Is the aspect ratio a reliable index for predicting the rupture of a saccular aneurysm?

OBJECTIVE

The present retrospective study was undertaken to prove the reliability of the aspect ratio (aneurysm depth to aneurysm neck width) for predicting an aneurysmal rupture. The aspect ratio is considered a better geometric index than aneurysm size for determining the intra-aneurysmal blood flow.

METHODS

We measured the aspect ratios and the sizes of aneurysms, as determined by examining angiographic films magnified 1.4x, in 129 patients with ruptured aneurysms and in 72 patients with 78 unruptured aneurysms. After categorizing the aneurysms into four groups on the basis of their locations (aneurysms of the anterior communicating artery, middle cerebral artery, internal carotid artery-posterior communicating artery [ICA-PComA], and other aneurysms), a statistical analysis of ruptured and unruptured aneurysms was performed.

RESULTS

The mean aneurysm size was found to be statistically significant in the aneurysms at the ICA-PComA and in locations excluding the anterior communicating artery, the middle cerebral artery, and the ICA-PComA. However, the mean aspect ratio was statistically significant at all four locations. In patients with ruptured aneurysms, no ruptured aneurysms with an aspect ratio of less than 1.0 were found. The distribution of the ruptured group versus the unruptured group with an aspect ratio of less than 1.6 at each location was 13 versus 79%, respectively, at the anterior communicating artery, 11 versus 58% at the middle cerebral artery, 11% versus 85% at the ICA-PComA, and 7 versus 81% at other locations.

CONCLUSION

The aspect ratio between ruptured aneurysms and unruptured aneurysms was found to be statistically significant, and almost 80% of the ruptured aneurysms showed an aspect ratio of more than 1.6, whereas almost 90% of the unruptured aneurysms showed an aspect ratio of less than 1.6. This study therefore suggests that the aspect ratio may be useful in predicting imminent aneurysmal ruptures.

Diagnosis and management of pemphigus: Recommendations of an international panel of experts

BACKGROUND

Several European countries recently developed international diagnostic and management guidelines for pemphigus, which have been instrumental in the standardization of pemphigus management.

OBJECTIVE

We now present results from a subsequent Delphi consensus to broaden the generalizability of the recommendations.

METHODS

A preliminary survey, based on the European Dermatology Forum and the European Academy of Dermatology and Venereology guidelines, was sent to a panel of international experts to determine the level of consensus. The results were discussed at the International Bullous Diseases Consensus Group in March 2016 during the annual American Academy of Dermatology conference. Following the meeting, a second survey was sent to more experts to achieve greater international consensus.

RESULTS

The 39 experts participated in the first round of the Delphi survey, and 54 experts from 21 countries completed the second round. The number of statements in the survey was reduced from 175 topics in Delphi I to 24 topics in Delphi II on the basis of Delphi results and meeting discussion.

LIMITATIONS

Each recommendation represents the majority opinion and therefore may not reflect all possible treatment options available.

CONCLUSIONS

We present here the recommendations resulting from this Delphi process. This international consensus includes intravenous CD20 inhibitors as a first-line therapy option for moderate-to-severe pemphigus.

Effects of size and shape (aspect ratio) on the hemodynamics of saccular aneurysms: a possible index for surgical treatment of intracranial aneurysms

OBJECTIVE

The present study was undertaken to explore the relationship between the characteristic geometry of aneurysms prone to rupture and the blood flow patterns therein, using microsurgically produced aneurysms that simulated human middle cerebral artery aneurysms in scale and shape.

METHODS

We measured in vivo velocity profiles using our 20-MHz, 80-channel, Doppler ultrasound velocimeter. We produced small (< or =5 mm, 5 cases) and large (6-13 mm, 12 cases) aneurysms with round, dumbbell, or multilobular shapes.

RESULTS

The fundamental patterns of intra-aneurysmal flow were composed of inflow, circulating flow, and outflow. The inflow, which entered the aneurysm only during the systolic phase, was strongly influenced by the position and size of the neck and the flow ratio into the distal branches. The outflow was usually nonpulsatile and of low velocity. The circulating flow depended on the aspect ratio (depth/neck width). A single recirculation zone was observed in aneurysms with aspect ratios of less than 1.6. This circulation did not seem to extend to areas with aspect ratios greater than this value; in aneurysms with aspect ratios of more than 1.6, a much slower circulation was observed near the dome. Furthermore, in the dome of dumbbell-shaped aneurysms and daughter aneurysms, no flow was detected. Intra-aneurysmal flow was determined by the aspect ratio, rather than the aneurysm size.

CONCLUSION

The localized, extremely low-flow condition that was observed in the dome of aneurysms with aspect ratios of more than 1.6 is a common flow characteristic in the geometry of ruptured aneurysms, so great care should be taken for patients with unruptured intracranial aneurysms with aspect ratios of more than 1.6.

Autoantibody Profile Differentiates between Inflammatory and Noninflammatory Bullous Pemphigoid

Bullous pemphigoid (BP) is a major autoimmune blistering skin disorder, in which a majority of the autoantibodies (autoAbs) target the juxtamembranous extracellular noncollagenous 16A domain (NC16A) domain of hemidesmosomal collagen XVII. BP-autoAbs may target regions of collagen XVII other than the NC16A domain; however, correlations between epitopes of BP-autoAbs and clinical features have not been fully elucidated. To address correlations between the clinical features and specific epitopes of BP-autoAbs, we evaluated the epitope profiles of BP-autoAbs in 121 patients. A total of 87 patients showed a typical inflammatory phenotype with erythema and autoAbs targeting the anti-NC16A domain, whereas 14 patients showed a distinct noninflammatory phenotype, in which autoAbs specifically targeted the midportion of collagen XVII, but not NC16A. Interestingly, this group clinically showed significantly reduced erythema associated with scant lesional infiltration of eosinophils. Surprisingly, 7 of the 14 cases (50.0%) received dipeptidyl peptidase-IV inhibitors for the treatment of diabetes. Dipeptidyl peptidase-IV inhibitors were used in 3 of 76 (3.9%) typical cases of BP with autoAbs targeting NC16A; thus, dipeptidyl peptidase-IV inhibitors are thought to be involved in the development of atypical noninflammatory BP. This study shows that the autoAb profile differentiates between inflammatory and noninflammatory BP, and that noninflammatory BP may be associated with dipeptidyl peptidase-IV inhibitors.

Unmet Medical Needs in Chronic, Non-communicable Inflammatory Skin Diseases

An estimated 20-25% of the population is affected by chronic, non-communicable inflammatory skin diseases. Chronic skin inflammation has many causes. Among the most frequent chronic inflammatory skin diseases are atopic dermatitis, psoriasis, urticaria, lichen planus, and hidradenitis suppurativa, driven by a complex interplay of genetics and environmental factors. Autoimmunity is another important cause of chronic skin inflammation. The autoimmune response may be mainly T cell driven, such as in alopecia areata or vitiligo, or B cell driven in chronic spontaneous urticaria, pemphigus and pemphigoid diseases. Rare causes of chronic skin inflammation are autoinflammatory diseases, or rheumatic diseases, such as cutaneous lupus erythematosus or dermatomyositis. Whilst we have seen a significant improvement in diagnosis and treatment, several challenges remain. Especially for rarer causes of chronic skin inflammation, early diagnosis is often missed because of low awareness and lack of diagnostics. Systemic immunosuppression is the treatment of choice for almost all of these diseases. Adverse events due to immunosuppression, insufficient therapeutic responses and relapses remain a challenge. For atopic dermatitis and psoriasis, a broad spectrum of innovative treatments has been developed. However, treatment responses cannot be predicted so far. Hence, development of (bio)markers allowing selection of specific medications for individual patients is needed. Given the encouraging developments during the past years, we envision that many of these challenges in the diagnosis and treatment of chronic inflammatory skin diseases will be thoroughly addressed in the future.

Bullous pemphigoid autoantibodies directly induce blister formation without complement activation

Complement activation and subsequent recruitment of inflammatory cells at the dermal/epidermal junction are thought to be essential for blister formation in bullous pemphigoid (BP), an autoimmune blistering disease induced by autoantibodies against type XVII collagen (COL17); however, this theory does not fully explain the pathological features of BP. Recently, the involvement of complement-independent pathways has been proposed. To directly address the question of the necessity of the complement activation in blister formation, we generated C3-deficient COL17-humanized mice. First, we show that passive transfer of autoantibodies from BP patients induced blister formation in neonatal C3-deficient COL17-humanized mice without complement activation. By using newly generated human and murine mAbs against the pathogenic noncollagenous 16A domain of COL17 with high (human IgG1, murine IgG2), low (murine IgG1), or no (human IgG4) complement activation abilities, we demonstrate that the deposition of Abs, and not complements, is relevant to the induction of blister formation in neonatal and adult mice. Notably, passive transfer of BP autoantibodies reduced the amount of COL17 in lesional mice skin, as observed in cultured normal human keratinocytes treated with the same Abs. Moreover, the COL17 depletion was associated with a ubiquitin/proteasome pathway. In conclusion, the COL17 depletion induced by BP autoantibodies, and not complement activation, is essential for the blister formation under our experimental system.

Type XVII collagen coordinates proliferation in the interfollicular epidermis

Type XVII collagen (COL17) is a transmembrane protein located at the epidermal basement membrane zone. COL17 deficiency results in premature hair aging phenotypes and in junctional epidermolysis bullosa. Here, we show that COL17 plays a central role in regulating interfollicular epidermis (IFE) proliferation. Loss of COL17 leads to transient IFE hypertrophy in neonatal mice owing to aberrant Wnt signaling. The replenishment of COL17 in the neonatal epidermis of COL17-null mice reverses the proliferative IFE phenotype and the altered Wnt signaling. Physical aging abolishes membranous COL17 in IFE basal cells because of inactive atypical protein kinase C signaling and also induces epidermal hyperproliferation. The overexpression of human COL17 in aged mouse epidermis suppresses IFE hypertrophy. These findings demonstrate that COL17 governs IFE proliferation of neonatal and aged skin in distinct ways. Our study indicates that COL17 could be an important target of anti-aging strategies in the skin.

Clinical analysis of incidentally discovered unruptured aneurysms

BACKGROUND AND PURPOSE

We analyzed the risk factors for rupture of an intracranial aneurysm based on a retrospective angiographic study of ruptured and unruptured aneurysms.

METHODS

The 44 cases of asymptomatic aneurysms were selected from 1612 patients whose lesions had been discovered fortuitously by angiography (2.7%) during the period from 1980 to 1989. All these patients were free from any sign of intracranial aneurysm. The variations in age, sex, and location of the aneurysms were analyzed compared with 638 ruptured aneurysms that had been treated in our institute during the same period. The size, shape, and arterial geometry of the unruptured aneurysms were examined angiographically.

RESULTS

Unruptured aneurysm was discovered fortuitously in 44 (2.7%) of 1612 patients, with greater incidence in women aged older than 60 years. Unruptured aneurysms were less likely to occur in the anterior communicating artery (12.8%) and the middle cerebral artery (6.4%). However, they were frequently found in the internal carotid artery, with an incidence of 10.6% in cavernous portion of the internal carotid artery, 19.1% in the internal carotid-ophthalmic artery, 19.1% in the internal carotid-posterior communicating artery, and 12.8% in the internal carotid-anterior choroidal artery. Seven of the nine internal carotid-posterior communicating artery aneurysms showed a hypoplastic or aplastic posterior communicating artery. The mean diameter of the unruptured aneurysms was 4.8 mm, and 80% were smaller than 6 mm.

CONCLUSIONS

Intracranial aneurysms are formed not only at the bifurcation of an artery but also at its branching and bending points. However, an aneurysm located at the bifurcation, such as the anterior communicating artery and the middle cerebral artery, bleeds easily in contrast with lateral aneurysms such as those found at the branching and bending points on the internal carotid artery.

Paper-based ELISA for the detection of autoimmune antibodies in body fluid-the case of bullous pemphigoid

Bullous pemphigoid (BP), a common autoimmune blistering disease, is increasing in incidence and conveys a high mortality. Detection of autoantibodies targeting the noncollagenous 16A (NC16A) domain of type XVII collagen using enzyme-linked immunosorbent assay (ELISA) has demonstrated high sensitivity and specificity for diagnosing BP. We have developed a rapid, low-cost, and widely applicable ELISA-based system to detect the NC16A autoimmune antibody and then diagnose and monitor BP disease activity using a piece of filter paper, a wax-printer, and NC16A antigens. Both sera and/or blister fluids from 14 untreated BP patients were analyzed. The control group included healthy volunteers and patients with other blistering disorders such as pemphigus vulgaris. In our established paper-based ELISA (P-ELISA) system, only 2 μL of serum or blister fluid and 70 min were required to detect anti-NC16A autoimmune antibodies. The relative color intensity was significantly higher in the BP group than in the control groups when using either serum (P < 0.05) or blister fluid (P < 0.001) specimens from BP patients. The results of P- ELISA were moderately correlated with the titer of the commercial ELISA kit (MBL, Japan) (rho = 0.5680, P = 0.0011). This newly developed system allows for rapid and convenient diagnosis and/or monitoring of BP disease activity.

Hemodynamic study of the anterior communicating artery

BACKGROUND AND PURPOSE

The anterior communicating artery (ACoA) is a site of predilection for intracranial saccular aneurysms causing subarachnoid hemorrhage. ACoA aneurysms are frequently associated with an asymmetrical circle of Willis. In such cases, the ACoA is probably exposed to high hemodynamic stress caused by a considerable shunt flow across the ACoA to the distal segment of the contralateral anterior cerebral artery (ACA). In the present study, the flow pattern and flow-induced shear stress in the ACoA complex that may initiate aneurysmal lesions were studied under steady and pulsatile flow conditions.

METHODS

Flow visualization was studied with dye injection and birefringent flow visualization in symmetrical and asymmetrical models of various sizes of ACoA. The distribution of wall shear stress was measured using an electrochemical method based on a diffusion-controlled reaction of ferricyanide ion to ferrocyanide ion at a platinum electrode embedded in the wall of the ACoA model.

RESULTS

With equal flow rate (Reynolds number 150 to 600), vortical flow was formed in the mouth of the ACoA, and no cross flow through the ACoA was observed. The wall shear stress on the mid-wall of the ACoA was almost zero. However, as soon as the flow rate became unequal, a cross flow through the ACoA was observed. The stagnation point also appeared at the medial junction of the ACoA and ACA. The wall shear stress increased to a very high level at the wall of the ACoA and around the stagnation point.

CONCLUSIONS

Geometric changes from the symmetrical to the asymmetrical ACoA develop higher shear stress on the ACoA than critical values and the stagnation point at the ACoA junction. A combination of these hemodynamic factors is considered to play an important role in initiation of aneurysm.

Antibodies to pathogenic epitopes on type XVII collagen cause skin fragility in a complement-dependent and -independent manner

In bullous pemphigoid (BP), the most prevalent autoimmune blistering disease, type XVII collagen (COL17) is targeted by circulating autoantibodies. BP is thought to be an autoantibody-mediated complement-fixing blistering disease, and a juxtamembranous noncollagenous 16A (NC16A) domain spanning Glu(490) to Arg(566) was proved to be the main pathogenic region on COL17, although precise pathogenic epitopes within NC16A have not been elucidated. In this study, we showed that injection of rabbit IgG Abs targeting Asp(522) to Gln(545) induced skin fragility associated with in vivo deposition of IgG and complement in neonatal COL17-humanized mice. Notably, immunoadsorption of rabbit anti-NC16A IgG Ab with this epitope (Asp(522) to Gln(545)) or the anti-NC16A IgG administered together with the peptides of this epitope as a decoy ameliorated skin fragility in the injected neonatal COL17-humanized mice compared with the anti-NC16A IgG alone even though all of the mice showed both IgG and complement deposition. These results led us to investigate an additional, complement-independent mechanism of skin fragility in the mice injected with anti-COL17 Abs. The rabbit anti-NC16A IgG depleted the expression of COL17 in cultured normal human keratinocytes, whereas immunoadsorption of the same IgG with this epitope significantly suppressed the depletion effect. Moreover, passive transfer of F(ab')(2) fragments of the human BP or rabbit IgG Abs against COL17 demonstrated skin fragility in neonatal COL17-humanized mice. In summary, this study reveals the importance of Abs directed against distinct epitopes on COL17, which induce skin fragility in complement-dependent as well as complement-independent ways.

Regulatory T-cell dysfunction induces autoantibodies to bullous pemphigoid antigens in mice and human subjects

BACKGROUND

Regulatory T (Treg) cells play a crucial role in peripheral immune tolerance in multiple organs, including the skin. Thus far, the effect of peripheral immune tolerance failure on autoantibody-related autoimmune reactions to the skin is unclear.

OBJECTIVE

We sought to elucidate the target autoantigens in the skin under the condition of Treg cell dysfunction caused by forkhead box P3 (Foxp3) gene mutations in scurfy mice and patients with immunodysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome.

METHODS

Sera and skin from scurfy mice and sera from patients with IPEX syndrome were analyzed to detect target autoantigens by using immunofluorescence studies, ELISAs, and immunoblotting. The pathogenicity of scurfy IgG was examined by using a passive transfer experiment. CD4⁺ T cells from scurfy mice were transferred to immunodeficient mice to examine their pathogenicity. Signal transducer and activator of transcription 6 (Stat6)^-/- scurfy mice were analyzed to further clarify the molecular pathway of autoantibody production. Follicular helper T-cell counts are measured in Stat6^-/- scurfy mice and scurfy mice.

RESULTS

Scurfy mice spontaneously generated IgG autoantibodies to the dermal-epidermal junction, which had been class-switched from IgM within 12 days after birth. The target autoantigens were murine BP230 and type XVII collagen (COL17). The scurfy polyclonal autoantibodies did not induce skin fragility in neonatal mice. Autoantibody production was induced by CD4⁺ T cells from scurfy mice and was ameliorated by Stat6 gene knockout in association with a decrease of follicular helper T cells. We also identified autoantibodies to COL17 and BP230 in patients with IPEX syndrome and found an association between production of autoantibodies to COL17 and an eczematous skin phenotype.

CONCLUSIONS

Dysregulation of Treg cells generates autoantibodies to COL17 and BP230 in vivo.

A novel active mouse model for bullous pemphigoid targeting humanized pathogenic antigen

Bullous pemphigoid (BP), the most common autoimmune blistering disease, is caused by autoantibodies against type XVII collagen (COL17). To establish an active stable BP animal model that demonstrates the persistent inflammatory skin lesions initiated by the anti-human COL17 Abs, we used COL17-humanized (COL17(m-/-,h+)) mice that we recently produced. First, we generated immunodeficient Rag-2(-/-)/COL17-humanized mice by crossing Rag-2(-/-) mice with COL17-humanized mice. Then, splenocytes from wild-type mice that had been immunized by grafting of human COL17-transgenic mouse skin were transferred into Rag-2(-/-)/COL17-humanized mice. The recipient mice continuously produced anti-human COL17 IgG Abs in vivo and developed blisters and erosions corresponding to clinical, histological, and immunopathological features of BP, although eosinophil infiltration, one of the characteristic histological findings observed in BP patients, was not detected in the recipients. Although the depletion of CD8(+) T cells from the immunized splenocytes was found to produce no effects in the recipients, the depletion of CD4(+) T cells as well as CD45R(+) B cells was found to inhibit the production of anti-human COL17 IgG Abs in the recipients, resulting in no apparent clinical phenotype. Furthermore, we demonstrated that cyclosporin A significantly suppressed the production of anti-human COL17 IgG Abs and prevented the development of the BP phenotype in the treated recipients. Although this model in an immunodeficient mouse does not exactly reproduce the induction mechanism of BP in human patients, this unique experimental system targeting humanized pathogenic Ag allows us to investigate ongoing autoimmune responses to human molecules in experimental animal models.

In vivo analysis of IgE autoantibodies in bullous pemphigoid: a study of 100 cases

BACKGROUND

Bullous pemphigoid (BP) is an acquired autoimmune blistering disease characterized by subepidermal blister formation, in vivo linear deposition of immunoglobulin G (IgG) and complements at the dermal-epidermal junction (DEJ). The circulating IgG autoantibodies are directed against two epidermal hemidesmosomal glycoproteins: BP180, also known as type XVII collagen (COL17), and BP230. In addition, recent studies have shown that IgE autoantibodies may be involved in the pathogenesis of BP, although in vivo IgE deposition in lesional skin has not been fully characterized in large numbers of BP patients.

OBJECTIVE

This study investigated the incidence of in vivo deposition of IgE autoantibodies at the DEJ in lesional skin from a large number of BP patients.

METHODS

Peri-lesional skin samples from 100 patients who met the clinical and histopathological criteria for BP were investigated by direct immunofluorescence for the deposition of autoantibodies and complement. Patients' sera were also investigated by enzyme-linked immunosorbent assay and indirect immunofluorescence.

RESULTS

18% of BP patients were found to show IgE deposition at the DEJ. Disease severity, clinical course and outcome did not differ between IgE-positive and IgE-negative patients. In 3 IgE-positive cases, IgG was undetectable in vivo, and these cases showed atypical manifestations.

CONCLUSION

The results of in vivo IgE deposition may not be useful in predicting the disease course of BP, although predominant IgE deposition could alter the pattern of clinical manifestations.

Purification and properties of D-aspartate oxidase from Cryptococcus humicolus UJ1

D-Aspartate oxidase (EC 1.4.3.1), which is highly specific to D-aspartate, was inducibly produced by a yeast strain which was isolated from soil and identified as Cryptococcus humicolus UJ1. The enzyme was purified to homogeneity as indicated on SDS-polyacrylamide gel electrophoresis. The molecular mass of the monomer subunit was determined to be 40 kDa. The native enzyme was suggested to be a homotetramer by its behavior on gel filtration. The enzyme was shown to be a flavoprotein by its absorption spectral properties, and the flavin was found to be tightly, but not covalently, bound FAD. The purified preparation had a specific activity of 76.1 mumol/min per mg protein with D-aspartate as substrate. Optimum pH was 7.5 and optimum temperature was around 35 degrees C. D-Glutamate was a very poor substrate for the enzyme. N-Methyl-D-aspartate was better than D-glutamate as substrate but markedly poorer than D-aspartate. Malonate was the most effective competitive inhibitor of the compounds tested. The N-terminal amino-acid sequence of the enzyme showed a significant homology with those of D-aspartate oxidases from beef kidney and Octopus vulgaris and those of D-amino-acid oxidases from various sources.

Japanese guidelines for the management of pemphigoid (including epidermolysis bullosa acquisita)

The pemphigoid group is a category of autoimmune subepidermal blistering diseases in which autoantibodies deposit linearly at the epidermal basement membrane zone (BMZ). The main subtypes of pemphigoid mediated by immunoglobulin G autoantibodies are bullous pemphigoid (BP), mucous membrane pemphigoid (MMP) and epidermolysis bullosa acquisita (EBA). To establish the first guidelines approved by the Japanese Dermatological Association for the management of pemphigoid diseases, the Committee for Guidelines for the Management of Pemphigoid Diseases (Including EBA) was founded as part of the Study Group for Rare Intractable Skin Diseases under the Ministry of Health, Labor and Welfare Research Project on Overcoming Intractable Diseases. These guidelines aim to provide current information for the management of BP, MMP and EBA in Japan. Based on evidence, the guidelines summarize the clinical and immunological manifestations, pathophysiologies, diagnostic criteria, disease severity determination criteria, treatment algorithms and treatment recommendations. Because of the rarity of these diseases, there are few clinical studies with a high degree of evidence, so several parts of these guidelines were established based on the opinions of the Committee. To further optimize these guidelines, periodic revision in line with the new evidence is necessary.

Blockade of autoantibody-initiated tissue damage by using recombinant fab antibody fragments against pathogenic autoantigen

Activation of the complement cascade via the classical pathway is required for the development of tissue injury in many autoantibody-mediated diseases. It therefore makes sense to block the pathological action of autoantibodies by preventing complement activation through inhibition of autoantibody binding to the corresponding pathogenic autoantigen using targeted Fab antibody fragments. To achieve this, we use bullous pemphigoid (BP) as an example of a typical autoimmune disease. Recombinant Fabs against the non-collagenous 16th-A domain of type XVII collagen, the main pathogenic epitope for autoantibodies in BP, were generated from antibody repertoires of BP patients by phage display. Two Fabs, Fab-B4 and Fab-19, showed marked ability to inhibit the binding of BP autoantibodies and subsequent complement activation in vitro. In the in vivo experiments using type XVII collagen humanized BP model mice, these Fabs protected mice against BP autoantibody-induced blistering disease. Thus, the blocking of pathogenic epitopes using engineered Fabs appears to demonstrate efficacy and may lead to disease-specific treatments for antibody-mediated autoimmune diseases.

Pyoderma gangrenosum associated with Takayasu's arteritis

Pyoderma gangrenosum (PG) is a neutrophilic dermatosis characterized by destructive, necrotizing and noninfective ulceration of the skin mostly on lower extremities. PG is well known as a complication of Takayasu's arteritis in Japan. However, this association is not commonly observed in North American and European patients. We describe a case of PG that was associated with Takayasu's arteritis who was successfully treated with systemic cyclosporin. We have reviewed 35 well-documented PG cases with Takayasu's arteritis in comparison to 106 PG cases without Takayasu's arteritis. The results demonstrate that this association occurs predominantly in young females and that these cases exhibit more widespread PG lesions.

Meeting Report of the Pathogenesis of Pemphigus and Pemphigoid Meeting in Munich, September 2016

Autoimmune blistering diseases are a heterogeneous group of about a dozen complex disorders that are characterized by intraepidermal (pemphigus) and subepidermal blistering (pemphigoid diseases and dermatitis herpetiformis). The Pathogenesis of Pemphigus and Pemphigoid Meeting, organized by the Departments of Dermatology in Lübeck and Marburg and the Institute of Anatomy and Cell Biology, Munich, was held in September 2016 in Munich. The meeting brought together basic scientists and clinicians from all continents dedicating their work to autoimmune blistering diseases. Considerable advances have been made in describing incidences and prevalences of these diseases and linking comorbidities with autoantibody reactivities and clinical variants, for example, dipeptidyl peptidase-IV inhibitor-associated noninflammatory bullous pemphigoid. Although new entities are still being described, diagnosis of most autoimmune blistering diseases can now be achieved using standardized and widely available serological test systems. Various experimental mouse models of pemphigus and pemphigoid disease are increasingly being used to understand mechanisms of central and peripheral tolerance and to evaluate more specific treatment approaches for these disorders, such as molecules that target autoreactive T and B cells and anti-inflammatory mediators, that is, dimethyl fumarate, phosphodiesterase 4, and leukotriene B4 inhibitors in pemphigoid disorders, and chimeric antigen receptor T cells in pemphigus. Very recent experimental data about the immunopathology and the determinants of autoantibody formation and keratinocyte susceptibility in pemphigus were discussed. With regard to cellular mechanisms leading to the loss of cell-cell adhesion, new ideas were shared in the field of signal transduction. Major steps were taken to put the various partly contradictory and controversial findings about the effects of pemphigus autoantibodies and other inflammatory mediators into perspective and broaden our view of the complex pathophysiology of this disease. Finally, two investigator-initiated multicenter trials highlighted doxycycline and dapsone as valuable medications in the treatment of bullous pemphigoid.