Disease Endotypes Predict the Severity of Mucous Membrane Pemphigoid.

Mucous membrane pemphigoid is an autoimmune disease with variable clinical presentation and multiple autoantigens. To determine whether disease endotypes could be identified on the basis of the pattern of serum reactivity, the clinical and diagnostic information of 70 patients with mucous membrane pemphigoid was collected, and reactivity to dermal or epidermal antigens, using indirect immunofluorescence, and specific reactivity to bullous pemphigoid (BP) autoantigens BP180 and BP230, collagen VII, and laminin 332 were evaluated. Most patients had lesions at multiple mucosae, with the most prevalent being oropharyngeal (mouth, gingiva, pharynx; 98.6%), followed by ocular (38.6%), nasal (32.9%), genital or anal (31.4%), laryngeal (20%), and esophageal (2.9%) sites and skin (45.7%). Autoantigen profiling identified BP180 (71%) as the most common autoantigen, followed by laminin 332 (21.7%), collagen VII (13%), and BP230 IgG (11.6%). Reactivity to dermal antigens predicted a more severe disease characterized by a higher number of total sites involved, especially high-risk sites, and a decreased response to rituximab. In most cases, identification of dermal indirect immunofluorescence reactivity is an accurate predictor of disease course; however, confirmation of laminin 332 reactivity is important, with dermal indirect immunofluorescence positivity because of an increased risk of solid tumors. In addition, the ocular mucosae should be monitored in patients with IgA on direct immunofluorescence.

Elevated levels of sCD48 are inversely correlated with markers of disease activity in bullous pemphigoid.

sCD48 is elevated in diseases characterized by IgE and eosinophilia. Thus, serum levels sCD48 were evaluated in relation to clinical characteristics of Bullous pemphigoid (BP) patients. sCD48 levels were determined by ELISA in sera from 26 patients with classic BP and 26 healthy controls. Disease severity scores, differential blood counts, and circulating autoantibody levels were obtained. A correlation analysis was performed to establish relationships between sCD48 and clinical and laboratory markers of disease severity. Overall, circulating levels of sCD48 were significantly elevated in BP patients; however, when stratified based on disease severity, patients with mild-moderate disease had higher levels of sCD48 than those with severe disease. A Spearman's correlation analysis identified an inverse relationship between sCD48 and disease activity, serum BP180 IgE and peripheral eosinophil numbers. Further studies are needed to determine the pathologic relevance of these findings.

Evaluation of a Case Series of Patients With Generalized Pustular Psoriasis in the United States.

IMPORTANCE: Generalized pustular psoriasis (GPP) is a chronic, orphan disease with limited epidemiological data. OBJECTIVE: To describe the clinical characteristics, treatments, longitudinal disease course, and disease-specific health care utilization among patients with GPP across the United States. DESIGN, SETTING, AND PARTICIPANTS: A retrospective longitudinal case series involving 95 adults who met the European Rare and Severe Psoriasis Expert Network consensus definition for GPP and were treated at 20 US academic dermatology practices between January 1, 2007, and December 31, 2018. MAIN OUTCOMES AND MEASURES: The primary outcome is to describe the patient characteristics, associated medical comorbidities, treatment patterns complications, and GPP-specific health care utilization. RESULTS: Sixty-seven of 95 patients (70.5%) were women (mean age, 50.3 years [SD, 16.1 years]). In the initial encounter, 35 patients (36.8%) were hospitalized and 64 (67.4%) were treated with systemic therapies. In total, more than 20 different systemic therapies were tried. During the follow-up period, 19 patients (35.8%) reported hospitalizations at a median rate of 0.5 hospitalizations per year (IQR, 0.4-1.6). Women had a decreased risk of an emergency department or hospital encounter (odds ratio, 0.19; 95% CI, 0.04-0.83). CONCLUSIONS AND RELEVANCE: Generalized pustular psoriasis is a rare, chronic disease without standard treatment and is associated with continued health care utilization over time.

Evaluation of a Case Series of Patients With Palmoplantar Pustulosis in the United States.

IMPORTANCE: Palmoplantar pustulosis (PPP) is a is a chronic, orphan disease with limited epidemiological data. OBJECTIVE: To describe the clinical characteristics, treatments, longitudinal disease course, and health care utilization in adults with PPP across the US. DESIGN, SETTING, AND PARTICIPANTS: This retrospective, longitudinal case series from 20 academic dermatology practices in the US included a consecutive sample of 197 adults who met the European Rare and Severe Psoriasis Expert Network consensus definition for PPP between January 1, 2007, and December 31, 2018. Data analysis was performed June 2020 to December 2020. MAIN OUTCOMES AND MEASURES: The primary outcome was to describe the patient characteristics, associated medical comorbidities, treatment patterns, complications, and PPP-specific health care utilization. RESULTS: Of 197 patients, 145 (73.6%) were female, and the mean (SD) age at presentation was 53.0 (12.6) years, with a mean (SD) follow-up time of 22.1 (28.0) months. On initial presentation, 95 (48.2%) patients reported skin pain, and 39 (19.8%) reported difficulty using hands and/or feet. Seventy patients (35.5%) were treated with systemic treatments, and use of more than 20 different systemic therapies was reported. In patients with at least 6 months of follow-up (n = 128), a median (IQR) of 3.7 (4-10) dermatology visits per year were reported; 24 (18.8%) patients had 5 or more visits during the study period. CONCLUSIONS AND RELEVANCE: In this case series, PPP was associated with persistent symptoms, continued health care utilization, and a lack of consensus regarding effective treatments, emphasizing the unmet medical need in this population. Additional research is necessary to understand treatment response in these patients.

TSST-1+Staphylococcus aureus in Bullous Pemphigoid.

A potential role of Staphylococcus aureus in bullous pemphigoid was explored by examining the colonization rate in patients with new-onset disease compared with that in age- and sex-matched controls. S. aureus colonization was observed in 85% of bullous pemphigoid lesions, 3-6-fold higher than the nares or unaffected skin from the same patients (P ≤ 0.003) and 6-fold higher than the nares or skin of controls (P ≤ 0.0015). Furthermore, 96% of the lesional isolates produced the toxic shock syndrome toxin-1 superantigen, and most of these additionally exhibited homogeneous expression of the enterotoxin gene cluster toxins. Toxic shock syndrome toxin-1‒neutralizing antibodies were not protective against colonization. However, S. aureus colonization was not observed in patients who had recently received antibiotics, and the addition of antibiotics with staphylococcal coverage eliminated S. aureus and resulted in clinical improvement. This study shows that toxic shock syndrome toxin-1‒positive S. aureus is prevalent in bullous pemphigoid lesions and suggests that early implementation of antibiotics may be of benefit. Furthermore, our results suggest that S. aureus colonization could provide a source of infection in patients with bullous pemphigoid, particularly in the setting of high-dose immunosuppression.

Mixed Individual-Aggregate Data on All-Cause Mortality in Bullous Pemphigoid: A Meta-analysis.

Importance: The 1-year standardized mortality ratio (SMR) of bullous pemphigoid (BP) has been reported as 2.15 to 7.56 and lower in the US than in Europe. Objective: To estimate the worldwide 1-year SMR of BP. Data Sources: PubMed, Embase, Cochrane Library, Google Scholar, Lissa, and gray literature (eg, medRxiv) were screened for studies of BP published from inception to June 10, 2020, with review of reference lists. Study Selection: Retrospective and prospective studies reporting 1-year all-cause mortality rate in patients with BP and providing age statistics (eg, mean [SD]). Data Extraction and Synthesis: Two reviewers independently extracted the data. The 1-year SMR was computed in studies reporting 1-year mortality by combining information on age obtained from studies with aggregate data and individual data. Risk of representativity, misclassification, and attrition bias were assessed by a custom tool. Main Outcomes and Measures: The primary end point was the worldwide 1-year SMR. Secondary analysis included comparison of 1-year SMRs between continents in a meta-regression. Results: Three studies were performed in the US (n = 260), 1 in South America (n = 45), 16 in Asia (n = 1903), and 36 in Europe (n = 10 132) for a total of 56 unique studies and 12 340 unique patients included in the meta-analysis (mean [SD] age, 77.3 [12.7] years; 55.9% women). The mean (SD) patient age in the United States was 75.6 (13.7) years; in Asia, 73.8 (13.6) years; and in Europe, 78.1 (12.3) years. The worldwide 1-year SMR was estimated at 2.93 (95% CI, 2.59-3.28; I2 = 85.6%) for all 56 studies. The 1-year SMR in the US was 2.40 (95% CI, 0.89-3.90; I2 = 86.3%) for 3 studies; in Asia, 3.53 (95% CI, 2.85-4.20; I2 = 86.3%) for 16 studies; and in Europe, 2.77 (95% CI, 2.35-3.19; I2 = 86.3%) for 36 studies. After adjustment on the expected 1-year mortality rate, the European 1-year SMR did not differ significantly from the 1-year SMR in the United States (-0.48 vs Europe; 95% CI, -2.09 to 1.14; P = .56) and Asia (0.51 vs Europe; 95% CI, -0.56 to 1.58; P = .35). Risk of attrition bias was high (>10% censorship) in 16 studies (28.6%), low in 16 (28.6%), and unclear in 24 (42.9%). Only 4 studies (7.1%) had a sampling method guaranteeing the representativity of BP cases in a population. Conclusions and Relevance: Although heterogeneity was high and overall quality of follow-up was poor, this meta-analysis confirms the high mortality rate among patients with BP.

The Intersection of IgE Autoantibodies and Eosinophilia in the Pathogenesis of Bullous Pemphigoid.

Bullous pemphigoid (BP) is an autoimmune blistering disease characterized by autoantibodies targeting cellular adhesion molecules. While IgE autoantibodies are occasionally reported in other autoimmune blistering diseases, BP is unique in that most BP patients develop an IgE autoantibody response. It is not known why BP patients develop self-reactive IgE and the precise role of IgE in BP pathogenesis is not fully understood. However, clinical evidence suggests an association between elevated IgE antibodies and eosinophilia in BP patients. Since eosinophils are multipotent effector cells, capable cytotoxicity and immune modulation, the putative interaction between IgE and eosinophils is a primary focus in current studies aimed at understanding the key components of disease pathogenesis. In this review, we provide an overview of BP pathogenesis, highlighting clinical and experimental evidence supporting central roles for IgE and eosinophils as independent mediators of disease and via their interaction. Additionally, therapeutics targeting IgE, the Th2 axis, or eosinophils are also discussed.

Demographics and Autoantibody Profiles of Pemphigoid Patients with Underlying Neurologic Diseases.

Bullous pemphigoid (BP) is an autoantibody-mediated blistering disease that is often associated with neurologic disease. BP antibodies target two epidermal adhesion molecules, known as BP180 and BP230. Homologues to these proteins are found in the brain, and it is hypothesized that neurologic disease leads to the production of autoantibodies that can cross-react with their cutaneous forms. To better understand the link between BP and neurologic disease, we evaluated primary demographic features (age, sex, race, ethnicity, and elapsed time between onset of skin symptoms and BP diagnosis), severity of BP, and IgG and IgE autoantibody levels in BP control individuals and patients with BP with preceding Parkinson disease, dementia, and stroke. The main findings of this study are that patients with BP with preceding neurologic disease have a shorter elapsed time between onset of skin disease and BP diagnosis and that patients with preceding Parkinson disease or dementia, but not stroke, are significantly older than patients with BP without neurologic disease. However, no significant differences in clinical presentation, BP severity scores, or autoantibody (IgG and IgE) responses were observed among the groups. These findings suggest that, despite the age difference, the clinical phenotype of BP is not affected by preceding neurologic disease.

A cross-sectional survey and analysis of Dermatology Foundation Career Development Award recipients.

BACKGROUND: The Dermatology Foundation (DF) has a comprehensive career development award (CDA) program. OBJECTIVE: To assess the impact of this program, a cross-sectional survey of recipients receiving support between 1990 and 2012 was performed. METHODS: Award recipients completed a questionnaire concerning their career status and record of research funding. To verify the self-reported funding data, information about each awardee was extracted from the National Institutes of Health Research Portfolio Online Reporting Tools database and used to define funding acquired by CDA recipients. RESULTS: In all, 84% of CDA recipients responded to the survey. A total of 213 awardees (79%) hold full- or part-time positions in academic medicine. Approximately 70% of the award recipients in academic medicine have received federal research funding. The National Institutes of Health Research Portfolio Online Reporting Tools database and other sources indicated that the funding acquired by CDA recipients through 2015 and 2017 amounted to approximately $365.4 million and $451.8 million, respectively. Each dollar of DF CDA funding through 2015 (ie, $36.2 million) was linked to more than $10 in grant support through 2015 and $12 through 2017. LIMITATIONS: This cross-sectional survey was retrospective and (in part) self-reported. CONCLUSIONS: The DF has succeeded in supporting the career development of basic, translational, and clinical investigators and fostered the promotion and retention of these individuals in academic medicine.

Perspective From the 5th International Pemphigus and Pemphigoid Foundation Scientific Conference.

The 5th Scientific Conference of the International Pemphigus and Pemphigoid Foundation (IPPF), "Pemphigus and Pemphigoid: A New Era of Clinical and Translational Science" was held in Orlando, Florida, on May 15-16, 2018. Scientific sessions covered recent, ongoing, and future clinical trials in pemphigus and bullous pemphigoid, disease activity and quality of life instruments, and the IPPF Natural History Study. Furthermore, the meeting provided an opportunity to hear firsthand from patients, investigators, and industry about their experience enrolling for clinical trials.

Eosinophils Mediate Tissue Injury in the Autoimmune Skin Disease Bullous Pemphigoid.

Eosinophils are typically associated with unique inflammatory settings, including allergic inflammation and helminth infections. However, new information suggests that eosinophils contribute more broadly to inflammatory responses and participate in local immune regulation and the tissue remodeling/repair events linked with a variety of diseases. Eosinophilic infiltration has long been a histologic hallmark of bullous pemphigoid (BP), a subepidermal autoimmune blistering disease characterized by autoantibodies directed against basement membrane protein BP180. However, the exact role of eosinophils in disease pathogenesis remains largely unknown. We show here that eosinophils are necessary for IgE autoantibody-mediated BP blister formation in a humanized IgE receptor mouse model of BP. Disease severity is IgE dose dependent and correlates with the degree of eosinophil infiltration in the skin. Furthermore, IgE autoantibodies fail to induce BP in eosinophil-deficient mice, confirming that eosinophils are required for IgE-mediated tissue injury. Thus, eosinophils provide the cellular link between IgE autoantibodies and skin blistering in this murine model of BP. These findings suggest a role for eosinophils in autoimmune disease and have important implications for the treatment of BP and other antibody-mediated inflammatory and autoimmune diseases.

Eosinophil localization to the basement membrane zone is autoantibody- and complement-dependent in a human cryosection model of bullous pemphigoid.

Bullous pemphigoid (BP) is an autoimmune blistering disease characterized by antibodies (IgG and IgE) targeting cell-substrate adhesion proteins. A variety of BP models suggest that autoantibody-dependent neutrophil degranulation is essential for blister formation. However, lesional biopsies reveal a predominance of eosinophils and few neutrophils. Our goal was to evaluate the role of antibodies and complement in eosinophil localization, degranulation and split formation at the dermo-epidermal junction (DEJ) utilizing a human skin cryosection model of BP paired with a human eosinophilic cell line, 15HL-60. Expression of receptors for IgG (FcγRII), IgE (FcεRI) and complement (CR1 and CR3) was confirmed on 15HL-60 cells using flow cytometry. 15HL-60 expression of granule protein [eosinophil derived neurotoxin (EDN) and eosinophil peroxidase (EPO)] mRNA and their degranulation in vitro was confirmed using RT-PCR and ELISA, respectively. For cryosection experiments, BP or control sera or IgG and IgE antibodies purified from BP sera were utilized in combination with 15HL-60 cells ± fresh complement. Both BP serum and fresh complement were required for localization of 15-HL60 cells to the DEJ. Interestingly, eosinophil localization to the DEJ was dependent on IgG, but not IgE, and complement. However, no subepidermal split was observed. Additionally, the 15HL-60 cells did not degranulate under any experimental conditions and direct application of cell lysate to cryosections did not result in a split. Our observation that eosinophil localization to the DEJ is dependent on IgG mediated complement fixation provides additional insight into the sequence of events during the development of BP lesions.