Autoimmune Subepidermal Blistering Disease Research Articles

Low pH condition impairs BP-IgG binding to the basement membrane zone.

Bullous pemphigoid (BP), an autoimmune subepidermal blistering disease, shows tense blisters associated with urticarial erythema. Tissue-bound Immunoglobulin G (IgG) at the basement membrane zone (BMZ) detected by direct immunofluorescence (DIF) is strong evidence for a diagnosis of BP. The sensitivity of DIF is higher in complement component 3 (C3) than in IgG, but the reason for this different sensitivity is not fully understood. In this study, we performed several exvivo studies to investigate the possible mechanism of IgG negativity and C3 positivity at the BMZ by DIF in some BP cases. First, sera from BP patients showing IgG negativity by DIF were found to clearly react to the BMZ in their own DIF skin samples. Next, indirect immunofluorescence (IIF) was performed using sera diluted with different pH phosphate-buffered saline (PBS), pH 7.4, 6.0, and 3.0. Patients' sera diluted with pH 7.4 PBS showed linear staining at the BMZ, but sera diluted with pH 6.0 PBS and pH 3.0 PBS showed lower fluorescence intensities. Finally, sections of skin from BP patients were pre-incubated with different pH PBS (pH 3.0, 6.0, and 7.4), followed by staining with anti-human IgG and C3. The fluorescence intensities were notably lower for IgG and C3 that had been pre-incubated with pH 3.0 PBS and pH 6.0 PBS than for IgG and C3 that had been pre-incubated with pH 7.4 PBS. These results suggest that a low pH condition hinders the binding of autoantibodies to the BMZ, that is, the drop in tissue pH induced by inflammation inhibits autoantibodies from depositing at the BMZ. Furthermore, the drop in tissue pH causes tissue-bound autoantibodies to detach from the BMZ. Complement fragments are activated not only on IgG but also on the cell surface of cells close to IgG during complement activation. IgG may detach from the BMZ under low pH condition induced by inflammation, but some complement fragments remain at the BMZ. These phenomena may help to explain why C3 is more sensitive than IgG when DIF is used to diagnose BP.

Anti-BP230 IgE autoantibodies in bullous pemphigoid intraindividually correlate with disease activity

BackgroundBullous pemphigoid (BP), the most common subepidermal autoimmune blistering disease, is classically defined by the presence of IgG autoantibodies directed against the hemidesmosomal proteins BP180 (type XVII collagen) and BP230 and the predominance of skin lesions. Several studies have addressed the role of anti-BP180 IgE in patients and experimental models, while data on anti-BP230 IgE are scarce. ObjectiveTo assess anti-BP230 IgE level by ELISA in BP sera and to correlate it with disease severity and clinical characteristics. MethodsBP sera underwent anti-BP230 IgE ELISA and Western blotting against human BP230 fragments. ResultsWe demonstrate that 36/154 (23%) of BP sera were positive for anti-BP230 IgE. Anti-BP230 IgE levels had no correlation with clinical phenotype or disease activity per se. Interestingly, anti-BP230 IgE was significantly associated with disease activity within individuals during the course of the disease. Additionally, anti-BP230 IgE and total IgE levels showed a significant correlation. Notably, anti-BP230 IgG correlated interindividually with disease activity. By Western blotting, the C-terminal domain of BP230 fragments (C2; amino acids 2024–2349 and C3; amino acids 2326–2649), provided the best serological assay for anti-BP230 IgE detection. ConclusionAs a complementary tool, IgE immunoblotting is recommended to obtain an optimal serological diagnosis, particularly in patients with severe disease without IgG reactivity by BP180- or BP230-specific ELISA. Although the detection of serum anti-BP230 IgE is not of major diagnostic significance, it may be relevant for therapeutic decisions, e.g., for anti-IgE-directed treatment, which has been successfully used in case series of BP.

Bullous pemphigoid and diabetes mellitus: a systematic review and meta-analysis.

We aimed to systematically review and meta-analyze the association between diabetes mellitus (DM) and bullous pemphigoid (BP). Bullous pemphigoid (BP) is a prevalent autoimmune subepidermal blistering disease. Comorbid health conditions like neurological diseases and malignancies have been associated with BP. Growing evidence suggests that type 2 diabetes mellitus (T2DM) may increase the risk of developing BP. This review aims to synthesize this evidence. A systematic literature review was performed using Medline, PubMed, and Scopus in March 2022. Studies exploring the association between BP and DM were included. Data were extracted, and quality was assessed using the Newcastle-Ottawa scale. Meta-analysis was conducted to identify the odds ratio (OR) and 95% confidence intervals (CI) of the association. Seventeen studies were included, most being case-control studies from Europe and Asia. The pooled OR was 2.06 (95% CI: 1.61-2.62), suggesting a significant association between DM and BP. However, strong heterogeneity (I2 = 88%) was observed. Evidence consolidates a significant relationship between DM and BP, potentially due to alterations in the immune system and skin properties caused by diabetes. Strengths of this review include a comprehensive search, rigorous methodology, large sample size, and heterogeneity evaluation. However, varying study quality, potential publication bias, and unaccounted confounding factors present limitations. There is a potential link between T2DM and an increased risk of BP. Further studies are required to understand this association and the underlying mechanisms.

Laminin β4 is a constituent of the cutaneous basement membrane zone and additional autoantigen of anti-p200 pemphigoid

Anti-p200 pemphigoid is a subepidermal autoimmune blistering disease (AIBD) characterized by autoantibodies against a 200kDa protein. Laminin γ1 has been described as target antigen in 70% to 90% of patients. No diagnostic assay is widely available for anti-p200 pemphigoid, which might be due to the unclear pathogenic relevance of anti-laminin γ1 autoantibodies. To identify a target antigen with higher clinical and diagnostic relevance. Immunoprecipitation, mass spectrometry, and immunoblotting were employed for analysis of skin extracts and sera of patients with anti-p200 pemphigoid (n=60), other AIBD (n=33), and healthy blood donors (n=29). To localize the new antigen in skin, cultured keratinocytes and fibroblasts, quantitative real-time polymerase chain reaction and immunofluorescence microscopy were performed. Laminin β4 was identified as target antigen of anti-p200 pemphigoid in all analyzed patients. It was located at the level of the basement membrane zone of the skin with predominant expression in keratinocytes. A higher number of sera needs to be tested to verify that laminin β4 is the diagnostically relevant antigen of anti-p200 pemphigoid. The identification of laminin β4 as an additional target antigen in anti-p200 pemphigoid will allow its differentiation from other AIBD and as such, improve the management of these rare disorders.

Accuracy of serration pattern analysis by direct immunofluorescence in subepidermal autoimmune blistering diseases.

Background Direct immunofluorescence (DIF) is essential for the diagnosis of sub-epidermal immunobullous diseases (SIBD). Bullous pemphigoid (BP), a sub-epidermal immunobullous disease, shows linear IgG and C3 deposition along the dermo-epidermal junction by DIF. However, similar histological and DIF findings are also seen in epidermolysis bullosa acquisita (EBA). High-power examination of antibody deposition by DIF in a "u" or "n" serrated pattern can help differentiate these two entities. Aims/Objectives The aim of this study was to determine the diagnostic accuracy of serration patterns in IgG-mediated sub-epidermal immunobullous disease. Methods All cases of IgG-mediated sub-epidermal immunobullous disease diagnosed over the past 2 years and 9 months period and confirmed serologically, were included. Examination of the serration pattern in DIF was assessed on oil emersion. Salt split skin indirect immunofluorescence (SSS IIF), BP180 enzyme-linked immunosorbent assay (ELISA), profile ELISA and BIOCHIP mosaic were performed, wherever available. Results This study included 74 cases of bullous pemphigoid, eight cases of mucus membrane pemphigoid (MMP) and one case of epidermolysis bullosa acquisita. The characteristic zigzag "n" pattern was visualised in 66 out of 82 cases (80.5%) of the pemphigoid group (BP + MMP); the single epidermolysis bullosa acquisita case showed the "u" serrated pattern. No statistical correlation was seen between serration pattern and BP180 positivity by ELISA (P = 0.05). Limitations The study is limited by the single case of epidermolysis bullosa acquisita (which could be due to rarity of this disease in north Indian population due to genetic variation), lack of detailed serological investigations and immunoblot in all cases. Conclusion Serration pattern analysis is an easy-to-interpret and highly useful technique for characterisation of sub-epidermal immunobullous diseases.

Dietary habits in Japanese patients with bullous pemphigoid: low intake of retinol.

Bullous pemphigoid (BP) is an autoimmune subepidermal blistering disease. Dietary habits may modulate the pathogenesis of BP. We evaluated dietary habits in Japanese patients with BP and compared their results to those of age- and sex-matched healthy controls. We also examined the relationship between dietary habits versus IgG anti-BP180NC16A antibody or parameters of BP disease area index (BPDAI); cutaneous blisters/erosions, cutaneous urticaria/erythema, and mucosal blisters/erosions. Dietary habits were assessed by the validated, Brief-type self-administered Diet History Questionnaire. Severity of disease was assessed with BPDAI. Patients with BP showed a lower intake of retinol (vitamin A1) and beverages, and a higher intake of seasoning/spices, compared to controls. The bivariate and multivariable logistic regression analysis showed that BP was associated with a low intake of retinol and beverages. There were no significant correlations between IgG anti-BP180NC16A antibody levels and intake of nutrients/foods. The BPDAI score for cutaneous blisters/erosions significantly positively correlated with intake of carbohydrate and negatively with intake of retinol, vitamin A, animal fat, cholesterol, phosphorus, and vitamin B2. The BPDAI score for cutaneous urticaria/erythema significantly negatively correlated with intake of vitamin A. BP patients with mucosal blisters/erosions had a higher intake of cholesterol, n-6 polyunsaturated fatty acid, and eggs, and lower intake of seasoning/spices, compared to patients without BP. The supplementation of vitamin A might have prophylactic and/or therapeutic effects on BP.

Anti-NC16A IgA from Patients with Linear IgA Bullous Dermatosis Induce Neutrophil-Dependent Subepidermal Blistering in Mice

Linear IgA bullous dermatosis (LABD) is an acquired autoimmune subepidermal blistering skin disease characterized by circulating and tissue-bound IgA autoantibodies that recognize epitopes within the hemidesmosomal protein BP180, including its NC16A domain. Histologically, LABD has long been defined by neutrophil infiltration and dermal-epidermal separation. However, the pathogenic roles of anti-NC16A IgA and neutrophils in LABD, as well as their interactions, have not been thoroughly studied. We show that passive transfer of patient-derived anti-NC16A IgA induce clinical and histologic LABD pathology in humanized NC16A mice that are reconstituted locally or systemically with human neutrophils. The lesional skin of mice exhibits significantly elevated levels of the neutrophil chemoattractants CXCL-1 and CXCL-2. Furthermore, we show significantly increased levels of the neutrophil chemoattractant IL-8 in blister fluids of patients with LABD. This study provides direct evidence that anti-NC16A IgA in patients with LABD are pathogenic and interact with neutrophils to mediate tissue injury and subepidermal blister formation. This study further corroborates the importance of neutrophil-mediated tissue injury in LABD disease physiology and establishes a clinically relevant invivo model system that can be used to systematically dissect the immunopathogenesis of LABD.

Elevated levels of interleukin-9 in the serum of bullous pemphigoid: possible association with the pathogenicity of bullous pemphigoid.

Bullous pemphigoid (BP) is an autoimmune subepidermal blistering disease (sAIBD). In addition to disease causing autoantibodies, several leukocyte subsets, including mast cells and eosinophils, play key roles in mediating skin inflammation. Detailed immunophenotyping and, more recently, the therapeutic effects of interleukin-4 (IL-4) receptor alpha inhibition in BP pointed to a prominent role of T helper 2 (Th2) cells. Among other cell types, IL-9 is expressed by Th2 and mast cells and potentially drives allergic, Th2-dominated inflammation. Although cytokines in BP have been relatively well investigated, the role of IL-9 has remained enigmatic. This study aimed to evaluate the effect of IL-9 in BP. Serum IL-9 levels were significantly elevated in patients with BP and decreased upon induction of remission. Serum IL-9 levels were not elevated in epidermolysis bullosa acquisita, another sAIBD. The time-course analysis using serum sets from four patients with BP revealed that serum IL-9 was a sensitive biomarker of BP. IL-9-positive cells infiltrated dominantly in BP lesions, especially in the blister fluid, and Th9 cells were abundant. Therefore, IL-9 was elevated in the serum and lesions of BP, which could be a biomarker of BP.

Localized Bullous Pemphigoid

A man in his 80s presented with a pruritic, focally ulcerated pink plaque with overlying blisters on the left lateral thigh (Figures 1 and 2). This had been the site of an excision 9 months earlier. Over time, pruritic vesicles and bullae developed at the surgical site. Punch biopsies showed a subepidermal bulla with extensive eosinophilic infiltrate on histopathology and linear deposition of C3 and immunoglobulin G (IgG) at the basement membrane zone on direct immunofluorescence, confirming the diagnosis of localized bullous pemphigoid (BP).Figure 2Close-up view of vesicles and bullae at the periphery.View Large Image Figure ViewerDownload Hi-res image Download (PPT) BP is a subepidermal autoimmune blistering disease caused by autoantibodies to hemidesmosome proteins BP180 (BP antigen 2) or BP230 (BP antigen 1). Classically, patients present with pruritic urticarial papules and plaques and tense vesicles and bullae. Diagnosis is made by examination of the tissue and direct immunofluorescence, which show a subepidermal accumulation of eosinophils and linear deposition of IgG and/or C3 in an n-serrated pattern along the basement membrane zone, respectively. Enzyme-linked immunosorbent assay (ELISA) for autoantibodies to the NC16a domain of BP180 and to BP230 is supportive, and anti-BP180-NC16a ELISA may aid in monitoring disease activity during treatment.1Schmidt E. Zillikens D. Pemphigoid diseases.Lancet. 2013; 381: 320-332https://doi.org/10.1016/S0140-6736(12)61140-4Abstract Full Text Full Text PDF PubMed Scopus (705) Google Scholar,2Feliciani C. Joly P. Jonkman M.F. et al.Management of bullous pemphigoid: the European Dermatology Forum consensus in collaboration with the European Academy of Dermatology and Venereology.Br J Dermatol. 2015; 172: 867-877https://doi.org/10.1111/bjd.13717Crossref PubMed Scopus (233) Google Scholar Most cases of BP are generalized. Rarely, it is localized, usually to sites of previous skin injury, surgery, radiation, or venous insufficiency.3Ständer S. Kasperkiewicz M. Thaçi D. et al.Prevalence and presumptive triggers of localized bullous pemphigoid.J Dermatol. 2021; 48: 1257-1261https://doi.org/10.1111/1346-8138.15912Crossref PubMed Scopus (4) Google Scholar Although the pathophysiology of localized BP is not well understood,4Danescu S. Chiorean R. Macovei V. Sitaru C. Baican A. Role of physical factors in the pathogenesis of bullous pemphigoid: case report series and a comprehensive review of the published work.J Dermatol. 2016; 43: 134-140https://doi.org/10.1111/1346-8138.13031Crossref PubMed Scopus (39) Google Scholar topical steroids are first-line therapy and are generally effective.2Feliciani C. Joly P. Jonkman M.F. et al.Management of bullous pemphigoid: the European Dermatology Forum consensus in collaboration with the European Academy of Dermatology and Venereology.Br J Dermatol. 2015; 172: 867-877https://doi.org/10.1111/bjd.13717Crossref PubMed Scopus (233) Google Scholar Our patient was treated with topical clobetasol 0.05% ointment twice daily for 3 weeks with excellent results, and subsequent use as needed to maintain clearance. The authors report no competing interests.

Erosive and ulcerative stomatitis in dogs and cats: which immune-mediated diseases to consider?

Immune-mediated and autoimmune diseases of the skin often present with oral cavity involvement. Autoimmune subepidermal blistering diseases and pemphigus vulgaris are classic examples. While the primary lesions (vesicles and bullae) are relatively specific, these fragile lesions evolve rapidly into erosions and ulcers, which are lesion types that overlap with many diseases. Furthermore, some immune-mediated diseases such as severe adverse drug reactions, lupus diseases, canine uveodermatological syndrome, and vasculitis, may or may not involve the oral cavity, and often nonoral clinical manifestations are more diagnostic. In these situations, disease knowledge combined with signalment, lesion distribution, and history help to narrow the differentials. Surgical biopsy is required for confirmation in most diseases, while immunosuppressive treatments most typically involve glucocorticoids with or without nonsteroidal immunosuppressants.

Nail abnormalities in subepidermal blistering diseases: a cross-sectional study.

Nail involvement in subepidermal autoimmune blistering diseases (SEABD) is not common. Although these changes can be transient, permanent changes can also occur. This study addresses nail involvement manifestations and their associated factors in patients with SEABD. From March 2020 to March 2021, we enrolled 56 patients with SEABD who were being examined at a tertiary skin hospital and checked their nail changes. We investigated the association between the SEABD subtypes and treatments that patients were receiving and the nail abnormalities. Additional factors including age, gender, duration since diagnosis, presence of mucosal involvement, and anti-bp230 and anti-bp180 IgG antibody quantitative levels (in those patients with bullous pemphigoid) were analyzed. The most common nail abnormalities were ridging, onycholysis, and onychoschizia. We observed a lower prevalence of onycholysis in EBA, a lower prevalence of periungual bullae in MMP, and a higher prevalence of scarring loss in EBA. Rituximab and dapsone were effective in preventing onycholysis as well as prednisolone in preventing subungual hematoma. Multiple lesions were found to be more common in the foot digits including great toes, probably because of higher exposure to trauma. In summary, in patients with SEABD and concomitant nail involvement, the underlying disease control, proper treatment, and avoidance of trauma may be helpful.

Epidermolysis Bullosa Acquisita-Current and Emerging Treatments.

Epidermolysis bullosa acquisita (EBA) is a rare chronic autoimmune subepidermal blistering disease of the skin and mucous membranes, usually beginning in adulthood. EBA is induced by autoantibodies to type VII collagen, a major component of anchoring fibrils in the dermal-epidermal junction (DEJ). The binding of autoantibodies to type-VII collagen subsequently leads to the detachment of the epidermis and the formation of mucocutaneous blisters. EBA has two major clinical subtypes: the mechanobullous and inflammatory variants. The classic mechanobullous variant presentation consists of skin fragility, bullae with minimal clinical or histological inflammation, erosions in acral distribution that heal with scarring, and milia formation. The inflammatory variant is challenging to differentiate from other autoimmune bullous diseases, most commonly bullous pemphigoid (BP) but also mucous membrane pemphigoid (MMP), Brunsting-Perry pemphigoid, and linear IgA dermatosis. Due to its recalcitrance conventional treatment of epidermolysis bullosa acquisita is shown to be demanding. Here we discuss novel therapeutic strategies that have emerged and which could potentially improve the quality of life in patients with EBA.

The efficacy of adding oral sodium cromoglycate to stable treatment for controlling bullous pemphigoid-related pruritus: A retrospective study.

Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease which mainly affects the elderly. It manifests as severe pruritus, urticarial plaques, and tense bullae and is associated with significant mortality. Therapy options for itch in BP patients are limited, mainly because the pathogenesis of itch in BP remains unclear. Sodium cromoglycate was commonly used in the past as an inhaled drug for the management of bronchial asthma and as an oral treatment for children with urticaria pigmentosa. In this study we sought to assess its efficacy in reducing BP associated itch. Assessing the efficacy of oral sodium cromoglycate in reducing BP-related pruritus after stabilization of disease activity. We retrospectively reviewed the medical records of patients with a confirmed diagnosis of BP who were treated with sodium cromoglycate. Patient reported outcome measures (PROM) including: BPDAI pruritus, ABQOL and TABQOL, and BPDAI activity score were compared at two points in time: before commencing treatment with sodium cromoglycate or before commencing maximal dose of this treatment, and at least 4 weeks after treatment commencement. A total of 21 patients met the inclusion criteria. After at least 4 weeks of treatment with oral sodium cromoglycate BPDAI pruritus, ABQOL and TABQOL scores were statistically significantly decreased compared to the scores prior to treatment commencement, P < 0.000, P < 0.008, and P < 0.004, respectively. Oral treatment with sodium cromoglycate for the management of pruritus in BP patients may be beneficial, however, further prospective studies are required to better assess its efficacy.

Rituximab in Subepidermal Blistering Diseases

Background: Although rituximab is known to be effective in the treatment of pemphigus, its role in subepidermal autoimmune blistering diseases is unclear and currently limited to off-label use. Summary: This is a meta-analysis of case reports, case series, and retrospective studies on the effectiveness and safety of rituximab in bullous pemphigoid, mucous membrane pemphigoid, ocular pemphigoid, and epidermolysis bullosa acquisita. We compared remission and relapse rates in patients who received rituximab with those who only received conventional medical therapy. Comparisons were also made among disease subgroups. Key Message: The present analysis suggests that patients with subepidermal autoimmune blistering diseases treated with rituximab achieve a higher rate of complete remission and encounter their first relapse after a longer time interval. However, time to remission and total relapse rates were similar between groups. Adverse events and mortality rates were no more common in patients who received rituximab. This analysis was limited by the absence of randomized controlled trials and the observation that rituximab was used as a late rescue therapy in most reports. In conclusion, rituximab may be effective in subepidermal blistering disease, but randomized controlled studies are required for the validation of current observational data.

Survival and prognostic factors in bullous pemphigoid: A retrospective cohort study.

Background Bullous pemphigoid is the most common subepidermal autoimmune blistering disease. Till now, the reported prognostic factors in bullous pemphigoid vary considerably. Aims The purpose of this study was to determine the overall survival rate and prognostic factors in bullous pemphigoid. Methods We conducted a retrospective cohort study on newly diagnosed bullous pemphigoid patients between July 2001 and November 2019 in a referral unit for autoimmune blistering skin diseases in Romania. Results One hundred forty-eight patients were included in the study. The Kaplan-Meier overall survival rates at 1, 3, 5 and 10 years were respectively 74.2% (95% confidence interval, 67.5-81.6%), 53.4% (45.7-62.2%), 43.6% (35.9-53%) and 31.3% (23.5-41.7%). The median follow-up among survivors was 48 months (interquartile range: 11-150). Ninety (60.8%) patients died during the follow-up period; of them, 38 (42.2%) had active disease at the time of death. Advanced age, neurological diseases, valvular heart disease, malignancies, use of statins, skin infections and extensive cutaneous involvement were linked to poorer outcomes, while the use of topical corticosteroids was associated with increased overall survival. Limitations This study lacks a control cohort to validate the obtained results. It was conducted in a retrospective manner in a single centre. In addition, indirect immunofluorescence microscopy was not performed in all patients. Conclusion Beyond ageing and neurological comorbidities, the prognosis of bullous pemphigoid patients was significantly influenced by the presence of skin infections, valvular heart disease, use of statins and extensive cutaneous involvement. Topical corticosteroid treatment was associated with increased survival in these patients.

The significance of preclinical anti-BP180 autoantibodies.

Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease. Although the pathomechanism of BP onset has yet to be elucidated in detail, BP autoantibodies targeting two hemidesmosomal components, BP180 and BP230, are known to play a pivotal role in BP pathogenesis. Thus, the detection and measurement of BP autoantibodies are necessary for diagnosing BP and monitoring the disease activity. Immune assays such as immunofluorescence microscopy, immunoblotting, and ELISAs using BP180 and BP230 detect BP autoantibodies in most BP cases with high specificity; however, BP autoantibodies are sometimes detected in BP patients before the onset of this disease. BP autoantibodies that are detected in patients without typical tense blisters are defined as “preclinical BP autoantibodies”. These preclinical BP autoantibodies are detected even in a low percentage of normal healthy individuals. Although the importance of preclinical BP autoantibodies remains elusive, these autoantibodies might be a potential risk factor for subsequent BP development. Therefore, previous comparative epidemiological studies have focused on the prevalence of preclinical BP autoantibodies in populations susceptible to BP (e.g., the elderly) or in diseases with a higher risk of comorbid BP. This mini-review summarizes the literature on the prevalence of preclinical BP autoantibodies in patients with various conditions and diseases, and we discuss the significance of preclinical BP autoantibody detection.

Updated S2 K guidelines for the management of bullous pemphigoid initiated by the European Academy of Dermatology and Venereology (EADV).

Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease of the skin and mucous membranes. This disease typically affects the elderly and presents with itch and localized or, most frequently, generalized bullous lesions. A subset of patients only develops excoriations, prurigo-like lesions, and eczematous and/or urticarial erythematous lesions. The disease, which is significantly associated with neurological disorders, has high morbidity and severely impacts the quality of life. The Autoimmune blistering diseases Task Force of the European Academy of Dermatology and Venereology sought to update the guidelines for the management of BP based on new clinical information, and new evidence on diagnostic tools and interventions. The recommendations are either evidence-based or rely on expert opinion. The degree of consent among all task force members was included. Treatment depends on the severity of BP and patients' comorbidities. High-potency topical corticosteroids are recommended as the mainstay of treatment whenever possible. Oral prednisone at a dose of 0.5 mg/kg/day is a recommended alternative. In case of contraindications or resistance to corticosteroids, immunosuppressive therapies, such as methotrexate, azathioprine, mycophenolate mofetil or mycophenolate acid, may be recommended. The use of doxycycline and dapsone is controversial. They may be recommended, in particular, in patients with contraindications to oral corticosteroids. B-cell-depleting therapy and intravenous immunoglobulins may be considered in treatment-resistant cases. Omalizumab and dupilumab have recently shown promising results. The final version of the guideline was consented to by several patient organizations. The guidelines for the management of BP were updated. They summarize evidence- and expert-based recommendations useful in clinical practice.

Deciphering the Contribution of BP230 Autoantibodies in Bullous Pemphigoid.

Bullous pemphigoid (BP) is a subepidermal autoimmune blistering disease predominantly affecting elderly patients and carries significant morbidity and mortality. Patients typically suffer from severe itch with eczematous lesions, urticarial plaques, and/or tense blisters. BP is characterized by the presence of circulating autoantibodies against two components of the hemidesmosome, BP180 and BP230. The transmembrane BP180, also known as type XVII collagen or BPAG2, represents the primary pathogenic autoantigen in BP, whereas the intracellular BP230 autoantigen is thought to play a minor role in disease pathogenesis. Although experimental data exist suggesting that anti-BP230 antibodies are secondarily formed following initial tissue damage mediated by antibodies targeting extracellular antigenic regions of BP180, there is emerging evidence that anti-BP230 IgG autoantibodies alone directly contribute to tissue damage. It has been further claimed that a subset of patients has a milder variant of BP driven solely by anti-BP230 autoantibodies. Furthermore, the presence of anti-BP230 autoantibodies might correlate with distinct clinical features. This review summarizes the current understanding of the role of BP230 and anti-BP230 antibodies in BP pathogenesis.

Rapid Disease Control in First-Line Therapy-Resistant Mucous Membrane Pemphigoid and Bullous Pemphigoid with Omalizumab as Add-On Therapy: A Case Series Of 13 Patients.

The role of IgE autoantibodies has been demonstrated in the pathogenesis of bullous pemphigoid for many years. Recently, omalizumab (OMZ), a humanized monoclonal anti-IgE antibody that depletes total serum IgE, has been used off-label in a few case series of bullous pemphigoids demonstrating a rapid efficacy and allowing significant improvements or complete remission as add-on therapy in first-line treatment-resistant patients. Herein, we report the largest retrospective study to evaluate OMZ effectiveness in patients with subepidermal autoimmune blistering diseases. Our series included 13 patients from a single center with bullous pemphigoid or mucous membrane pemphigoid, of whom 7 had mucous membrane involvement. OMZ was added to the unchanged immunosuppressive therapies. Detailed clinical and immunological data during the first year were collected, notably for specific anti-BP180-NC16A IgE and IgG, and the median total follow-up was 30 months (range: 3–81). Our series demonstrated that OMZ induced a significant improvement in pruritus, urticarial score, and daily blister count on day 15, allowing disease control to be achieved in a 1-month median time and complete remission (CR) in a 3-month median time in 85% of these patients previously in therapeutic impasse. At the end of the follow-up, 31% of patients achieved CR on minimal therapy after OMZ weaning without relapses, and 54% achieved CR on OMZ continuation with a minimal dose of concomitant treatment. Two patients experienced therapeutic failure (15%). At baseline, clinical variables reflecting activity were significantly positively correlated with eosinophil blood count, total IgE serum level, specific anti-BP180 IgE and IgG. While baseline anti-BP180 IgG and specific anti-BP180 IgE were significantly positively correlated, only the two patients who experienced a therapeutic failure with OMZ did not fit with this correlation, demonstrating elevated levels of anti-BP180 IgG with no measurable BP180-specific IgE. Follow-up of immunological variables demonstrated a rapid decrease of eosinophilia towards normalization, whereas a slower decline towards negativation was observed over 1 year for anti-BP180 IgG and anti BP180 IgE in patients who responded to OMZ. This case series demonstrated that OMZ is a rapidly effective biologic therapy for refractory bullous pemphigoid and mucous membrane pemphigoid, permitting rapid disease control and reduction of concomitant therapeutics.

Clinical features of chronic bullous dermatosis of childhood

Chronic bullous dermatosis of childhood (CBDC) is a rare autoimmune subepidermal blistering disease, which can develop following vaccination or medication, or with an autoimmune condition or illness, among other causes. To identify and better understand the clinical features of CBDC by performing a systematic review, in line with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Eligible studies included publication since 1980, CBDC diagnosis, case studies, subjects aged < 18 years, clinical features and no language restriction. A database search was conducted including Embase, MEDLINE and Scopus on 14 July 2021 (see Appendix for search terms). Data were assessed for risk of bias. Jamovi was used for statistical analysis. Age and sex were compared with mucocutaneous involvement, cutaneous involvement, other symptoms, human leucocyte antigen type and lesion descriptions. After removing duplicate references using Endnote, 351 papers were identified, of which 91 met the inclusion criteria. These papers included 130 cases of CBDC: 110 children and 20 neonates. The ratio of male : female patients was 19 : 1 for neonates and 74:55 for children. χ² analysis with 1 degree of freedom showed that CBDC in neonates was associated with facial (χ²(1) = 9.67, P < 0.01), mouth (χ²(1) = 31.0, P < 0.001), upper airway (χ²(1) = 52.7, P < 0.001), oesophageal (χ²(1) = 34.6, P < 0.001), ophthalmic (χ²(1) = 6.27, P = 0.01) involvement and with respiratory distress (χ²(1) = 22.7 P < 0.001). CBDC in children was associated with genital (χ²(1) = 3.96, P < 0.05), arm (χ²(1) = 6.99, P < 0.01) and leg (χ²(1) = 7.03, P < 0.01) involvement. CBDC in male patients was associated with facial (χ²(1) = 7.01, P < 0.01), scalp (χ²(1) = 5.96, P < 0.02) and perianal (χ²(1) = 7.22, P < 0.01) involvement. Neonates with CBDC are more likely to have a mucocutaneous distribution of lesions, whereas children are more likely to have cutaneous lesions. The limitations of this study include selection bias, and the small neonate sample size makes the study unrepresentative of the population. The review highlights the need for further research into the clinical features of CBDC in neonates.