The gut microbiome in bullous pemphigoid: implications of the gut-skin axis for disease susceptibility.

Bullous pemphigoid (BP) is an autoimmune blistering disease that primarily affects the elderly. An altered skin microbiota in BP was recently revealed. Accumulating evidence points toward a link between the gut microbiota and skin diseases; however, the gut microbiota composition of BP patients remains largely underexplored, with only one pilot study to date, with a very limited sample size and no functional profiling of gut microbiota. To thoroughly investigate the composition and function of the gut microbiota in BP patients, and explore possible links between skin conditions and gut microbiota, we here investigated the gut microbiota of 66 patients (81.8% firstly diagnosed) suffering from BP and 66 age-, sex-, and study center-matched controls (CL) with non-inflammatory skin diseases (132 total participants), using 16S rRNA gene and shotgun sequencing data. Decreased alpha-diversity and an overall altered gut microbial community is observed in BP patients. Similar trends are observed in subclassifications of BP patients, including first diagnoses and relapsed cases. Furthermore, we observe a set of BP disease-associated gut microbial features, including reduced Faecalibacterium prausnitzii and greater abundance of pathways related to gamma-aminobutyric acid (GABA) metabolism in BP patients. Interestingly, F. prausnitzii is a well-known microbiomarker of inflammatory diseases, which has been reported to be reduced in the gut microbiome of atopic dermatitis and psoriasis patients. Moreover, GABA plays multiple roles in maintaining skin health, including the inhibition of itching by acting as a neurotransmitter, attenuating skin lesions by balancing Th1 and Th2 levels, and maintaining skin elasticity by increasing the expression of type I collagen. These findings thus suggest that gut microbiota alterations present in BP may play a role in the disease, and certain key microbes and functions may contribute to the link between gut dysbiosis and BP disease activity. Further studies to investigate the underlying mechanisms of the gut-skin interaction are thus clearly warranted, which could aid in the development of potential therapeutic interventions.

Characterization of the skin microbiota in bullous pemphigoid patients and controls reveals novel microbial indicators of disease.

INTRODUCTION: Bullous pemphigoid (BP) is the most common autoimmune blistering disease. It predominately afflicts the elderly and is significantly associated with increased mortality. The observation of age-dependent changes in the skin microbiota as well as its involvement in other inflammatory skin disorders suggests that skin microbiota may play a role in the emergence of BP blistering. We hypothesize that changes in microbial diversity associated with BP might occur before the emergence of disease lesions, and thus could represent an early indicator of blistering risk. OBJECTIVES: The present study aims to investigate potential relationships between skin microbiota and BP and elaborate on important changes in microbial diversity associated with blistering in BP. METHODS: The study consisted of an extensive sampling effort of the skin microbiota in patients with BP and age- and sex-matched controls to analyze whether intra-individual, body site, and/or geographical variation correlate with changes in skin microbial composition in BP and/or blistering status. RESULTS: We find significant differences in the skin microbiota of patients with BP compared to that of controls, and moreover that disease status rather than skin biogeography (body site) governs skin microbiota composition in patients with BP. Our data reveal a discernible transition between normal skin and the skin surrounding BP lesions, which is characterized by a loss of protective microbiota and an increase in sequences matching Staphylococcus aureus, a known inflammation-promoting species. Notably, Staphylococcus aureus is ubiquitously associated with BP disease status, regardless of the presence of blisters. CONCLUSION: The present study suggests Staphylococcus aureus may be a key taxon associated with BP disease status. Importantly, we however find contrasting patterns in the relative abundances of Staphylococcus hominis and Staphylococcus aureus reliably discriminate between patients with BP and matched controls. This may serve as valuable information for assessing blistering risk and treatment outcomes in a clinical setting.

[Turning point in skin cancer mortality : An analysis of the trend in Germany from 1998 to 2017]. / Trendwende bei der Hautkrebsmortalität : Eine Analyse der Entwicklung in Deutschland von 1998 bis 2017.

Including non-melanocytic types, skin cancer is still the most common cancer in Germany. The objective of this study is to investigate current trends of skin cancer mortality in Germany. Data of the death statistics from 1998 to 2017 were analyzed using joinpoint regression models. Age standardized skin cancer mortality declined since 2013 (annual percentage change -2.1% [95% CI: -4.0 to -0.2%]), while in previous years an increase of +3.4% (95% CI: 1.3 to 5.4%) was observed. The development is mainly driven by a decreasing melanoma mortality. Possible causes of the trend change are especially the nationwide skin cancer screening which was introduced in 2008 and the growing availability of new systemic therapies from about 2011. Further research is needed to estimate the extent of the respective causal contributions.

Lichen Planus Pemphigoides: From Lichenoid Inflammation to Autoantibody-Mediated Blistering.

Lichen planus pemphigoides (LPP) is a very rare autoimmune sub-epidermal blistering disease associated with lichenoid skin changes. Initially thought to be a mere variant of more common inflammatory dermatoses, particularly Bullous Pemphigoid (BP) or Lichen Planus (LP), a growing body of evidence suggests that it is a disease entity in its own right. In common with a range of autoimmune blistering diseases, including BP, pemphigoid gestationis (PG), mucous membrane pemphigoid (MMP) and linear IgA dermatosis (LAD), a key feature of the disease is the development of autoantibodies against type XVII collagen (COL17). However, accurately establishing the diagnosis is dependent on a careful correlation between the clinical, histological and immunological features of the disease. Therefore, we present an up to date summary of the epidemiology and etiopathogenesis of LPP, before illustrating the predisposing and precipitating factors implicated in the development of the disease. In addition to a selective literature search, we compare reports of potential drug-induced cases of LPP with pharmacovigilance data available via OpenVigil. We subsequently outline the cardinal clinical features, important differential diagnoses and current treatment options. We conclude by demonstrating that an improved understanding of LPP may not only lead to the development of novel treatment strategies for the disease itself, but may also shed new light on the pathophysiology of more common and treatment-refractory autoimmune blistering diseases.

[Immunoadsorption in dermatology]. / Immunadsorption in der Dermatologie.

Autoimmmune bullous diseases are mediated by pathogenetically relevant autoantibodies against components of the epidermis and/or superficial mucous membranes (in pemphigus) and structural proteins of the dermal-epidermal junction (in pemphigoid diseases). Using immunoadsorption (IA), an already well-established procedure in cardiac and rheumatic disorders, antibodies can be removed from the plasma. At present, most data on the adjuvant use of IA in dermatology are derived from patients with severe and/or refractory pemphigus vulgaris or pemphigus foliaceus and also from patients with pemphigoid diseases. Additionally, in the last few years different protocols for IA in patients with severe atopic dermatitis and elevated total serum IgE levels have been published. While panimmunoglobulin adsorbers are mainly used in dermatology, an IgE-specific adsorber has been used in some patients with atopic dermatitis and in the future, antigen-specific adsorbers are to be expected that will enable the specific reduction of autoantibodies.

Adjuvant treatment of severe/refractory bullous pemphigoid with protein A immunoadsorption.

BACKGROUND: While depletion of circulating autoantibodies using immunoadsorption (IA) is an established therapeutic approach in patients with pemphigus vulgaris, IA has only sporadically been used in other autoimmune bullous disorders. Although bullous pemphigoid (BP) usually responds well to topical and systemic corticosteroids, rapid depletion of serum autoantibodies may be an effective adjuvant treatment option in patients with severe and/or refractory disease. PATIENTS AND METHODS: Case series of 20 patients (13 women, 7 men; mean age 78.6 years; range 56-94 years) with severe or refractory BP. In addition to oral prednisolone (0.25-0.5 mg/kg/day), dapsone (1.0-1.5 mg/kg/day), and clobetasol propionate 0.05 % ointment (lesional application, twice daily), treatment consisted of protein A IA (three sessions on consecutive days). The mean follow-up period was 33.6 months (1-84 months). RESULTS: The majority of patients showed a rapid and sustained response. One month after treatment, eight patients (42 %; 19 patients were included in the follow-up) were in complete remission; at the last follow-up visit (after 1 to 84 months), that number was 13 (68 %). Not only was there an initial drop in anti-BP180 autoantibodies (by 92 %), the effect also continued after one and three months, with mean autoantibody levels at 26 % and 13 % of baseline, respectively (p < 0.001). Both previously treated and treatment-naive patients showed a significant reduction in anti-BP180NC16A antibody levels throughout the observation period. Adverse events occurred in 13 of the 20 patients (65 %). Three were severe of which two were likely or probably related to IA. CONCLUSION: Immunoadsorption is an effective adjuvant treatment option for (the usually elderly) patients with severe and/or refractory BP.

Adjuvante Behandlung des schweren/refraktären bullösen Pemphigoids mit Protein-A-Immunadsorption.

HINTERGRUND: Mittels Immunadsorption (IA) können Immunglobuline und Immunkomplexe aus dem Plasma entfernt werden. Während dieses therapeutische Verfahren beim Pemphigus vulgaris bereits etabliert ist, wird es bei anderen blasenbildenden Autoimmundermatosen bislang nur sporadisch eingesetzt. Das bullöse Pemphigoid (BP) spricht zwar meist gut auf eine Therapie mit topischen und systemischen Kortikosteroiden an, jedoch könnte bei Patienten mit ausgedehnten Läsionen oder bei einem Rezidiv die rasche Reduktion der pathogenen Autoantikörper eine effektive adjuvante Therapie darstellen. PATIENTEN UND METHODIK: Fallserie mit 20 Patienten (13 Frauen, 7 Männer; mittleres Alter 78,6 Jahre; 56-94 Jahre) mit schwerem oder refraktärem BP, die zusätzlich zur Basistherapie bestehend aus Prednisolon (0,25-0,5 mg/kg/d), Dapson (1,0-1,5 mg/kg/d) und Clobetasolpropionat 0,05 % Salbe (läsional 2 x/d) mit Protein-A-IA (3 IAs an aufeinander folgenden Tagen) behandelt wurden. Die durchschnittliche Nachbeobachtungszeit betrug 33,6 Monate (1-84 Monate). ERGEBNISSE: Bei der Mehrzahl der Patienten zeigte sich ein rascher und langandauernder Therapieeffekt. Nach einem Monat befanden sich acht Patienten (von 19 nachbeobachteten, 42 %) und zum Zeitpunkt des letzten Kontakts (nach 1-84 Monaten) 13 Patienten (68 %) in kompletter Remission. Die Anti-BP180-Autoantikörper wurden nicht nur initial (um 92 %) gesenkt, sondern lagen auch nach ein und drei Monaten im Mittel bei 26 % und 13 % des Wertes vor Therapiebeginn (p < 0,001). Bei Differenzierung in vortherapierte bzw. therapienaive Patienten zeigten sich in beiden Subgruppen signifikante Absenkungen der Anti-BP180NC16A-Antikörper-Spiegel zu allen Zeitpunkten. Unerwünschte Ereignisse traten bei dreizehn (65 %) der 20 Patienten auf, Drei der Ereignisse waren schwer und zwei davon wahrscheinlich oder möglicherweise in Zusammenhang mit der IA. SCHLUSSFOLGERUNGEN: Die IA ist eine effektive adjuvante Therapieoption bei den in aller Regel älteren Patienten mit einem schweren und/oder therapierefraktären BP.

Prospective studies on the routine use of a novel multivariant enzyme-linked immunosorbent assay for the diagnosis of autoimmune bullous diseases.

BACKGROUND: Serologic diagnosis of autoimmune blistering disease (AIBD) usually follows a sophisticated multistep algorithm. OBJECTIVE: We sought validation of a multivariant enzyme-linked immunosorbent assay (ELISA) in the routine diagnosis of AIBD. METHODS: The multivariant ELISA comprising 6 recombinant immunodominant forms of major AIBD target antigens, ie, desmoglein 1, desmoglein 3, envoplakin, BP180, BP230, and type VII collagen was applied in: (1) a cohort of well-characterized AIBD (n = 173) and control sera (n = 130), (2) a prospective multicenter study with 204 sera from patients with newly diagnosed AIBD with positive direct immunofluorescence microscopy, and (3) a prospective monocenter study with 292 consecutive sera from patients with clinical suspicion of AIBD in comparison with the conventional multistep diagnostic algorithm. RESULTS: Concordant results in the multivariant ELISA compared with direct immunofluorescence microscopy were seen in 94% of patients with pemphigus and 71% of patients with pemphigoid (Cohen κ value, 0.95 and 0.66) and with the conventional multistep diagnostic approach in 91% of patients with pemphigus and 88% of patients with bullous pemphigoid and 93% of autoantibody-negative sera (Cohen κ, 0.95, 0.84, and 0.78). LIMITATIONS: IgA autoantibodies and less common target antigens were not analyzed. CONCLUSIONS: The multivariant ELISA is a practical, highly standardized, and widely available novel diagnostic tool for the routine diagnosis of AIBD.