Annals of the Rheumatic Diseases最新文献

Objectives: Hypervascularisation is a dominant feature of the inflamed synovium in rheumatoid arthritis (RA). As RA synovial fibroblasts (RASFs) are key cells of synovial pathophysiology and are located adjacent to the aberrant endothelial cells (ECs), we hypothesised that this interaction might be responsible for the pathological hypervascularisation.

Methods: In the severe combined immunodeficiency (SCID) mouse model for RA, RASF-mediated helix-like vessel (HLV) formation was described and modulated by canstatin, an antiangiogenic collagen IV fragment that blocks the angiopoietin (ANGPT)/Tie2 pathway in EC. ANGPT2/CD31 and CXCL2 immunofluorescence on implants and human synovium was performed. RASF were stimulated with interleukin (IL)-1β once or repetitively and immunoassays, real-time polymerase chain reaction and RNA sequencing were performed. Two-dimensional (2D) tube formation and 3-dimensional spheroid-based assays using human umbilical vein ECs and fluorescent-stained RASF with/without canstatin, IL-11 and CXCL2 were evaluated.

Results: In SCID mice, RASF-specific HLV formation started early and increased until day 30. The number of HLV was significantly reduced by canstatin. Compared to osteoarthritis synovium, ANGPT2 was significantly upregulated in RA vessels. Repetitive RASF stimulation significantly decreased IL-6, IL-11 and CXCL-2 compared to RASF stimulated once with IL-1β. When RASF was stimulated once, CXCL2 and IL-11 were significantly reduced along with 2D tube formation, while repetitive stimulation significantly attenuated hypervascularisation. RNAseq revealed underlying pathways leading to altered tube formation.

Conclusions: We showed that RASF affect vascularisation in vitro and in vivo. The results support the idea that canstatin is able to alter the RASF pathological HLV formation. In the SCID mouse model, this was regulated on a molecular level mediated by ANGPT2 in a vascular endothelial growth factor A-independent manner, contributing significantly to one of the central aspects of RA pathophysiology.

Objectives: The APEX study evaluated the effects of guselkumab, a fully human, dual-acting monoclonal antibody able to bind CD64 and selectively inhibit the interleukin (IL)-23p19 subunit, on clinical and radiographic outcomes in active psoriatic arthritis (PsA).

Methods: APEX (ongoing, phase 3b, double-blind, placebo-controlled) randomised (5:7:7) biologic-naïve adults with active PsA (≥3 tender, ≥3 swollen joints; C-reactive protein ≥0.3 mg/dL; ≥2 erosive joints) to subcutaneous guselkumab 100 mg every 4 weeks (Q4W); guselkumab 100 mg at week 0, week 4, then every 8 weeks (Q8W); or placebo every 4 weeks. Primary (proportion of participants achieving ≥20% improvement in American College of Rheumatology response criteria [ACR20]) and major secondary (total PsA-modified van der Heijde-Sharp [vdH-S] score least squares mean [LSM] change from baseline) endpoints at week 24 were multiplicity-controlled for comparing each guselkumab group versus placebo.

Results: Among 1020 participants (Q4W: 273; Q8W: 371; placebo: 376), significantly greater proportions of participants receiving guselkumab Q4W (66.6%) and Q8W (68.3%) versus placebo (47.0%) achieved ACR20 at week 24 (both P < 0.001). Baseline mean total vdH-S scores were 26.7 to 27.7 across groups; guselkumab Q4W- and Q8W-treated participants exhibited significantly lower rates of radiographic progression versus placebo at week 24 (total vdH-S score LSM change: 0.55 and 0.54 vs 1.35; P = 0.002 and P < 0.001, respectively). Through week 24, 38.2%, 42.5%, and 37.3% of participants receiving guselkumab Q4W, Q8W, and placebo, respectively, had ≥1 adverse event, with no new safety signals.

Conclusions: Guselkumab, a fully human monoclonal antibody able to bind CD64 and simultaneously inhibit the IL-23p19 subunit, provided significantly higher rates of clinical improvement and significant inhibition of structural damage progression versus placebo, with no new safety signals, at week 24 in biologic-naïve participants with active and erosive PsA.

Objectives: Lupus nephritis (LN) is a severe complication of systemic lupus erythematosus (SLE), characterised by kidney inflammation, tubular injury, and interstitial fibrosis. However, the spatial organisation of these heterogeneous cell populations and their regulatory mechanisms in LN remain poorly understood. The objective of this study was to investigate the regulatory mechanisms underlying region-specific kidney lesions and tubular damage in LN.

Methods: We performed single-cell multiome and spatial transcriptomic analyses on kidney biopsy samples from patients with LN and controls, integrating data from the largest East Asian SLE genome-wide association studies (GWAS) (208,370 samples) to date. Validation experiments were performed using multiplex immunohistochemistry (mIHC), in vitro lentiviral-mediated transcription factor overexpression, and functional stimulation assays.

Results: We identified VCAM1-expressing proximal tubule (PT_VCAM1) cells as components of an LN-specific inflammatory niche (niche 5) localised in the kidney cortex. Both in silico and in vitro experiments demonstrated that interactions between PT_VCAM1 cells and myofibroblasts, as well as immune cells in niche 5, promote their epithelial-mesenchymal transition. Trajectory analysis suggested that PT_VCAM1 cells originate from a failed-repair pathway in proximal tubule cells, regulated by transcriptional networks involving BACH2. Integrative GWAS analysis further linked SLE-associated risk single-nucleotide polymorphisms to cis-regulatory elements specific to PT_VCAM1 cells, including single-nucleotide polymorphisms within the distal enhancer of the BMP2K locus, which establishes a BACH2 motif.

Conclusions: Collectively, our findings characterise PT_VCAM1 cells as injury-responsive cell states that contribute to the inflammatory and fibrotic niche in LN, linking genetic predisposition to cellular injury and disease progression.

Objectives: Catastrophic antiphospholipid syndrome (CAPS) is a complement-driven thrombotic disorder, characterised by widespread thrombosis and multiorgan failure. We identified rare germline variants including complement receptor 1 (CR1) in 50% of patients with CAPS. Here, we define CR1 dysregulation mechanisms (genetic/epigenetic) underlying complement-mediated thrombosis in CAPS and support C5 inhibition as a potential therapy.

Methods: We quantified CR1 expression by flow cytometry across haematopoietic cell types. CRISPR/Cas9 genome editing of TF-1 (erythroleukaemia) cells was performed to generate CR1 'knock-out' and 'knock-in' lines with patient-specific CR1 variants. Multiomics analysis was performed to investigate the role of methylation in patients with reduced CR1 expression. Functional impact of low CR1 was assessed by complement-mediated cell killing using modified Ham assay, cell-bound complement degradation products through flow cytometry, and circulatory immune complexes in serum samples through ELISA.

Results: CR1 expression in erythrocytes was markedly reduced on CAPS erythrocytes (n = 9, 21.80%) compared to healthy controls (HCs; n = 35, 84.04%), with promoter hypermethylation emerging as a plausible epigenetic mechanism for CR1 downregulation. Novel germline variant (CR1-V2125L; rs202148801) mitigated CR1 expression and increased complement-mediated cell death of knock-in cell lines. Erythrocytes from the patient with the CR1-V2125L variant had low CR1 expression. Levels of circulating immune complexes, which are bound and cleared by CR1 on erythrocytes, were higher in acute CAPS (n = 3, 25.55 µg Eq/mL) than HCs (n = 3, 7.445 µg Eq/mL). Five patients were treated with C5 inhibition which mitigated thrombosis.

Conclusions: Genetic or epigenetic-mediated CR1 deficiency is a potential hallmark of CAPS and predicts response to C5 inhibition.

Objectives: Systemic lupus erythematosus (SLE) is a complex autoimmune disease strongly associated with the major histocompatibility complex (MHC) region, but precisely pinpointing the risk variants remains challenging. This study aimed to comprehensively profile SLE-driving variants using a newly developed East Asian MHC imputation reference panel, capable of simultaneously imputing diverse MHC variants, including multilevel human leukocyte antigen (HLA) variants and copy number variations (CNVs) of C4 elements, such as C4A, C4B, and human endogenous retrovirus (HERV).

Methods: Using the whole-genome-sequencing (WGS) data from ∼2000 Korean samples, we genotyped and phased MHC variants, including HLA variants and C4-related CNVs, to construct an MHC reference panel. Imputation performance of the panel was assessed through leave-one-out cross-validation and validated using WGS and droplet digital polymerase chain reaction methodology. The panel was applied to 2 independent SLE genome-wide association study datasets, followed by stepwise conditional analyses, fine-mapping, and model comparisons.

Results: The MHC panel achieved high imputation accuracies of 95% for HLA and 94% for C4 at the haploid-level. Independent contributions to SLE risk were identified from 6 amino acid positions altering the epitope-binding surfaces of HLA-DRB1 and HLA-C. Reduced C4A copy numbers and increased HERV copy numbers, collectively lowering C4 protein levels, were associated with increased SLE risk, independent of HLA variants. Our refined MHC-SLE association model provided superior explanations for SLE risk over previous association models in an independent Korean population.

Conclusions: This study enhanced the understanding of HLA and C4 in SLE pathogenesis and holds promise for advancing MHC association studies for immune-mediated inflammatory disorders in East Asians using our MHC panel, accessible via https://coda.nih.go.kr/usab/kis/intro.do.

Objectives: Despite advances in rheumatoid arthritis (RA) treatment, a significant proportion of patients fail to achieve adequate remission. The dynamic cellular and architectural changes within the synovium that underpin therapeutic success remain poorly understood. This study aimed to unravel the synovial landscape during effective RA treatment, identifying key cellular networks and molecular pathways associated with remission.

Methods: We performed high-dimensional imaging mass cytometry on synovial tissues from healthy controls, patients with osteoarthritis, and patients with early RA longitudinally before and after 6 months of conventional synthetic disease-modifying antirheumatic drugs (csDMARD) therapy. Findings were validated using whole-tissue RNA-sequencing and immunofluorescence in larger patient cohorts, and integrated with ligand-receptor analyses from public single-cell RNA-seq datasets and in vitro functional coculture assays.

Results: Our deep spatial profiling pinpointed a critical LYVE1⁺CD206⁺tissue-resident macrophage network, localised within perivascular niches alongside fibroblasts and vascular cells. This homeostatic network was disrupted in active RA but restored in patients responding well to csDMARDs. This restoration correlated with the re-establishment of specific cell-cell interactions and was governed by distinct molecular pathways, including chemokines, annexins, and TAM (TYRO3, AXL, MERTK) receptors. Functionally, LYVE1⁺ macrophages demonstrated a regulatory, anti-inflammatory phenotype in vitro, contrasting with proinflammatory myeloid cells.

Conclusions: This study provides an unprecedented spatial and dynamic blueprint of the RA synovium's response to therapy. We identify the LYVE1⁺ macrophage network as a pivotal component of synovial homeostasis and its restoration as a hallmark of clinical remission. These findings unveil novel cellular and molecular targets, paving the way for more active therapeutic strategies.