Association of methotrexate polyglutamates concentration with methotrexate efficacy and safety in patients with rheumatoid arthritis treated with predefined dose: results from the MIRACLE trial.

OBJECTIVES: The usefulness of methotrexate-polyglutamates (MTX-PGs) concentration for management of rheumatoid arthritis has been debated. We aimed to clarify the association of MTX-PGs concentration with efficacy and safety in MTX-naïve patients initiating MTX in a prospective interventional clinical trial. METHODS: The MIRACLE trial enrolled 300 MTX-naïve patients. Oral MTX was initiated and increased to the maximum tolerated dose by week 12. Patients who did not achieve remission according to the Simplified Disease Activity Index at week 24 were randomised to either the continued dose or reduced dose group and were started on subcutaneous adalimumab. We measured the concentrations of MTX-PGs in erythrocytes using liquid chromatography-tandem mass spectrometry and analysed the association of these concentrations with efficacy and safety. RESULTS: The mean concentration of total MTX-PGs increased with an increasing dose of MTX and continued to elevate for another 12 weeks after the dose was fixed. At week 24, the total MTX-PGs concentration was 110.5 (SD 43.8) nmol/L with MTX dose of 12.6 (3.0) mg/week (0.23 (0.07) mg/kg/week). During MTX monotherapy, the higher MTX-PGs concentration was an independent factor for lower disease activity; however, this association disappeared after adalimumab initiation in patients with continued MTX dose. Hepatotoxicity was related to the higher MTX-PGs concentration regardless of adalimumab use. The total MTX-PGs concentration was significantly elevated by lower estimated glomerular filtration rate, serum albumin and body mass index. CONCLUSIONS: The MIRACLE trial demonstrated that higher total MTX-PGs concentration in erythrocytes is related to the higher efficacy and lower safety of MTX. TRIAL REGISTRATION NUMBER: NCT03505008.

Low remission rates and high incidence of adverse events in a prospective VEXAS syndrome registry.

OBJECTIVE: We aimed to gather real-world clinical evidence of detailed disease activity, treatments, remission rates, and adverse events (AEs) associated with vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome in a prospective study. METHODS: Patients in Japan suspected of having VEXAS syndrome were enrolled in a registry study. A novel disease activity measure (VEXASCAF) assessing 11 symptoms associated with VEXAS syndrome was evaluated at enrolment and after 3 months. AEs, survival, CRP levels, and treatments were also recorded at enrolment and 3 months after enrolment. All exons of UBA1 were sequenced using a next-generation sequencer to determine the variant allele frequencies of pathogenic variants in the peripheral blood of all patients. RESULTS: Of the 55 registered patients, 30 patients were confirmed to have pathogenic variants of UBA1. All patients were male, with a median age of 73.5 years. VEXASCAF and CRP levels decreased significantly at 3 months post-enrolment, but the oral prednisolone dose did not change. Only two patients achieved complete remission according to FRENVEX at 3 months after enrolment. During the observation period of 6 months, 28 AEs were observed, including 3 deaths, 4 malignancies from two cases, 2 thromboses, and 13 infections (including 4 mycobacterial infections). Inflammation of the lung and cervical region (i.e. parotid and submandibular gland swelling, tonsillitis, cervical swelling, and pain) were the most common AEs. CONCLUSIONS: Patients with VEXAS syndrome required high-dose glucocorticoids to achieve remission, and complications-such as malignancy, thrombosis, and infection-occurred frequently within a short observation period.

Integrating point of care ultrasound into rheumatology practice.

A scenario-based probability approach integrating point of care rheumatology ultrasound (POCRUS) into rheumatology practice has recently been proposed as a teaching methodology to encourage greater awareness of US for practicing clinicians especially with respect to the management of overlapping clinical conditions. This article reviews the rheumatological areas where application of POCRUS substantially enhances clinical reasoning to confirm or exclude target conditions. It highlights the definitions of ultrasound-detected pathologies in rheumatoid arthritis (RA), spondylarthritis, gout and crystal arthritis, osteoarthritis, polymyalgia rheumatica and discusses the added value of POCRUS in diagnosing these conditions. It summarizes advances in predicting giant cell arteritis with sequential application of a probability score and ultrasonography. It discusses the potential for salivary gland ultrasound in the diagnostic workup of suspected Sjogren's syndrome. Other areas for POCRUS application such as in suspected nerve entrapment are reviewed.

Calcium pyrophosphate crystal arthritis associated with immune checkpoint inhibitor successfully treated with intra-articular glucocorticoid: A case report.

Immune checkpoint inhibitors (ICIs) sometimes induce immune-related adverse events (irAEs), and arthritis is one of the irAE symptoms. Recently, crystal-induced arthritis, such as calcium pyrophosphate (CPP) crystal deposition disease and gout, has been reported to occur after ICI administration. However, the distinction between ICI-associated crystal arthritis and ICI-induced non-crystal arthritis is difficult because their symptoms are similar. Besides, optimal treatment for ICI-associated crystal arthritis has not been established. Here, we report a patient who developed CPP crystal arthritis twice after pembrolizumab (ICI) administration and was successfully treated with intra-articular glucocorticoid injection. He suffered arthritis and acute interstitial nephritis simultaneously after ICI administration. Musculoskeletal ultrasound of his affected joint suggests that his arthritis was crystal-induced arthritis, and arthrocentesis detected CPP crystal in synovial fluid. Thus, we diagnosed his arthritis as ICI-associated cystal arthritis. Therefore, our case encourages the use of musculoskeletal ultrasound in patients with arthritis after treatment with ICI because it may distinguish between ICI-associated crystal arthritis and ICI-induced non-crystal arthritis. Besides, ICI-associated crystal arthritis could be treatable by intra-articular glucocorticoid injection.

Single-cell RNA sequencing of submandibular gland reveals collagen type XV-positive fibroblasts as a disease-characterizing cell population of IgG4-related disease.

OBJECTIVES: IgG4-related disease (IgG4-RD) is a systemic autoimmune disease with an unknown etiology, affecting single/multiple organ(s). Pathological findings include the infiltration of IgG4-producing plasma cells, obliterative phlebitis, and storiform fibrosis. Although immunological studies have shed light on the dysregulation of lymphocytes in IgG4-RD pathogenesis, the role of non-immune cells remains unclear. This study aimed to investigate the demographics and characteristics of non-immune cells in IgG4-RD and explore potential biomarkers derived from non-immune cells in the sera. METHODS: We conducted single-cell RNA sequence (scRNA-seq) on non-immune cells isolated from submandibular glands of IgG4-RD patients. We focused on fibroblasts expressing collagen type XV and confirmed the presence of those fibroblasts using immunohistochemistry. Additionally, we measured the levels of collagen type XV in the sera of IgG4-RD patients. RESULTS: The scRNA-seq analysis revealed several distinct clusters consisting of fibroblasts, endothelial cells, ductal cells, and muscle cells. Differential gene expression analysis showed upregulation of COL15A1 in IgG4-RD fibroblasts compared to control subjects. Notably, COL15A1-positive fibroblasts exhibited a distinct transcriptome compared to COL15A1-negative counterparts. Immunohistochemical analysis confirmed a significant presence of collagen type XV-positive fibroblasts in IgG4-RD patients. Furthermore, immune-suppressive therapy in active IgG4-RD patients resulted in decreased serum levels of collagen type XV. CONCLUSIONS: Our findings suggest that collagen type XV-producing fibroblasts may represent a disease-characterizing non-immune cell population in IgG4-RD and hold potential as a disease-monitoring marker.

Immunogenicity and influence on disease activity of recombinant zoster vaccine in patients with rheumatoid arthritis treated with DMARDs.

OBJECTIVES: This study aimed to determine the immunogenicity and the influence on disease activity of an adjuvanted recombinant varicella-zoster virus (VZV) subunit vaccine (RZV) in patients with rheumatoid arthritis (RA) treated with disease-modifying antirheumatic drugs (DMARDs). METHODS: This prospective longitudinal study enrolled 53 patients with RA (aged ≥50 years) treated with DMARDs (conventional synthetic (cs)DMARDs 20, biological (b)DMARDs 23 and targeted synthetic (ts)DMARDs 10) and 10 control individuals. The participants received two intramuscular RZV 2 months apart. VZV-specific CD4+ T cell responses (cell-mediated immunity; CMI) and IgG antibody responses (humoral immunity; HI) were assessed at 0 and 3 months after the first RZV administration using flow cytometry and enzyme immunoassay, respectively. Disease activity (Disease Activity Score 28-C reactive protein and Clinical Disease Activity Index), flares and adverse events were monitored for 6 months after the first vaccination. RESULTS: VZV-specific CMI and HI significantly increased in the three DMARDs-treated patients with RA after RZV administration compared with the corresponding prevaccination values (p<0.001-0.014), and the magnitudes and fold-increases of those responses were not significantly different among the three DMARDs-treated patients with RA. Furthermore, the vaccine response rates of CMI and HI were not significantly different between csDMARDs-treated patients and b-DMARDs or ts-DMARDs-treated patients. Meanwhile, no significant increases in disease activity indices or adverse events were observed in these patients during the 6-month follow-up period after the first vaccination. RZV-induced RA flares occurred in two patients (3.8%) but were mild and controllable. CONCLUSION: RZV is robustly immunogenic and has a clinically acceptable safety profile in elderly patients with RA receiving DMARDs.

Short-term and long-term outcomes of patients with anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis.

OBJECTIVES: Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (MDA5-DM) is a subtype of dermatomyositis characterized by frequent interstitial lung disease and reduced muscle involvement. This study aimed to determine the short-term and long-term outcomes of patients with MDA5-DM. METHODS: Information on baseline characteristics, treatments, and short-term and long-term outcomes of patients with MDA5-DM including survival, relapse, and the titer of anti-MDA5 antibody, was retrospectively collected. Descriptive statistics regarding clinical outcomes were calculated, and a comparison of clinical parameters between patients with and without relapse was performed. The short-term survival according to the use of Janus kinase inhibitors (JAKi) was also assessed. RESULTS: A total of 154 patients with MDA5-DM were included in the study. Forty patients (25.9%) died during the remission induction phase, with respiratory failure being the most common cause of mortality. Among the 114 patients who survived the remission induction phase, the 5-year cumulative survival and relapse-free survival rates were 96.8% and 77.4%, respectively, and 7.9% of patients achieved complete drug-free remission. Fifty-four patients achieved normalization of anti-MDA5 antibody titers and only two of them relapsed after normalization. In the severe patients, the 6-month survival rate became significantly higher after the emergence of the JAKi treatment compared with before its existence (p= 0.03). CONCLUSIONS: Although relapse often occurs, the long-term survival of MDA5-DM patients who survived the remission induction phase is generally favorable. The status of the anti-MDA5 antibody is associated with relapse. JAKi may improve the survival of refractory patients with severe MDA5-DM.

Why does malaise/fatigue occur? Underlying mechanisms and potential relevance to treatments in rheumatoid arthritis.

INTRODUCTION: Fatigue and malaise are commonly associated with a wide range of medical conditions, including rheumatoid arthritis (RA). Evidence suggests that fatigue and malaise can be overwhelming for patients, yet these symptoms remain inadequately-managed, largely due to an incomplete elucidation of the underlying causes. AREAS COVERED: In this assessment of the published literature relating to the pathogenesis of fatigue or malaise in chronic conditions, four key mechanistic themes were identified. Each theme (inflammation, hypothalamic-pituitary-adrenal axis, dysautonomia, and monoamines) is discussed, as well as the complex network of interconnections between themes which suggests a key role for inflammatory cytokines in the development and persistence of fatigue. EXPERT OPINION: Fatigue is multifaceted, poorly defined, and imperfectly comprehended. Moreover, the cause and severity of fatigue may change over time, as a consequence of the natural disease course or pharmacologic treatment. This detailed synthesis of available evidence permits us to identify avenues for current treatment optimization and future research, to improve the management of fatigue and malaise in RA. Within the development pipeline, several new anti-inflammatory therapies are currently under investigation, and we anticipate that the next five years will herald much-needed progress to reduce the debilitating nature of fatigue in patients with RA.

Reduced-dose versus high-dose glucocorticoids added to rituximab on remission induction in ANCA-associated vasculitis: predefined 2-year follow-up study.

OBJECTIVES: The LoVAS trial reported non-inferiority in remission induction rates between the reduced-dose and conventional high-dose glucocorticoid regimens plus rituximab for antineutrophil cytoplasm antibody (ANCA)-associated vasculitis at 6 months; however, maintenance glucocorticoid requirements and long-term outcomes are unknown. METHODS: A total of 140 patients with new-onset ANCA-associated vasculitis without severe glomerulonephritis or alveolar haemorrhage were randomised to receive reduced-dose prednisolone (0.5 mg/kg/day) plus rituximab (375 mg/m2/week×4) or high-dose prednisolone (1 mg/kg/day) plus rituximab. After achieving remission, patients received the rituximab maintenance therapy (1 g/6 months). RESULTS: A total of 134 patients were analysed. Among patients who achieved remission with the protocolised treatments, the majority of patients in the reduced-dose group (89.7%) and 15.5% in the high-dose group discontinued prednisolone (median time to withdrawal, 150 and 375 days, respectively). During 24-month trial period, two patients in the reduced-dose group (2.8%) died, while five patients in the high-dose group (7.6%) died (p=0.225). Relapse occurred in nine patients in the reduced-dose group (13.0%) (two major and seven minor) and five in the high-dose group (7.6%) (two major and three minor) (p=0.311). Serious adverse events (SAEs) were less frequent in the reduced-dose group (36 events in 19 patients, 27.5%) than in the high-dose group (54 events in 30 patients, 46.2%) (p=0.025). CONCLUSION: At 24 months, frequencies of relapse did not differ between the groups, and SAEs were less frequent in the reduced-dose group due to the lower event rate in the 6-month induction phase. The bias to myeloperoxidase-ANCA positivity (85.8%) in the trial population should be noted. TRIAL REGISTRATION NUMBER: NCT02198248.

Impact of an artificial intelligence-aided endoscopic diagnosis system on improving endoscopy quality for trainees in colonoscopy: Prospective, randomized, multicenter study.

OBJECTIVE: This study was performed to evaluate whether the use of CAD EYE (Fujifilm, Tokyo, Japan) for colonoscopy improves colonoscopy quality in gastroenterology trainees. METHODS: The patients in this multicenter randomized controlled trial were divided into Group A (observation using CAD EYE) and Group B (standard observation). Six trainees performed colonoscopies using a back-to-back method in pairs with gastroenterology experts. The primary end-point was the trainees' adenoma detection rate (ADR), and the secondary end-points were the trainees' adenoma miss rate (AMR) and Assessment of Competency in Endoscopy (ACE) tool scores. Each trainee's learning curve was evaluated using a cumulative sum (CUSUM) control chart. RESULTS: We analyzed data for 231 patients (Group A, n = 113; Group B, n = 118). The ADR was not significantly different between the two groups. Group A had a significantly lower AMR (25.6% vs. 38.6%, P = 0.033) and number of missed adenomas per patient (0.5 vs. 0.9, P = 0.004) than Group B. Group A also had significantly higher ACE tool scores for pathology identification (2.26 vs. 2.07, P = 0.030) and interpretation and identification of pathology location (2.18 vs. 2.00, P = 0.038). For the CUSUM learning curve, Group A showed a trend toward a lower number of cases of missed multiple adenomas by the six trainees. CONCLUSION: CAD EYE did not improve ADR but decreased the AMR and improved the ability to accurately locate and identify colorectal adenomas. CAD EYE can be assumed to be beneficial for improving colonoscopy quality in gastroenterology trainees. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trials Registry (UMIN000044031).

Healthcare resource utilisation and economic burden of patients with adequate and inadequate responses to biological and targeted synthetic disease-modifying antirheumatic drugs for rheumatoid arthritis in Japan.

OBJECTIVE: To compare healthcare resource utilisation (HCRU) and direct costs between responders vs non-responders to advanced therapies for rheumatoid arthritis (RA). METHODS: Patients initiating ≥1 advanced therapy (Oct 2018-Sept 2019) with ≥1 RA claim (6-month pre-index period), ≥2 RA claims (any period), and ≥12 months follow-up were identified from the Medical Data Vision claims database. HCRU and all-cause and RA-related costs (direct medical, emergency department [ED], laboratory, and pharmacy) were compared between responders vs non-responders. Adjusted incidence rate ratios (IRRs) for HCRU or cost were calculated via multivariable analyses. RESULTS: Among 2,446 patients (non-responders [n=1,817]; responders [n=629]), non-responders had significantly longer hospitalisation days (IRR: 1.8 [95% CI: 1.2-2.6]), and significantly more ED visits (2.5 [1.5-4.2]) and prescriptions (1.1 [1.1-1.2]). Mean all-cause hospital/outpatient medical costs were significantly higher for non-responders (1.4 [1.3-1.6], ¥530,895 vs ¥357,009 [$;3,992 vs $;2,684] for responders; ¥173,886 [$;1,307] difference); RA-related medical costs showed a similar trend (¥351,306 vs ¥253,030 [$;2,641 vs $1,902]; ¥98,276 [$;739] difference). No differences between responders and non-responders were observed in mean all-cause and RA-related pharmacy costs. CONCLUSIONS: Non-responders to advanced therapies had greater HCRU and all-cause/RA-related direct costs as compared with responders, suggesting a need for more effective RA therapies to reduce the economic burden associated with non-response.

Mechanistic Study of Reduction of Nitrite to NO by the Copper(II) Complex: Different Concerted Proton-Electron Transfer Reactivity between Nitrite and Nitro Complexes.

The literature contains numerous reports of copper complexes for nitrite (NO2-) reduction. However, details of how protons and electrons arrive and how nitric oxide (NO) is released remain unknown. The influence of the coordination mode of nitrite on reactivity is also under debate. Kundu and co-workers have reported nitrite reduction by a copper(II) complex [J. Am. Chem. Soc. 2020, 142, 1726-1730]. In their report, the copper(II) complex reduced nitrite using a phenol derivative as a reductant, resulting in NO, a hydroxyl copper(II) complex, and the corresponding biphenol. Also, the involvement of proton-coupled electron transfer was proposed by mechanistic studies. Herein, density functional theory calculations were performed to determine a mechanism for reduction of nitrite by a copper(II) complex. As a result of geometry optimization of an initial complex, two possible structures were obtained: Cu-ONO and Cu-NO2. Two possible reaction pathways initiated from Cu-ONO or Cu-NO2 were then considered. The calculation results indicated that the Cu-ONO pathway is energetically favorable. When changes in the electronic structure were considered, both pathways were found to involve concerted proton-electron transfer (CPET). In addition, an intrinsic reaction coordinate analysis revealed that the two pathways were achieved by different types of CPET. Furthermore, an intrinsic bond orbital analysis clearly indicated that, in the Cu-ONO pathway, the chemical events involved proceeded concertedly yet asynchronously.

Treatment pattern and changes in oral glucocorticoid dose after tocilizumab treatment in patients with adult Still's disease: An analysis of a Japanese claims database.

AIM: Intravenous tocilizumab (TCZ-IV) was approved for the treatment of adult Still's disease (ASD) in Japan in May 2019 based on its efficacy and safety in a phase III randomized controlled trial. This study determined treatment patterns in patients with ASD and assessed oral glucocorticoid (GC) dose changes after TCZ-IV administration in Japanese clinical practice. METHODS: Patients in the Medical Data Vision database aged 16 years or older with one or more of International Classification of Diseases, 10th revision codes M061 (ASD) or M082 (systemic juvenile idiopathic arthritis) during January 2017-March 2021 (cohort 1) and those initiating TCZ-IV during May 2019-March 2021 (cohort 2) were included. RESULTS: In cohort 1, the proportion of patients who were prescribed interleukin-6 inhibitors (mainly TCZ-IV) increased from 10.8% (January-April 2019 [before TCZ-IV approval]; n = 2002) to 18.3% (January-March 2021 [after TCZ-IV approval]; n = 2008). In cohort 2 (n = 193), 84.5% of patients were on oral GCs (≤5 mg/day: 23.8%) at index date (initial TCZ-IV prescription date); 46/70 (65.7%) were on oral GC at 5 mg/day or higher 12 months after TCZ-IV treatment (primary outcome). After 12 months of treatment, the TCZ-IV retention rate was 73.6% and the TCZ-IV administration interval was every 4 weeks and every 2 weeks in 31.9% and 27.7% of patients, respectively. CONCLUSION: The use of interleukin-6 inhibitors increased by 7.5% points in Japanese patients with ASD ~2 years after TCZ-IV approval, suggesting that an unmet medical need existed. This study suggests the potential GC-sparing effect of TCZ-IV in patients with ASD in clinical practice.

CCR4 predicts the efficacy of abatacept in rheumatoid arthritis patients through the estimation of Th17 and Treg cell abundance.

OBJECTIVE: Predicting the efficacy of biological disease-modifying anti-rhematic drugs (bDMARDs) is challenging. In this study, we aimed to explore markers that predict the efficacy of abatacept in rheumatoid arthritis (RA) patients. METHODS: Thirty RA patients receiving abatacept were recruited, and peripheral blood mononuclear cells (PBMCs) from the participants were subjected to DNA microarray analysis. The expression of CCR4, which was selected by the result of DNA microarray, was determined by flow cytometry in 16 newly diagnosed treatment-naïve RA patients. CCR4 expression on each helper T cell subset was also measured. RESULTS: CCR4 was upregulated in the abatacept responder. The expression levels of CCR4 were significantly correlated with the improvement of clinical disease activity index (CDAI). CCR4 expression was predominantly observed in CD4+ T cells in PBMCs. The percentage of CCR4-expressing CD4+ T cells was significantly higher in RA patients than in healthy individuals. Interestingly, Th17 and Treg cells expressed high levels of CCR4 compared to non-Th17-related helper T cells. CONCLUSION: CCR4 is a Th17- and Treg-related gene, and the high CCR4 expression in peripheral blood samples may predict the efficacy of abatacept in RA.

Early initiation of angiotensin-converting enzyme inhibitor in patients with scleroderma renal crisis: A nationwide inpatient database study.

OBJECTIVES: To evaluate the effectiveness of early initiation of angiotensin-converting enzyme inhibitor (ACEi) in patients with scleroderma renal crisis (SRC). METHODS: This was a retrospective cohort study using a nationwide inpatient database in Japan from July 2010 to March 2020. All hospitalized patients with SRC were divided into those who received ACEi within two days of admission (early ACEi group) and those who did not (control group). Propensity-score overlap weighting analysis was performed to adjust for confounding factors. The primary outcome was the composite of in-hospital mortality or hemodialysis dependence at discharge. RESULTS: Of the 475 eligible patients, 248 (52.2%) were in the early ACEi group and 227 (47.8%) were in the control group. After overlap weighting, the primary outcome was significantly lower in the early ACEi group than in the control group (40.1% vs. 49.0%; odds ratio, 0.69; 95% confidence interval, 0.48-1.00; P= 0.049). CONCLUSIONS: The present study showed that early initiation of ACEi was associated with lower composite outcome of in-hospital mortality or hemodialysis dependence at discharge in patients with SRC. Further prospective studies are warranted to verify the present findings.

Patient-Physician Communication and Perception of Treatment Goals in Rheumatoid Arthritis: An Online Survey of Patients and Physicians.

INTRODUCTION: To evaluate patient-physician communication and patients' understanding of treatment goals in rheumatoid arthritis (RA). METHODS: A cross-sectional online survey of patients with RA and physicians treating RA was conducted between 16 and 30 June 2021. Participants were asked to rate the importance of 17 goals on a 6-point Likert scale, and mean scores were compared between patients and physicians by the Wilcoxon rank sum test. Patients' satisfaction with physician communication and their understanding of treatment goals were also assessed. RESULTS: The responses of 502 patients and 216 physicians were analyzed. The most common patient age group was 50-59 years (28.5%), and the mean disease duration was 10.3 years. Physicians had a mean of 19.2 years of treatment experience and were treating a mean of 44.3 patients. Among the 17 goals assessed, patients placed significantly more importance on drug tapering or discontinuation as short-term goals (3-6 months) and on performing basic activities of daily living, being able to engage in daily tasks, achieving and maintaining remission, maintaining better laboratory values, and drug tapering or discontinuation as long-term goals (5-10 years; all adjusted p < 0.05). Patient treatment satisfaction was significantly associated with disease activity, a feeling of treatment effectiveness, satisfaction with physician communication, and agreement with physician goals. CONCLUSION: Differences exist among patients with RA and physicians treating RA regarding the importance of short- and long-term treatment goals. Good patient-physician communication appears to be important for improving patient satisfaction. TRIAL REGISTRATION: University Hospital Medical Information Network identifier: UMIN000044463.

TAp63, a methotrexate target in CD4+ T cells, suppresses Foxp3 expression and exacerbates autoimmune arthritis.

Methotrexate (MTX) is a standard, first-line therapy for rheumatoid arthritis (RA); however, its precise mechanisms of action other than antifolate activity are largely unknown. We performed DNA microarray analyses of CD4+ T cells in patients with RA before and after MTX treatment and found that TP63 was the most significantly downregulated gene after MTX treatment. TAp63, an isoform of TP63, was highly expressed in human IL-17-producing Th (Th17) cells and was suppressed by MTX in vitro. Murine TAp63 was expressed at high levels in Th cells and at lower levels in thymus-derived Treg cells. Importantly, TAp63 knockdown in murine Th17 cells ameliorated the adoptive transfer arthritis model. RNA-Seq analyses of human Th17 cells overexpressing TAp63 and those with TAp63 knockdown identified FOXP3 as a possible TAp63 target gene. TAp63 knockdown in CD4+ T cells cultured under Th17 conditions with low-dose IL-6 increased Foxp3 expression, suggesting that TAp63 balances Th17 cells and Treg cells. Mechanistically, TAp63 knockdown in murine induced Treg (iTreg) cells promoted hypomethylation of conserved noncoding sequence 2 (CNS2) of the Foxp3 gene and enhanced the suppressive function of iTreg cells. Reporter analyses revealed that TAp63 suppressed the activation of the Foxp3 CNS2 enhancer. Collectively, TAp63 suppresses Foxp3 expression and exacerbates autoimmune arthritis.

Prognosis of spontaneous pneumomediastinum occurring in dermatomyositis or polymyositis patients with interstitial lung disease according to antimelanoma differentiation-associated gene 5 antibody status: a retrospective cohort study.

OBJECTIVES: Spontaneous pneumomediastinum (SPNM) historically has been considered a poor prognostic factor in dermatomyositis/polymyositis patients complicated with interstitial lung disease (ILD). However, there is a lack of actual data regarding the association between SPNM occurrence and mortality in dermatomyositis/polymyositis patients. This study aimed to assess the association between SPNM occurrence and mortality in myositis patients with ILD according to antimelanoma differentiation-associated gene 5 (MDA5) antibody status. METHODS: Dermatomyositis/polymyositis patients with ILD who were hospitalised at five Japanese hospitals from 2016 to 2020 were included in this retrospective observational study. We collected data about baseline characteristics including myositis-specific autoantibodies, treatments, SPNM and death within 1 year from therapy initiation or strengthening. Baseline characteristics and outcomes were compared between patients with and without SPNM (the SPNM group and the non-SPNM group, respectively). RESULTS: A total of 119 patients were analysed. SPNM occurred in 23 patients, and 15 patients died. Fifteen patients with SPNM were anti-MDA5 antibody positive. The mortality rate was significantly higher in the SPNM group (34.8%) than in the non-SPNM group (7.3%) (p=0.001). All deaths in the SPNM group occurred in anti-MDA5 antibody-positive patients (8/15), whereas none of the anti-MDA5 antibody-negative patients in the SPNM group died (0/8). In anti-MDA5 antibody-positive patients, the mortality rate was significantly higher in patients with SPNM occurrence (53.3%) than in those without SPNM occurrence (4.0%) (p=0.001). CONCLUSION: SPNM occurred more frequently in anti-MDA5 antibody-positive than in anti-MDA5 antibody-negative myositis patients. SPNM occurrence was associated with higher mortality risk, especially in anti-MDA5 antibody-positive patients.