Pathophysiologic mechanisms of itch in bullous pemphigoid.

BACKGROUND: One of the hallmarks of bullous pemphigoid (BP) is moderate to severe chronic itch. Managing this is difficult because little is known about the mechanisms of itch in BP. OBJECTIVE: We sought to elucidate the pathophysiologic mechanisms of itch in BP. METHODS: The expression of itch mediators in lesions of 24 patients with BP and 6 healthy individuals were examined through immunofluorescence staining. Furthermore, the expression of itch mediators and itch severity was correlated. RESULTS: Itch severity was correlated with eosinophils, substance P, neurokinin 1R, interleukin (IL) 31 receptor A, oncostatin M receptor-ß, IL-13, periostin, and basophils. There was also a trend between itch severity and IL-31 expression. Most of the cells expressing IL-31 or neurokinin 1R were identified as eosinophils. Intraepidermal nerve fiber density was decreased. Other itch mediators, including mast cells, IL-4, thymic stromal lymphopoietin, transient receptor potential vanilloid 1 and ankyrin 1, and protease activated receptor 2 were not significantly correlated with itch severity. LIMITATIONS: The relatively small sample size, the examination of protein expression exclusively through immunofluorescent analysis, and lack of functional assays in patients are the limitations. CONCLUSIONS: Multiple factors are involved in BP-associated itch, including eosinophils, substance P, neurokinin 1R, IL-31, IL-31 receptor A, oncostatin M receptor-ß, IL-13, periostin, and basophils. They could be useful therapeutic targets.

[Autoimmune blistering dermatoses in children]. / Bullöse Autoimmundermatosen im Kindesalter.

Autoimmune blistering skin disorders represent a rare group of autoantibody-induced dermatoses against desmosomal and hemidesmosomal molecules. The common age of onset for pemphigus and pemphigoid, as well as dermatitis herpetiformis, encompasses the adult age, but all these disorders can be observed neonatally and/or during childhood. If the disease occurs postpartum or neonatally, physicians should consider transplacental transmission of pathogenic maternal immunoglobulin G (IgG)-autoantibodies, and both mother and child should be included in the diagnostic work up. If the disorder is suspected in childhood, early immunoserological testing and skin biopsies for direct immunofluorescence analyses are recommended for the correct diagnosis and subsequently for the right choice of treatment. First-line recommendations are nonhalogenated topical steroids, followed by oral dapsone. All therapies require preliminary examinations, e. g. enzyme-activity testing (as is glucose-6-phophate dehydrogenase in dapsone treatment). In refractory cases, further treatment choices like high-dose intravenous immunoglobins, plasmapheresis/immunoadsorption or targeted therapies like anti-CD20 autoantibody therapies are indicated. An intense dermatological support and good medical care are essential for an age-appropriate development of the child and to lower possible treatment-associated adverse events.

[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.

Prospective study in bullous pemphigoid: association of high serum anti-BP180 IgG levels with increased mortality and reduced Karnofsky score.

BACKGROUND: Bullous pemphigoid (BP) is a subepidermal blistering disease characterized by autoantibodies against the two hemidesmosomal proteins, BP180 (type XVII collagen) and BP230. The multicentre prospective BLISTER (Bullous Pemphigoid Steroids and Tetracyclines) trial randomized 253 patients with BP to compare the benefits and harms between initial treatment with doxycycline or prednisolone. OBJECTIVES: To analyse distinct autoantibody profiles for the prediction of the disease course in a well-characterized cohort of BP sera. METHODS: One hundred and forty-three patients of the BLISTER trial consented to participate in this serological study. Sera taken at baseline were analysed by (i) indirect immunofluorescence, (ii) anti-BP180 NC16A (16th noncollagenous domain) and anti-BP230 enzyme-linked immunosorbent assay and (iii) immunoblotting with various substrates. Results were then linked with clinical parameters including age, Karnofsky score, number of blisters, related adverse events and mortality. RESULTS: Disease activity correlated with immunoglobulin (Ig)G anti-BP180 levels but not with levels of anti-BP230 IgG and anti-BP180 IgE. High levels of both anti-BP180 IgG and anti-BP230 IgG were associated with a low Karnofsky score. The presence of anti-BP230 IgG was more frequent in older patients. Those with higher total IgE serum levels suffered from fewer adverse events. Higher IgG anti-BP180 levels were associated with an increased 1-year mortality rate. CONCLUSIONS: Analysis of the autoantibody profile is not only of diagnostic relevance but may also be helpful in predicting the course of the disease.

Spectrum of orocutaneous disease associations: Immune-mediated conditions.

There are a number of diseases that manifest both on the skin and the oral mucosa, and therefore the importance for dermatologists in clinical practice to be aware of these associations is paramount. In the following continuing medical education series, we outline orocutaneous disease associations with both immunologic and inflammatory etiologies.

Pemphigoid diseases.

Pemphigoid diseases are a group of well defined autoimmune disorders that are characterised by autoantibodies against structural proteins of the dermal-epidermal junction and, clinically, by tense blisters and erosions on skin or mucous membranes close to the skin surface. The most common of these diseases is bullous pemphigoid, which mainly affects older people and the reported incidence of which in Europe has more than doubled in the past decade. Prognosis and treatments vary substantially between the different disorders and, since clinical criteria are usually not sufficient, direct immunofluorescence microscopy of a perilesional biopsy specimen or serological tests are needed for exact diagnosis. In eight pemphigoid diseases the target antigens have been identified molecularly, which has allowed the development of standard diagnostic assays for detection of serum autoantibodies-some of which are commercially available. In this Seminar we discuss the clinical range, diagnostic criteria, diagnostic assay systems, and treatment options for this group of diseases.

Bullous pemphigoid: role of complement and mechanisms for blister formation within the lamina lucida.

Bullous pemphigoid (BP), an autoimmune subepidermal blistering skin disease, demonstrates tense blisters with or without widespread erythema, blistering along the lamina lucida, immunoglobulin G and/or complement deposits at the basement membrane zone, and the presence of circulating autoantibodies against hemidesmosomal molecules. These autoantibodies usually react against 180-kDa and/or 230-kDa proteins, designated as BP180 and BP230, respectively. The precise blistering mechanisms after autoantibodies bind to antigens are not fully understood. Immune complexes are thought to initially activate the complement cascade, which may induce activation of proteases and/or cytokines and cause dermal-epidermal separation. However, why does separation run specifically within the lamina lucida in a space as narrow as 500 nm wide? This review mainly focuses on the possible mechanisms of BP-specific blistering and how separation occurs along the lamina lucida, based on existing evidence.

Evidence for vitamin D deficiency and increased prevalence of fractures in autoimmune bullous skin diseases.

BACKGROUND: Vitamin D deficiency plays a role in autoimmune diseases and risk of fractures. No data are available on vitamin D levels and vertebral fractures in autoimmune bullous skin diseases. OBJECTIVES: To assess serum vitamin D levels and the prevalence of vertebral fractures in patients with pemphigus vulgaris (PV) and bullous pemphigoid (BP), potentially fatal autoimmune bullous disorders. METHODS: We studied 13 consecutive inpatients with untreated active PV (six men and seven women, mean ± SD age 53·5 ± 14·3 years), 15 with BP (seven men and eight women, mean ± SD age 76·9 ± 12·4 years) and 28 age-, body mass index- and sex-matched controls. The 25-hydroxyvitamin D (25-OHD) levels and presence of vertebral fractures on spinal X-ray were assessed in all subjects. RESULTS: In patients with PV, 25-OHD levels were lower (mean ± SD 12 ± 4·4 ng mL(-1) ) and prevalence of severe hypovitaminosis D higher (62%) than in controls (mean ± SD 22·2 ± 11·7 ng mL(-1) , P = 0·012; 23%, P = 0·0047, respectively). The prevalence of fractures was 54% and 31% in patients with PV and controls, respectively. Patients with BP showed lower 25-OHD levels (mean ± SD 9·6 ± 7·2 ng mL(-1) ) and higher prevalence of severe hypovitaminosis D (73%) than controls (mean ± SD 22·6 ± 18·7 ng mL(-1) , P = 0·022; 27%, P = 0·01, respectively). The prevalence of fractures tended to be higher in patients with BP than in controls (67% vs. 33%, respectively, P = 0·068). CONCLUSIONS: The low 25-OHD levels found in PV and BP may suggest a role for this agent in their pathogenesis. The increased prevalence of fractures should be taken into consideration in patients who must be given corticosteroids.

The levels of soluble ST2 in sera and bullous fluid from patients with bullous pemphigoid.

Soluble ST2 (sST2) is a soluble form of the transmembrane receptor for interleukin (IL)-33, ST2L, and is a member of the IL-1 receptor family. sST2 antagonizes IL-33-ST2L signaling by competing with ST2L as a decoy receptor for IL-33. We investigated the sST2 and IL-33 levels in the sera and bullous fluid of bullous pemphigoid patients and compared these with the corresponding levels in normal healthy controls. As controls, we used the bullous fluid of burn patients and that from suction blisters induced in normal healthy volunteers. The serum sST2 concentrations of bullous pemphigoid patients were higher than those of healthy controls. Serum sST2 levels correlated with the area of skin involvement and serum lactate dehydrogenase levels, suggesting that serum sST2 levels reflect disease severity. The sST2 concentrations in bullous fluid from bullous pemphigoid patients were higher than those from controls. The concentration of IL-33 ligand was below the detectable limits in all enzyme-linked immunosorbent assay samples. Thus, our study suggested that the serum sST2 level may be a useful marker of disease severity and that sST2 functions as a negative regulator in the pathophysiology of bullous pemphigoid.

Prevalence and clinical features of Thai patients with bullous pemphigoid.

BACKGROUND: Bullous pemphigoid (BP) is a rare, subepidermal autoimmune blistering disease. Studies from different regions show discrepancies in clinical features and courses. OBJECTIVES: To reveal clinical characteristics, investigations and clinical outcomes of Thai patients with BP and to evaluate the association of BP with malignancy, diabetes mellitus and neurologic diseases. METHODS: Patients diagnosed as BP who had visited the autoimmune skin clinic at Siriraj Hospital between 1991 and 2009 were retrospectively studied. RESULTS: Fifty-eight patients were enrolled. Mean age of onset was 69.3 years. The female to male ratio was 2.7:1. Fifteen percent of the patients had mucosal involvement and 38.9% showed peripheral blood eosinophilia. The sensitivity of the direct and indirect immunofluorescence test in the diagnosis of BP was 95.7% and 73.5%, respectively. The frequency of diabetes mellitus in BP patients was significantly higher than that in the general population (p < 0.001). BP patients had a significantly higher chance of having neurologic diseases compared with other autoimmune vesiculobullous disease patients (adjusted odd ratios 4, 95% confidence interval 1.2-13.3). Disease control was achieved in 89.7% of the patients. One-year and three-year 6.4% remission rate was and 66.3%, respectively. CONCLUSIONS: BP usually occurred in the seventh and eighth decade of life and affected females more than males. BP is associated with diabetes mellitus and neurologic diseases. Corticosteroids are the mainstay of the treatment. Two-thirds of patients are likely to be in remission within three years.

Combined bullous pemphigoid and pemphigus vulgaris in an 18-year-old female.

We present a case of an 18-year-old female with clinical, histological and immunopathological features of overlapping pemphigus vulgaris and bullous pemphigoid. This case is unique both in the context of the distinctive hybrid nature of the bullous disorder and the young age of onset. An initial biopsy showed a combined pemphigus pattern histologically and a dominant pemphigoid pattern by immunofluorescence, hence posing a diagnostic conundrum. A subsequent biopsy however confirmed a combined pemphigus and pemphigoid pattern both in the context of the light microscopic findings and by immunofluorescence. The pathophysiologic basis of this distinctive hybrid dermatosis along with the other reported cases of overlapping pemphigus and pemphigoid are reviewed.

Clinical characteristics, mortality, and prognostic factors for bullous pemphigoid in a Thai population.

Bullous pemphigoid is an uncommon, autoimmune, blistering disease. Clinical features, associated conditions, and outcomes differ according to country. We aimed to determine the mortality rate and clinical characteristics of Thai patients and to evaluate the risk factors associated with survival.A retrospective analysis was conducted on 119 patients, over a ten-year period, at Songklanagarind Hospital, the largest tertiary university hospital in Southern Thailand.The median age of onset was 82 years [interquartile range 72, 90], and 60 (50.4%) patients were men. The underlying diseases were hypertension (53.8%), neurological disease (42.8%), and diabetes mellitus (31.9%). Fifty-eight patients (48.7%) experienced pruritus, and 61.3% of patients had mild cutaneous lesions (less than 10% of the body surface area) on the day of diagnosis. Nine percent of patients presented with mucosal involvement. Complete blood counts showed anemia (32.8%), neutrophilia (30.3%), and eosinophilia (42.9%). The 1-, 3- and 5-year overall mortality rates were 28.1% [95% confidence interval (CI), 7.8-36.6], 55.7% (95% CI, 44.4-64.7) and 71.9% (95% CI 59.9-80.2), respectively. On multivariate analysis, high neutrophil/lymphocyte ratio [odds ratio (OR) 5.55, P < .001] and anemia (OR 2.93, P = .025) were found to be independently associated with mortality rate, whereas disease remission (OR 0.25, P = .003) was demonstrated to be a good prognostic factor.This is the first study to analyze the mortality rate of Bullous pemphigoid in Thailand. Mortality was associated with high neutrophil/lymphocyte ratio and anemia.

Coagulation activation in autoimmune bullous diseases.

The main autoimmune blistering skin disorders are pemphigus vulgaris (PV) and bullous pemphigoid (BP). They differ in the inflammatory infiltrate, which is more intense in BP. Inflammation is known to activate coagulation in several disorders. Local and systemic activation of coagulation was evaluated in BP and PV. We studied 20 BP patients (10 active and 10 remittent), 23 PV patients (13 active and 10 remittent) and 10 healthy subjects. The coagulation markers prothrombin fragment F1+2 and D-dimer were measured by enzyme-immunoassays in plasma. The presence of tissue factor (TF), the main initiator of blood coagulation, was evaluated immunohistochemically in skin specimens from 10 patients with active PV, 10 patients with active BP and 10 controls. Plasma F1+2 and D-dimer levels were significantly high in active BP (P = 0.001), whereas in active PV the levels were normal. During remission, F1+2 and D-dimer plasma levels were normal in both BP and PV. TF immunoreactivity was found in active BP but neither in active PV nor in normal skin. TF reactivity scores were higher in active BP than in controls or active PV (P = 0.0001). No difference in TF scores was found between active PV and controls. BP is associated with coagulation activation, which is lacking in PV. This suggests that BP but not PV patients have an increased thrombotic risk. The observation that thrombotic complications occur more frequently in BP than in PV further supports this view.

Role of methotrexate in the treatment of bullous pemphigoid in the elderly.

Bullous pemphigoid (BP) is an autoimmune blistering disease that commonly occurs in the elderly. Immunosuppressive medications are effective at controlling the disease in the majority of cases. Mortality can occur as a consequence of severe disease or as a result of the therapies that are frequently employed as treatment. Commonly employed therapies include systemic corticosteroids, azathioprine and mycophenolate mofetil. In a small subset of patients, these first- and second-line therapies do not control disease or are not tolerated by the patients. Optional therapies include nicotinamide (niacinamide), tetracycline, intravenous immunoglobulin, cyclophosphamide, dapsone and methotrexate. The majority of BP patients are elderly, and several considerations need to be taken into account before a specific therapy is chosen. Methotrexate provides several advantages in the elderly population in terms of practicality, cost and tolerability. Several retrospective and prospective studies have evaluated its effectiveness in the treatment of BP in the elderly population. The results of these studies indicate that methotrexate is an effective therapy for BP and is a reasonable option for treatment in the elderly population, although maybe not as a first- or second-line therapy.

Bullous pemphigoid in infancy: Clinical and epidemiologic characteristics.

BACKGROUND: Recent cases of infants with bullous pemphigoid (BP) prompted us to explore the clinical and laboratory features of childhood BP. OBJECTIVES: We sought to explore the characteristics of infantile BP and compare them with childhood BP. METHODS: All new consecutive cases of infantile BP referred to dermatologic departments in Israel during 2004 to 2006 were retrospectively reviewed. All reported cases in the English- and foreign-language medical literature were gathered and statistical analysis of all cases was performed. RESULTS: Reports on infantile BP are rapidly increasing. Among 78 reported children with BP, 42 (53%) occurred in the first year of life. The incidence of infantile BP in Israel in the last years is 2.36:100,000/y. Predisposition for acral involvement is significantly higher in infantile BP than in childhood BP (79% vs 17%, P < .001), whereas genital involvement is very rare (5% vs 44%, P = .002). Laboratory parameters were not significantly different, except for a more frequent IgM deposition at the dermoepidermal junction in childhood BP (29% vs 10%, P = .042). LIMITATIONS: Statistical analyses of published cases may not be representative and could be affected by possible reporting biases. CONCLUSIONS: Infantile BP may not be as rare as commonly stated. Age-related differences in regional distribution of lesions in BP were demonstrated. No major differences regarding laboratory results, treatment, and prognosis were found.

A review of bullous pemphigoid associated with PD-1 and PD-L1 inhibitors.

BACKGROUND: Dermatologic toxicity represents a substantial portion of all immune-related adverse events (irAEs) associated with PD-1/PD-L1 inhibitors. Bullous pemphigoid (BP) is a rare cutaneous side effect of these medications, which can initially be clinically indistinguishable from other, low-grade cutaneous toxicity. OBJECTIVE: To better characterize the clinical features of BP associated with PD-1/PD-L1 inhibitors, evaluate the efficacy of various treatment regimens, determine the frequency of prodromal pruritus, and assess whether immunological diagnostic studies for BP are warranted in patients treated with checkpoint inhibitors who develop intractable pruritus. METHODS: A comprehensive review of the English-language medical literature was performed using key terms. Papers published on any date and from all origins were considered. Fourteen publications, containing 21 patient cases, were selected independently by two reviewers and deemed relevant to the present publication. RESULTS: Pruritus was a prominent feature of the majority (12/21) of cases and preceded or occurred concurrently with BP development. Bullae developed within 6-8 months of initiation of PD-1/PD-L1 inhibitors; however, a smaller subset of patients did not develop bullae for 1-1.5 years following initiation of therapy. Mean time to pruritus was similar for pembrolizumab and nivolumab at 19 and 21 weeks, respectively. Development of BP required discontinuation of immunotherapy in 76% (16/21) of cases. CONCLUSION: Prodromal or "non-bullous" variants of BP must be considered in patients treated with checkpoint inhibitors who develop protracted or worsening pruritus. Early diagnostic immunological evaluation of the skin may lead to improved patient outcomes by facilitating timely initiation of treatment and prevent disruptions in cancer therapy.

Survey of bullous pemphigoid in an Italian university hospital: clinical-epidemiological characteristics and follow-up.

BACKGROUND: The clinical-epidemiological characteristics and course of bullous pemphigoid in the general population is not clear. Few studies have been performed to date, and only one in the Italian population more than ten years ago. We decided to evaluate the characteristics and outcome of patients admitted for a bullous pemphigoid at our Hospital in the last 4 years. METHODS: We retrospectively reviewed the last 4 years' medical records of the Department of Dermatology of the University of Bologna, identifying all patients with histological and immunological data typical for bullous pemphigoid. The patients were contacted and, whenever possible, re-evaluated clinically and serologically. Finally, we made a reviews of therapies administered in these cases. RESULTS: We identified 53 patients with a diagnosis of sub-epidermal autoimmune blistering disease. At re-evaluation, resolution of the disease was observed in 13 cases (24.52%) while the disease persisted in 32 cases. An improvement was observed in 35 (66.03%) patients, a worsening was observed in 3 (5.66%) patients, while the class did not change in 5 (9.43%) patients. All patients received systemic steroids as first line therapy, although most patients underwent more than one therapy. Fifteen patients received systemic steroid therapy alone, 22 patients received azathioprin, 16 patients received methotrexate, all patients received a prescription of topical steroid. Twenty-eight patients had abnormal values of eosinophilia, extremely susceptible to systemic steroid therapy. CONCLUSIONS: The findings of our study differ slightly from data collected by other authors in literature. Methotrexate is the drug of choice in terms of efficacy, practicality, cost and tolerability, particularly in the elderly population.

A subset of patients with pemphigoid (herpes) gestationis has serological evidence of celiac disease.

BACKGROUND: Pemphigoid (herpes) gestationis (PG) is an uncommon, self-limited disease with other autoimmune associations; however, celiac disease (CD) is not recognized as one. METHODS: From 71 patients' sera submitted for herpes gestationis factor (HGF) testing over a 5-year period, 12 were consistent with PG demonstrating HGF and increased IgG BP180 antibody levels; these sera were tested for IgA and IgG endomysial antibodies (EMA), epithelial basement membrane zone and cell surface antibodies by indirect immunofluorescence, and for IgA and IgG tissue transglutaminase (transglutaminase 2 or TG2) antibodies, IgA epidermal transglutaminase (transglutaminase 3 or TG3) antibodies, IgG BP230, and IgG desmoglein 1 and desmoglein 3 antibodies by enzyme-linked immunosorbent assays (ELISAs). RESULTS: Three of 12 patients' sera with PG (25%) had CD antibodies with positive IgA EMA and increased IgA TG2 antibody levels; two of these had positive IgG EMA, and one other had an increased IgA TG3 antibody level. CONCLUSIONS: A subset of patients with serological findings of PG also has serological evidence of CD, which may have implications in the etiopathogenesis of PG and which reveals important information about the mother's, and possibly her infant's, health.