex immunohistochemical analysis revealed that exposure to PM increased the expression of these two molecules at the same site. Furthermore, image cytometry analysis revealed increased expression of these proteins, particularly, in the alveolar type 2 cells and macrophages, which are potential targets for SARS-CoV-2. Our findings provide an experimental evidence that exposure to PM may adversely affect the manifestation and progression of COVID-19, mediated by the impact of SARS-CoV-2 on the site of entry. The study results suggest that examining these effects might help to advance our understanding of COVID-19 and aid the development of appropriate social interventions.