Baricitinib for anti-melanoma differentiation-associated protein 5 antibody-positive dermatomyositis-associated interstitial lung disease: a case series and literature review on Janus kinase inhibitors for the disease

Anti-melanoma differentiation-associated protein 5 antibody-positive dermatomyositis (anti-MDA5-DM) is frequently complicated by progressive interstitial lung disease (ILD), the prognosis of which is poor, and management is a major challenge. We treated three patients with anti-MDA5-DM-associated ILD (anti-MDA5-DM-ILD) using the Janus kinase (JAK) inhibitor, baricitinib, which improved lung opacities and saved two patients. We reviewed 6 patients with anti-MDA5-DM-ILD who had been treated with tofacitinib at our institution. Five of the patients survived, although discontinuation of tofacitinib due to complications was frequently observed. In addition, a literature search of patients with anti-MDA5-DM-ILD who were treated with JAK inhibitors yielded 21 articles involving 79 cases. All patients except one were treated with tofacitinib, and the survival rate was 75.9%. Although not statistically confirmed, the deceased patients tended to be older and had higher ferritin levels. A total of 92 complications were observed, 11 of which resulted in JAK inhibitor discontinuation. Cytomegalovirus reactivation comprised a substantial percentage of all complications and of those patients who required JAK inhibitor discontinuation. Five cases with fatal infective complications were also observed. While tofacitinib has been proposed to be a therapeutic option for anti-MDA5-DM-ILD, other JAK inhibitors, including baricitinib, are a treatment option. Further investigation is warranted to optimize treatment of anti-MDA5-DM-ILD.

Upper gastrointestinal involvement of Behçet's disease in Japan: endoscopic findings and clinical features

AIM

Behçet's disease (BD) can involve any gastrointestinal (GI) tract site. We analyzed the characteristics, risk factors, and treatment responses to upper GI (UGI) involvement in patients with BD.

METHODS

This retrospective cohort study analyzed UGI findings in 101 patients with BD who underwent endoscopy between April 2005 and December 2022 at the University of Tokyo Hospital. The patients were divided into two groups based on the presence or absence of UGI findings. Patient backgrounds, clinical symptoms, colonoscopy (CS) findings, and blood test findings were compared between the groups.

RESULTS

In total, 18.8% (19/101) of the patients had UGI lesions. The prevalence rates in the esophagus, stomach, and duodenum were 6.9%, 6.9%, and 8.9%, respectively. Of these 19 patients, BD treatment were intensified in 10 (52.6%) patients after esophagogastroduodenoscopy (EGD), and all showed improvement in symptoms or endoscopic findings. In the multivariate analysis, symptoms (OR: 37.1, P < 0.001), CRP > 1 mg/dL (OR: 11.0, P = 0.01), and CS findings (OR: 5.16, P = 0.04) were independent predictors of UGI involvement in BD patients. The prediction model for UGI involvement using these three factors was highly accurate, with an AUC of 0.899 on the ROC curve. In the subgroup analysis of intestinal BD, symptoms (OR: 12.8, P = 0.01) and ESR > 20 mm/h (OR: 11.5, P = 0.007) were independent predictors.

CONCLUSIONS

EGD should be conducted in BD patients with high CRP, GI symptoms, and lower GI involvement, which leads to better management of BD in terms of improving symptoms and endoscopic findings.

Age-associated CD4+ T cells with B cell-promoting functions are regulated by ZEB2 in autoimmunity

Aging is a significant risk factor for autoimmunity, and many autoimmune diseases tend to onset during adulthood. We conducted an extensive analysis of CD4+ T cell subsets from 354 patients with autoimmune disease and healthy controls via flow cytometry and bulk RNA sequencing. As a result, we identified a distinct CXCR3midCD4+ effector memory T cell subset that expands with age, which we designated "age-associated T helper (THA) cells." THA cells exhibited both a cytotoxic phenotype and B cell helper functions, and these features were regulated by the transcription factor ZEB2. Consistent with the highly skewed T cell receptor usage of THA cells, gene expression in THA cells from patients with systemic lupus erythematosus reflected disease activity and was affected by treatment with a calcineurin inhibitor. Moreover, analysis of single-cell RNA sequencing data revealed that THA cells infiltrate damaged organs in patients with autoimmune diseases. Together, our characterization of THA cells may facilitate improved understanding of the relationship between aging and autoimmune diseases.

Autoantibodies to nuclear valosin-containing protein-like protein: systemic sclerosis-specific antibodies revealed by in vitro human proteome

OBJECTIVES

To identify and characterize undescribed systemic sclerosis (SSc)-specific autoantibodies targeting nucleolar antigens and to assess their clinical significance.

METHODS

We conducted proteome-wide autoantibody screening (PWAS) against serum samples from SSc patients with nucleolar patterned anti-nuclear antibodies (NUC-ANAs) of specific antibodies (Abs) unknown, utilizing wet protein arrays fabricated from in vitro human proteome. Controls included SSc patients with already-known SSc-specific autoantibodies, patients with other connective tissue diseases, and healthy subjects. The selection of nucleolar antigens was performed by database search in the Human Protein Atlas. The Presence of autoantibodies was certified by immunoblots and immunoprecipitations. Indirect immunofluorescence assays on HEp-2 cells were also conducted. Clinical assessment was conducted by retrospective review of electric medical records.

RESULTS

PWAS identified three candidate autoantibodies, including anti-nuclear valosin-containing protein-like (NVL) Ab. Additional measurements in disease controls revealed that only anti-NVL Abs are exclusively detected in SSc. Detection of anti-NVL Abs was reproduced by conventional assays such as immunoblotting and immunoprecipitation. Indirect immunofluorescence assays demonstrated homogeneous nucleolar patterns. Anti-NVL Ab-positive cases were characterized by significantly low prevalence of diffuse skin sclerosis and interstitial lung disease, compared with SSc cases with NUC-ANAs other than anti-NVL Abs, such as anti-U3-RNP and anti-Th/To Abs.

CONCLUSION

Anti-NVL Ab is an SSc-specific autoantibody associated with a unique combination of clinical features, including limited skin sclerosis and lack of lung involvement.

Pulmonary Hypertension Associated with Anti-synthetase Syndrome: A Case Report and Literature Review

Pulmonary hypertension (PH) is a serious condition in which there is an abnormally high pressure in the pulmonary arteries that can occur as a complication of connective tissue diseases. Although the relationship between PH and systemic lupus erythematosus or systemic sclerosis has been well-characterized, PH rarely occurs in patients with anti-synthetase syndrome (ASS), and little is known about the pathophysiology and clinical outcome of patients with ASS-PH. We herein report a patient with anti-Jo-1-positive ASS complicated by PH and discuss the treatment strategy through a review of previously reported cases.

Multimodal repertoire analysis unveils B cell biology in immune-mediated diseases

OBJECTIVES

Despite the involvement of B cells in the pathogenesis of immune-mediated diseases (IMDs), biological mechanisms underlying their function are scarcely understood. To overcome this gap, here we constructed and investigated a large-scale repertoire catalogue of five B cell subsets of patients with IMDs.

METHODS

We mapped B cell receptor regions from RNA sequencing data of sorted B cell subsets. Our dataset consisted of 595 donors under IMDs and health. We characterised the repertoire features from various aspects, including their association with immune cell transcriptomes and clinical features and their response to belimumab treatment.

RESULTS

Heavy-chain complementarity-determining region 3 (CDR-H3) length among naïve B cells was shortened among autoimmune diseases. Strong negative correlation between interferon signature strength and CDR-H3 length was observed in naïve B cells and suggested the role for interferon in premature B cell development. VDJ gene usage was skewed especially in plasmablasts and unswitched-memory B cells of patients with systemic lupus erythematosus (SLE). We developed a scoring system to quantify this skewing, and it positively correlated with peripheral helper T cell transcriptomic signatures and negatively correlated with the amount of somatic hyper mutations in plasmablasts, suggesting the association of extrafollicular pathway. Further, this skewing led to high usage of IGHV4-34 gene with 9G4 idiotypes in unswitched-memory B cells, which showed a prominent positive correlation with disease activity in SLE. Gene usage skewing in unswitched-memory B cells was ameliorated after belimumab treatment.

CONCLUSIONS

Our multimodal repertoire analysis enabled us the system-level understanding of B cell abnormality in diseases.

Investigation of immune-related diseases using patient-derived induced pluripotent stem cells

The precise pathogenesis of immune-related diseases remains unclear, and new effective therapeutic choices are required for the induction of remission or cure in these diseases. Basic research utilizing immune-related disease patient-derived induced pluripotent stem (iPS) cells is expected to be a promising platform for elucidating the pathogenesis of the diseases and for drug discovery. Since autoinflammatory diseases are usually monogenic, genetic mutations affect the cell function and patient-derived iPS cells tend to exhibit disease-specific phenotypes. In particular, iPS cell-derived monocytic cells and macrophages can be used for functional experiments, such as inflammatory cytokine production, and are often employed in research on patients with autoinflammatory diseases.On the other hand, the utilization of disease-specific iPS cells is less successful for research on autoimmune diseases. One reason for this is that autoimmune diseases are usually polygenic, which makes it challenging to determine which factors cause the phenotypes of patient-derived iPS cells are caused by. Another reason is that protocols for differentiating some lymphocytes associated with autoimmunity, such as CD4+T cells or B cells, from iPS cells have not been well established. Nevertheless, several groups have reported studies utilizing autoimmune disease patient-derived iPS cells, including patients with rheumatoid arthritis, systemic lupus erythematosus (SLE), and systemic sclerosis. Particularly, non-hematopoietic cells, such as fibroblasts and cardiomyocytes, differentiated from autoimmune patient-derived iPS cells have shown promising results for further research into the pathogenesis. Recently, our groups established a method for differentiating dendritic cells that produce interferon-alpha, which can be applied as an SLE pathological model. In summary, patient-derived iPS cells can provide a promising platform for pathological research and new drug discovery in the field of immune-related diseases.

Nonepisodic Angioedema with Eosinophilia Following Receipt of the BNT162b2 mRNA COVID-19 Vaccine

Angioedema with eosinophilia (AE) is a rare disease of unknown etiology characterized by episodic (EAE) or nonepisodic AE (NEAE). Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA-based vaccines function as immunogens and intrinsic adjuvants and have been shown to be safe in large-scale trials. However, the long-term adverse reactions, especially those related to eosinophilic complications, have not been fully clarified. We herein report a case of self-limited but severe NEAE that developed in a young woman one week after receiving the second BNT162b2 mRNA vaccine. The symptoms that impaired her activities of daily living, such as edema, gradually resolved with supportive care over 10 weeks without corticosteroid treatment.

Long-Term Results of a Phase II Study of Accelerated Hyperfractionated Thoracic Radiotherapy with Dose Escalation to 54 Gy for Limited-Stage Small-Cell Lung Cancer

PURPOSE/OBJECTIVE(S)

The combination of accelerated hyperfractionated thoracic radiotherapy (AHF-TRT) of 45 Gy and concurrent chemotherapy is the standard treatment for limited-stage small-cell lung cancer (LS-SCLC). However, the optimal dose and fractionation remain controversial. We herein report the results of a phase II study investigating the utility of dose escalation to 54 Gy on AHF-RT for LS-SCLC.

MATERIALS/METHODS

We enrolled patients ≤80 years old with treatment-naïve confirmed LS-SCLC and an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2. The radiation dose was 54 Gy delivered in 36 fractions in 18 treatment days over 3.6 weeks. The chemotherapy regimens were PE (cisplatin and etoposide)- or CE (carboplatin and etoposide)-based. AHF-TRT was given in 2 phases: patients initially received 36 Gy to the gross tumor plus uninvolved mediastinal nodes, followed by a boost to the gross tumor of 18 Gy. All patients were treated with three-dimensional conformal radiation therapy with multiple fields to reduce the elevated dose volume to the surrounding tissues, such as the lungs and esophagus, as much as possible. All patients were evaluated for the overall survival (OS), progression-free survival (PFS), and non-hematological toxicity.

RESULTS

Between 2013 and 2016, a total of 13 patients were enrolled in the present study. All the patients were assessable for the response and toxicity. The median age was 67 (range, 54-78) years old, and 9 patients were male, while 4 were female. Twelve patients had a ECOG performance status of 0. The numbers of patients with Stage IIA, IIB, IIIA, and IIIB disease were one, one, eight, and three, respectively. The median follow-up for all patients was 79 (range, 13-107) months, and that for surviving patients was 90 (range, 79-107) months. The patterns of failure were locoregional-only recurrence in 0% (0 patients), both locoregional and distant in 15.4% (2 patients), and distant-only in 30.8% (4 patients). Recurrence from the elective nodal irradiation area was seen in 0% (0 patients). The 1-, 3-, 5-, and 7-year OS rates were 100%, 76.9%, 53.9%, and 44.9%, respectively, and the median OS was 83.0 months. The 1-, 3-, 5-, and 7-year PFS rates were 76.9%, 53.9%, 53.9%, and 44.9%, respectively, and the median PFS was 83.0 months. No patient experienced a grade ≥3 non-hematological adverse effect, such as esophagitis or pneumonitis, during treatment or follow-up. Grade 2 pneumonitis was observed in 2 patients (15.4%), Grade 2 esophagitis was observed in 12 patients (92.3%), and Grade 2 esophageal pain was observed in 2 patients (15.4%).

CONCLUSION

In this study, AHF-TRT of 54 Gy with concurrent PE- or CE-based regimens resulted in a good OS and PFS without increasing severe toxicity. Although this regimen needs to be evaluated in more patients to fully confirm its efficacy, these outcomes suggest that dose escalation to 54 Gy may be a promising radical treatment for LS-SCLC.

Functional evaluation of rare OASL variants by analysis of SLE patient-derived iPSCs

BACKGROUND

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease characterized by genetic heterogeneity and an interferon (IFN) signature. The overall landscapes of the heritability of SLE remains unclear.

OBJECTIVES

To identify and elucidate the biological functions of rare variants underlying SLE, we conducted analyses of patient-derived induced pluripotent stem cells (iPSCs) in combination with genetic analysis.

METHODS

Two familial SLE patient- and two healthy donor (HD)-derived iPSCs were established. Type 1 IFN-secreting dendritic cells (DCs) were differentiated from iPSCs. Genetic analyses of SLE-iPSCs, and 117 SLE patients and 107 HDs in the ImmuNexUT database were performed independently. Genome editing of the variants on iPSCs was performed with the CRISPR/Cas9 system.

RESULTS

Type 1 IFN secretion was significantly increased in DCs differentiated from SLE-iPSCs compared to HD-iPSCs. Genetic analyses revealed a rare variant in the 2'-5'-Oligoadenylate Synthetase Like (OASL) shared between SLE-iPSCs and another independent SLE patient, and significant accumulation of OASL variants among SLE patients (HD 0.93%, SLE 6.84%, OR 8.387) in the database. Genome editing of mutated OASL 202Q to wild-type 202 R or wild-type OASL 202 R to mutated 202Q resulted in reduced or enhanced Type 1 IFN secretion of DCs. Three other OASL variants (R60W, T261S and A447V) accumulated in SLE patients had also capacities to enhance Type 1 IFN secretion in response to dsRNA.

CONCLUSIONS

We established a patient-derived iPSC-based strategy to investigate the linkage of genotype and phenotype in autoimmune diseases. Detailed case-based investigations using patient-derived iPSCs provide information to unveil the heritability of the pathogenesis of autoimmune diseases.

Immunomics analysis of rheumatoid arthritis identified precursor dendritic cells as a key cell subset of treatment resistance

OBJECTIVES

Little is known about the immunology underlying variable treatment response in rheumatoid arthritis (RA). We performed large-scale transcriptome analyses of peripheral blood immune cell subsets to identify immune cells that predict treatment resistance.

METHODS

We isolated 18 peripheral blood immune cell subsets of 55 patients with RA requiring addition of new treatment and 39 healthy controls, and performed RNA sequencing. Transcriptome changes in RA and treatment effects were systematically characterised. Association between immune cell gene modules and treatment resistance was evaluated. We validated predictive value of identified parameters for treatment resistance using quantitative PCR (qPCR) and mass cytometric analysis cohorts. We also characterised the identified population by synovial single cell RNA-sequencing analysis.

RESULTS

Immune cells of patients with RA were characterised by enhanced interferon and IL6-JAK-STAT3 signalling that demonstrate partial normalisation after treatment. A gene expression module of plasmacytoid dendritic cells (pDC) reflecting the expansion of dendritic cell precursors (pre-DC) exhibited strongest association with treatment resistance. Type I interferon signalling was negatively correlated to pre-DC gene expression. qPCR and mass cytometric analysis in independent cohorts validated that the pre-DC associated gene expression and the proportion of pre-DC were significantly higher before treatment in treatment-resistant patients. A cluster of synovial DCs showed both features of pre-DC and pro-inflammatory conventional DC2s.

CONCLUSIONS

An increase in pre-DC in peripheral blood predicted RA treatment resistance. Pre-DC could have pathophysiological relevance to RA treatment response.

Significance of anti-transcobalamin receptor antibodies in cutaneous arteritis revealed by proteome-wide autoantibody screening

Cutaneous arteritis (CA) is a single-organ vasculitis that exclusively affects the small to medium-sized arteries of the skin. Diagnosis depends on a histological investigation with skin biopsy, which could be burdensome for both patients and clinicians. Moreover, the pathogenesis of CA remains unstudied, and treatment has not yet been established. Herein, we applied our proteome-wide autoantibody screening method to explore autoantibodies in the serum of CA patients. As a result, anti-transcobalamin receptor (TCblR) antibodies (Abs) were specifically detected in 24% of CA patients. Patients with positive anti-TCblR Abs were spared from peripheral neuropathy compared to those with negative anti-TCblR Abs, showing characteristics as CA confined to the skin. In addition, we revealed that anti-TCblR Abs trigger the autocrine loop of interleukin-6 mediated by tripartite motif-containing protein 21 in human endothelial cells and induce periarterial inflammation in murine skin. Furthermore, we demonstrated that methylcobalamin, a ligand of TCblR, ameliorates inflammation caused by anti-TCblR Abs both in vitro and in vivo. Collectively, our investigation unveils the pathologic significance of anti-TCblR Abs in CA and their potential as a diagnostic marker and a pathophysiology-oriented therapeutic target.

Transcriptome Profiling of Immune Cell Types in Peripheral Blood Reveals Common and Specific Pathways Involved in the Pathogenesis of Myositis-Specific Antibody-Positive Inflammatory Myopathies

OBJECTIVE

Idiopathic inflammatory myopathies (IIM) demonstrate characteristic clinical phenotypes depending on the myositis-specific antibody (MSAs) present. We aimed to identify common or MSA-specific immunological pathways in different immune cell types from peripheral blood by transcriptome analysis.

METHODS

We recruited 33 patients with IIM who were separated into the following groups: 15 patients with active disease at onset and 18 with inactive disease under treatment. All patients were positive for MSAs: anti-melanoma differentiation-associated gene 5 (MDA5) antibody (Ab) in 10 patients, anti-Mi-2 Ab in 7, and anti-aminoacyl-transfer RNA synthetase (ARS) Ab in 16. The patients were compared with 33 healthy controls. Twenty-four immune cell types sorted from peripheral blood were analyzed by flow cytometry, RNA sequencing, and differentially expressed gene analysis combined with pathway analysis.

RESULTS

The frequencies of memory B cell types were significantly decreased in active patients, and the frequency of plasmablasts was prominently increased in active patients with anti-MDA5 Ab in comparison with healthy controls. The expression of type I interferon (IFN)-stimulated genes of all immune cell types was increased in the active, but not inactive, patients. Endoplasmic reticulum stress-related genes in all IIM memory B cells and oxidative phosphorylation-related genes in inactive IIM double negative B cells were also increased, suggesting prominent B cell activation in IIM. Furthermore, active patients with anti-MDA5 Ab, anti-Mi-2 Ab, or anti-ARS Ab were distinguished by IFN-stimulated and oxidative phosphorylation-related gene expression in plasmablasts.

CONCLUSION

Unique gene expression patterns in patients with IIM with different disease activity levels and MSA types suggest different pathophysiologies. Especially, B cells may contribute to common and MSA-specific immunological pathways in IIM.

Efficacy and safety of plasma exchange in interstitial lung diseases with anti-melanoma differentiation-associated 5 gene antibody positive clinically amyopathic dermatomyositis

OBJECTIVE

Clinically amyopathic dermatomyositis (CADM) patients frequently develop refractory interstitial lung disease (ILD), with a poor prognosis. We aimed to verify the efficacy and safety of plasma exchange (PE) treatment for ILD in CADM.

METHOD

A retrospective case-control study was conducted to compare clinical outcomes with and without PE treatment in CADM-ILD patients refractory to combination therapy of high-dose glucocorticoids, calcineurin inhibitors, and cyclophosphamide. Among 19 enrolled patients, 11 were further treated with PE. We compared survival rates and other clinical characteristics. PE consisted of either fresh-frozen plasma or albumin as a replacement solution.

RESULTS

Basal clinical characteristics at diagnosis, including age, gender, serum ferritin, Krebs von den Lungen-6 (KL-6), C-reactive protein, and respiratory function tests, did not differ between the two groups. The survival rate for treatment with PE was higher than for treatment without PE (91% and 50%, respectively, p < 0.05). Among PE-treated patients, anti-melanoma differentiation-associated gene-5 (anti-MDA-5) antibody titre, ferritin, and KL-6 as serological activity markers were sustainably reduced only after initiating PE. Therapeutic intervention with PE reduced the frequency of exacerbation of ILD requiring methylprednisolone pulse therapy. The occurrence of bacterial, fungal, and cytomegalovirus infection did not differ between the groups with and without PE, and adverse events associated with PE resolved with appropriate intervention.

CONCLUSION

Combination therapy with PE was associated with an improved survival rate, and may be effective for the management of refractory ILD in CADM patients. A personalized therapeutic strategy including PE could be introduced for fatal rapidly progressive ILD.

Role of autotaxin in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a prototypic systemic autoimmune disease characterized by the production of various autoantibodies and deposition of immune complexes. SLE is a heterogenous disease, and the pattern of organ involvement and response to treatment differs significantly among patients. Novel biological markers are necessary to assess the extent of organ involvement and predict treatment response in SLE. Lysophosphatidic acid is a lysophospholipid involved in various biological processes, and autotaxin (ATX), which catalyzes the production of lysophosphatidic acid in the extracellular space, has gained attention in various diseases as a potential biomarker. The concentration of ATX is increased in the serum and urine of patients with SLE and lupus nephritis. Recent evidence suggests that ATX produced by plasmacytoid dendritic cells may play an important role in the immune system and pathogenesis of SLE. Furthermore, the production of ATX is associated with type I interferons, a key cytokine in SLE pathogenesis, and ATX may be a potential biomarker and key molecule in SLE.

Control of naive and effector CD4 T cell receptor repertoires by rheumatoid-arthritis-risk HLA alleles

OBJECTIVE

Human Leukocyte Antigen (HLA) alleles regulate susceptibility to rheumatoid arthritis (RA) and immune-mediated diseases. This study aims to elucidate the impact of HLA alleles to T cell subsets.

METHODS

We performed genome-wide and HLA allele association analysis for T cell receptor (TCR) beta chain repertoire in 13 purified T cell subsets from the ImmuNexUT database, consisting of 407 donors with ten immune-mediated diseases and healthy controls.

RESULTS

HLA class II alleles were associated with TRBV gene usage and the public clones of CD4 T cells, while HLA class I alleles were associated with CD8 T cells. RA-risk and immune-mediated diseases-risk HLA alleles were associated with TRBV gene usage of naive and effector CD4 T cell subsets and public clones accumulating in Th17. Clonal diversity was independent of HLA alleles and was correlated with transcriptome changes that reflect TCR signaling.

CONCLUSION

This study revealed in vivo evidence that both HLA alleles and environmental factors shape naive and effector TCR repertoires in RA and immune-mediated diseases patients.

Serum extracellular traps associate with the activation of myeloid cells in SLE patients with the low level of anti-DNA antibodies

Neutrophil extracellular traps (NETs) are involved in systemic lupus erythematosus (SLE). We sought to cluster SLE patients based on serum NET levels. Serum NET levels were higher in SLE patients than healthy controls. Frequencies of pleuritis and myositis were increased in patients with high serum NET levels. Serum NET levels negatively correlated with anti-double stranded DNA (anti-dsDNA) antibody titers and C1q-binding immune complexes, but positively correlated with C-reactive protein (CRP) and monocyte counts. Neutrophil transcriptome analysis demonstrated no difference in NET-associated signatures, irrespective of serum NET levels, suggesting anti-dsDNA antibody-mediated clearance of NETs. In serum, NET levels were significantly correlated with myeloid cell-derived inflammatory molecules. Serum NET-based cluster analysis revealed 3 groups of patients based on serum NET and CRP levels, anti-dsDNA antibody titers, and monocyte count. Monocytes were consistently activated following NET-containing immune complex (NET-IC) stimulation. In conclusion, SLE patients with high serum NET levels had lower anti-dsDNA antibody titers and higher inflammatory responses. NET-IC-stimulated monocytes might associate with an inflammatory response characterized by elevated CRP levels. These findings can apply to precision medicine, as inflammatory processes, rather than antibody-dependent processes, can be targeted in specific subpopulations of SLE patients.

Autotaxin is a potential link between genetic risk factors and immunological disturbances of plasmacytoid dendritic cells in systematic lupus erythematosus

BACKGROUND

The importance of autotaxin, an enzyme that catalyzes lysophospholipid production, has recently been recognized in various diseases, including cancer and autoimmune diseases. Herein, we examined the role of autotaxin in systemic lupus erythematosus (SLE), utilizing data from ImmuNexUT, a comprehensive database consisting of transcriptome data and expression quantitative trait locus (eQTL) data of immune cells from patients with immune-mediated disorders.

METHODS

Serum autotaxin concentrations in patients with SLE and healthy controls (HCs) were compared. The transcriptome data of patients with SLE and age- and sex-matched HCs were obtained from ImmuNexUT. The expression of ENPP2, the gene encoding autotaxin, was examined in peripheral blood immune cells. Next, weighted gene correlation network analysis (WGCNA) was performed to identify genes with expression patterns similar to ENPP2. The ImmuNexUT eQTL database and public epigenomic databases were used to infer the relationship between autotaxin and pathogenesis of SLE.

RESULTS

Autotaxin levels were elevated in the serum of patients with SLE compared to HCs. Furthermore, the expression of ENPP2 was higher in plasmacytoid dendritic cells (pDCs) than in other immune cell subsets, and its expression was elevated in pDCs of patients with SLE compared to HCs. In WGCNA, ENPP2 belonged to a module that correlated with disease activity. This module was enriched in interferon-associated genes and included genes whose expression was influenced by single-nucleotide polymorphisms associated with SLE, suggesting that it is a key module connecting genetic risk factors of SLE with disease pathogenesis. Analysis utilizing the ImmuNexUT eQTL database and public epigenomic databases suggested that the increased expression of ENPP2 in pDCs from patients with SLE may be caused by increased expression of interferon-associated genes and increased binding of STAT3 complexes to the regulatory region of ENPP2.

CONCLUSIONS

Autotaxin may play a critical role in connecting genetic risk factors of SLE to disease pathogenesis in pDCs.

A diagnostic score for eosinophilic granulomatosis with polyangiitis among eosinophilic disorders

BACKGROUND

Eosinophilic granulomatosis with polyangiitis (EGPA) is a form of systemic vasculitis with eosinophilic inflammation. However, existing classification criteria are all designed to classify EGPA among vasculitis and there is no established method distinguishing EGPA from other eosinophilic disorders. The aim of the present study was to propose a scoring system to differentiate EGPA among eosinophilic disorders.

METHODS

Non-supervised hierarchical clustering using Ward's method and principal component analysis (PCA) were performed for 19 clinical parameters of 58 patients with eosinophilia-related diseases at a tertiary university hospital. The newly proposed scoring system was externally validated in 40 patients at another tertiary institution.

RESULTS

Two distinct clusters were identified, and clinical features including peripheral neuropathy, asthma, skin involvement, lung involvement, rheumatoid factor (RF) positivity, myeloperoxidase (MPO)-anti-neutrophil cytoplasmic antibody (ANCA) positivity, IgE elevation, C-reactive protein (CRP) elevation, and vasculitis pathological findings were predominantly observed in one of these clusters (p < 0.05). Ten features defining the cluster with a high rate of vasculitis were weighted by PCA to create the E-CASE (EGPA classification among systemic eosinophilia) scoring system, on a 16-point scale. Based on the distribution of scores in the primary cohort, we defined an E-CASE score ≥12 as positive, ≤ 8 as negative, and 9-11 as undeterminable. The sensitivity and specificity of the E-CASE score in the validation cohort were 93.3% and 100%, respectively.

CONCLUSIONS

We developed and verified a novel scoring system for differentiating EGPA from other types of eosinophilic disorders.

Distinct transcriptome architectures underlying lupus establishment and exacerbation

Systemic lupus erythematosus (SLE) is a complex autoimmune disease involving multiple immune cells. To elucidate SLE pathogenesis, it is essential to understand the dysregulated gene expression pattern linked to various clinical statuses with a high cellular resolution. Here, we conducted a large-scale transcriptome study with 6,386 RNA sequencing data covering 27 immune cell types from 136 SLE and 89 healthy donors. We profiled two distinct cell-type-specific transcriptomic signatures: disease-state and disease-activity signatures, reflecting disease establishment and exacerbation, respectively. We then identified candidate biological processes unique to each signature. This study suggested the clinical value of disease-activity signatures, which were associated with organ involvement and therapeutic responses. However, disease-activity signatures were less enriched around SLE risk variants than disease-state signatures, suggesting that current genetic studies may not well capture clinically vital biology. Together, we identified comprehensive gene signatures of SLE, which will provide essential foundations for future genomic and genetic studies.

Transcriptome analysis of immune cells from Behçet's syndrome patients: the importance of IL-17-producing cells and antigen-presenting cells in the pathogenesis of Behçet's syndrome

Background

Behçet’s syndrome (BS) is an immune-mediated disease characterized by recurrent oral ulcers, genital ulcers, uveitis, and skin symptoms. HLA-B51, as well as other genetic polymorphisms, has been reported to be associated with BS; however, the pathogenesis of BS and its relationship to genetic risk factors still remain unclear. To address these points, we performed immunophenotyping and transcriptome analysis of immune cells from BS patients and healthy donors.

Methods

ImmuNexUT is a comprehensive database consisting of RNA sequencing data and eQTL database of immune cell subsets from patients with immune-mediated diseases and healthy donors, and flow cytometry data and transcriptome data from 23 BS patients and 28 healthy donors from the ImmuNexUT study were utilized for this study. Differential gene expression analysis and weighted gene co-expression network analysis (WGCNA) were performed to identify genes associated with BS and clinical features of BS. eQTL database was used to assess the relationship between genetic risk factors of BS with those genes.

Results

The frequency of Th17 cells was increased in BS patients, and transcriptome analysis of Th17 cells suggested the activation of the NFκB pathway in Th17 cells of BS patients. Next, WGCNA was used to group genes into modules with similar expression patterns in each subset. Modules of antigen-presenting cells were associated with BS, and pathway analysis suggested the activation of antigen-presenting cells of BS patients. Further examination of genes in BS-associated modules indicated that the expression of YBX3, a member of a plasmacytoid dendritic cell (pDC) gene module associated with BS, is influenced by a BS risk polymorphism, rs2617170, in pDCs, suggesting that YBX3 may be a key molecule connecting genetic risk factors of BS with disease pathogenesis. Furthermore, pathway analysis of modules associated with HLA-B51 indicated that the association of IL-17-associated pathways in memory CD8⁺ T cells with HLA-B51; therefore, IL-17-producing CD8⁺ T cells, Tc17 cells, may play a critical role in BS.

Conclusions

Various cells including CD4⁺ T cells, CD8⁺ T cells, and antigen-presenting cells are important in the pathogenesis of BS. Tc17 cells and YBX3 may be potential therapeutic targets in BS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02867-x.

The Pathophysiological Roles of Regulatory T Cells in the Early Phase of Systemic Sclerosis

Systemic sclerosis (SSc) is an autoimmune disease that is characterized by vascular damage and fibrosis. Both clinical manifestations and immunological disturbances are diverse according to the disease duration. Particularly, changes in immunological processes are prominent in the early phase of SSc. The orchestration of several subsets of immune cells promotes autoimmune responses and inflammation, and eventually stimulates pro-fibrotic processes. Many reports have indicated that CD4⁺ T cells play pivotal roles in pathogenesis in the early phase of SSc. In particular, the pathogenic roles of regulatory T (Treg) cells have been investigated. Although the results were controversial, recent reports suggested an increase of Treg cells in the early phase of SSc patients. Treg cells secrete transforming growth factor-β (TGF-β), which promotes myofibroblast activation and fibrosis. In addition, the dysfunction of Treg cells in the early phase of SSc was reported, which results in the development of autoimmunity and inflammation. Notably, Treg cells have the plasticity to convert to T-helper17 (Th17) cells under pro-inflammatory conditions. Th17 cells secrete IL-17A, which could also promote myofibroblast transformation and fibrosis and contributes to vasculopathy, although the issue is still controversial. Our recent transcriptomic comparison between the early and late phases of SSc revealed a clear difference of gene expression patterns only in Treg cells. The gene signature of an activated Treg cell subpopulation was expanded in the early phase of SSc and the oxidative phosphorylation pathway was enhanced, which can promote Th17 differentiation. And this result was accompanied by the increase in Th17 cells frequency. Therefore, an imbalance between Treg and Th17 cells could also have an important role in the pathogenesis of the early phase of SSc. In this review, we outlined the roles of Treg cells in the early phase of SSc, summarizing the data of both human and mouse models. The contributions of Treg cells to autoimmunity, vasculopathy, and fibrosis were revealed, based on the dysfunction and imbalance of Treg cells. We also referred to the potential development in treatment strategies in SSc.

POS0844 LONG-TERM AND SHORT-TERM RISK OF MALIGNANCY IN IDIOPATHIC INFLAMMATORY MYOPATHY

Background

Idiopathic inflammatory myopathy (IIM) is associated with a high prevalence of malignancy, in which anti-transcriptional intermediary factor 1-γ(TIF1-γ) antibody is at a high risk of malignancy compared to the other myositis-specific antibodies, including anti-aminoacyl-tRNA synthetase (ARS), melanoma differentiation-associated gene 5 (MDA5), and Mi-2 antibody [1]. Although some subgroups of IIM have a high risk of malignancy up to 10 years after diagnosis [2], long-term relationships between malignancy and each antibody are not elucidated so far.

Objectives

To clarify the risk of malignancy in IIM in each antibody type with standard incidence ratios (SIR) of malignancy and the long-term occurrence of malignancy.

Methods

From our IIM cohort at the University of Tokyo hospital, we enrolled patients who fulfilled with Bohan and Peter criteria for dermatomyositis/polymyositis or 2017 European League Against Rheumatism/American College of Rheumatology classification criteria for IIMs and with positivity for anti-ARS, MDA5, Mi-2, or TIF1-γ antibody. We retrospectively collected the data and calculated SIRs by using the database of Cancer Statistics, Cancer Information Service, National Cancer Center, Japan. Fisher exact test and Wilcoxon test were used to compare the clinical features in each group. Cumulative incidence of cancer occurrence was estimated by Kaplan-Meier methods, and Log-rank test was used to compare the cancer-free survival.

Results

The study included 111 patients, including 16 patients being diagnosed with a malignancy within a three-year before and after the occurrence of IIM. Patients with malignancy were significantly older age at the onset of IIM (median age (interquartile range) 67.5 (62.3-70.8) vs. 52.0 (41.5-61.5). p<0.001) and more frequently with anti-TIF1-γ antibody (25.0% vs. 4.2%, p=0.015). After adjustment for age, the proportion of anti-TIF1-γ antibody remains significantly higher in the malignancy group (p=0.01). SIRs (95% confidence interval) in each type of antibody were anti-ARS of 2.21 (1.03-4.55), anti-MDA5 of 1.89 (0.49-6.02), anti-Mi-2 of 2.75 (0.14-17.84), and anti-TIF1-γ of 14.73 (4.72-40.50) (Table 1). Types of malignancy included four gastric cancers, two bladder cancers, breast cancers, cervical cancers, ovarian cancers, and lung cancer, one pancreatic cancer, rectal cancer, and renal cancer. Kaplan-Meier estimated cancer-free survival was significantly lower in patients with anti-TIF1-γ antibody than patients with anti-ARS antibody (p<0.01) (Figure 1). The frequencies of malignancy of IIM patients with anti-ARS, MDA5, Mi-2, or TIF1-γ antibody through the follow-up period were 15.6%, 20.0%, 11.1%, 50.0%, respectively.

Figure 1.

Comparison of malignancy rate of idiopathic inflammatory myopathy with anti-ARS, and TIF1-γ antibodies in 10 years.

Table 1.

Standard incident ratio (SIR) of malignancy in idiopathic inflammatory myopathy according to myositis-specific antibodies.

Total (Person-years)ObservedExpectedSIR (95% CI)Anti-ARS antibody51083.622.21 (1.03-4.55)Anti-MDA5 antibody21031.591.89 (0.49-6.02)Anti-Mi-2 antibody5610.362.75 (0.14-17.84)Anti-TIF1-γ antibody3940.2714.73 (4.72-40.50)Total815165.842.74 (1.62-4.56)

Conclusion

IIM patients with anti-TIF1-γ antibody and with anti-ARS antibody had a higher prevalence of malignancy than the general population. In addition, anti-TIF1-γ antibody are more associated with malignancy rather than anti-ARS antibody in 10 years as well. Malignancy associated with anti-TIF1-γ positive IIM occurred exclusively within the one year before and after the IIM diagnosis, and cancer should be particularly investigated at the IIM diagnosis.

References

[1]DeWane ME, Waldman R, Lu J. Dermatomyositis: Clinical features and pathogenesis. J Am Acad Dermatol. 2020;82:267-281.

[2]Lundberg IE, Fujimoto M, Vencovsky J, Aggarwal R, Holmqvist M, Christopher-Stine L, Mammen AL, Miller FW. Idiopathic inflammatory myopathies. Nat Rev Dis Primers. 2021;7:86.

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Disclosure of Interests

Shinji Izuka: None declared, Toshihiko Komai Speakers bureau: Tanabe Mitsubishi, Kissei, Pfizer, Amgen GlaxoSmithKline and Chugai., Grant/research support from: GlaxoSmithKline., Hirofumi Shoda Speakers bureau: Pfizer, Bristol-Myers Squibb, Eli Lilly, Sanofi, AbbVie, GlaxoSmithKline, Gilead, Boehringer Ingelheim, Jansen, Novartis, Chugai, Takeda, Astellas, Eisai, Asahi Kasei and Daiichi-Sankyo., Grant/research support from: Novartis, Keishi Fujio Speakers bureau: Tanabe Mitsubishi, Bristol-Myers Squibb, Eli Lilly, Chugai, Jansen, Pfizer, Ono, AbbVie, Ayumi, Astellas, Sanofi, Novartis, Daiichi Sankyo, Eisai, Asahi Kasei and AstraZeneca., Grant/research support from: Tanabe Mitsubishi, Bristol-Myers Squibb, Eli Lilly, Chugai, Eisai, Tsumura and Asahi Kasei.

OP0110 CELL-TYPE-SPECIFIC TRANSCRIPTOME ARCHITECTURE UNDERLYING THE ESTABLISHMENT AND EXACERBATION OF SYSTEMIC LUPUS ERYTHEMATOSUS

Background

Systemic lupus erythematosus (SLE) is a complex autoimmune disease with unknown etiology involving multiple immune cells and has diverse clinical phenotypes. This heterogeneous nature has hampered a better understanding of SLE pathogenesis and the development of effective therapeutic agents. While recent single-cell RNA sequencing studies of SLE identified several important cell subpopulations, they were limited by sparse expression information at single-cell level and small sample sizes.

Objectives

This study aimed to elucidate the dysregulated gene expression pattern linked to multiple clinical statuses of SLE with a fine cellular resolution and higher sensitivity. We also attempted to resolve a complex interaction between risk variants and the transcriptome dysregulation seen in SLE patients.

Methods

We conducted a large-scale bulk transcriptome study of 6,386 RNA-sequencing data including 27 purified immune cell types in peripheral blood from 136 SLE and 89 healthy donors in the Immune Cell Gene Expression Atlas from the University of Tokyo (ImmuNexUT) cohort1. At enrollment, SLE patients had diverse clinical manifestations (disease activity, organ involvement and treatment profiles) and 22 patients were re-evaluated after belimumab treatment.

Results

We first profiled two distinct cell-type-specific transcriptomic signatures: disease-state and disease-activity signatures, reflecting disease establishment and exacerbation, respectively.

After confirming the high replicability of both signatures in independent cohorts, we identified candidates of biological processes unique to each signature: e.g., upregulated E2F transcriptional activity in Th1, CD8+ memory T-lineage and NK cells, and dynamic increase of IL21 and CXCL13 in Th1 cells in an active phase of SLE. Pathway analysis highlighted the importance of immunometabolic process for SLE (e.g., oxidative phosphorylation) in cell-type-specific resolution.

Moreover, we demonstrated cell-type-specific contributions to diverse organ involvement, e.g., Th1 for mucocutaneous, monocyte-lineage cells for musculoskeletal, neutrophil-lineage cells for renal activity, respectively.

We also observed the strong associations of disease-activity signatures with treatment effect: (i) belimumab suppressed activity signatures from B-lineage cells, especially in good responders and (ii) mycophenolate mofetil substantially suppressed activity signatures from plasmablast, Th1, and central memory CD8 cells.

However, through stratified LD score regression using large-scale SLE-GWASs, we revealed that disease-activity signatures were less enriched around SLE risk variants than disease-state signatures. Consistent with this result, the directions of SLE risk alleles’ expression quantitative trait locus (eQTL) effects were significantly concordant with the directions of disease-state signatures, but not with those of activity signatures. These findings suggested that the current genetic case-control studies may not well capture clinically vital biology linked to drug target discovery for SLE. Meanwhile, we also detected some examples of activity signatures that might contribute to the disease risk by modulating risk allele’s eQTL effects.

Figure 1.

Conclusion

We identified comprehensive gene signatures reflecting the establishment and exacerbation of SLE, which provide essential foundations for future genomic, genetic, and clinical studies.

References

[1]Ota, M. et al. Dynamic landscape of immune cell-specific gene regulation in immune-mediated diseases. Cell 2021;184:3006-21.e17.

Acknowledgements

This study was supported by Chugai Pharmaceutical Co., Ltd., Tokyo, Japan; the Ministry of Education, Culture, Sports; and the Japan Agency for Medical Research and Development (AMED) (JP21tm0424221 and JP21zf0127004).

Disclosure of Interests

Masahiro Nakano: None declared, Mineto Ota Grant/research support from: Mineto Ota belongs to the Social Cooperation Program, Department of functional genomics and immunological diseases, supported by Chugai Pharmaceutical., Yusuke Takeshima Grant/research support from: Yusuke Takeshima belonged to the Social Cooperation Program, Department of functional genomics and immunological diseases, supported by Chugai Pharmaceutical., Yukiko Iwasaki: None declared, Hiroaki Hatano: None declared, Yasuo Nagafuchi Grant/research support from: Yasuo Nagafuchi belongs to the Social Cooperation Program, Department of functional genomics and immunological diseases, supported by Chugai Pharmaceutical., Kwangwoo Kim: None declared, So-Young Bang: None declared, Hye Soon Lee: None declared, Hirofumi Shoda: None declared, Xuejun Zhang: None declared, Sang-Cheol Bae: None declared, Chikashi Terao: None declared, Kazuhiko Yamamoto: None declared, Tomohisa Okamura Grant/research support from: Tomohisa Okamura belongs to the Social Cooperation Program, Department of functional genomics and immunological diseases, supported by Chugai Pharmaceutical., Kazuyoshi Ishigaki: None declared, Keishi Fujio Speakers bureau: Keishi Fujio receives speaker fees from Chugai Pharmaceutical., Consultant of: Keishi Fujio receives consulting honoraria from Chugai Pharmaceutical., Grant/research support from: Keishi Fujio receives research support from Chugai Pharmaceutical.

Efficacy of canakinumab on AA amyloidosis in late-onset NLRP3-associated autoinflammatory disease with an I574F somatic mosaic mutation

There have been hundreds of reports on mutations in the NLRP3 gene related to NLRP3-associated autoinflammatory disease, but few of these mutations have occurred as both germline and somatic mosaic mutations. In this case-based review, we report a 68-year-old man with an NLRP3-associated autoinflammatory disease. He developed secondary amyloidosis, including a renal and colorectal presentation in his 50 s. Sequencing of the NLRP3 gene revealed an I574F somatic mosaic mutation, which has up to now only been reported in germline mutations. The patient was treated with canakinumab, which had great efficacy not only on the NLRP3-mediated inflammation, but also on the chronic renal failure and proteinuria provoked by secondary renal amyloidosis. To evaluate the effectiveness of canakinumab, we conducted a literature research on renal amyloidosis related to NLRP3-associated autoinflammatory disease treated with canakinumab. Although our patient had a relatively long medical history and greater amounts of proteinuria than other reported cases, canakinumab had great efficacy on renal impairment, in similar to other reported cases. Along with the first report of a late-onset I574F somatic mosaic mutation in NLRP3-associated autoinflammatory disease, this report demonstrates the effectiveness of canakinumab on renal amyloidosis, probably through the way that IL-1β blockade minimizes podocyte injury.

The differential diagnosis of IgG4-related disease based on machine learning

INTRODUCTION

To eliminate the disparity and maldistribution of physicians and medical specialty services, the development of diagnostic support for rare diseases using artificial intelligence is being promoted. Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a rare disorder often requiring special knowledge and experience to diagnose. In this study, we investigated the possibility of differential diagnosis of IgG4-RD based on basic patient characteristics and blood test findings using machine learning.

METHODS

Six hundred and two patients with IgG4-RD and 204 patients with non-IgG4-RD that needed to be differentiated who visited the participating institutions were included in the study. Ten percent of the subjects were randomly excluded as a validation sample. Among the remaining cases, 80% were used as training samples, and the remaining 20% were used as test samples. Finally, validation was performed on the validation sample. The analysis was performed using a decision tree and a random forest model. Furthermore, a comparison was made between conditions with and without the serum IgG4 concentration. Accuracy was evaluated using the area under the receiver-operating characteristic (AUROC) curve.

RESULTS

In diagnosing IgG4-RD, the AUROC curve values of the decision tree and the random forest method were 0.906 and 0.974, respectively, when serum IgG4 levels were included in the analysis. Excluding serum IgG4 levels, the AUROC curve value of the analysis by the random forest method was 0.925.

CONCLUSION

Based on machine learning in a multicenter collaboration, with or without serum IgG4 data, basic patient characteristics and blood test findings alone were sufficient to differentiate IgG4-RD from non-IgG4-RD.

Self-limited Polymyalgia Rheumatica-like Syndrome Following mRNA-1273 SARS-CoV-2 Vaccination

Polymyalgia rheumatica (PMR) is an inflammatory rheumatic disease characterized by stiffness and aching mainly in the shoulders, neck and hip girdles. The underlying pathogenesis of PMR involves myeloid lineage activation with a high expression of pattern recognition receptors. In addition, vaccination against severe acute respiratory syndrome coronavirus 2 with mRNA-1273 functions as both an immunogen and intrinsic adjuvant. It leads to the activation of innate immunity, resulting in antibody production. We herein report the first case of PMR-like syndrome seven days after mRNA-1273 vaccination. Reassuringly, the symptoms, such as pain of the neck, shoulder girdle and pelvic girdle, as well as elevated inflammatory markers were resolved within a month without glucocorticoid or immunosuppressant administration.

Rheumatoid arthritis in a patient with compound heterozygous variants in the COL11A2 gene and progressive hearing loss: A case report

RATIONALE

Collagen type XI alpha 2 chain is a component of type XI collagen and is expressed in various tissues including articular cartilage and tectorial membrane of the cochlea. Variants in the COL11A2 gene, which encodes collagen type XI alpha 2 chain, has been reported to cause hearing loss and has been associated with osteoarthritis and ossification of the posterior longitudinal ligament of the spine. Despite the importance of type XI collagen in the joints, association of rheumatoid arthritis (RA) with COL11A2 has not been reported.

PATIENT CONCERNS

The patient is a 60-year-old female, born to Japanese parents of no known consanguinity. She had progressive hearing loss since childhood. Her father also had progressive hearing loss before middle age. She developed joint pain in the knees and the hips in her forties. When she was 56, she developed polyarthritis. Rheumatoid factor and anti-CCP antibodies were positive.

DIAGNOSES

She was diagnosed with osteoarthritis and RA. Whole exome analysis detected 2 rare variants, c.4201C>T, p.(Arg1401Trp) and c4265C>T, p.(Pro1422Leu), in the COL11A2 gene (NM_080680.2). Whole genome analysis with a long insert size confirmed 2 variants that are in trans.

INTERVENTIONS AND OUTCOMES

She received a cochlear implant, which improved her hearing. She was treated with methotrexate, golimumab, tocilizumab, and upadacitinib with partial responses for her RA.

LESSONS

We herein report a patient with RA with compound heterozygous variants in the COL11A2 gene. Autoantibodies against type XI collagen are detected in the sera of patients with RA, suggesting the possibility that type XI collagen may be involved in the pathogenesis of RA as an autoantigen. The hearing loss and osteoarthritis in this patient may be due to the compound heterozygous variants in the COL11A2 gene, and the conformational changes induced by the variants may have changed the immunogenicity of type XI collagen, leading to the development of RA.

Dysregulation of the gene signature of effector regulatory T cells in the early phase of systemic sclerosis

OBJECTIVES

We evaluated flow-cytometric and transcriptome features of peripheral blood immune cells from early-phase (disease duration < 5 years) systemic sclerosis (SSc) in comparison to late-phase SSc.

METHODS

Fifty Japanese patients with SSc (12 early SSc cases and 38 late SSc cases) and 50 age- and sex-matched healthy controls were enrolled. A comparison of flow-cytometric subset proportions and RNA-sequencing of 24 peripheral blood immune cell subsets was performed. We evaluated differentially expressed genes (DEGs), characterized the co-expressed gene modules, and estimated the composition of subpopulations by deconvolution based on single-cell RNA-sequencing data. As a disease control, idiopathic inflammatory myositis (IIM) patients were also evaluated.

RESULTS

Analyzing the data from early and late SSc, Fraction II effector regulatory T cell (Fr. II eTreg) genes showed a remarkable differential gene expression, which was enriched for genes related to oxidative phosphorylation. Although the flow-cytometric proportion of Fr. II eTregs was not changed in early SSc, deconvolution indicated expansion of the activated subpopulation. Co-expressed gene modules of Fr. II eTregs demonstrated enrichment of the DEGs of early SSc and correlation with the proportion of the activated subpopulation. These results suggested that DEGs in Fr. II eTregs from patients with early SSc were closely associated with the increased proportion of the activated subpopulation. Similar dysregulation of Fr. II eTregs was also observed in data from patients with early IIM.

CONCLUSIONS

RNA-seq of immune cells indicated the dysregulation of Fr. II eTregs in early SSc with increased proportion of the activated subpopulation.

Anti-Ku Antibody-Positive Myositis Presenting as a Wide Range of Axial Myopathies and Myocarditis: A Case Report and Review of the Literature

Idiopathic inflammatory myopathies (IIMs) are autoimmune diseases predominantly affecting proximal muscles; paraspinal muscle involvement is relatively rare. Because paraspinal myopathies do not always cause clinically-evident symptoms, the diagnosis of IIMs with axial myopathies can be challenging. Anti-Ku autoantibodies, initially reported in polymyositis/systemic sclerosis overlap syndrome, are myositis-associated antibodies (MAAs) observed in patients with a wide variety of connective tissue diseases (CTDs). Few reports have been published demonstrating predominant axial myopathy in IIM patients with anti-Ku antibodies. Herein, we investigated a previously healthy Japanese woman in her early 70s who presented with Raynaud's phenomenon, back pain, and exertional dyspnea. The creatine kinase (CK) was elevated and antinuclear antibody staining was positive, but myositis-specific antibodies (MSAs) were negative. Magnetic resonance imaging (MRI) revealed myocarditis and a wide range of axial muscle inflammation, including bilateral thoracolumbar paraspinal, infraspinatus, and trapezius muscles. The muscle biopsy was consistent with IIM. In addition, anti-Ku antibody was positive. Administration of prednisolone and tacrolimus quickly alleviated the symptoms and the CK level returned to normal. The diagnosis of IIM was arduous in this case because she did not present with camptocormia, muscle weakness involving the proximal limbs was not apparent, and MSAs were negative. Whether axial myopathy and myocarditis are more prevalent in IIM patients with than without anti-Ku antibodies is uncertain. Clinicians should suspect axial myopathy and MAAs, such as anti-Ku antibodies, especially in patients in whom muscle weakness of the proximal limbs is not noticeable.

Immature platelet levels correlate with disease activity and predict treatment response of thrombocytopenia in lupus patients

OBJECTIVE

The immature platelet fraction (IPF) represents recently produced platelets in bone marrow and this parameter is increased in patient with primary immune thrombocytopenia (ITP). We investigated the associations between IPF and absolute immature platelet count (AIPC), and clinical parameters in systemic lupus erythematosus (SLE), which has more complex pathological mechanisms than in primary ITP.

METHODS

Patients with SLE were retrospectively reviewed at the University of Tokyo Hospital from May, 2012 to January, 2021. The correlations between clinical parameters and the number of immature platelets were assessed with Spearman's rank correlation coefficients. A multiple logistic regression model was used to identify the independent clinical parameters for IPF and AIPC. The difference in the distribution of time for a complete response (CR) after prednisolone (PSL) administration was also evaluated by log-rank test.

RESULTS

A total of 282 SLE patients were enrolled, and 12.41% of those patients showed thrombocytopenia. IPF correlated with clinical parameters such as platelet count (r = -0.58), AIPC (r = 0.64) and systemic lupus erythematosus disease activity index 2000 (SLEDAI-2K) (r = 0.24). SLEDAI-2K [odds ratio (OR) (per unit increase), 1.07; 95% CI, 1.013 - 1.13] and thrombocytopenia (OR, 32.23; 95% CI, 11.072 - 93.80) were independent clinical parameters to account for IPF increase. IPF correlated with the number of bone marrow megakaryocytes (n = 19, r = 0.57). Notably, the probability of CR in response to PSL in AIPC-high patients was higher than in AIPC-low patients (hazard ratio, 4.62; 95% CI, 1.07 - 20.02).

CONCLUSION

IPF correlated with disease activity of SLE and represented platelet production in the bone marrow, whereas AIPC predicted a rapid response to steroids in thrombocytopenic patients with SLE.

Dynamic landscape of immune cell-specific gene regulation in immune-mediated diseases

Genetic studies have revealed many variant loci that are associated with immune-mediated diseases. To elucidate the disease pathogenesis, it is essential to understand the function of these variants, especially under disease-associated conditions. Here, we performed a large-scale immune cell gene-expression analysis, together with whole-genome sequence analysis. Our dataset consists of 28 distinct immune cell subsets from 337 patients diagnosed with 10 categories of immune-mediated diseases and 79 healthy volunteers. Our dataset captured distinctive gene-expression profiles across immune cell types and diseases. Expression quantitative trait loci (eQTL) analysis revealed dynamic variations of eQTL effects in the context of immunological conditions, as well as cell types. These cell-type-specific and context-dependent eQTLs showed significant enrichment in immune disease-associated genetic variants, and they implicated the disease-relevant cell types, genes, and environment. This atlas deepens our understanding of the immunogenetic functions of disease-associated variants under in vivo disease conditions.

Intestinal ulcers induced by intravesical bacillus Calmette-Guérin therapy

Intravesical bacillus Calmette-Guérin (iBCG) therapy, one of the established treatments for bladder carcinoma, is known for its association with adverse events, including rheumatic manifestations. We describe the case of a 72-year-old man with synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome who developed inflammatory bowel disease unclassified after iBCG therapy for bladder carcinoma. The critical role of the IL-23/IL-17 axis in the pathogenesis IBD and all the domains of SAPHO syndrome has been reported previously. In the present case, the activation of the IL-23/IL-17 axis, probably due to the disease, could have been exacerbated by iBCG therapy, as observed in mice that received BCG immunotherapy. We suggest that patients with rheumatic diseases on iBCG therapy should be observed carefully since iBCG could be a contributing factor for autoimmune pathology including IBD.

The Impact of Obesity and a High-Fat Diet on Clinical and Immunological Features in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with multiple organ involvement predominantly affecting women of childbearing age. Environmental factors, as well as genetic predisposition, can cause immunological disturbances that manifest as SLE. A habitual high-fat diet and obesity have recently been reported to play a role in the pathogenesis of autoimmune diseases. The frequency of obesity is higher in patients with SLE than in general populations. Vitamin D and adipokines, such as leptin and adiponectin, are possible mediators connecting obesity and SLE. Serum leptin and adiponectin levels are elevated in patients with SLE and can impact innate and adaptive immunity. Vitamin D deficiency is commonly observed in SLE. Because vitamin D can modulate the functionality of various immune cells, we review vitamin D supplementation and its effects on the course of clinical disease in this work. We also discuss high-fat diets coinciding with alterations of the gut microbiome, or dysbiosis. Contingent upon dietary habits, microbiota can be conducive to the maintenance of immune homeostasis. A high-fat diet can give rise to dysbiosis, and patients who are affected by obesity and/or have SLE possess less diverse microbiota. Interestingly, a hypothesis about dysbiosis and the development of SLE has been suggested and reviewed here.

Fertility preservation in patients receiving gonadotoxic therapies for systemic autoimmune diseases in Japan

OBJECTIVES

Gonadotoxic therapies, mainly cyclophosphamide, are used for the treatment of various systemic autoimmune diseases. In Japan, the number of patients who undergo gonadotoxic therapy for autoimmune diseases, fertility preservation procedures performed in these patients, and problems associated with performing such procedures have not been reported. This study was performed to address these issues.

METHODS

A questionnaire was sent to Certified Educational Facilities of the Japanese Society of Rheumatology, and a single rheumatologist at each center completed the questionnaire.

RESULTS

A total of 63 facilities completed the questionnaire. Between April 2014 and March 2019, a total of 1302 men and premenopausal women had received gonadotoxic therapies for systemic autoimmune disease. Nearly half of the respondents reported that gonadotropin releasing hormone analog therapy was available in their area. However, the availability of other fertility preservation procedures was limited, and the number of patients undergoing fertility preservation procedures was limited. 85.7% of the respondents responded that measures to preserve fertility in patients receiving gonadotoxic therapies for autoimmune diseases were inadequate.

CONCLUSIONS

A substantial number of patients are receiving gonadotoxic therapies for the treatment of autoimmune diseases in Japan, and those patients may not be receiving adequate care regarding their fertility.

Limbic encephalitis in a patient with systemic lupus erythematosus successfully treated with high-dose glucocorticoids and intravenous cyclophosphamide therapy: the potential pathogenicity of anti-glutamate receptor antibodies

Limbic encephalitis (LE) is a clinically defined syndrome characterised by an acute or subacute impairment of short-term memory, seizures and psychiatric symptoms (i.e. depression, anxiety and hallucination). LE could come from certain conditions where the neuropsychiatric systemic lupus erythematosus (NPSLE) of the multiple central nervous system is layered. In this report, we describe a 46-year-old Japanese female with SLE that suddenly presented with seizures, sensory aphasia and pseudobulbar affect. She was diagnosed with severe NPSLE presenting clinical LE (LE-SLE) by excluding malignancies, infectious encephalitis and symptomatic epilepsy using diffusion-weighted magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT). The patient showed a rapid response to treatment with methylprednisolone pulses followed by high-dose prednisolone and intravenous cyclophosphamide. She had elevated anti-glutamate receptor antibodies (anti-GluRs) in her serum and cerebrospinal fluid (CSF) on admission, and the titres decreased to a normal range at a one-year follow up. Our case highlights the importance of measuring anti-neuron antibodies including anti-GluRs in NPSLE patients, and suggests that the reduction of these pathogenic autoantibodies in serum or CSF could be a prognostic marker.

Successful treatment by mycophenolate mofetil of subacute progressive interstitial lung disease associated with systemic lupus erythematosus

Symptomatic interstitial lung disease (ILD) is rare in systemic lupus erythematosus (SLE), and there is no established treatment for it. We report a case of subacute progressive ILD in a patient with SLE, which was successfully treated by mycophenolate mofetil. Mycophenolate mofetil may be a promising therapeutic choice for SLE-associated ILD.

A case of granulomatous myositis in a patient with rheumatoid arthritis receiving anti-TNF-α treatment

A 66-year old woman with a 14-year history of rheumatoid arthritis (RA) and uveitis was admitted to our department for evaluation of a mass in the left neck. Fourteen months prior to this admission the patient was started on golimumab. Serum creatine kinase (CK) level was elevated and myositis-specific and -associated antibodies were negative. Manual muscle test showed weakness in the neck flexor, sternocleidomastoid and deltoid muscles. Magnetic resonance imaging (MRI) of the neck, erector muscle of spine, breech, thigh and lower thigh demonstrated high-intensity lesions in the muscles in short-tau inversion recovery images. Electromyography in the right deltoid detected fibrillation potentials. Muscle biopsy from the left neck mass showed granulomatous myositis. Muscle weakness improved and CK levels normalized after discontinuation of golimumab. We report a case of granulomatous myositis under anti-TNF-α treatment for RA.