En Shu

Anti-desmoglein 3 (Dsg3) monoclonal antibodies deplete desmosomes of Dsg3 and differ in their Dsg3-depleting activities related to pathogenicity

Pemphigus vulgaris (PV) is an autoimmune blistering disease, characterized by the loss of cell-cell adhesion between epidermal keratinocytes and the presence of autoantibody against desmoglein 3 (Dsg3), which provides adhesive integrity to desmosomes between adjacent keratinocytes. We have previously shown that PV-IgG purified from patients depletes desmosomes of Dsg3. However, PV-IgG contains not only antibodies against a variety of different epitopes of Dsg3 but also against other unknown antigens. Therefore, we examined whether the Dsg3-depleting activity of PV-IgG is generated specifically by anti-Dsg3 activity in a human squamous cell carcinoma cell line (DJM-1) and normal human keratinocytes by using four different pathogenic and nonpathogenic monoclonal antibodies against Dsg3. We demonstrate that these monoclonal antibodies deplete cells and desmosomes of Dsg3, as PV-IgG does. Individual monoclonal anti-Dsg3 antibodies display characteristic limits to their Dsg3-depleting activity, which correlates with their pathogenic activities. In combination, these antibodies exert a cumulative or synergistic effect, which may explain the potent Dsg3-depleting capability of PV-IgG, which is polyclonal. Finally, although Dsg3-depletion activity correlated with AK-monoclonal antibody pathogenicity in mouse models, the residual level of Dsg3, when below ∼50%, does not correlate with the adhesive strength index in the present study. This may suggest that although the Dsg3 depletion is not indicative for adhesive strength, the level of Dsg3 can be used as a read-out of pathogenic changes within the cell and that the Dsg3 depletion from desmosomes plays an important role in skin fragility or susceptibility to blister formation in PV patients.

Intraperitoneal injection of pemphigus vulgaris-IgG into mouse depletes epidermal keratinocytes of desmoglein 3 associated with generation of acantholysis

Pemphigus vulgaris is an autoimmune blistering disease caused by antibodies against desmoglein (Dsg) 3. We previously reported that pemphigus vulgaris (PV)-IgG caused the formation of Dsg3-depleted desmosomes in normal human cultured keratinocytes and DJM-1, a human squamous cell carcinoma cell line. In the present study, we injected PV-IgG and normal human IgG into neonatal mice and examined the quantities of Dsg3 in the mouse skin. We showed that injection of PV-IgG into neonatal mice caused suprabasal blister formation and approximately 30% reduction of Dsg3 in mouse epidermal keratinocytes, compared to mice injected with normal human IgG. In addition, we showed that the quantity of Dsg3 in the skin of patients with PV did decrease, as compared to that in healthy volunteers. Our data suggests the reduction of Dsg3 might be relevant to blister formation. These results also suggest that even a partial depletion of Dsg3 may contribute to blistering in PV patients.

Lack of Plasminogen Activator Inhibitor-1 Enhances the Preventive Effect of DX-9065a, a Selective Factor Xa Inhibitor, on Venous Thrombus and Acute Pulmonary Embolism in Mice

We have studied the physiological effects of DX-9065a, a selective factor Xa (FXa) inhibitor, and heparin in experimental venous thrombus and acute pulmonary embolism. Moreover, the effects of these compounds were also evaluated under the condition of plasminogen activator inhibitor-1 (PAI-1) deficiency. A thrombus was induced in the murine femoral vein. The compounds prolonged the time to occlusion in a dose-dependent manner. Pulmonary embolism was induced by continuous induction of venous thrombi in the left jugular vein. The mortality of mice increased time-dependently. Histological evidence of thromboembolism in the lung was obtained in all mice. Treatment with DX-9065a, but not heparin, reduced the mortality at 6 h after initiation of venous thrombi. In separate experiments, pulmonary thromboembolism was induced in PAI-1 knockout mice. The mortality in PAI-1 knockout mice was reduced compared with that of wild-type mice. Moreover, when DX- 9065a was administered to PAI-1 knockout mice with pulmonary thromboembolism, mice survived well without marked bleeding. These findings indicate that the dual inhibition of coagulation FXa and PAI-1 could be beneficial in the treatment of acute pulmonary embolism.

The Antifibrotic Effect of α2AP Neutralization in Systemic Sclerosis Dermal Fibroblasts and Mouse Models of Systemic Sclerosis

Systemic sclerosis (SSc) is a connective tissue disease of autoimmune origin characterized by the fibrosis of skin and visceral organs, and peripheral circulatory disturbance. We recently demonstrated that α2-antiplasmin (α2AP), which is the physiological inhibitor of plasmin, is associated with the development of fibrosis. The aim of this study was to clarify the role of α2AP in the pathogenesis of SSc. The administration of α2AP in mice induced profibrotic changes, such as increased dermal thickness, collagen production, and myofibroblast differentiation. Conversely, the α2AP neutralization prevented not only profibrotic changes, but also the production of autoantibodies in bleomycin-induced mouse models of SSc. The expression of α2AP was elevated in dermal fibroblasts obtained from patients with SSc. Furthermore, α2AP treatment promoted profibrotic changes in human normal dermal fibroblasts, and α2AP neutralization reversed a profibrotic phenotype of SSc dermal fibroblasts, in the absence of plasmin. Our findings demonstrated that α2AP has a profibrotic effect probably not by the action as a plasmin inhibitor, and that the blocking of α2AP exerts an antifibrotic effect in humans and mice with SSc.

Recurrent superficial cellulitis‐like erythema associated with Helicobacter cinaedi bacteremia

1 Rapaport J. Primary chancriform syndrome caused by Nocardia brasiliensis. Arch Dermatol 1966; 93: 62–64. 2 Moore M, Conrad AH. Sporotrichoid nocardiosis caused by Nocardia brasiliensis. Arch Dermatol 1967; 95: 390–393. 3 Mitchell G, Wells GM, Goodman JS. Sporotrichoid Nocardia brasiliensis infection. Response to potassium iodide. Am Rev Respir Dis 1975; 112: 721–723. 4 Aozasa N, Kiso M, Kaneko T. Primary lymphocutaneous nocardiosis due to Nocardia brasiliensis which was successfully treated with only oral potassium iodide. J Dermatol 2011; 38: 826–828. 5 Dodiuk-Gad R, Cohen E, Ziv M et al. Cutaneous nocardiosis: report of two cases and review of the literature. Int J Dermatol 2010; 49: 1380–1385.

Primary localized cutaneous nodular amyloidosis that appeared in a patient with severe atopic dermatitis

Dear Editor, Primary localized cutaneous nodular amyloidosis (PLCNA) can occur on the skin of any part of the body and is clinically characterized by ovoid, shiny, pink-yellow nodules or plaques with a glossy appearance. Histological findings show amyloid deposition in the papillary and reticular dermis. We present a patient with severe atopic dermatitis treated with cyclosporine, who noticed two nodules with amyloid deposition stained with anti-immunoglobulin (Ig)G kappa light chain antibody. Two factors, atopic dermatitis and treatment with cyclosporine, might have affected the patient’s immunity, resulting in the amyloid deposition in the dermis. A 33-year-old Japanese man had a long history of severe atopic dermatitis, bronchial asthma and cataracts from childhood. There was no amyloidosis in his family history. He had been administrated 150 mg ⁄ day of cyclosporine for 7 years, to a total of approximately 330 g, which was effective against atopic dermatitis. He noticed a nodule on his left cheek in March 2008, which gradually enlarged. Another nodule appeared on the preauricular portion of his left cheek in September 2008. The first nodule was 2 cm · 2.5 cm in size, and the second one was 1.2 cm in diameter. The nodules were elastic, hard, glossy and orange-colored, but did not cause any pain or itching (Fig. 1). The patient’s laboratory data were as follows: leukocyte count, 5670 ⁄ lL; platelet count, 30.3 · 10 ⁄ lL; aspartate aminotransferase, 22 U ⁄ L; alanine aminotransferase, 22 U ⁄ L; lactate dehydrogenase, 184 U ⁄ L; blood urea nitrogen, 8 mg ⁄ dL; creatinine, 0.56 mg ⁄ dL; Ca, 9.5 mg ⁄ dL; C-reactive protein, 0.09 mg ⁄ dL; IgG, 1697 mg ⁄ dL; IgM, 86 mg ⁄ dL; IgA, 413 mg ⁄ dL; IgD, 0.9 mg ⁄ dL; and IgE radioimmunosorbent test (RIST), more than 16 000 IU ⁄ mL. Antinuclear antibody, anti-SS-A ⁄ Ro antibodyand anti-SS-B ⁄ La antibody were negative. We determined the serum light chain concentration using highperformance liquid chromatography, which demonstrated the following findings: kappa chain, 22.7 mg ⁄ L (standard range: 3.3– 19.4); lambda chain, 24.7 mg ⁄ L (5.7–26.3); and kappa ⁄ lambda ratio, 0.92 (0.26–1.65). The b2-microglobulin concentration in his urine was within the normal range, andnoBence–Jones proteinwas detected.Thepatient’sserumproteinprofile,anelectrocardiogram and chest X-ray were also normal. Neither laboratory data nor X-raysupported thediagnosisofmyelomaor gammopathy. Histological examination in hematoxylin–eosin stain showed that eosinophilic amorphous material was deposited nodularly in the dermis (Fig. 2a). The deposits were found to be congophilic (Fig. 2b) and were seen around the skin appendage and just beneath the flattened epidermis. In the immunochemical staining, the deposits were positive for human kappa light chain (Fig. 2c) but negative for human lambda light chain (Fig. 2d). Dense dermal infiltration of plasma cells and lymphocytes was observed, usually adjacent to the deposits. In the electron microscopic study, amyloid islets were observed around the vessels in the upper dermis (Fig. 2e), small fibrils were found among the elastic fibers at the dermoepidermal junction

Anti-p155/140 antibody-positive dermatomyositis with metastasis originating from an unknown site.

Dermatomyositis (DM) is a systemic inflammatory myopathy with characteristic cutaneous manifestations (a heliotrope rash, Gottrons papules, paronychial erythema and nailfold bleeding) and is often associated with interstitial lung disease and internal malignancy. Thus far, some autoantibodies specific for myositis have been discovered, including antibodies to aminoacyl-tRNA synthetases (ARS), anti-Mi-2 antibodies, anti-CADM 140 antibody, anti-p155/140 antibody and others (1-3). The various autoantibody-positive subgroups of DM vary in their clinical features. Of these myositis-specific autoantibodies, the anti-p155/140 antibody is a 155-kDa reactive nuclear protein relevant to cancer-associated DM (1, 4-8). However, the frequency of malignancies in patients with anti-p155/140 antibody is undefined because no large epidemiological studies have been undertaken. We describe here a patient with anti-p155/140 antibody-positive DM who had a poorly differentiated metastatic adenocarcinoma; however, the primary tumour could not be identified despite comprehensive examination.

MR imaging findings of pilomatricomas: a radiological–pathological correlation

Background Magnetic resonance imaging (MRI) findings of pilomatricomas have yet to be determined. Purpose To assess the correlation between MRI and pathological findings of pilomatricomas. Material and Methods MR images were obtained on patients with histologically proven pilomatricomas using a 1.5-T MR scanner. The images were retrospectively reviewed for size, signal intensity compared with skeletal muscles, and enhancement patterns. Furthermore, we assessed the presence of a reticular appearance, a ring-like appearance, and peritumoral fat stranding. Results We included 11 consecutive patients with 12 histologically proven pilomatricomas (3 boys/men, 8 girls/women; age range, 4–76 years; mean age, 20 years; median age, 14 years). The tumors were located in the head and neck (n = 6), upper extremities (n = 5), and lower extremities (n = 1). The maximum tumor diameter was in the range of 7–32 mm (mean, 16.5 mm). On T2-weighted (T2W) images, five tumors showed homogeneous hypointensity, whereas six showed reticular hyperintensity and one showed cystic hyperintensity. On fat-suppressed T2W images, nine tumors showed reticular hyperintensity, eight showed ring-like hyperintensity, and five showed peritumoral fat stranding. On fat-suppressed gadolinium-enhanced T1-weighted (T1W) images, one tumor showed no enhancement, whereas three showed reticular enhancement and five showed ring-like enhancement. Histologically, edematous and fibrous stroma was observed in 10 tumors, tumor capsules in 11, and inflammatory cell infiltration of the peritumoral fat tissue in nine. Conclusion MRI features of pilomatricomas included reticular and ring-like hyperintensities on fat-suppressed T2W images and reticular and ring-like enhancement on fat-suppressed gadolinium-enhanced T1W images.

Potential inhibition of development of rapidly progressive interstitial lung disease by prompt and sufficient immunosuppressive treatment in patients with anti‐melanoma differentiation‐associated gene 5 antibody‐positive dermatomyositis

Dear Editor, Anti-melanoma differentiation-associated gene (MDA)5 antibodies are considered to be related to amyopathic dermatomyositis (DM) and are associated with a high rate of rapidly progressive interstitial lung disease (RP-ILD), which usually requires intensive treatment and yet yields a poor prognosis. However, we found that not all patients with this antibody develop lethal ILD. We herein evaluated the clinical manifestations, laboratory findings, treatments and prognosis of six DM patients who tested positive for anti-MDA5 antibody by enzyme-linked immunoassay (Table 1). These patients were diagnosed and treated in the Department of Dermatology, Gifu University Hospital. This study was approved by the ethical review board of Gifu University School of Medicine (approval No. 25-382). Gottron’s sign and arthralgia were observed in all patients, whereas heliotrope rash was found in four patients. Patients who did not have heliotrope rash exhibited a seborrheic dermatitis-like rash or erythema adjacent to medial canthus. In most patients, skin rash was the first symptom and the interval between the onset of symptoms and the first hospital visit ranged from 2 weeks to 9 months, with most patients consulting a physician within 1–3 months after the onset of rash. Despite the lack of respiratory symptoms, interstitial lung disease (ILD) was observed in all of the patients. Four of the six patients showed lower reticular opacities with subpleural sparing and were therefore diagnosed with non-specific interstitial pneumonia (NSIP). The other two had organizing pneumonia (OP) with lower consolidation of the lungs. All of the patients were treated with a combination of corticosteroids (0.6–1 mg/kg per day) and immunosuppressive agents. Five patients also received i.v. steroid pulse therapy (1 g/day for 3 days consecutively) at the beginning of the treatment. Two patients experienced relapses of ILD; however, they improved after the dose of corticosteroids was increased. None of the patients developed RP-ILD or died of other complications during a follow-up period of 18– 112 months. In the present study, although ILD was not obvious at the onset of symptoms, it gradually became evident in most patients. Moreover, the serum levels of ferritin kept increasing even after the initiation of treatment, suggesting a strong potential for disease progression. However, no patients developed RP-ILD and all of them showed a good response to treatments. In comparison with previous reports, our patients seemed to have a milder course. Although the reason for this phenomenon is unknown, there

Sonographic Findings of Subcutaneous Sarcoidosis in 3 Cases

Subcutaneous sarcoidosis occurs infrequently among cases of cutaneous sarcoidosis. To our knowledge, few studies have described the sonographic characteristics of subcutaneous sarcoidosis. Here we report the sonographic characteristics of 3 cases of this condition. Our results revealed 4 features: (1) an irregular hypoechoic appearance, (2) heterogeneous echogenicity, (3) perilesional hyperechoic changes, and (4) abnormal Doppler signals. Sonography is a rapid, simple, and noninvasive procedure that is useful for initial evaluation of granulomatous lesions such as subcutaneous sarcoidosis.