Systemic sclerosis

Systemic sclerosis (SSc) is a multisystem autoimmune disease characterized by vasculopathy and tissue fibrosis of the skin and various internal organs. A series of genetic and epidemiological studies have demonstrated that SSc onset is determined by the accumulation of predisposing factors related to environmental influences, while genetic factors affect the susceptibility to and the severity of this disease. This notion has been confirmed by recent advance in animal models. The initial trigger of SSc is believed to be autoimmune attacks to endothelial cells, which occur in individuals with the genetic susceptibility to autoimmune diseases and/or the cumulative exposure to certain SSc‐related environmental influences. Then, endothelial cells are aberrantly activated or damaged, leading to the development of vascular structural changes, such as destructive vasculopathy and proliferative obliterative vasculopathy, and tissue fibrosis. In parallel, inflammatory cells activate SSc fibroblasts and modify the metabolism of extracellular matrix by soluble factors and autoantibodies. Prior to or during these processes, SSc fibroblasts acquire the ability to selectively respond to profibrotic growth factors and cytokines, persistently producing excessive amount of extracellular matrix. SSc fibroblasts also modify immune responses, at least those of CD4⁺ T cells, in the microenvironment through the secretion of immune regulatory molecules. Thus, various types of individually activated cells interact with each other and coordinately drive an SSc‐specific disease cascade, leading to the development of unique clinical symptoms. This article provides an overview of the current understanding of the pathogenesis of SSc with the recent advance in the research field of this disease.     

Serum levels of anti‐Fcγ receptor IIB/C antibodies are increased in patients with systemic sclerosis

Systemic sclerosis (SSc) is a systemic autoimmune disorder that results in fibrosis of the skin and multiple internal organs. Although the precise mechanism is unknown, it appears to result from the overproduction of extracellular matrix proteins and aberrant immune activations. Receptors for the Fc region of immunoglobulin (Ig)G (FcγR) are members of the Ig superfamily that modulate both activation and inhibition of immune responses. FcγRIIB is the sole inhibitory member, which has an intrinsic cytoplasmic immunoreceptor tyrosine‐based inhibitory motif. The present study was undertaken to investigate the circulating concentrations of anti‐FcγRIIB/C antibodies (Ab) in patients with SSc. Serum levels of anti‐FcγRIIB/C Ab were significantly increased in patients with SSc compared to those in controls and in patients with localized scleroderma. Serum levels of anti‐FcγRIIB/C Ab in patients with limited cutaneous SSc were similar to those in patients with diffuse cutaneous SSc. Among SSc patients, serum levels of anti‐FcγRIIB/C Ab were increased in those with nail‐fold bleeding and decreased in those with diffuse pigmentation and calcinosis. These findings support the notion that increased serum anti‐FcγRIIB/C Ab levels are involved in aberrant immune responses in SSc.     

Sindbis Viral Vectors Transiently Deliver Tumor-associated Antigens to Lymph Nodes and Elicit Diversified Antitumor CD8+ T-cell Immunity

Tumors are theoretically capable of eliciting an antitumor immune response, but are often poorly immunogenic. Oncolytic viruses (OVs) have recently emerged as a promising strategy for the immunogenic delivery of tumor-associated antigens (TAAs) to cancer patients. However, safe and effective OV/TAA therapies have not yet been established. We have previously demonstrated that vectors based on Sindbis virus (SV) can inhibit tumor growth and activate the innate immune system in mice. Here, we demonstrate that SV vectors carrying a TAA generate a dramatically enhanced therapeutic effect in mice bearing subcutaneous, intraperitoneal, and lung cancers. Notably, SV/TAA efficacy was not dependent on tumor cell targeting, but was characterized by the transient expression of TAAs in lymph nodes draining the injection site. Early T-cell activation at this site was followed by a robust influx of NKG2D expressing antigen-specific cytotoxic CD8⁺ T cells into the tumor site, subsequently leading to the generation of long-lasting memory T cells which conferred protection against rechallenge with TAA-positive as well as TAA-negative tumor cells. By combining in vivo imaging, flow cytometry, cytotoxicity/cytokine assays, and tetramer analysis, we investigated the relationship between these events and propose a model for CD8⁺ T-cell activation during SV/TAA therapy.     

Possible pro‐inflammatory role of heparin‐binding epidermal growth factor‐like growth factor in the active phase of systemic sclerosis

Heparin‐binding epidermal growth factor (EGF)‐like growth factor (HB‐EGF) is a member of the EGF family growth factors, which affects multiple aspects of the wound healing process such as epithelialization, wound contraction and angiogenesis. In our study, we measured the serum HB‐EGF levels of 51 systemic sclerosis (SSc) patients, which showed a significant increase compared with those of 20 normal subjects. Further analysis revealed a positive correlation between the HB‐EGF level and pulmonary ground‐glass score but no correlation between the former and pulmonary fibrosis score. Other findings include: a significant increase of serum sialylated carbohydrate antigen KL‐6 levels and significant shortness of disease duration in the diffuse cutaneous SSc patients with elevated HB‐EGF levels; and significantly higher HB‐EGF levels in the presence of Raynaud's phenomenon, in that of telangiectasia, and in the absence of contracture of phalanges in all SSc patients. We then evaluated HB‐EGF mRNA levels of fibroblasts harvested from skin samples of the SSc patients and those of foreskin‐derived fibroblasts treated with transforming growth factor‐β, both of which were significantly higher than each control. In conclusion, we speculate that HB‐EGF plays a pro‐inflammatory role in the active skin and lung lesions of SSc.     

Cavernous hemangioma of the stomach: A case report and review of the literature

A cavernous hemangioma of the stomach in a 41-year-old Japanese man was reported. The patient had numerous hemorrhagic telangiectasias in the skin and was also diagnosed as having a submucosal tumor of the stomach by an incidental upper gastrointestinal X-ray study. Wedge resection of the stomach was performed. The tumor was located in the submucosal, proper muscular and subserosal layers. The resected specimen showed proliferation of vascular spaces lined with a layer of endothelial cells and filled with red blood cells together with a partially calcified thrombus. The histopathologic diagnosis was cavernous hemangioma of the stomach with calcified thrombus. The patient has been doing well for twenty years. We report the case and briefly review the literature. This study is supported in part by a Grant from Federation of National Public Service and Affiliated Personnel Mutual Aid Association, Tokyo, Japan.     

Serial evaluation of high-resolution computed tomography findings in patients with idiopathic pulmonary fibrosis in usual interstitial pneumonia

BACKGROUND: The development of well-matured fibrosis in usual interstitial pneumonia (UIP) is strongly associated with an unfavorable outcome of patients with idiopathic pulmonary fibrosis (IPF). However, differences in the rates of development are likely to result in variable clinical courses in IPF patients. OBJECTIVE: We tried to evaluate the progression of honeycombing and ground-glass opacity on CT using a scoring system, and to examine those serial changes in the clinical course of disease. METHODS: A hospital-based, retrospective cohort study. Twenty-three patients with IPF diagnosed as UIP by surgical lung biopsy were analyzed during the initial examination by scoring the presence of honeycombing (HC: range, 0-24) and ground-glass opacity (GG: range, 0-24) on CT scan. We also compared the serial changes observed in the CT scores (interval: 2-42 months, 2-6 examinations). RESULTS: (1) The serial change in the HC score in treated patients (n = 10) was similar to that in untreated patients (n = 16); (2) the HC score at the time of the initial examination and the rate of HC progression were both higher in the non-surviving patients (HC 12.3 +/- 3.7, mean +/- SD; deltaHC 4.2 +/- 1.3 per year) than in the surviving patients (HC 5.8 +/- 2.7; deltaHC 1.2 +/- 0.7 per year) (p < 0.05); (3) the GG score did not correlate with the HC score at any of the examinations; (4) the HC score was higher in the lower lung field than in the upper and middle lung fields. CONCLUSIONS: Scoring of the honeycombing and its serial changes using the high-resolution computed tomography scoring method was useful for predicting the prognosis in patients with IPF/UIP. Corticosteroid treatment did not prevent the progression of HC.