IgG4-related skin disease, a mimic of angiolymphoid hyperplasia with eosinophilia.

Mikulicz's disease is considered one of the IgG4-related diseases that are characterized by elevated serum IgG4 concentrations and the immunohistochemical finding of IgG4-positive plasma cells. The IgG4-related diseases often exhibit a wide variety of eosinophil infiltration. A 66-year-old male with Mikulicz's disease developed multiple, nonpruritic, red papules on the left opisthotic region 2 years after diagnosis. A biopsy of the skin lesions revealed follicle-like formation in the dermis and subcutaneous tissue containing nodular lymphocytic infiltration with numerous eosinophils and plasma cells, predominately around venules, mimicking angiolymphoid hyperplasia with eosinophilia (ALHE). Immunohistochemically, most IgG-expressing plasma cells were positive for IgG4 (IgG4/IgG ratio = 72%). Our patient appeared to have a condition associated with the IgG4-related diseases. Caution should be exercised in diagnosing skin lesions of the IgG4-related diseases, which are confusingly similar in appearance and histology to ALHE.

A novel inhibitor of Smad-dependent transcriptional activation suppresses tissue fibrosis in mouse models of systemic sclerosis.

OBJECTIVE: Tissue fibrosis is a major cause of morbidity and mortality in systemic sclerosis (SSc), and an increasing number of promising molecular targets for antifibrotic therapies have been described recently. Transforming growth factor beta (TGFbeta) is well known to be the principal factor that leads to tissue fibrosis. The present study was undertaken to investigate the ability of HSc025, a novel small compound that antagonizes TGFbeta/Smad signaling through the activation of nuclear translocation of Y-box binding protein 1, to prevent tissue fibrosis in vitro or in mouse models of SSc. METHODS: Human dermal fibroblasts were exposed to HSc025 at various concentrations in the presence of TGFbeta, and levels of collagen or fibronectin expression were determined. HSc025 (15 mg/kg/day for 14 days) was administered orally to tight skin mice and to mice with bleomycin-induced pulmonary fibrosis. Improvement of tissue fibrosis was evaluated by histologic or biochemical examination in each model. RESULTS: Pretreatment with HSc025 prevented Smad-dependent promoter activation, in a dose-dependent manner; however, HSc025 had no effect on TGFbeta-induced phosphorylation of Smad3. The inhibitory effects of HSc025 on TGFbeta-induced collagen or fibronectin expression were also confirmed in vitro. Orally administered HSc025 significantly reduced hypodermal thickness and hydroxyproline content in tight skin mice, and markedly decreased the histologic score and hydroxyproline content in the lungs of bleomycin-treated mice. CONCLUSION: These results demonstrate that HSc025 is a novel inhibitor of TGFbeta/Smad signaling, resulting in the improvement of skin and pulmonary fibrosis. Orally available HSc025 might therefore be useful in the treatment of SSc.

Elevated serum levels of APRIL, but not BAFF, in patients with atopic dermatitis.

Elevated serum levels of B-cell-activating factor belonging to the tumor necrosis factor family (BAFF) and/or a proliferation-inducing ligand (APRIL) are shown in autoimmune diseases. We determined serum levels of BAFF and APRIL, and clinical association in patients with atopic dermatitis (AD). Serum levels of BAFF and APRIL from 35 patients with AD, 25 patients with psoriasis vulgaris, 25 patients with systemic lupus erythematosus and 25 normal healthy subjects were examined by enzyme-linked immunosorbent assay. Serum levels of APRIL, but not BAFF, were significantly elevated in patients with AD than in healthy controls or patients with psoriasis vulgaris. Patients with severe AD exhibited significantly increased APRIL levels compared to patients with moderate AD and mild AD, and serum APRIL levels were significantly decreased after treatment compared with those before treatment. In addition, increased APRIL levels were significantly associated with serum immunoglobulin E levels and blood eosinophil numbers. These results suggest that elevated serum levels of APRIL are associated with disease severity and activity in AD, and APRIL may have an important role in the pathogenesis of AD.

Endothelial selectins regulate skin wound healing in cooperation with L-selectin and ICAM-1.

Skin wound healing is mediated by inflammatory cell infiltration that is highly regulated by various adhesion molecules. Mice lacking intercellular adhesion molecule-1 (ICAM-1) delayed skin wound healing and mice lacking both L-selectin and ICAM-1 (L-selectin/ICAM-1(-/-)) show more delayed wound healing. Deficiency of both endothelial selectins (E-selectin or P-selectin) also delays wound healing. However, the relative contribution and interaction of selectins and ICAM-1 to the wound healing remain unknown. To clarify them, repair of excisional wounds was examined in L-selectin/ICAM-1(-/-) mice, wild-type mice with both E- and P-selectin blockade, and L-selectin/ICAM-1(-/-) mice with both E- and P-selectin blockade. Wild-type mice with both E- and P-selectin blockade showed delayed wound healing that was comparable with that in L-selectin/ICAM-1(-/-) mice. Combined E- and P-selectin blockade in L-selectin/ICAM-1(-/-) mice resulted in more significant delay. Mice lacking or blocked for adhesion molecules also showed suppressed keratinocyte migration, angiogenesis, granulation tissue formation, leukocyte infiltration, and cytokine expression, including transforming growth factor-beta and interleukin-6. Application of basic fibroblast growth factor (bFGF) but not platelet-derived growth factor to the wounds significantly improved wound healing in L-selectin/ICAM-1(-/-) mice with both E- and P-selectin blockade. bFGF significantly increased the leukocyte infiltration and subsequent fibrogenic cytokine production, as well as keratinocyte migration, angiogenesis, and collagen synthesis despite the loss of four kinds of adhesion molecules. These results indicate that skin wound healing is regulated cooperatively by all selectins and ICAM-1 and may provide critical information for the therapy of skin wounds.

BAFF antagonist attenuates the development of skin fibrosis in tight-skin mice.

The tight-skin (TSK/+) mouse, a genetic model for systemic sclerosis (SSc), develops cutaneous fibrosis and autoimmunity. Although immunological abnormalities have been demonstrated in TSK/+ mice, the roles of B-cell-activating factor belonging to the tumor necrosis factor family (BAFF), a potent B-cell survival factor, have not been investigated. Serum BAFF levels in TSK/+ mice were examined by ELISA. Newborn TSK/+ mice were treated with BAFF antagonist, and then skin fibrosis of 8-week-old mice was assessed. Serum BAFF levels were significantly elevated in TSK/+ mice. Remarkably, BAFF antagonist inhibited the development of skin fibrosis, hyper-gamma-globulinemia, and the autoantibody production in TSK/+ mice. The skin from TSK/+ mice showed upregulated expressions of fibrogenic cytokines, such as IL-6 and IL-10, while BAFF antagonist significantly suppressed them. Reciprocally, BAFF antagonist augmented antifibrogenic cytokines, such as IFN-gamma, in the skin of TSK/+ mice. Furthermore, TSK/+ B cells with BAFF stimulation had a significantly enhanced ability to produce IL-6. The results suggest that BAFF/BAFF receptor system is critical for the development of skin fibrosis in TSK/+ mice and could be a potent therapeutical target.

Intercellular adhesion molecule-1 deficiency attenuates the development of skin fibrosis in tight-skin mice.

The tight-skin (TSK/+) mouse, a genetic model for systemic sclerosis, develops cutaneous fibrosis. Although a fibrillin 1 gene mutation and immunological abnormalities have been demonstrated, the roles of adhesion molecules have not been investigated. To directly assess roles of adhesion molecules in skin fibrosis, TSK/+ mice lacking L-selectin and/or ICAM-1 were generated. The deficiency of ICAM-1, but not L-selectin, significantly suppressed ( approximately 48%) the development of skin sclerosis in TSK/+ mice. Similarly, ICAM-1 antisense oligonucleotides inhibited skin fibrosis in TSK/+ mice. Although T cell infiltration was modest into the skin of TSK/+ mice, ICAM-1 deficiency down-regulated this migration, which is consistent with the established roles of endothelial ICAM-1 in leukocyte infiltration. In addition, altered phenotype or function of skin fibroblasts was remarkable and dependent on ICAM-1 expression in TSK/+ mice. ICAM-1 expression was augmented on TSK/+ dermal fibroblasts stimulated with IL-4. Although growth or collagen synthesis of TSK/+ fibroblasts cultured with IL-4 was up-regulated, it was suppressed by the loss or blocking of ICAM-1. Collagen expression was dependent on the strain of fibroblasts, but not on the strain of cocultured T cells. Thus, our findings indicate that ICAM-1 expression contributes to the development of skin fibrosis in TSK/+ mice, especially via ICAM-1 expressed on skin fibroblasts.

Clinical evaluation of anti-aminoacyl tRNA synthetase antibodies in Japanese patients with dermatomyositis.

OBJECTIVE: To investigate the distribution of anti-aminoacyl-tRNA synthetase (anti-ARS) antibodies among patients with autoimmune diseases, and to analyze the clinical features of patients with dermatomyositis (DM) with anti-ARS antibodies. METHODS: Serum samples from 315 patients with autoimmune diseases or related disorders who had visited Kanazawa University Hospital or affiliated facilities were assessed for anti-ARS antibodies by immunoprecipitation. In particular, the association between anti-ARS antibodies and clinical features was investigated in detail in patients with DM. RESULTS: Anti-ARS antibody was positive in 16 (29%) of 55 patients with DM, 2 (22%) of 9 patients with polymyositis, and 7 (25%) of 28 patients with idiopathic pulmonary fibrosis. Although anti-ARS antibody was detected with high frequency (63%, 15/24) in DM patients with interstitital lung disease (ILD), the incidence of anti-ARS antibody was very low (3%, 1/31) in DM patients without ILD. Anti-ARS antibody-positive patients with DM had significantly higher incidences of ILD (94% vs 23%) and fever (64% vs 10%) than the antibody-negative patients. Some immunosuppressive agents, in addition to oral corticosteroids, were required more frequently in the antibody-positive patients with DM than the antibody-negative patients (88% vs 26%). Although 60% of DM patients with ILD simultaneously developed ILD and myositis, ILD preceded myositis in 33% of patients. CONCLUSION: Among patients with DM, anti-ARS antibodies are found in a subset with ILD. DM patients with anti-ARS antibodies appear to have a more persistent disease course that requires additional therapy compared to those without anti-ARS antibodies.

Elevated serum BAFF levels in patients with localized scleroderma in contrast to other organ-specific autoimmune diseases.

Serum levels of B-cell activating factor belonging to the tumor necrosis factor family (BAFF), a potent B-cell survival factor, are elevated in patients with systemic autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis and systemic sclerosis (SSc). The objective of this study was to determine serum BAFF levels and relate the results to the clinical features in patients with organ-specific autoimmune diseases of the skin, such as localized scleroderma and autoimmune bullous diseases. Serum BAFF levels were examined by enzyme-linked immunosorbent assay in 44 patients with localized scleroderma, 20 with pemphigus vulgaris/pemphigus foliaceus, 20 with bullous pemphigoid and 30 healthy controls. Twenty patients with SSc and 20 with SLE were also examined as disease controls. Serum BAFF levels were elevated in localized scleroderma patients compared with healthy controls. Concerning localized scleroderma subgroups, patients with generalized morphea, the severest form of localized scleroderma, had higher serum BAFF levels than linear scleroderma or morphea patients. The BAFF levels of generalized morphea were comparable with those of SSc or SLE. Furthermore, serum BAFF levels correlated positively with antihistone antibody levels and the severity of skin lesion as well as the number of skin lesions. By contrast, serum BAFF levels were not significantly elevated in patients with pemphigus or pemphigoid. These results suggest that BAFF may be contributing to autoimmunity and disease development in localized scleroderma.

E- and P-selectins synergistically inhibit bleomycin-induced pulmonary fibrosis.

The development of bleomycin-induced lung injury, which is a model of pulmonary fibrosis, results from inflammatory cell infiltration, a process highly regulated by the expression of multiple adhesion molecules. Therefore, bleomycin-induced lung fibrosis was examined in E-selectin-/- mice, P-selectin-/- mice, and E-selectin-/- mice treated with anti-P-selectin monoclonal antibody (mAb) in comparison of wild-type mice. E-selectin-/- mice treated with anti-P-selectin mAb exhibited augmented lung fibrosis histologically, increased lung collagen deposition, and increased mortality compared to wild-type mice. Furthermore, lung interferon-gamma mRNA expression decreased in E-selectin-/- mice treated with anti-P-selectin mAb relative to wild-type mice, while tumor necrosis factor-alpha and interleukin-6 mRNA expression increased in these mice. Similar changes were observed in E-selectin-/- mice, albeit to a lesser extent than those treated with anti-P-selectin mAb. Remarkably, flow cytometric analysis revealed that the frequency of interferon-gamma-producing natural killer T (NKT) cells in the bronchoalveolar lavage was decreased in E-selectin-/- mice and E-selectin-/- mice treated with anti-P-selectin mAb compared with wild-type mice. Moreover, the majority of NKT cells expressed high levels of CXCR3, suggesting that NKT cell infiltration is also dependent on CXCR3 expression. These results suggest that E- and P-selectins synergistically inhibit lung fibrosis by promoting the recruitment of NKT cells.

B-lymphocyte depletion reduces skin fibrosis and autoimmunity in the tight-skin mouse model for systemic sclerosis.

Systemic sclerosis (scleroderma) is an autoimmune disease characterized by excessive extracellular matrix deposition in the skin. A direct role for B lymphocytes in disease development or progression has remained controversial, although autoantibody production is a feature of this disease. To address this issue, skin sclerosis and autoimmunity were assessed in tight-skin mice, a genetic model of human systemic sclerosis, after circulating and tissue B-cell depletion using an anti-mouse CD20 monoclonal antibody before (day 3 after birth) and after disease development (day 56). CD20 monoclonal antibody treatment (10 to 20 microg) depleted the majority (85 to 99%) of circulating and tissue B cells in newborn and adult tight-skin mice by days 56 and 112, respectively. B-cell depletion in newborn tight-skin mice significantly suppressed (approximately 43%) the development of skin fibrosis, autoantibody production, and hypergammaglobulinemia. B-cell depletion also restored a more normal balance between Th1 and Th2 cytokine mRNA expression in the skin. By contrast, B-cell depletion did not affect skin fibrosis, hypergammaglobulinemia, and autoantibody levels in adult mice with established disease. Thereby, B-cell depletion during disease onset suppressed skin fibrosis, indicating that B cells contribute to the initiation of systemic sclerosis pathogenesis in tight-skin mice but are not required for disease maintenance.

L-selectin and intercellular adhesion molecule-1 regulate the development of Concanavalin A-induced liver injury.

Concanavalin A (Con A)-induced hepatitis is a model for human T cell-mediated hepatitis. We evaluated the role of L-selectin and intercellular adhesion molecule-1 (ICAM-1) in this model by injecting Con A intravenously in mice lacking L-selectin (L-selectin-/-), ICAM-1 (ICAM-1-/-), or both (L-selectin/ICAM-1-/-). Blood and liver samples were collected 0, 8, 24, and 48 h after Con A treatment. Increases in plasma transaminase levels, which peaked 8 h after injection, were reduced significantly in L-selectin-/-, ICAM-1-/-, and L-selectin/ICAM-1-/- mice compared with wild-type mice. Liver necrosis was more strongly inhibited in ICAM-1-/- mice than in L-selectin-/- mice but was most prominently reduced in L-selectin/ICAM-1-/- mice, in parallel with decreased plasma transaminase levels. The reduced severity of hepatitis in the mutant mice correlated with decreases in numbers of liver CD4+ T cells but not numbers of CD8+ T cells or neutrophils. Following Con A treatment, L-selectin deficiency reduced liver mRNA expression of tumor necrosis factor-alpha, and ICAM-1 deficiency reduced expression of interleukin-4. By contrast, reductions in liver macrophage inhibitor protein-1alpha mRNA occurred in all mutant mice. These results indicate that L-selectin and ICAM-1 contribute cooperatively to the development of Con A-induced hepatitis by regulating leukocyte infiltration and subsequent cytokine production.

P-selectin glycoprotein ligand-1 is required for the development of cutaneous vasculitis induced by immune complex deposition.

Immune complex (IC)-induced tissue injury is mediated by inflammatory cell infiltration that is highly regulated by various adhesion molecules. To assess the contribution of P-selectin glycoprotein ligand-1 (PSGL-1) and selectins in the pathogenetic process, the cutaneous reverse-passive Arthus reaction was examined in mice treated with monoclonal antibodies (mAb) to PSGL-1 or P- and/or E-selectin. Edema and hemorrhage were significantly reduced in mice treated with anti-P-selectin mAb compared with control mice while they were not inhibited in mice treated with anti-E-selectin mAb. It is remarkable that blocking PSGL-1 by mAb resulted in significant, further reduction in edema and hemorrhage compared with blocking anti-P- or anti-E-selectin. However, blockade of E- and P-selectins exhibited more significant reduction relative to PSGL-1 blockade. The inhibited edema and hemorrhage paralleled reduced infiltration of neutrophils and mast cells. Reduced infiltration of neutrophils and mast cells was observed in the peritoneal Arthus reaction and was associated with the decreased production of tumor necrosis factor alpha and interleukin-6. The results of this study indicate that PSGL-1 contributes to the Arthus reaction mainly as a ligand of P-selectin and partly as a ligand of E- and/or L-selectin by regulating neutrophil and mast-cell recruitment and that PSGL-1 would be a therapeutic target for human IC-mediated diseases.