Objective. To identify the 140-kd autoantigen recognized by anti-155/140 autoantibodies that are associated with adult cancer-associated dermatomyositis (DM) and juvenile DM and to determine the clinical relevance of anti-155/140 antibodies in a large cohort.Methods. Sera from 456 DM patients were assessed for the presence of anti-155/140 antibodies by immunoprecipitation using K562 cell extracts as substrate. Using immunoprecipitation and Western blotting, we then examined whether anti-155/140-positive sera recognized transcription intermediary factor 1␣ (TIF-1␣), TIF-1␤, and TIF-1␥. The clinical associations of antigen reactivity were also evaluated.Results. Anti-155/140-positive sera reacted with 140-kd TIF-1␣ in addition to 155-kd TIF-1␥. Among sera from 456 DM patients, 52 were reactive with both TIF-1␣ and TIF-1␥, while another 25 were reactive with TIF-1␥ alone. Additionally, 7 were reactive with TIF-1␤. Malignancy was more frequently found in adult patients with both anti-TIF-1␣ and anti-TIF-1␥ antibodies than in those with anti-TIF-1␥ antibodies alone (73% versus 50%; P < 0.05). In addition to juvenile DM patients and middle-aged and older DM patients with high percentages of malignancy, 8 "young adult" DM patients without malignancy had these autoantibodies.Conclusion. Anti-155/140 antibodies target TIF-1 family proteins, TIF-1␣ and TIF-1␤, in addition to TIF-1␥. Since TIF-1 proteins have significant roles in oncogenesis, these antibodies may be produced during misdirected antitumor immunity.Polymyositis (PM) and dermatomyositis (DM) are idiopathic inflammatory disorders that mainly affect the muscle and/or skin (1). Clinical manifestations of PM/DM are heterogeneous, with varying degrees of myositis, skin rash, and accompanying symptoms such as interstitial lung disease and internal malignancy. The association of malignancy with PM/DM, which is termed cancer-associated myositis, is well appreciated, particularly in patients with DM (2-6). Since malignant disease is one of the main causes of mortality in these patients, diagnosing occult cancer in them is important and challenging for clinicians.

Objectives. Myositis-specific autoantibodies (MSAs) are useful tools in identifying clinically homogenous subsets and predicting prognosis of patients with idiopathic inflammatory myopathies (IIM) including polymyositis (PM) and dermatomyositis (DM). Recent studies have revealed that anti-NXP2 antibody (Ab) is a major MSA in juvenile dermatomyositis (JDM). In this study, we evaluated the frequencies and clinical associations of anti-NXP2 Ab in adult IIM patients.Methods. Clinical data and sera were collected from 507 adult Japanese patients with IIM (445 adult DM, and 62 adult PM). As disease controls, 11 with JDM, 108 with systemic lupus erythematosus, 433 with systemic sclerosis, and 124 with idiopathic pulmonary fibrosis were assessed. Sera were examined for anti-NXP2 Ab by immunoprecipitation and Western blotting using polyclonal anti-NXP2 Ab.Results. Seven patients (1.6%) with adult DM and 1 (1.6%) with adult PM were positive for anti-NXP2 Ab. Except for 2 patients with JDM, no patients as disease controls were positive for this autoAb. Among 8 adult IIM patients, 3 had internal malignancies within 3 years of diagnosis of IIM. Another DM patient also had a metastatic cancer at the diagnosis. All of the carcinomas were advanced stage (stage IIIb-IV).Conclusions. While less common than in juvenile IIM, anti-NXP2 Ab was found in adult IIM. Anti-NXP2 Ab may be associated with adult IIM with malignancy.

Systemic sclerosis (SSc) is manifested by fibrosis, vasculopathy and immune dysregulation. So far, a unifying hypothesis underpinning these pathological events remains unknown. Given that SSc is a multifactorial disease caused by both genetic and environmental factors, we focus on the two transcription factors, which modulate the fibrotic reaction and are epigenetically suppressed in SSc dermal fibroblasts, Friend leukemia integration 1 (Fli1) and Krüppel-like factor 5 (KLF5). In addition to Fli1 silencing-dependent collagen induction, simultaneous knockdown of Fli1 and KLF5 synergistically enhances expression of connective tissue growth factor. Notably, mice with double heterozygous deficiency of Klf5 and Fli1 mimicking the epigenetic phenotype of SSc skin spontaneously recapitulate all the three features of SSc, including fibrosis and vasculopathy of the skin and lung, B cell activation, and autoantibody production. These studies implicate the epigenetic downregulation of Fli1 and KLF5 as a central event triggering the pathogenic triad of SSc.

Objective Fli-1, a potential predisposing factor for systemic sclerosis (SSc), is constitutively down-regulated in the lesional skin of patients with SSc by an epigenetic mechanism. To investigate the impact of Fli-1 deficiency on the induction of an SSc phenotype in various cell types, we generated bleomycin-induced skin fibrosis in Fli-1+/− mice and investigated the molecular mechanisms underlying its phenotypic alterations. Methods Messenger RNA (mRNA) levels and protein expression of target molecules were examined by quantitative reverse transcription–polymerase chain reaction and immunostaining. Transforming growth factor β (TGFβ) bioassay was used to evaluate the activation of latent TGFβ. The binding of Fli-1 to the target gene promoters was assessed with chromatin immunoprecipitation. Results Bleomycin induced more severe dermal fibrosis in Fli-1+/− mice than in wild-type mice. Fli-1 haploinsufficiency activated dermal fibroblasts via the up-regulation of αvβ3 and αvβ5 integrins and activation of latent TGFβ. Dermal fibrosis in Fli-1+/− mice was also attributable to endothelial-to-mesenchymal transition, which is directly induced by Fli-1 deficiency and amplified by bleomycin. Th2/Th17-skewed inflammation and increased infiltration of mast cells and macrophages were seen, partly due to the altered expression of cell adhesion molecules in endothelial cells as well as the induction of the skin chemokines. Fli-1+/− mouse macrophages preferentially differentiated into an M2 phenotype upon stimulation with interleukin-4 (IL-4) or IL-13. Conclusion Our findings provide strong evidence for the fundamental role of Fli-1 deficiency in inducing SSc-like phenotypic alterations in dermal fibroblasts, endothelial cells, and macrophages in a manner consistent with human disease.

Takahashi et al. find that epithelial cell–conditional knockdown of transcription factor Fli1 in mice drives systemic autoimmunity derived from thymic defects as well as selective tissue fibrosis in the skin and esophagus, mimicking human scleroderma. This study unravels the unanswered question about the origin of autoimmunity and selective tissue fibrosis in this disease.

These results suggest that sPD-1 and sPD-L2 contribute to disease development in SSc via the regulation of cognate interactions with T cells and B cells.

CXCL5 is a member of CXC chemokines with neutrophilic chemoattractant and pro-angiogenic properties, which has been implicated in the pathological angiogenesis of rheumatoid arthritis and inflammatory bowel diseases. Since aberrant angiogenesis is also involved in the developmental process of systemic sclerosis (SSc), we herein measured serum CXCL5 levels in 63 SSc and 18 healthy subjects and investigated their clinical significance and the mechanism explaining altered expression of CXCL5 in SSc. Serum CXCL5 levels were significantly lower in SSc patients than in healthy subjects. In diffuse cutaneous SSc (dcSSc), serum CXCL5 levels were uniformly decreased in early stage (<1 year) and positively correlated with disease duration in patients with disease duration of <6 years. In non-early stage dcSSc (≥1 year), decreased serum CXCL5 levels were linked to the development of digital ulcers. Consistently, the expression levels of CXCL5 proteins were decreased in dermal blood vessels of early stage dcSSc. Importantly, Fli1 bound to the CXCL5 promoter and its gene silencing significantly suppressed the CXCL5 mRNA expression in human dermal microvascular endothelial cells. Furthermore, endothelial cell-specific Fli1 knockout mice, an animal model of SSc vasculopathy, exhibited decreased CXCL5 expression in dermal blood vessels. Collectively, these results indicate that CXCL5 is a member of angiogenesis-related genes, whose expression is suppressed at least partially due to Fli1 deficiency in SSc endothelial cells. Since Fli1 deficiency is deeply related to aberrant angiogenesis in SSc, it is plausible that serum CXCL5 levels inversely reflect the severity of SSc vasculopathy.

Galectin-3 may be related to the developmental process of skin sclerosis in dcSSc and of DU and pulmonary vascular involvements in total SSc.