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Objectives: The aim of this article is to investigate the efficacy and safety of tocilizumab in Japanese patients with systemic sclerosis., Methods: Post hoc subgroup analysis of a global, randomised, controlled trial in patients treated with weekly tocilizumab 162 mg or placebo subcutaneously in a 48-week double-blind period (tocilizumab and placebo groups) followed by tocilizumab for 48 weeks in an open-label extension (continuous-tocilizumab and placebo-tocilizumab groups)., Results: Among 20 patients, 12 were randomised to tocilizumab (all had interstitial lung disease) and eight were randomised to placebo (six had interstitial lung disease). The modified Rodnan skin score improved in both treatment groups. The mean change in percent-predicted forced vital capacity was 3.3% [95% confidence interval (CI), -2.5 to 9.0] for tocilizumab and -3.8% (95% CI, -9.9 to 2.2) for placebo in the double-blind period and 2.0% (95% CI, -0.7 to 4.6) for continuous-tocilizumab and -1.4% (95% CI, -6.7 to 4.0) for placebo-tocilizumab in the open-label extension. Rates of serious adverse events per 100 patient-years were 19.3 for tocilizumab and 26.8 for placebo in the double-blind period and 0.0 for continuous-tocilizumab and 13.6 for placebo-tocilizumab in the open-label period., Conclusions: The efficacy and safety of tocilizumab in patients with systemic sclerosis were consistent between the Japanese subpopulation and the global trial population., (© Japan College of Rheumatology 2023. Published by Oxford University Press.)

Here we report the largest Asian genome-wide association study (GWAS) for systemic sclerosis performed to date, based on data from Japanese subjects and comprising of 1428 cases and 112,599 controls. The lead SNP is in the FCGR/FCRL region, which shows a penetrating association in the Asian population, while a complete linkage disequilibrium SNP, rs10917688, is found in a cis-regulatory element for IRF8. IRF8 is also a significant locus in European GWAS for systemic sclerosis, but rs10917688 only shows an association in the presence of the risk allele of IRF8 in the Japanese population. Further analysis shows that rs10917688 is marked with H3K4me1 in primary B cells. A meta-analysis with a European GWAS detects 30 additional significant loci. Polygenic risk scores constructed with the effect sizes of the meta-analysis suggest the potential portability of genetic associations beyond populations. Prioritizing the top 5% of SNPs of IRF8 binding sites in B cells improves the fitting of the polygenic risk scores, underscoring the roles of B cells and IRF8 in the development of systemic sclerosis. The results also suggest that systemic sclerosis shares a common genetic architecture across populations., (© 2024. The Author(s).)

Systemic sclerosis (SSc) is a rare and heterogeneous disease with no relevant environmental trigger or significant responsible gene. It has been and will continue to be difficult to identify large enough patients to conduct classic population-based epidemiologic exposure/non-exposure studies with adequate power to ascertain environmental and genetic risk factors for these entities. The complexity of pathogenesis and heterogeneity are likely to require personalized/precision medicine for SSc. Since several potential drugs are currently available for specific patients if not whole SSc, classification of SSc seems to form the foundation for a better therapeutic strategy. To date, SSc has been classified based on the extent/severity of the affected area as well as some disease markers, including the autoantibody profile. However, such an analysis should also lead to improvements in the design of appropriately stratified clinical trials to determine the effects and prediction of targeted therapies. An approach based on drug response preclinically conducted using patients' own fibroblasts in vitro , can provide a precise disease marker/therapeutic selection for clinical practice. Because scleroderma dermal fibroblasts have a persistent hyper-productive phenotype occurring not only in person, but also in cell culture conditions. Thus, an accumulating approach based on disease markers ensures progression and de-escalation to re-establish a better life with a personally optimized drug environment after the onset of SSc., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Komura, Yanaba, Bouaziz, Yoshizaki, Hasegawa, Varga, Takehara and Matsushita.)

Background: Systemic sclerosis (SSc) is a systemic autoimmune disease characterized by excessive fibrosis. FcγRIIB is a low-affinity receptor for the Fc fragment of IgG. FcγRIIB is expressed on the surface of various leukocyte subsets and signals negative feedback pathways to down-regulate B-cell antigen receptor signaling., Objective: The aim of the present study was to investigate the role of FcγRIIB in the development of a murine bleomycin-induced scleroderma model., Methods: The experimental fibrosis model was generated by the intradermal injection of bleomycin into wild-type (WT) and FcγRIIB-deficient (FcγRIIB -/- ) mice. We histologically assessed skin and lung fibrosis as well as inflammatory cell infiltration. Cytokine and chemokine expression levels were measured with RT-PCR., Results: The severity of fibrosis in the skin and lung was significantly worse in FcγRIIB -/- mice than in WT mice. In the skin of bleomycin-treated mice, the numbers of CD8 + T cells, F4/80 + macrophages, MPO + neutrophils, NK1.1 + NK cells, and B220 + B cells were significantly higher in FcγRIIB -/- mice than in WT mice. The expression of TNF-α and IL-1β was significantly higher in FcγRIIB -/- mice than in WT mice as was the expression of ICAM-1, CXCL2, and CCL3 in the affected skin. An adoptive transfer of splenic leukocytes from FcγRIIB -/- mice into WT mice showed exacerbated skin and lung fibrosis compared to WT mice without an adoptive transfer., Conclusion: These results indicate that FcγRIIB plays an inhibitory role in skin and lung fibrosis. Moreover, modulating FcγRIIB signaling has potential as a therapeutic approach for SSc., Competing Interests: Conflict of Interest The authors have declared no conflicts of interest., (Copyright © 2021 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.)

Bullous pemphigoid (BP) is a cutaneous autoimmune blistering disorder. Recently, it has been reported that dipeptidyl peptidase-4 inhibitors (DPP4i) is associated with the development of BP (DPP4i-BP). Patients with DPP4i-BP have autoantibodies (autoAbs) preferentially targeting full-length BP180, but not the BP180NC16a domain. In this report, we described a case of anti-BP230 antibody (Ab)-positive BP receiving DPP4i. A 78-year-old male with a medical history of type 2 diabetes receiving vildagliptin at 100 mg daily for 38 months was referred to our hospital with itching blisters on his body and extremities. Skin biopsy showed subepidermal bulla with eosinophil infiltration. Direct immunofluorescence staining revealed a linear staining pattern with complement C3 and IgG at the subepidermal basement membrane zone. By laboratory testing, autoAbs against BP180NC16a and full-length BP180 were negative by enzyme-linked immunosorbent assay (ELISA); however, anti-BP230 Abs were positive by ELISA (index: 123.91). His HLA genotype was DQB1*04:01 and 05:01. Based on these results, we diagnosed the patient with anti-BP230 Abs-positive BP associated with DPP4i. To the best of our knowledge, this is the first case of DPP4i-BP with only anti-BP230 Abs. Further accumulation of DPP4i-BP cases is needed to clarify the relationship between overall features of DPP4i-BP and anti-BP230 Abs.

Objective: To identify initial parameters that predict worsening of skin thickening in patients with diffuse cutaneous systemic sclerosis (dcSSc) using a multicentre, prospective, observational cohort in Japan., Methods: A total of 171 patients with dcSSc were selected from a prospective cohort database based on the following criteria: dcSSc, modified Rodnan total skin thickness score (mRSS) ≥7, disease duration <60 months, and valid mRSS data at one year. Worsening of skin thickness was defined as an increase in mRSS ≥3 points and an increase ≥25% from baseline to one year. Initial demographic and clinical parameters useful for predicting the progression of skin thickness were identified using univariate and multivariable analysis, and prediction models of skin thickening progression were built based on combinations of independent predictive parameters., Results: Only 23 patients (13.5%) experienced worsening mRSSs at one year. Short disease duration, low mRSS, absence of nailfold bleeding, arthritis, and a high erythrocyte sedimentation rate at diagnosis were identified as predictors of subsequent worsening of the mRSS even after adjusting for the treatment. Assessment of the best predictive model revealed that patients with a disease duration ≤12 months and mRSS ≤19 had a risk of mRSS worsening within one year, with a sensitivity of 73.9% and specificity of 81.1%., Conclusion: Identification of predictors of subsequent worsening of skin thickness in dcSSc patients is useful for identifying patients who require intensive treatment with potential disease-modifying agents and for improving clinical trial design by characterizing eligible progressors in the Japanese population.

Objectives: To investigate the clinical course of Japanese patients with early diffuse cutaneous systemic sclerosis (dcSSc) and early SSc with interstitial lung disease (ILD)., Methods: We prospectively analyzed the clinical features of 207 Japanese patients with early dcSSc (n = 150) and limited cutaneous SSc (lcSSc) with ILD (n = 57) in 10 medical centers every year for 7 consecutive years., Results: Mean modified Rodnan total skin thickness score (mRSS) was 18.3 and 67.4% of the cohort had ILD. Most patients started immunosuppressive therapy and vasodilators during 7 years (83.4% and 87.9%, respectively). Mean value of mRSS of total patients was significantly reduced from the initial registration after the first year. However, other parameters for physical function associated with skin sclerosis including fist closure, hand extension, and oral aperture were not so ameliorated during the study period. Health Assessment Questionnaire-disability index and serum KL-6 levels were constant throughout the course. Percent vital capacity and the presence of ILD, clinically suspected pulmonary arterial hypertension, and digital ulcers were gradually exacerbated during the period., Conclusion: In Japanese early dcSSc patients and SSc patients with ILD, mRSS was continuously reduced during 7 years of follow-up, but there was little improvement of physical disability and organ involvement.

Nail fold videocapillaroscopy (NVC) abnormalities are a characteristic finding of microangiopathy in dermatomyositis (DM). The aim of the present study was to examine long-term changes in NVC abnormalities and serum fibroblast growth factor 23 (FGF23) and vascular endothelial growth factor (VEGF) levels in DM patients with anti-melanoma differentiation-associated gene 5 (MDA5) antibody (Ab). Serum levels of FGF23 and VEGF were measured by enzyme-linked immunosorbent assay. NVC abnormalities were evaluated by capillaroscopy in 11 DM patients with anti-MDA5 Ab at baseline and after treatment. NVC abnormalities included irregularly enlarged capillaries, reduced capillaries, hemorrhages, capillary ramifications, disorganization of the vascular array, loss of capillaries and giant capillaries. Serum FGF23 levels were significantly decreased in patients with anti-MDA5 Ab (0.3 ± 0.3 pmol/L) compared with healthy controls (1.0 ± 0.6 pmol/L, P < 0.01). Serum FGF23 levels significantly increased after treatment (0.3 ± 0.3 vs 1.0 ± 0.7 pmol/L, P < 0.005), but serum VEGF levels were comparable between at baseline and after treatment. At baseline, irregularly enlarged capillaries were observed in 10 of 11 patients, but after treatment, they were significantly reduced in only two (91% vs 18%, P < 0.001). Hemorrhages were observed in all 11 patients at baseline, but disappeared in all after treatment (100% vs 0%, P < 0.001). These results suggest that NVC abnormalities are reversible by treatment and that serum FGF23 levels reflect the degree of microvascular damage in DM patients with anti-MDA5 Ab., (© 2020 Japanese Dermatological Association.)

Objective: We examined the efficacy and safety of nintedanib in Japanese patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD) in the global Safety and Efficacy of Nintedanib in Systemic Sclerosis (SENSCIS) trial., Methods: Randomised patients received oral nintedanib 150 mg ( N  = 34) twice daily or placebo ( N  = 36) until the last patient reached 52 weeks of treatment (up to 100 weeks). Data were analysed using a subgroup analysis model with Japanese and non-Japanese patients as subgroup variables., Results: In Japanese patients, the adjusted annual rate of forced vital capacity (FVC) decline over 52 weeks was -86.2 mL/year (nintedanib) and -90.9 mL/year (placebo); treatment difference, 4.67 mL/year (95% confidence interval, -103.28, 112.63). Treatment effect heterogeneity between Japanese and non-Japanese patients was not detected (treatment-by-visit-by-subgroup interaction; p  = .49). FVC decline was smaller for nintedanib versus placebo through 100 weeks in Japanese patients. The most commonly reported adverse events with nintedanib were gastrointestinal and liver disorder events; most were mild-to-moderate in severity., Conclusion: In both Japanese and non-Japanese patients with SSc-ILD, nintedanib slowed the progression of ILD, with no heterogeneity detected between the subgroups. The safety profile for nintedanib in Japanese patients was similar to that observed in patients with idiopathic pulmonary fibrosis (ClinicalTrials.gov: NCT02597933).

Eosinophilic fasciitis is a relatively rare cutaneous fibrotic condition affecting the deep fascia of the extremities, with or without peripheral blood eosinophilia. To examine the characteristics of Japanese patients with eosinophilic fasciitis, we conducted a brief, multicenter, retrospective survey at seven university hospitals. In total, 31 patients were identified as having eosinophilic fasciitis, among whom 30 patients fulfilled the Japanese diagnostic criteria. The male : female ratio was 2.3:1, and the mean age was 47.7 years. Three of the patients were under 20 years old. The possible triggering factors included muscle training, sports, walking or sitting for a long time, physical work, insect bite and drug. Co-occurrence of morphea was observed in nine cases (29%), and malignancies were associated in three (two hematological malignancies and one internal malignancy). Immunological abnormalities in the serum showed positive antinuclear antibody, positive rheumatoid factor, increased aldolase levels and increased immunoglobulin G levels. The patients were treated with either monotherapy or combination therapy by oral prednisolone (20-80 mg/day), methotrexate (6-10 mg/week), cyclosporin (100-150 mg/day), mizoribine, infliximab and phototherapy. Methylprednisolone pulse therapy was performed in six cases. By contrast, spontaneous improvement due to resting only was observed in two cases, and skin hardening was improved by withdrawal of the anticancer drug in one case. This study suggests several characteristics of Japanese patients with eosinophilic fasciitis, namely male predominance, rare pediatric occurrence, immunological abnormalities and coexistence with morphea. Systemic prednisolone is the first-line therapy, but pulse therapy is occasionally required for severe cases. The triggering events of physical stress are not so frequent as have previously been reported, and various factors or even unknown factors may be associated with the induction of eosinophilic fasciitis., (© 2020 Japanese Dermatological Association.)

Objective: Susceptibility genes that can account for characteristic features of SSc such as fibrosis, vasculopathy and autoimmunity remain to be determined. In mice, deficiency of Friend leukaemia integration 1 transcription factor (Fli1) causes SSc-like disease with these features. The human FLI1 gene contains (GA)n microsatellite, which has been shown to be associated with expression level. Because microsatellite polymorphisms are difficult to capture by genome-wide association studies, we directly genotyped FLI1 (GA)n microsatellite and examined its association with SSc., Methods: Genomic DNA from 639 Japanese SSc patients and 851 healthy controls was genotyped for (GA)n microsatellite using the fragment assay. The cut-off repeat number for susceptibility to SSc was determined by receiver operating characteristics (ROC) analysis. Association with susceptibility and clinical characteristics was examined using logistic regression analysis. FLI1 mRNA levels were determined using quantitative RT-PCR., Results: Based on the ROC analysis, (GA)n alleles with ≥22 repeats were collectively defined as L alleles and alleles with ≤21 repeats as S alleles. (GA)n L alleles were significantly associated with susceptibility to SSc (P = 5.0e-04, odds ratio 1.34, additive model). Significant association was observed both in diffuse cutaneous and limited cutaneous SSc. Among the SSc, (GA)n L alleles were significantly enriched in the patients with a modified Rodnan total skin thickness score ≥10 compared with those with a score <10. FLI1 mRNA levels were significantly decreased in healthy controls carrying (GA)n L alleles as compared with non-carriers., Conclusion: Extended repeat alleles of FLI1 (GA)n microsatellite may be associated with lower FLI1 mRNA levels and susceptibility to human SSc., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Introduction/objectives: A line blot (LB) assay is a multi-analyte platform capable of simultaneously detecting multiple anti-nuclear antibody specificities. Here, we evaluated the performance of a commercial LB assay developed for the identification of myositis- or systemic sclerosis (SSc)-related autoantibodies (autoAbs)., Method: We screened 300 serum samples from patients with various connective tissue diseases using an LB assay and compared the results of myositis- or SSc-related autoAbs with those identified by RNA and protein immunoprecipitation (IP) assays or indirect immunofluorescence (IIF)., Results: The IP assays revealed anti-Jo-1 Abs in 14 patients, anti-EJ Abs in 12, anti-PL-7 Abs in 8, anti-PL-12 Abs in 4, anti-Mi-2 Abs in 6, anti-SRP Abs in 8, anti-topoisomerase I Abs in 54, anti-RNA polymerase III Abs in 24, anti-U3 RNP Abs in 9, anti-Th/To Abs in 9, anti-Ku Abs in 14 and anti-hUBF Abs in 4, whereas IIF identified anti-centromere in 35. Good agreement between the IP assays and the LB assay was found only for anti-Jo-1 and anti-centromere antibodies. When a cut-off was adjusted to reconcile with the results of IP assays, the detection performance of LB assay was improved for anti-EJ, anti-PL-7, anti-PL-12, anti-SRP, anti-topoisomerase I and anti-RNA polymerase III Abs. However, the results of anti-Mi-2, anti-U3 RNP, anti-Th/To, anti-hUBF and anti-Ku Abs remained discordant between the LB assay and IP assays at all cut-off levels., Conclusions: Detection of myositis- or SSc-related autoAbs using a commercial LB assay requires great caution since it can yield analytically false-positive or false-negative results. Key Points • A line blot (LB) assay is a multi-analyte platform capable of simultaneously detecting multiple antibodies with anti-nuclear specificities. • Detection of myositis- or systemic sclerosis-related autoantibodies using a commercial LB assay requires great caution since it can yield analytically false-positive or false-negative results.

Objective: To examine the clinical features of systemic sclerosis (SSc) patients negative for SSc-related autoantibodies (autoAbs)., Methods: Serum samples were collected from 546 SSc patients. The presence of antinuclear antibody (ANA) was screened by indirect immunofluorescence (IIF) staining using HEp-2 cells. SSc-related autoantibodies were identified by specific IIF staining, enzyme-linked immunosorbent assay, or immunoprecipitation assay. Clinical features were analyzed among patients negative for ANA/SSc-related autoAbs, anticentromere Abs (ACA), anti-topoisomerase I (anti-topo I) Abs, and anti-RNA polymerase (anti-RNAP) Abs., Results: Of the 546 SSc patients, 26 (4.8%) were negative for ANA and 29 (5.3%) were ANA-positive but negative for SSc-related autoAbs. Regarding clinical features, patients negative for ANA/SSc-related autoAbs (n = 55) had a significantly shorter disease duration, higher proportion of the diffuse type, contracture of phalanges, diffuse pigmentation, higher modified Rodnan total skin thickness score (mRSS), and lower incidence of telangiectasia than those with ACA (n = 224). On the other hand, younger disease onset, lower mRSS, and lower incidence of scleroderma renal crisis were observed in patients negative for ANA/SSc-related autoAbs than in those with anti-RNAP Abs (n = 52). Although pitting scars were less common in patients negative for ANA/SSc-related autoAbs than in those with anti-topo I Abs (n = 144), their clinical features were similar., Conclusion: Patients negative for ANA/SSc-related autoAbs form a clinically distinct subset among SSc patients., (© 2020 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.)

Objective: To assess the functional disability in Japanese patients with systemic sclerosis (SSc) using the EuroQol-5-Domain-5-Level health questionnaire (EQ-5D-5L), which was developed in Europe to demonstrate the cost utility of treatments for non-specific diseases. Methods: The EQ-5D-5L and Disability Index of the Health Assessment Questionnaire (HAQ-DI), which is a questionnaire for the quality of life for rheumatic diseases, were completed by 109 Japanese patients with SSc, and the clinical findings and laboratory data were collected at the same time. Results: There was a correlation between the EQ-5D-5L score and HAQ-DI score. The EQ-5D-5L index score was affected by the % of predicted vital capacity (%VC), pulmonary arterial hypertension, and renal crisis. The %VC and renal crisis were also indicated as factors reducing the quality of life in the HAQ-DI. There was no difference in the EQ-5D-5L score between the SSc subtypes or among autoantibodies. Conclusion: Our single-center study demonstrated the EQ-5D-5L to be a valuable assessment tool for functional disability in Japanese SSc patients, similarly to the disease specific HAQ-DI.

Objective: The human leukocyte antigen (HLA) is the strongest genetic risk factor for idiopathic inflammatory myopathy (IIM), and different HLA alleles have been reported to be associated with IIM susceptibility among different ethnic groups. In this study, we have investigated HLA alleles associated with IIM in Japanese patients. Methods: Genotyping of HLA-DRB1 and DPB1 were performed in 252 Japanese IIM patients (166 dermatomyositis [DM] and 86 polymyositis [PM] patients) and the association was analyzed with comparison to controls ( n  = 1026 for DRB1 and n  = 413 for DPB1 ). Results: DRB1*08:03 was associated with IIM ( p  = 1.60 × 10 -5 , p c = .0005, odds ratio [OR] 2.11, 95% confidence interval [CI] 1.52-2.92) and DM ( p  = .0004, p c = .0128, OR 2.06, 95%CI 1.40-3.02). DPB1*05:01 was also associated with IIM ( p  = .0001, p c = .0021, OR 1.96, 95%CI 1.38-2.77) and DM ( p  = .0005, p c = .0075, OR 2.05, 95%CI 1.37-3.08). DRB1*09:01 ( p  = .0012, p c = .0368, OR 0.35, 95% CI 0.18-0.69) and DPB1*04:01 ( p  = .0004, p c = .0057, OR 0.05, 95% CI 0.00-0.85) were protectively associated with PM. Two locus analyses suggested that DRB1*09:01 and DPB1*04:01 were independently associated with PM. Conclusion: Protective associations of HLA were detected in Japanese PM patients.

Aim: Systemic sclerosis (SSc) is an autoimmune disease characterized by skin and lung fibrosis. Although SSc has a high mortality risk, an effective treatment for the disease has not been established yet. Mesenchymal stromal/stem cells (MSCs) are multipotential nonhematopoietic progenitor cells that have the ability to regulate immune responses. Adipose-derived stromal/stem cells (ASCs), one of the types of MSCs, have the advantage of accessibility and potent immunomodulatory effects when compared with other MSCs, such as bone marrow-derived MSCs. This study aimed to investigate the antifibrotic effect of ASCs in scleroderma mouse models, including bleomycin-induced scleroderma and sclerodermatous chronic graft-versus-host disease (Scl-cGVHD) models., Method: ASCs were intravenously administered to a bleomycin-induced scleroderma or Scl-cGVHD model on day 0. We compared the skin and lung fibrosis of scleroderma model mice between the ASC-treated group and control group., Results: Administration of ASCs attenuated the skin and lung fibrosis of bleomycin-induced scleroderma and Scl-cGVHD model mice compared to that in the control mice. Immunohistochemical staining showed that ASCs suppressed the infiltration of CD4 + , CD8 + T cells and macrophages into the dermis of bleomycin model mice compared to that in control mice. In addition, ASCs attenuated the messenger RNA expression of collagen and fibrogenic cytokines, such as interleukin (IL)-6 and IL-13, in the skin of bleomycin model mice. ASCs also reduced the frequency of fibrogenic cytokine-producing CD4 + T cells and effector B cells in the spleen of bleomycin model mice., Conclusion: ASCs could prove to be a potential therapeutic agent for use in patients with SSc., (© 2019 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.)

Background: Systemic sclerosis (SSc) is a systemic autoimmune disease that is characterized by excessive fibrosis. CD22 and CD72 are B cell-specific cell surface molecules that negatively regulate B cell function., Objective: The aim of the present study was to investigate the roles of CD22 and CD72 in a murine scleroderma model., Methods: The experimental fibrosis model was generated by subcutaneous injection of bleomycin or hypochlorous acid (HOCL) into wild-type (WT), CD22-deficient (CD22 -/- ), CD72-deficient (CD72 -/- ) and CD22 and CD72 double-deficient (CD22 -/- /CD72 -/- ) mice. We histologically assessed skin fibrosis and inflammatory cell infiltration. Cytokine and chemokine expression levels were measured by real-time polymerase chain reaction., Results: The severity of fibrosis in the skin and lung was significantly less in CD22 -/- , CD72 -/- , and CD22 -/- /CD72 -/- mice than in WT mice in the bleomycin-induced model. In the skin of bleomycin-treated mice, the numbers of CD3 + T cells, CD8 + T cells, and F4/80 + macrophages were significantly lower in CD22 -/- , CD72 -/- , and CD22 -/- /CD72 -/- mice than in WT mice. The expression levels of mRNAs for IL-6, TNF-α, TGF-β, CTGF, IL-1β, IL-13, CXCL2, and ICAM-1 were significantly lower in CD22 -/- , CD72 -/- , and CD22 -/- /CD72 -/- mice than in WT mice. In the HOCL-induced model, both skin and lung fibrosis were ameliorated in CD22 -/- , CD72 -/- and CD22 -/- /CD72 -/- mice compared to WT mice., Conclusion: These results indicate that CD22 and CD72 likely play crucial roles in skin and lung fibrosis. Moreover, the inhibition of CD22 and CD72 function has potential as a therapeutic approach to SSc., Competing Interests: Declaration of Competing Interest The authors have declared no conflicts of interest., (Copyright © 2019 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.)

The presence of anti-transcriptional intermediary factor (TIF)1-γ antibody (Ab) is associated with cancer in adult patients with clinically amyopathic dermatomyositis (CADM) or dermatomyositis (DM). In this study, we examined whether anti-TIF1-γ Ab levels are associated with disease activity in patients with CADM/DM. Anti-TIF1-γ Ab levels were examined in 23 patients with CADM or DM (CADM, n = 6; DM, n = 17). Baseline characteristics and outcomes were recorded, and serial measurements of anti-TIF1-γ Ab levels were obtained. Of the 23 patients with detectable anti-TIF1-γ Ab, 16 (70%) had an internal malignancy, while two (9%) had interstitial lung disease. Mean initial anti-TIF1-γ Ab levels (134 ± 47 index) were significantly decreased after 24 months (54 ± 45 index, P < 0.0001) and remained decreased thereafter. Anti-TIF1-γ Ab became negative (index value, <32) in 10 patients (43%) and remained positive (index value, ≥32) in 13 patients (57%) during the clinical course. The frequency of remission in the anti-TIF1-γ Ab-negative conversion group (100%) was significantly higher than in the sustained positive group (0%, P < 0.0001). Furthermore, mortality in the anti-TIF1-γ Ab-negative conversion group (0%) was significantly lower than that in sustained positive group (69%, P < 0.001). This study indicates that anti-TIF1-γ Ab levels are a useful and relevant surrogate marker of disease activity during follow-up monitoring., (© 2019 Japanese Dermatological Association.)

Patients with dermatomyositis (DM) frequently have myositis-specific autoantibodies (MSA), which are closely associated with different clinical features. Patients with anti-aminoacyl-tRNA synthetase antibody (ARS-Ab) and anti-melanoma differentiation-associated gene 5 (MDA5)-Ab often have interstitial lung disease (ILD). Recently, anti-MDA5-Ab levels have been shown to correlate with disease activity in DM patients. Thus, B cells that are stimulated by excess B-cell activating factor (BAFF) play an important role in the pathogenesis of DM through auto-Ab production. In this study, we investigated the role of BAFF in DM patients. We measured the serum BAFF levels in 56 adult DM patients (14 with anti-ARS-Ab, 18 with anti-MDA5-Ab, seven with anti-Mi-2-Ab and 17 with anti-transcriptional intermediary factor-1γ-Ab) . For a longitudinal study, 130 serum specimens from 10 DM patients with anti-MDA5-Ab were analyzed. Serum BAFF levels were significantly higher in DM patients than in healthy controls. DM patients with elevated serum BAFF levels more frequently had ILD. In subgroup analysis, DM patients with anti-ARS-Ab and DM patients with anti-MDA5-Ab exhibited increased BAFF levels compared with controls, while DM patients with other MSA showed BAFF levels comparable with controls. In the longitudinal study, serum BAFF levels in DM patients with anti-MDA5-Ab were decreased after immunosuppressive therapy along with serum levels of anti-MDA5-Ab and ferritin, which are biomarkers of disease activity. These results suggest that BAFF plays an important role in the pathogenesis of ILD in DM patients with anti-ARS and anti-MDA5-Ab. Furthermore, serum BAFF level is associated with disease activity in DM patients with anti-MDA5-Ab., (© 2019 Japanese Dermatological Association.)

Genome-wide association studies of systemic lupus erythematosus (SLE) in Chinese and Korean populations demonstrated strong association of single nucleotide polymorphisms (SNPs) located in the GTF2I-NCF1 region, rs73366469 (GTF2I), rs117026326 (GTF2I), rs80346167(GTF2IRD1) and rs201802880 (NCF1). This region has also been associated with susceptibility to Sjögren syndrome and rheumatoid arthritis; however, association studies with systemic sclerosis (SSc) and ANCA-associated vasculitis (AAV) have not been reported. Here we made an attempt to confirm their associations with SLE in the Japanese population, to find the primarily associated SNP, and to investigate whether these SNPs are also associated with susceptibility to SSc and AAV. By genotyping these four SNPs on 842 SLE, 467 SSc, 477 AAV patients and 934 healthy controls, striking association was confirmed in Japanese SLE. In addition, these SNPs were significantly associated with susceptibility to SSc, but not with AAV. Conditional logistic regression analysis revealed that the association of NCF1 rs201802880, a missense SNP encoding p.Arg90His, can account for the association of other SNPs by linkage disequilibrium. These results suggested that GTF2I-NCF1 region is associated with susceptibility to multiple autoimmune rheumatic diseases but not with AAV, and the primarily associated variant may be the missense SNP in NCF1.

A 75-year-old man presented with a 1-cm large elastic soft subcutaneous nodule on the left side of the umbilicus, which when excised showed presence of a helminthic form within the granulomatous lesions. Morphologically, the helminth was considered to be of the genus Dirofilaria, and the patient showed increased serum antibody titer against canine filaria. The partial DNA sequence of the mitochondrial 12S rRNA gene locus of this clinical isolate showed the highest nucleotide identity (89.6%) with Dirofilaria repens; however, the phylogenetic analysis addressed the haplotype and Dirofilaria ursi as outgroups of the clusters of D. repens and Dirofilaria immitis, which are the causal agents of most human dirofilariasis. As like bear filaria D. ursi, a wide variety of other carnivore-parasitizing filaria species have rarely been reported in humans. The newly detected genetic haplotype in this case may correspond to one of these species of Dirofilaria, though the genetic references are not available thus far., (© 2019 Japanese Dermatological Association.)

Objective: To evaluate the performance of a line blot (LB) assay for identifying anti-PM-Scl antibody (Ab)., Methods: We screened 56 serum samples from systemic sclerosis patients using a protein immunoprecipitation (IP) assay and an LB assay (Systemic Sclerosis Profile Euroline® Blot test kit) to detect anti-PM-Scl Ab. We compared the results obtained by the IP and LB assays., Results: Among the 56 serum samples of SSc patients, 9 sera were positive for anti-PM-Scl75 Ab and 1 for anti-PM-Scl100 Ab by the LB assay. The protein IP assay revealed that none of the samples precipitated 75 or 100 kDa proteins identical to the anti-PM-Scl Ab reference serum, regardless of the positive or negative results obtained in the LB assay. Therefore, the false-positive rates for both anti-PM-Scl75 Ab and anti-PM-Scl100 Ab by the LB assay were 100%., Conclusion: Detection of anti-PM-Scl Ab assessed with a commercial LB assay requires extreme caution since it may yield false-positive data., (© 2019 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.)

Background: Local type III hypersensitivity reactions are acute inflammatory events induced by immune complex (IC) deposition. CD22 and CD72 are B cell-specific cell surface molecules that negatively regulate B cell function., Objective: To elucidate the roles of CD22 and CD72 in the development of IgG-mediated type III hypersensitivity reactions., Method: The reverse Arthus reaction model in the skin was induced in mice lacking CD22 (CD22 -/- ), CD72 (CD72 -/- ), and both of them (CD22 -/- /CD72 -/- ). Edema at 4h and hemorrhage at 8h after IC challenge were evaluated. Inflammatory cell infiltration and cytokine and chemokine expression were also examined., Results: Edema and hemorrhage were significantly reduced in CD22 -/- /CD72 -/- mice compared with wild-type mice. The loss of both membrane proteins resulted in a greater decrease in edema at 4h, but not hemorrhage at 8h, than the loss of each protein alone. Infiltration of neutrophils, macrophages, and T cells, and the expression of TNF-α, IL-6, MIP-1α, and CCR5 mRNA were also diminished in the knockout mice compared to wild-type mice, and most significantly reduced in CD22 -/- /CD72 -/- mice. Regulatory T (Treg) cells in the spleen were significantly increased in all knockout mice at 4h. Significant differences in the severity of edema and hemorrhage between wild-type and knockout mice were lost when Treg cells were depleted in the knockout mice., Conclusion: These results demonstrate that CD22 and CD72 expression contribute to the development of the reverse Arthus reaction model and CD22 and CD72 might be therapeutic targets for human IC-mediated diseases., (Copyright © 2019 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.)

Objectives: In systemic sclerosis (SSc), B cell hyperactivation and abnormality are considered to play an important role in the disease pathophysiology. We aimed to clarify if the abnormal activation of B cells involves inhibitory FcγRIIB on B cells in SSc patients., Methods: Blood samples were collected from 76 SSc patients (38 limited cutaneous SSc and 38 diffuse cutaneous SSc) and 59 healthy controls. We evaluated the expression levels of FcγRIIB on different B cell subsets. B cells were classified into five subsets based on their surface phenotype as measured by flow cytometry: naïve B cells (CD19+IgD+CD27-), pre-switched memory B cells (CD19+IgD+CD27+), double-negative (DN) memory B cells (CD19+IgD-CD27-), switched memory B cells (CD19+IgD-CD27mid), and plasmablasts (CD19+IgD-CD27high). The expression levels of the activation markers CD80, CD86, and CD95 were also examined., Results: The expression levels of FcγRIIB on SSc naïve and DN memory B cells were significantly increased compared to healthy controls (p<0.05 and p<0.001, respectively). CD80, CD86, and CD95 expression levels were significantly higher in all five B cell subsets, except for CD80 in switched memory B cells and plasmablasts. Increased FcγRIIB expression levels on DN memory B cells were associated with disease activity as assessed by the European Scleroderma Study Group Activity Index, presence of interstitial lung disease (ILD), and reduced lung function. Intravenous cyclophosphamide pulse therapy decreased FcγRIIB expression levels on memory B cell subsets., Conclusions: SSc B cells may exhibit compensatory elevation in the expression levels of FcγRIIB in order to suppress the abnormal activation of B cells. In addition, FcγRIIB expression levels may serve as a marker of severe complications, such as ILD, in SSc.

In tumor immunity, the participation of IL-10-producing regulatory B cells (Bregs), which play an important role in suppressing immune responses, is unclear. In this study, we demonstrated an increase in B16F10 melanoma growth and a decrease in the proportion of IFN-γ- and TNF-α-secreting tumor-infiltrating CD8 + T cells in B cell-specific PTEN-deficient mice in which Bregs were expanded. The number of tumor-infiltrating Bregs significantly increased in B cell-specific PTEN-deficient mice. More than 50% of tumor-infiltrating B cells consisted of Bregs, predominantly CD19 + CD5 + CD43 + B1a Bregs, in both B cell-specific PTEN-deficient and control mice. Adoptive B1a B cell transfer, which includes >30% of Bregs, increased melanoma growth, whereas non-B1a B cell transfer, which includes <2% of Bregs, exhibited no effect. In addition, adoptive transfer of B1a B cells from wild-type mice, but not IL-10 -/- mice, exacerbated B16F10 melanoma growth. The current study indicates that B1a Bregs negatively regulate anti-melanoma immunity by producing IL-10 and reducing T helper 1 type cytokine production in tumor-infiltrating CD8 + T cells. Therefore, B1a Bregs can be a potentially novel target for immunotherapy of melanomas., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: Severe skin sclerosis in patients with systemic sclerosis (SSc) can result in a loss of hand function. The aim of this study is to examine the long-term changes of finger passive range of motion (ROM) in Japanese SSc patients treated with self-administered stretching., Methods: This is a single-center, retrospective, observational cohort study. Forty-three Japanese patients with SSc were given instructions on self-administered stretching. ROM was assessed using a goniometer on their first visit and after 1 year, 3 years, 5 years and 9 years. Hand function was assessed by the Health Assessment Questionnaire disability index (HAQ-DI) at their first visit and after 9 years., Results: Total passive ROM significantly improved in each finger after 3 years of finger stretching. Most patients (37 of 43 patients, 86%) improved or maintained total passive ROM and hand function within 9 years after their first visit. However, significant improvement of total passive ROM was lost in 6 of 43 SSc patients (14%) 9 years after their first visit. The HAQ-DI also was increased in these six patients. Multivariable analyses revealed that re-elevation of modified Rodnan total skin thickness score during the clinical course (OR = 5.260e + 7, 95% CI 1.52e + 150-uncalculated p = .0096) was the independent factor associated with deterioration of total passive ROM at 9 years., Conclusion: Patients with progressive skin sclerosis during the clinical course need multimodality therapy to maintain finger joint motion, since the effect of self-administered stretching is limited in these patients.

Sphingosine-1-phosphate (S1P), a lipid mediator, regulates lymphocyte migration between lymphoid tissue and blood. Furthermore, S1P participates in several physiological phenomena including angiogenesis, inflammation, immune regulation, and neurotransmitter release. Moreover, S1P/S1P receptor signaling involves in systemic sclerosis (SSc) pathogenesis. This study aimed to investigate whether the selective S1P 1 receptor modulator cenerimod attenuates murine sclerodermatous models. Cenerimod was orally administered to murine sclerodermatous chronic graft versus host disease (Scl-cGVHD) mice, either from day 0 to 42 or day 22 to 42 after bone marrow transplantation. Bleomycin-induced SSc model mice were administered cenerimod from day 0 to 28. Early cenerimod administration inhibited, and delayed cenerimod administration attenuated skin and lung fibrosis in Scl-cGVHD mice. Cenerimod suppressed the infiltration of CD4 + T cells, CD8 + T cells, and CD11b + cells into the inflamed skin of Scl-cGVHD mice as opposed to control mice. In contrast, cenerimod increased the frequency of regulatory T cells in the spleen and skin of Scl-cGVHD mice. Additionally, cenerimod attenuated the mRNA expression of extracellular matrix and fibrogenic cytokines in the skin. Furthermore, cenerimod attenuated bleomycin-induced fibrosis in the skin and lung. Hence, the selective S1P 1 receptor modulator cenerimod is a promising candidate for treating patients with SSc and Scl-cGVHD.

We established diagnostic criteria and severity classification of lichen sclerosus et atrophicus, because there is no established diagnostic criteria or widely accepted severity classification of the disease. Also, there is no clinical guideline for lichen sclerosus et atrophicus in Japan, so we proposed its clinical guideline. The clinical guidelines were formulated by clinical questions and recommendations on the basis of evidence-based medicine according to the New Minds Clinical Practice Guideline Creation Manual (version 1.0). We aimed to make the guidelines easy to use and reliable including the newest evidence, and to present guidance for various clinical problems in treatment of lichen sclerosus et atrophicus., (© 2017 Japanese Dermatological Association.)

We established diagnostic criteria and severity classification of eosinophilic fasciitis because there is no established diagnostic criteria or widely accepted severity classification of the disease. Also, there has been no clinical guideline for eosinophilic fasciitis, so we established its clinical guideline ahead of all over the world. In particular, the clinical guideline was established by clinical questions based on evidence-based medicine according to the New Minds Clinical Practice Guideline Creation Manual (version 1.0). We aimed to make the guideline easy to use and reliable based on the newest evidence, and to present guidance as specific as possible for various clinical problems in treatment of eosinophilic fasciitis., (© 2017 Japanese Dermatological Association.)

Systemic sclerosis (SSc) is an autoimmune disease characterized by skin and lung fibrosis. More than 90% of patients with SSc are positive for autoantibodies. In addition, serum B cell activating factor (BAFF) level is correlated with SSc severity and activity. Thus, B cells are considered to play a pathogenic role in SSc. However, there are two opposing subsets: regulatory B cells (Bregs) and effector B cells (Beffs). Interleukin-10 (IL-10)-producing Bregs negatively regulate the immune response, while IL-6-producing Beffs positively regulate it. Therefore, a protocol that selectively depletes Beffs would represent a potent therapy for SSc. The aims of this study were to investigate the roles of Bregs and Beffs in SSc and to provide a scientific basis for developing a new treatment strategy targeting B cells. A bleomycin-induced scleroderma model was induced in mice with a B cell-specific deficiency in IL-6 or IL-10. We also examined whether BAFF regulates cytokine-producing B cells and its effects on the scleroderma model. IL-6-producing Beffs increased in number and infiltrated the inflamed skin in the scleroderma model. The skin and lung fibrosis was attenuated in B cell-specific IL-6-deficient mice, whereas B cell-specific IL-10-deficient mice showed more severe fibrosis. In addition, BAFF increased Beffs but suppressed Bregs. Furthermore, BAFF antagonist attenuated skin and lung fibrosis in the scleroderma model with reduction of Beffs but not of Bregs. The current study indicates that Beffs play a pathogenic role in the scleroderma model, while Bregs play a protective role. BAFF inhibition is a potential therapeutic strategy for SSc via alteration of B cell balance.

We established diagnostic criteria and severity classification of localized scleroderma because there is no established diagnostic criteria or widely accepted severity classification of the disease. Also, there has been no clinical guideline for localized scleroderma, so we established its clinical guideline ahead of all over the world. In particular, the clinical guideline was established by clinical questions based on evidence-based medicine according to the New Minds Clinical Practice Guideline Creation Manual (version 1.0). We aimed to make the guideline easy to use and reliable based on the newest evidence, and to present guidance as specific as possible for various clinical problems in treatment of localized scleroderma., (© 2018 Japanese Dermatological Association.)

Several effective drugs have been identified for the treatment of systemic sclerosis (SSc). However, in advanced cases, not only their effectiveness is reduced but they may be also harmful due to their side-effects. Therefore, early diagnosis and early treatment is most important for the treatment of SSc. We established diagnostic criteria for SSc in 2003 and early diagnostic criteria for SSc in 2011, for the purpose of developing evaluation of each organ in SSc. Moreover, in November 2013, the American College of Rheumatology and the European Rheumatology Association jointly developed new diagnostic criteria for increasing their sensitivity and specificity, so we revised our diagnostic criteria and severity classification of SSc. Furthermore, we have revised the clinical guideline based on the newest evidence. In particular, the clinical guideline was established by clinical questions based on evidence-based medicine according to the New Minds Clinical Practice Guideline Creation Manual (version 1.0). We aimed to make the guideline easy to use and reliable based on the newest evidence, and to present guidance as specific as possible for various clinical problems in treatment of SSc., (© 2018 Japanese Dermatological Association.)

Localized scleroderma (LoS) involves dermal but not internal inflammation and fibrosis. Cosmetic changes often impact quality of life (QOL), however, impairment of activities of daily living (ADL) in LoS patients has not been investigated. To determine what factor(s) are associated with ADL in adult patients with LoS, we performed a retrospective observational study in 177 Japanese adult LoS patients using a novel LoS disability score based on Barthel's indices of ADL: feeding, bathing, grooming, dressing, bowels, bladder, toilet use, transfers, mobility and stairs. LoS disability scores increased in proportion to the number of affected body parts but were not correlated to age and duration of illness. The presence of leg lesions significantly impaired ADL of LoS patients compared with lesions on other body parts. Patients treated with systemic medications, who tended to have multiple lesions, presented higher LoS disability scores than those without systemic treatments. Our study proposes that physicians evaluate ADL, not only QOL, in LoS patients. Our findings using LoS disability scoring indicate that multiple affected body parts and leg lesions are risk factors for ADL impairment., (© 2018 Japanese Dermatological Association.)

Introduction: Systemic sclerosis (SSc) is an autoimmune disease characterized by excessive extracellular matrix deposition in the skin and internal organs. Three major abnormalities, autoimmunity, vasculopathy, and fibrosis, are considered to play important roles in the pathophysiology of SSc. SSc is a heterogeneous disease with clinical features, disease progress, therapeutic response, and prognosis. Therefore, identification of biomarkers, which can predict the course of the disease, is required for the progress of clinical practice. Areas covered: This review focuses on various SSc biomarkers for diagnosis, disease severity, and activity, as well as newly emerging and promising SSc biomarkers. Search was through PubMed and we focus on the papers in the last 5 years. Expert commentary: Biomarkers for SSc can be categorized into several groups: activity biomarker, severity biomarker, predictive biomarker, and biomarkers for specific clinical features (skin fibrosis, lung fibrosis, pulmonary arterial hypertension, peripheral vasculopathy, gastrointestinal, and malignancy). Some chemokines, such as CCL2 and CXCL4, have been identified as biomarkers of skin and lung fibrosis in SSc. In addition, anti-RNA polymerase III antibody has been noted to be a predictive biomarker of gastric antral vascular ectasia and malignancy.

Systemic sclerosis is a systemic autoimmune and connective tissue disorder associated with the human leukocyte antigen locus. However, the functional relationship between human leukocyte antigen gene(s) and disease development remains unknown. To elucidate major histocompatibility complex-linked systemic sclerosis genetics, we performed genotyping of major histocompatibility complex-borne microsatellites and HLA-DPB1 alleles using DNA obtained from 318 anti-topoisomerase I antibody-positive patients and 561 healthy controls, all of Japanese descent. Those results revealed two major histocompatibility complex haplotypes associated with systemic sclerosis. Exome sequencing and targeted analysis of these risk haplotypes identified rs17847931 in RXRB as a susceptibility variant (P = 1.3 × 10 -15 ; odds ratio [OR] = 9.4) with amino acid substitution p.V95A on the risk haplotype harboring HLA-DPB1∗13:01. No identical variant in the other haplotype including DPB1*09:01 was observed, though that haplotype also showed a significant association (P = 8.5 × 10 -22 ; OR = 4.3) with systemic sclerosis. Furthermore, the number of risk factors was shown to be a predominant factor, as individuals with two factors had elevated risk (P = 6.7 × 10 -13 ; OR = 30.2). We concluded that RXRB may be involved in antifibrotic activity in skin and chromatin remodeling., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: To classify Japanese patients with mild/early systemic sclerosis (SSc) by the 2013 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) Classification Criteria (new 2013 criteria)., Methods: We assessed 120 patients who visited Kanazawa University Hospital suspected of SSc and who did not meet the 1980 ACR preliminary classification criteria for SSc. We clinically diagnosed 16 patients with primary Raynaud's disease and 104 with mild/early SSc prior to being assessed by the new 2013 criteria., Results: None of the 16 patients with primary Raynaud's disease met the new 2013 criteria. On the other hand, 94 out of the 104 patients (90.3%) with mild/early SSc by our clinical diagnosis met the new 2013 criteria. Among the 94 SSc patients, sclerodactyly was detected in 58 (62%), puffy fingers in 62 (66%), abnormal nailfold capillaries in 89 (95%), Raynaud's phenomenon in 93 (99%), and SSc-related autoantibodies (Abs) in 85 (90%). The median (range) score of these 94 patients was 12 (9-14). Ten mild/early SSc patients who did not meet the new 2013 criteria had the following clinical features: puffy fingers in 1 (10%), abnormal nailfold capillaries in 8 (80%), Raynaud's phenomenon in 9 (90%), and SSc-related autoAbs in 8 (80%). The median (range) score of these 10 patients was 7 (5-8)., Conclusion: The new 2013 criteria can classify most mild/early Japanese SSc patients, which may contribute to early treatment interventions.

Objectives: Systemic sclerosis (SSc) is an autoimmune disease characterised by skin and systemic fibrosis culminating in organ damage. Previous genetic studies including genome-wide association studies (GWAS) have identified 12 susceptibility loci satisfying genome-wide significance. Transethnic meta-analyses have successfully expanded the list of susceptibility genes and deepened biological insights for other autoimmune diseases., Methods: We performed transethnic meta-analysis of GWAS in the Japanese and European populations, followed by a two-staged replication study comprising a total of 4436 cases and 14 751 controls. Associations between significant single nuclear polymorphisms (SNPs) and neighbouring genes were evaluated. Enrichment analysis of H3K4Me3, a representative histone mark for active promoter was conducted with an expanded list of SSc susceptibility genes., Results: We identified two significant SNP in two loci, GSDMA and PRDM1 , both of which are related to immune functions and associated with other autoimmune diseases (p=1.4×10 -10 and 6.6×10 -10 , respectively). GSDMA also showed a significant association with limited cutaneous SSc. We also replicated the associations of previously reported loci including a non-GWAS locus, TNFAIP3. PRDM1 encodes BLIMP1, a transcription factor regulating T-cell proliferation and plasma cell differentiation. The top SNP in GSDMA was a missense variant and correlated with gene expression of neighbouring genes, and this could explain the association in this locus. We found different human leukocyte antigen (HLA) association patterns between the two populations. Enrichment analysis suggested the importance of CD4-naïve primary T cell., Conclusions: GSDMA and PRDM1 are associated with SSc. These findings provide enhanced insight into the genetic and biological basis of SSc., Competing Interests: Competing interests: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)