Predictive factors and treatment outcomes associated with difficult-to-treat rheumatoid arthritis conditions: the ANSWER cohort study.

OBJECTIVES: To investigate the predictive factors for difficult-to-treat rheumatoid arthritis (D2T RA) and assess the efficacy of biological disease-modifying antirheumatic drugs (bDMARDs) and Janus kinase inhibitors (JAKi). METHODS: Retrospective analysis was conducted on data from the ANSWER cohort comprising 3,623 RA patients treated with bDMARDs or JAKi in Japan. Multivariate Cox proportional hazards modelling was used to analyse the hazard ratios (HRs) for treatment retention. RESULTS: Of these, 450 (12.4%) met the first two criteria of EULAR D2T RA definition (defined as D2T RA in this study). Factors contributing to D2T RA included age over 75 (compared to those under 65, HR = 0.46, 95% CI: 0.31 to 0.69), higher rheumatoid factor (RF) titres (HR = 1.005, 95% CI: 1.00 to 1.01), higher clinical disease activity index (HR = 1.02, 95% CI: 1.01 to 1.03), lower methotrexate dosage (HR = 0.97, 95% CI: 0.95 to 0.99), and comorbidities like hypertension (HR = 1.53, 95% CI: 1.2 to 1.95) and diabetes (HR = 1.37, 95% CI: 1.09 to 1.73). Anti-interleukin 6 receptor antibodies (aIL-6R, HR = 0.53, 95% CI: 0.37 to 0.75) and JAKi (HR = 0.64, 95% CI: 0.46 to 0.90) were associated with fewer discontinuations due to ineffectiveness compared to tumour necrosis factor inhibitors. Oral glucocorticoids usage (HR = 1.65, 95% CI: 1.11 to 2.47) was linked to increased discontinuation due to toxic adverse events. CONCLUSION: Younger onset, higher RF titres, and comorbidities predicted D2T RA development. For managing D2T RA, aIL-6R and JAKi exhibited superior drug retention.

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

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

Factors associated with drug retention of mepolizumab in patients with eosinophilic granulomatosis with polyangiitis: A multicentre REVEAL cohort study.

OBJECTIVES: To determine the current retention rate of mepolizumab (MPZ) and identify factors associated with drug retention in patients with eosinophilic granulomatosis with polyangiitis (EGPA) in the Kansai multicentre cohort (REVEAL cohort). METHODS: Sixty patients diagnosed with EGPA and treated with MPZ between December 2016 and June 2023 were enrolled. The clinical characteristics, including laboratory data, treatments administered, and disease course outcomes were collected retrospectively. The patients were stratified into MPZ continuation (n=53) and discontinuation (n=7) groups, and drug retention was statistically compared using the log-rank test. RESULTS: The median age of patients was 54.5 years, with 55% females, and 33% antineutrophil cytoplasmic antibody-positive at disease onset. MPZ exhibited a retention rate of 78.7% after five years. The reasons for discontinuation included treatment of coexisting diseases, inadequate response, and remission. Patient characteristics at disease onset were comparable between the groups. Patients receiving immunosuppressants (IS) before MPZ introduction demonstrated significantly higher retention rates (P = 0.038). During the final observation, the MPZ continuation group had a lower vasculitis damage index score (P = 0.027). CONCLUSIONS: MPZ exhibited a high 5-year retention rate, particularly in patients requiring IS. This study implies that long-term use of MPZ may mitigate irreversible organ damage.

Lymphoproliferative disorder progressing after partial remission following immunosuppressive drugs withdrawal in a patient with rheumatoid arthritis.

Lymphoproliferative disorders (LPDs) are serious complications that arise in patients with rheumatoid arthritis (RA) receiving immunosuppressive drugs (ISDs). Here, we reported a 73-year-old woman diagnosed with RA at 60 years of age and treated with methotrexate, bucillamine, prednisolone, and infliximab. She was referred to our hospital, Osaka Metropolitan University Hospital, with general malaise, pancytopenia, a right adrenal mass, and enlarged periaortic lymph nodes. Epstein-Barr virus was detected in serum. We suspected LPD development and performed a bone marrow biopsy, on which no malignant cells could be detected. Upon ISDs withdrawal, her symptoms and blood counts improved, and the right adrenal mass and enlarged lymph nodes regressed. The patient was followed up for clinical LPD. However, 7 months after the initial visit to our hospital, she developed fever and pancytopenia. A repeat bone marrow biopsy confirmed the diagnosis of Epstein-Barr virus-positive diffuse large B-cell lymphoma complicated by haemophagocytic syndrome. After pulse steroid therapy, the patient received rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone therapy, which resulted in a complete response. In conclusion, when LPDs develop in patients with RA during ISD treatment, LPDs can progress and complicate haemophagocytic syndrome after partial remission following ISDs withdrawal. Therefore, we should carefully follow up RA patients with LPDs, and aim to achieve an early diagnosis of LPD and promptly initiate chemotherapy.

Comparison of retention of biologics in Japanese patients with elderly-onset rheumatoid arthritis-the ANSWER cohort study.

OBJECTIVES: This multicentre, retrospective study aimed to compare retention and reasons for discontinuation between Janus kinase inhibitors (JAKi) and biologic disease-modifying antirheumatic drugs in patients with elderly-onset rheumatoid arthritis (EORA). METHODS: Patients with RA enrolled in a Japanese multicentre observational registry between 2015 and 2022 were included. EORA was defined as RA with onset at 60 or over. To adjust confounding factors by indication for initiation of tumor necrosis factor inhibitors (TNFi), interleukin-6 inhibitors (IL-6i), cytotoxic T-lymphocyte associated antigen 4 immunoglobulin (CTLA4-Ig) blockers, or JAKi, a propensity score based on baseline characteristics was used to compare drug retention. To assess the reasons for discontinuation, retention rates for ineffectiveness, adverse events, and remission were analyzed as secondary outcomes. RESULTS: A total of 572 patients with 835 treatment courses were identified (314 TNFi, 175 IL-6i, 228 CTLA4-Ig, and 118 JAKi). After adjusting for differences in baseline characteristics, drug retention was significantly higher for IL-6i (HR = 0.38, 95%CI = 0.27-0.55, p< 0.01) as compared with TNFi. Discontinuation due to lack of effectiveness was lower with the JAKi (HR = 0.38, 95%CI = 0.22-0.66, p< 0.01) and the IL-6i (HR = 0.29, 95%CI = 0.19-0.46, p< 0.01) as compared with the TNFi although the CTLA4-Ig had a similar HR to TNFi. The adjusted incidence of discontinuation due to adverse event was higher in the JAKi (HR = 2.86, 95%CI = 1.46-5.59, p< 0.01) than the TNFi. CONCLUSIONS: In EORA patients, IL-6i and JAKi had longer retention and less discontinuation due to ineffectiveness than TNFi. The potential risks of JAKi should be approached with an individualized perspective.

IL-6 inhibitors and JAK inhibitors as favourable treatment options for patients with anaemia and rheumatoid arthritis: ANSWER cohort study.

OBJECTIVES: Anaemia, a common comorbidity of RA, is related to high disease activity and poor prognosis. It is unknown which biologic/targeted synthetic (b/ts)-DMARDs are optimal for patients with anaemia and RA in regulating anaemia and controlling disease activity. METHODS: We investigated the change in haemoglobin (Hb) levels, drug retention rates and disease activities after the administration of b/ts-DMARDs with different modes of action [TNF inhibitors (TNFis), immunoglobulin fused with cytotoxic T-lymphocyte antigen (CTLA-4-Ig), IL-6 receptor inhibitors (IL-6Ris) and Janus kinase inhibitors (JAKis)] in patients with RA stratified by baseline Hb levels using the multicentre observational registry for patients with RA in Japan (ANSWER cohort). RESULTS: A total of 2093 patients with RA were classified into three groups based on tertiles of the baseline Hb levels (Hblow, anaemic; Hbint, intermediate; Hbhigh, non-anaemic). IL-6Ri increased Hb levels in all groups (the mean change at 12 months in Hblow was +1.5 g/dl, Hbint +0.7 g/dl and Hbhigh +0.1 g/dl). JAKis increased the Hb level in patients with anaemia and RA and retained or decreased the Hb level in non-anaemic patients (the mean change at 12 months in Hblow was +0.6 g/dl, Hbint 0 g/dl and Hbhigh -0.3 g/dl). In patients with anaemia and RA, overall adjusted 3-year drug retention rates were higher in JAKi followed by IL-6Ri, CTLA4-Ig and TNFi (78.6%, 67.9%, 61.8% and 50.8%, respectively). Change of disease activity at 12 months was not different among different b/ts-DMARDs treatments. CONCLUSION: IL-6Ri and JAKi can effectively treat patients with anaemia and RA in a real-world setting.

Risk prediction model for mortality in microscopic polyangiitis: multicentre REVEAL cohort study.

BACKGROUND: To establish refined risk prediction models for mortality in patients with microscopic polyangiitis (MPA) by using comprehensive clinical characteristics. METHODS: Data from the multicentre Japanese registry of patients with vasculitis (REVEAL cohort) were used in our analysis. In total, 194 patients with newly diagnosed MPA were included, and baseline demographic, clinical, laboratory, and treatment details were collected. Univariate and multivariate analyses were conducted to identify the significant risk factors predictive of mortality. RESULTS: Over a median follow-up of 202.5 (84-352) weeks, 60 (30.9%) of 194 patients died. The causes of death included MPA-related vasculitis (18.3%), infection (50.0%), and others (31.7%). Deceased patients were older (median age 76.2 years) than survivors (72.3 years) (P < 0.0001). The death group had shorter observation periods (median 128.5 [35.3-248] weeks) than the survivor group (229 [112-392] weeks). Compared to survivors, the death group exhibited a higher smoking index, lower serum albumin levels, higher serum C-reactive protein levels, higher Birmingham Vasculitis Activity Score (BVAS), higher Five-Factor Score, and a more severe European Vasculitis Study Group (EUVAS) categorization system. Multivariate analysis revealed that higher BVAS and severe EUVAS independently predicted mortality. Kaplan-Meier survival curves demonstrated lower survival rates for BVAS ≥20 and severe EUVAS, and a risk prediction model (RPM) based on these stratified patients into low, moderate, and high-risk mortality groups. CONCLUSIONS: The developed RPM is promising to predict mortality in patients with MPA and provides clinicians with a valuable tool for risk assessment and informed clinical decision-making.

Comparative effectiveness of biological disease-modifying antirheumatic drugs and Janus kinase inhibitor monotherapy in rheumatoid arthritis.

OBJECTIVES: To examine the effectiveness and drug tolerability of biological disease-modifying antirheumatic drugs (bDMARDs) and Janus kinase inhibitor (JAKi) monotherapy in patients with rheumatoid arthritis (RA) in a multicentre cohort study. METHODS: Patients with RA initiated with bDMARD/JAKi monotherapy without conventional synthetic DMARDs were included. Monotherapy regimens were categorised as interleukin-6 receptor inhibitors (IL-6Ri), cytotoxic T-lymphocyte-associated protein 4 immunoglobulin (CTLA4Ig), JAKi, or tumour necrosis factor inhibitors (TNFi). Multiple propensity score-based inverse probability weighting (IPW) was used to reduce selection bias. Linear mixed-effect models with IPW were used to examine changes in the disease activity score in 28 joints (DAS28)-erythrocyte sedimentation rate (ESR) at 24 weeks, and drug retention was compared among monotherapy using IPW Cox proportional hazards models. RESULTS: A total of 849 treatment courses from 635 patients were included (IL-6Ri, 218; CTLA4Ig, 183; JAKi, 92; TNFi, 356). The difference in change in DAS28-ESR at week 24 as the primary outcome was -0.93 (95% CI: -1.20 to -0.66) lower in the IL-6Ri group than TNFi, while that of CTLA4Ig and JAKi was similar with that of TNFi (-0.20 [-0.48 to 0.08], -0.25 [-0.67 to 0.16], respectively). IL-6Ri use was associated with significantly lower overall drug discontinuation than TNFi use (hazard ratio = 0.55 [0.39-0.78], P = 0.001). Similar retention rates were identified among CTLA4Ig and JAKi compared to TNFi. CONCLUSION: In the analysis with IPW to reduce selection bias, IL-6Ri monotherapy was superior to TNFi monotherapy in terms of effectiveness and drug retention. No significant differences were identified between CTLA4Ig, JAKi, and TNFi monotherapy.

Eosinophilic Granulomatosis with Polyangiitis: Latest Findings and Updated Treatment Recommendations.

Eosinophilic granulomatosis with polyangiitis (EGPA) causes necrotizing vasculitis and eosinophil-rich granulomatous inflammation in small- to medium-sized vessels, resulting in multiple organ damage. EGPA is classified as an antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, with myeloperoxidase-ANCA detected in approximately one-third of the patients. Conventional treatment of EGPA relies on systemic glucocorticoids (GCs) in combination with cyclophosphamide when poor prognostic factors are present; however, the dilemma between disease control and drug-related adverse effects has long been a challenge. Recent studies have revealed that the genetic background, pathophysiology, and clinical manifestations differ between ANCA-positive and ANCA-negative patients; however, mepolizumab, an interleukin (IL)-5 inhibitor, is effective in both groups, suggesting that the IL-5-eosinophil axis is deeply involved in the pathogenesis of both ANCA-positive and ANCA-negative EGPA. This review summarizes the latest knowledge on the pathophysiology of EGPA and focuses on the roles of eosinophils and ANCA. We then introduce the current treatment recommendations and accumulated evidence for mepolizumab on EGPA. Based on current unmet clinical needs, we discuss potential future therapeutic strategies for EGPA.

Serum Concentrations of Infliximab and IL-6 for Predicting One-Year Discontinuation of Infliximab Treatment Owing to Secondary Non-response in Patients with Rheumatoid Arthritis.

Secondary non-response to infliximab (IFX) occurs in some patients with rheumatoid arthritis (RA). Although therapeutic drug monitoring (TDM) is a useful tool to optimize IFX therapy, it is unclear whether it can help to identify the risk of secondary non-response. This study aimed to explore the utility of serum levels of IFX or other biomarkers to predict IFX discontinuation owing to secondary non-response. A single-center, retrospective study was conducted using the Kyoto University Rheumatoid Arthritis Management Alliance cohort database between 2011 and 2020. Serum IFX levels were measured using liquid chromatography-tandem mass spectrometry. An electrochemiluminescence assay was used to quantify serum levels of tumor necrosis factor-α and interleukin-6 and detect anti-drug antibodies. Eighty-four out of 310 patients were eligible for this study. The cutoff levels of biomarkers were determined by receiver operating characteristic analysis. IFX persistence was similar between groups stratified using IFX levels, tumor necrosis factor-α levels, interleukin-6 levels, and anti-drug antibodies positivity. The group with lower IFX and higher interleukin-6 levels had the worst therapy persistence (p = 0.017) and the most frequent disease worsening (90.0%, p < 0.001). Evaluating both interleukin-6 and IFX levels, not just IFX alone, enabled us to identify patients at risk of discontinuing IFX treatment. These findings support the utility of measuring IFX and interleukin-6 levels for successful maintenance therapy for RA.

Drug retention of biologics and Janus kinase inhibitors in patients with rheumatoid arthritis: the ANSWER cohort study.

OBJECTIVES: This multicentre retrospective study in Japan aimed to assess the retention of biological disease-modifying antirheumatic drugs and Janus kinase inhibitors (JAKi), and to clarify the factors affecting their retention in a real-world cohort of patients with rheumatoid arthritis. METHODS: The study included 6666 treatment courses (bDMARD-naïve or JAKi-naïve cases, 55.4%; tumour necrosis factor inhibitors (TNFi) = 3577; anti-interleukin-6 receptor antibodies (aIL-6R) = 1497; cytotoxic T lymphocyte-associated antigen-4-Ig (CTLA4-Ig) = 1139; JAKi=453 cases). The reasons for discontinuation were divided into four categories (ineffectiveness, toxic adverse events, non-toxic reasons and remission); multivariate Cox proportional hazards modelling by potential confounders was used to analyse the HRs of treatment discontinuation. RESULTS: TNFi (HR=1.93, 95% CI: 1.69 to 2.19), CTLA4-Ig (HR=1.42, 95% CI: 1.20 to 1.67) and JAKi (HR=1.29, 95% CI: 1.03 to 1.63) showed a higher discontinuation rate due to ineffectiveness than aIL-6R. TNFi (HR=1.28, 95% CI: 1.05 to 1.56) and aIL-6R (HR=1.27, 95% CI: 1.03 to 1.57) showed a higher discontinuation rate due to toxic adverse events than CTLA4-Ig. Concomitant use of oral glucocorticoids (GCs) at baseline was associated with higher discontinuation rate due to ineffectiveness in TNFi (HR=1.24, 95% CI: 1.09 to 1.41), as well as toxic adverse events in JAKi (HR=2.30, 95% CI: 1.23 to 4.28) and TNFi (HR=1.29, 95%CI: 1.07 to 1.55). CONCLUSIONS: TNFi (HR=1.52, 95% CI: 1.37 to 1.68) and CTLA4-Ig (HR=1.14, 95% CI: 1.00 to 1.30) showed a higher overall drug discontinuation rate, excluding non-toxicity and remission, than aIL-6R.

Rheumatic Immune-Related Adverse Events due to Immune Checkpoint Inhibitors-A 2023 Update.

With the aging of the population, malignancies are becoming common complications in patients with rheumatoid arthritis (RA), particularly in elderly patients. Such malignancies often interfere with RA treatment. Among several therapeutic agents, immune checkpoint inhibitors (ICIs) which antagonize immunological brakes on T lymphocytes have emerged as a promising treatment option for a variety of malignancies. In parallel, evidence has accumulated that ICIs are associated with numerous immune-related adverse events (irAEs), such as hypophysitis, myocarditis, pneumonitis, and colitis. Moreover, ICIs not only exacerbate pre-existing autoimmune diseases, but also cause de novo rheumatic disease-like symptoms, such as arthritis, myositis, and vasculitis, which are currently termed rheumatic irAEs. Rheumatic irAEs differ from classical rheumatic diseases in multiple aspects, and treatment should be individualized based on the severity. Close collaboration with oncologists is critical for preventing irreversible organ damage. This review summarizes the current evidence regarding the mechanisms and management of rheumatic irAEs with focus on arthritis, myositis, and vasculitis. Based on these findings, potential therapeutic strategies against rheumatic irAEs are discussed.

Muscle Biopsy-proven Drug-induced Microscopic Polyangiitis in a Patient with Tuberculosis.

We herein report a case of muscle biopsy-proven microscopic polyangiitis (MPA) in a patient with tuberculosis. The patient had developed a persistent fever after the initiation of treatment for tuberculosis and was positive for myeloperoxidase-antineutrophil cytoplasmic antibody (ANCA). However, because conventional symptoms were lacking, determination of the biopsy site was difficult. Based on the findings of a biopsy of the biceps femoris, which confirmed small vessel vasculitis, the patient was diagnosed with MPA. The fever was alleviated by glucocorticoids. Tuberculosis and antituberculosis drugs can cause ANCA-associated vasculitis (AAV). A muscle biopsy is useful for the diagnosis of AAV.

Management of sarcopenia in patients with rheumatoid arthritis.

This review summarizes the evidence for the management of sarcopenia in patients with rheumatoid arthritis (RA) in terms of drugs, exercise, and nutrition. Sarcopenia is a decrease in skeletal muscle mass and muscle strength or physical function. The prevalence of sarcopenia in patients with RA is higher than that in the general population. The treatment and management of sarcopenia in patients with RA are clinically important for long-term prognosis. One of the mechanisms of muscle metabolism is the pro-inflammatory cytokine pathway, which involves tumour necrosis factor α and interleukin-6, and is a common pathway in the pathogenesis of RA. Thus, tumour necrosis factor α and interleukin-6 inhibitors may play a potential role in controlling sarcopenia. In exercise therapy, a combination of moderate resistance and aerobic exercise may be effective in improving muscle strength, muscle mass, and physical function; however, intense exercise may exacerbate the inflammatory response in RA. Regarding nutrition, protein intake is generally considered beneficial, but other nutrients such as vitamin D and carotenoids have also been studied. Overall, there remains a lack of concrete evidence on sarcopenia treatment and management in patients with RA from any perspective; more longitudinal and intervention studies are needed in the future.

Comment on "The effect of disease-modifying anti-rheumatic drugs on skeletal muscle mass in rheumatoid arthritis patients: a systematic review with meta-analysis".

We read with great interest the article by Hein et al., which described the meta-analysis study on the impact of disease-modifying anti-rheumatic drugs (DMARDs) therapy on skeletal muscle mass in rheumatoid arthritis (RA) patients. While the data presented are impressive, we add some remarks about methodological issues that should be considered. First, this meta-analysis does not include several necessary studies that have provided data on the relationship between anti-tumor necrosis factor (anti-TNF) therapy and body composition. To make the meta-analysis more comprehensive, it could be necessary to incorporate these studies into this analysis. Second, this study did not employ a representative measure of skeletal muscle mass that was adjusted for body size, such as skeletal muscle mass index (SMI). It is well recognized that skeletal muscle mass varies with body size, particularly height and body mass index. Given the heterogeneity background of body size in the studies included in this meta-analysis, it may be worthwhile to conduct an additional analysis regarding the associations between DMARDs and the adjusted measure of skeletal muscle mass such as SMI, which is recommended in several guidelines when determining and contrasting the quantity of skeletal muscle mass. Third, when determining body composition, several reports show variances between bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DEXA) in RA as well as in general. In this regard, it may not be appropriate to simultaneously perform a meta-analysis of skeletal muscle mass determined by DEXA and BIA. With the issues described above, we conclude by recommending additional investigations to strengthen the arguments presented by this valuable meta-analysis.

Vasculitis associated with VEXAS syndrome: A literature review.

Vasculitis is an inflammatory disorder of the blood vessels that causes damage to a wide variety of organs through tissue ischemia. Vasculitis is classified according to the size (large, medium, or small) of the blood vessels. In 2020, VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome, a novel autoinflammatory syndrome, was described. Somatic mutations in methionine-41 of UBA1, the major E1 enzyme that initiates ubiquitylation, are attributed to this disorder. This new disease entity connects seemingly unrelated conditions: inflammatory syndromes (relapsing chondritis, Sweet's syndrome, or neutrophilic dermatosis) and hematologic disorders (myelodysplastic syndrome or multiple myeloma). Notably, such patients sometimes develop vasculitis, such as giant cell arteritis and polyarteritis nodosa, and fulfill the corresponding classification criteria for vasculitis. Thus, vasculitis can be an initial manifestation of VEXAS syndrome. In this research topic exploring the link between autoinflammatory diseases and vasculitis, we first provide an overview of the disease mechanisms and clinical phenotypes of VEXAS syndrome. Then, a literature review using the PubMed database was performed to delineate the clinical characteristics of vasculitis associated with VEXAS syndrome. Finally, the therapeutic options and unmet needs of VEXAS syndrome are discussed.

Pathogenic role of monocytes/macrophages in large vessel vasculitis.

Vasculitis is an autoimmune vascular inflammation with an unknown etiology and causes vessel wall destruction. Depending on the size of the blood vessels, it is classified as large, medium, and small vessel vasculitis. A wide variety of immune cells are involved in the pathogenesis of vasculitis. Among these immune cells, monocytes and macrophages are functionally characterized by their capacity for phagocytosis, antigen presentation, and cytokine/chemokine production. After a long debate, recent technological advances have revealed the cellular origin of tissue macrophages in the vessel wall. Tissue macrophages are mainly derived from embryonic progenitor cells under homeostatic conditions, whereas bone marrow-derived circulating monocytes are recruited under inflammatory conditions, and then differentiate into macrophages in the arterial wall. Such macrophages infiltrate into an otherwise immunoprotected vascular site, digest tissue matrix with abundant proteolytic enzymes, and further recruit inflammatory cells through cytokine/chemokine production. In this way, macrophages amplify the inflammatory cascade and eventually cause tissue destruction. Recent studies have also demonstrated that monocytes/macrophages can be divided into several subpopulations based on the cell surface markers and gene expression. In this review, the subpopulations of circulating monocytes and the ontogeny of tissue macrophages in the artery are discussed. We also update the immunopathology of large vessel vasculitis, with a special focus on giant cell arteritis, and outline how monocytes/macrophages participate in the disease process of vascular inflammation. Finally, we discuss limitations of the current research and provide future research perspectives, particularly in humans. Through these processes, we explore the possibility of therapeutic strategies targeting monocytes/macrophages in vasculitis.

Dynamics of Type I and Type II Interferon Signature Determines Responsiveness to Anti-TNF Therapy in Rheumatoid Arthritis.

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

Aging-Related Vascular Inflammation: Giant Cell Arteritis and Neurological Disorders.

Aging is characterized by the functional decline of the immune system and constitutes the primary risk factor for infectious diseases, cardiovascular disorders, cancer, and neurodegenerative disorders. Blood vessels are immune-privileged sites and consist of endothelial cells, vascular smooth muscle cells, macrophages, dendritic cells, fibroblasts, and pericytes, among others. Aging also termed senescence inevitably affects blood vessels, making them vulnerable to inflammation. Atherosclerosis causes low-grade inflammation from the endothelial side; whereas giant cell arteritis (GCA) causes intense inflammation from the adventitial side. GCA is the most common autoimmune vasculitis in the elderly characterized by the formation of granulomas composed of T cells and macrophages in medium- and large-sized vessels. Recent studies explored the pathophysiology of GCA at unprecedented resolutions, and shed new light on cellular signaling pathways and metabolic fitness in wall-destructive T cells and macrophages. Moreover, recent reports have revealed that not only can cerebrovascular disorders, such as stroke and ischemic optic neuropathy, be initial or coexistent manifestations of GCA, but the same is true for dementia and neurodegenerative disorders. In this review, we first outline how aging affects vascular homeostasis. Subsequently, we review the updated pathophysiology of GCA and explain the similarities and differences between vascular aging and GCA. Then, we introduce the possible link between T cell aging, neurological aging, and GCA. Finally, we discuss therapeutic strategies targeting both senescence and vascular inflammation.

Differential efficacy of TNF inhibitors with or without the immunoglobulin fragment crystallizable (Fc) portion in rheumatoid arthritis: the ANSWER cohort study.

Rheumatoid factor (RF) binds to the fragment crystallizable (Fc) portion of immunoglobulin. It could bind to the Fc portion of anti-TNF inhibitors (TNFi) and attenuate the clinical efficacy. We tried to determine whether the therapeutic efficacy of TNFi with Fc might be lower than that of TNFi without Fc in rheumatoid arthritis (RA) patients with high titres of RF. The Kansai Consortium for Well-being of Rheumatic Disease Patients (ANSWER) cohort is an observational multi-center registry of patients with RA in the Kansai district of Japan. RA patients treated with TNFi were included and divided into two groups based on the structural characteristics between TNFi with Fc (infliximab, adalimumab, golimumab, and etanercept) and TNFi without Fc (certolizumab pegol). Patients were classified into 4 groups according to RF titre quartiles. The sequential disease activity score in 28 joints using erythrocyte sedimentation rate (DAS28-ESR) was compared by Mann-Whitney U test between TNFi with and without Fc in each RF titre group. Multiple linear regression analysis was used to analyze the effect of TNFi without Fc for the change of DAS28-ESR adjusted after potential confounders. A total of 705 RA patients were classified into four groups (RF1; RF 0-15.0 IU/mL, RF2; 15.0-55.0, RF3; 55.0-166, RF4; 166-7555). In RF4, RA patients treated with TNFi without Fc had a significantly lower DAS28-ESR than those treated with TNFi with Fc [3.2 (2.3-4.2) vs. 2.7 (2.0-3.0)] after 12 months. This effect of TNFi without Fc for the change of DAS28-ESR after 12 months treatment retained in multivariate analysis in RF4. TNFi without Fc may be more efficacious than TNFi with Fc in RA patients with high RF titres.