Takashi Hashimoto

Molecular diagnosis of anti-laminin 332 (epiligrin) mucous membrane pemphigoid

BackgroundMucous membrane pemphigoid is a group of chronic subepithelial autoimmune blistering diseases that mainly affect mucous membranes. Laminin 332-specific autoantibodies are present in approximately 1/3 of the patients, being associated with an increased risk of malignancy. Because of the severe complications, an early recognition of the disease allowing a timely therapy is essential. The gold standard methods for detection of laminin 332-specific autoantibodies, including the immunoprecipitation and immunoblotting are non-quantitative, laborious and restricted to a few specialized laboratories worldwide. In addition, the use of radioimmunoassays, although highly sensitive and specific, are laborious, expensive and tightly regulated. Therefore, there is a stringent need for a quantitative immunoassay for the routine detection of laminin 332-specific autoantibodies more broadly available to diagnostic laboratories. The aim of this study was to compare different antigenic substrates, including native, recombinant laminin 332 and laminin 332-rich keratinocyte extracellular matrix, for development of an ELISA to detect autoantibodies in mucous membrane pemphigoid.ResultsUsing a relatively large number of sera from MMP patients with well-characterized autoantibody reactivity we show the suitability of ELISA systems using laminin 332 preparations as adjunct diagnostic tools in MMP. While glycosylation of laminin 332 does not appear to influence its recognition by MMP autoantibodies, ELISA systems using both purified, native and recombinant laminin 332 demonstrated a high sensitivity and good correlation with the detection of autoantibodies by immunoblotting. ELISA systems using different laminin 332 preparations represent a feasible and more accessible alternative for a broad range of laboratories.ConclusionsOur findings qualify the use of immunoassays with the laminin 332-rich preparations as an ancillary diagnostic tool in mucous membrane pemphigoid.

Meta-analysis of the clinical and immunopathological characteristics and treatment outcomes in epidermolysis bullosa acquisita patients

BackgroundEpidermolysis bullosa acquisita (EBA) is an orphan autoimmune disease. Several clinical phenotypes have been described, but subepidermal blistering is characteristic of all variants. Limited data on clinical and immunopathological characteristics and treatment outcomes in EBA are available. To fill this gap, we collected this information from EBA cases, meeting current diagnostic criteria, published between 1971 and 2016.ResultsWe identified 1159 EBA cases. This number must be, however, interpreted with caution, as it is not possible to check for multiple reporting. The analysis of all cases indicated that EBA affects all age groups (median: 50xa0years, range: 1 to 94xa0years) at an equal gender distribution. Non-mechanobullous (non-MB) forms of EBA were observed in 55% of patients, whereas the mechanobullous variant (MB-EBA) or a combination of both variants was described in 38 or 7% of patients, respectively. Type VII collagen (COL7)-specific autoantibodies were primarily of the IgG isotype, but anti-COL7 IgA, IgM and IgE were also documented. Comparison of the 2 clinical EBA types showed a higher frequency of IgA deposits in non-MB EBA as opposed to MB EBA. Mucous membrane involvement was observed in 23% of patients, and 4.4% of cases were associated with other chronic inflammatory diseases. Of note, IgA deposits were more frequently observed in cases with mucous membrane involvement. Our analysis indicated that EBA is difficult to treat and that the choice of treatment varies widely. Chi square was applied to identify medications associated with complete remission (CR). Considering all EBA cases, intravenous immunoglobulin (IVIG, pu2009=u20090.0047) and rituximab (pu2009=u20090.0114) were associated with CR. Subgroup analysis demonstrated that no treatment was associated with CR for non-MB EBA, while IVIG (pu2009=u20090.003) was associated with CR in MB EBA.ConclusionsWithin the limitations of the study, we here document the clinical and immunopathological characteristics and treatment outcomes in a large cohort of EBA patients. The observed associations of single drugs with treatment outcome may serve as a guide to develop clinical trials.

Superficial Neutrophilic Dermatoses: From Subcorneal Pustular Dermatosis (Sneddon-Wilkinson Disease) to Intercellular IgA Dermatoses

Since the initial description of the subcorneal pustular dermatosis by Sneddon and Wilkinson in 1956 [1], our understanding of the pathophysiology of diseases associated with the accumulation of neutrophils in the epidermis and intraepidermal blistering has significantly evolved. Sneddon-Wilkinson disease is now regarded as condition belonging to the spectrum of neutrophilic dermatoses characterized by neutrophilic infiltration of the skin and potential extracutaneous involvement, such as Sweet syndrome and pyoderma gangrenosum [2–4]. This group of inflammatory conditions, which show considerable clinical and histological overlap, is frequently associated with systemic diseases. Recently, it has been suggested to use the term of superficial neutrophilic dermatoses for all neutrophilic diseases associated with intraepidermal neutrophil accumulation [5]. Intriguingly, there is a group of patients who develop a superficial neutrophilic disease very similar to Sneddon-Wilkinson disease, showing either subcorneal or intraepidermal pustule formation. However, in contrast to Sneddon-Wilkinson disease, these patients show characteristically IgA deposits on the cell surface of epidermal keratinocyte in a pemphigus-like pattern or more rarely linear deposits in the subcorneal zone.

Laminins in an in vitro anterior lens capsule model established using HLE B-3 cells

Cataracts are the most common eye disease to cause blindness in patients. The abnormal deposition of laminins (LMs) in the lens capsule and the disruption of capsular epithelium contribute to cataract development, although the mechanism by which this occurs is currently unclear. The present study aimed to reproduce HLE B-3 basement membranes (BMs) using HLE B-3 cells and to analyze the similarities of LM expression between HLE B-3 BMs and human anterior lens capsule (ALC). Immunohistochemistry (IHC), ELISA, western blot analysis and immunoprecipitation (IP)-western blot analysis were used to detect total LMs, LM trimers and 11 LM subunits in HLE B-3 cells, HLE B-3 BMs and human ALCs. In IHC staining, HLE B-3 cells and human ALCs were positive for LMs. In LM ELISA, all samples analyzed were positive for LMs. Western blot analysis detected all LM subunits except for LMγ3 in HLE B-3 cell lysate, 4 subunits (LMα4, LMα2, LMα1 and LMγ1) in HLE B-3 cell culture supernatant, 5 subunits (LMα4, LMα2, LMα1, LMβ3 and LMγ1) in HLE B-3 BMs, and 3 subunits (LMα4, LMγ2 and LMγ1) in human ALCs. The results of IP-western blot analysis revealed that the LM411 trimer was detected in HLE B-3 cell culture supernatant. These results indicated that HLE B-3 BMs were similar to human ALCs in terms of LM expression. Therefore, HLE B-3 BMs could be used as an in vitro ALC model to determine the role of LMs in ALC in the pathogenesis of cataracts and to select potential anti-cataract drugs.

Paraneoplastic pemphigus presenting lichen planus-like lesions

patch test was recommended but he refused. He did not want topical immunotherapy inducing an allergic response. Therefore, tofacitinib 5 mg twice daily was prescribed. After 1 month, hair growth first began at the area of contact dermatitis; this became more conspicuous after 2 months (Fig. 1b). After 5 months, complete regrowth was achieved (Fig. 1c) and was well-maintained during 4 additional months of tofacitinib administration. Then, the patient was lost to follow up. There is some evidence that contact dermatitis can help to treat AA. For example, the therapeutic effect of allergic contact dermatitis (ACD) from diphenylcyclopropenone on AA is wellknown. Similarly, ACD from wig adhesive tape demonstrated an incidental therapeutic effect on AA. Antigenic competition and alteration of the cytokine milieu during the resolution of ACD may ameliorate the follicular autoimmune reaction. A recent gene-level study supported this: negative immune regulation transcripts showed greater relative expression than activation transcripts during the resolution of ACD. These targets may be modulated by RNA interference to promote hair growth. Irritant contact dermatitis (ICD) can also induce hair growth in AA (e.g. anthralin), but its mechanism is less clear. Although early stage ACD is distinguished from ICD by the presence of a sensitization phase, later stage ACD in the elicitation phase manifests similarly to ICD, sharing cytokines and chemokines. Moreover, regulatory cytokines are produced to limit inflammation during repeated irritant application, which may regulate the autoimmune process of AA. Notably, either contact dermatitis or tofacitinib alone might have improved AA. However, we suspect that tofacitinib and contact dermatitis acted synergistically to restore hair growth because hair began to grow from the area of contact dermatitis only after tofacitinib administration. Tofacitinib significantly downregulates genetic expression of various pro-inflammatory mediators in the affected skin. Therefore, immune downregulation with tofacitinib might have acted as an RNA interference signal, encouraging the inhibition of follicular autoimmune reactions during the resolution of contact dermatitis. The reverse interaction is also plausible. Interestingly, we detected a similar phenomenon, wherein tofacitinib caused more rapid hair growth within psoriatic plaques in an AA patient with psoriasis. Unfortunately, we could not define the nature of the contact dermatitis because the patient refused a patch test. Although silicone is generally known as an inert material, several case reports of silicone-induced ACD exist. However, ICD is also possible because the lesion was limited to the contact site. To our knowledge, this is the first case report of the synergistic effect of contact dermatitis and oral tofacitinib in AA. Further accumulation of cases is necessary to elucidate details of their synergistic effects and mechanism of inducing hair growth.

Atypical pemphigus developed in a patient with urothelial carcinoma treated with nivolumab

melanoma in adults, such as Hutchinson sign, broad pigment band and nail dystrophy. In addition, although rare, there have been some reports of childhood LM that have resulted from melanoma. To better manage the childhood LM, accumulation of the data about the natural course of its clinical features, especially over the long term, is necessary. Here, we report a clinical course of childhood LM followed up for 10 years. A 1-year-old Japanese girl was referred to our department for a linear pigmentation on the nail of her right index finger. Her parents noticed the pigmentation when she was 10 months old. The pigmentation gradually enlarged and became 3.5 mm wide on her first visit (Fig. 1a). The clinical appearance showed a homogeneous, blackish-brown pigmentation with a sharp lateral border. A nail dystrophy was observed at the tip of the nail. In addition, a small brownish pigmentation was observed at the fingertip by dermoscopy (Fig. 1g). We diagnosed the pigmentation as LM due to congenital melanocytic nevus or lentigo, and decided to take a “wait and see” approach. At the age of 2 years, the LM lesion was further enlarged and the color at the proximal part of the nail plate progressed to blackish (Fig. 1b). The pigmentation spread all over the nail at the age of 3 years, and has subsequently maintained that distribution (Fig. 1c–f). On the other hand, the pigmentation on the fingertip (Fig. 1h) gradually regressed and had almost disappeared by the age of 11 years (Fig. 1i). The nail deformity also improved, becoming a minimal distal fissure. The patient is still under follow up once a year. Clinical features of LM that raise concern for melanoma include a broad pigment band (broader than 3 mm), change in pigmentation or shape, nail dystrophy, Hutchinson sign, nonhomogeneous color, blurred lateral borders, irregular lines that are not parallel on dermoscopy and rapid evolution. Although our case showed some of these worrisome features, such as a broad pigment band, change in pigmentation/shape, nail dystrophy and Hutchinson sign, the pigmentation was homogenous with clear lateral borders. In addition, the nail dystrophy was mild and limited only at the tip. Furthermore, the dystrophy and Hutchinson sign almost disappeared during the follow up. These clinical manifestations are strongly indicative of LM due to benign nevi. Considering the difficulty of histological diagnosis and the risks of surgical complications, biopsy for childhood LM should be performed with extreme caution. Further accumulation of the long-time follow-up data would lead to better management of childhood LM.

Monitoring of immunoglobulin A antibodies to epidermal and tissue transglutaminases over an 18-month period in a Japanese patient with dermatitis herpetiformis

Dear Editor, Dermatitis herpetiformis (DH) is a subtype of autoimmune bullous diseases and is considered as the cutaneous expression of a gluten-sensitive enteropathy (GSE), which is indistinguishable from celiac disease. DH is relatively common in Caucasian populations, but it is very rare in the Japanese. Also, several differences between Caucasian and Japanese DH have been reported. Japanese DH shows a high frequency of fibrillar immunoglobulin A (IgA) deposition in the papillary dermis, rarely associates with GSE and has no human leukocyte antigen (HLA) DQ2/DQ8 haplotype. Additionally, in contrast to high sensitivity (60–80%) and specificity (90–100%) of IgA antiepidermal transglutaminase (eTG) antibodies in Caucasian DH, IgA antibodies to both eTG and tissue transglutaminase (tTG) are infrequently detected in Japanese DH. A 26-year-old Japanese man was referred to our hospital with a 3-week history of pruritic erythema, papules and vesicles on the face, trunk and extremities (Fig. 1a,b). There was no history of GSE. Histological examination from a chest lesion revealed a neutrophilic infiltrate in the subepidermal blister formation (Fig. S1). Direct immunofluorescence (IF) showed granular IgA deposition in the papillary dermis (Fig. S2). Indirect IF studies were negative. HLA haplotypes were A24, A33, B60, B44, DR12 and DR13. The patient was diagnosed with DH based on these findings. Immunoglobulin A anti-eTG and anti-tTG antibodies in the patient sera were monitored over an 18-month period. At the first visit, IgA anti-eTG and anti-tTG antibodies were positive (145 and 35 AU/mL, respectively; cut-off, <22) (Fig. 1f). Four weeks after administration of dapsone 75 mg/day, no new skin lesions developed (Fig. 1c), and only IgA anti-eTG antibodies decreased to 103.42 AU/mL. Thereafter, dapsone was tapered and discontinued in 6 months, when only pigmented lesions remained (Fig. 1d). At this time, IgA antibodies to both eTG and tTG decreased to 84.13 and 29.84 AU/mL, respectively. After dapsone was discontinued, IgA anti-eTG antibodies remained positive but stable. In contrast, IgA antitTG antibodies decreased to the normal range in 12 months.

A case of mucous membrane pemphigoid with IgG antibodies against the β3 and γ2 subunits of laminin‐332, and the C‐terminal domain of BP180

Mucous membrane pemphigoid (MMP) is a rare autoimmune subepidermal blistering disease that predominantly affects the mucous membranes, including the ocular, oral, gingival, nasopharyngeal, esophageal, and genital mucosae. MMP usually results in permanent scarring of the affected area, which can eventually lead to serious complications including blindness and upper aerodigestive tract stenosis. Target autoantigens identified in MMP include two major autoantigens, the C-terminal domain of BP180 (BPAG2 or type XVII collagen) and laminin-332, and the 120-kDa ectodomain of BP180, BP230, laminin-311, type VII collagen, a6 integrin, b4 integrin and uncein, and three as unidentified epithelial proteins of 45, 168, and 120 kDa. We herein report a case of MMP with IgG antibodies against the b3 and c2 subunits of laminin-332, as well as the C-terminal domain of BP180. Case report

Clinical and Immunological Study of 30 Cases With Both IgG and IgA Anti-Keratinocyte Cell Surface Autoantibodies Toward the Definition of Intercellular IgG/IgA Dermatosis

Several sporadic cases, in which direct and indirect immunofluorescence studies simultaneously detected IgG and IgA autoantibodies to keratinocyte cell surfaces, have been reported mainly under the name of IgG/IgA pemphigus. However, there have been no systematic studies for this condition. In this study, we collected 30 cases of this condition from our cohort of more than 5,000 autoimmune bullous disease cases, which were consulted for our diagnostic methods from other institutes, and summarized their clinical and immunological findings. Clinically, there was no male–female prevalence, mean age of disease onset was 55.6u2009years, and mean duration before this condition was suspected was 18u2009months. The patients showed clinically bullous and pustular skin lesions preferentially on the trunk and extremities, and histopathologically intraepidermal pustules and blisters with infiltration of neutrophils and eosinophils. Immunologically, ELISAs frequently detected IgG and IgA autoantibodies to both desmogleins and desmocollins. From the characteristic clinical, histopathological, and immunological features, which are considerably different from those in classical IgG types of pemphigus, we propose this disease as a new disease entity with preferential name of intercellular IgG/IgA dermatosis (IGAD). This was the largest study of IGAD to date.

A case of bullous pemphigoid with IgG antibodies against LAD-1, but not BP180 NC16a domain or BP230

Figure 1. Clinical and histopathological features. A, B) Darkred discolouration of the second finger with purpura and ulcers. C) Proliferation of capillaries and extravasated red blood cells in the upper dermis (hematoxylin and eosin staining; original magnification: ×40). D) MR angiography shows dilated superficial veins on the dorsal side of the second finger. E) Ligation of the dorsal branch of the radial cutaneous vein (arrowhead).