Mortality and prognostic factors in patients with bullous pemphigoid: a retrospective multicenter Italian study.

INTRODUCTION: Bullous pemphigoid is the most common autoimmune bullous dermatosis. In recent years several studies have tried to identify the main factors of the disease related with an increased risk of death. The aim of this multicenter Italian study was to assess the risk score of death considering epidemiologic, clinical, immunological, and therapeutic factors in a cohort of patients affected by bullous pemphigoid and try to identify the cumulative survival up to 120 months. METHODS: We retrospectively reviewed the medical records of patients with bullous pemphigoid who were diagnosed between 2005 and 2020 in the 12 Italian centers. Data collected included sex, age at the time of diagnosis, laboratory findings, severity of disease, time at death/censoring, treatment, and multimorbidity. RESULTS: A total of 572 patients were included in the study. The crude mortality rate was 20.6%, with an incidence mortality rate of 5.9 × 100 person/year. The mortality rate at 1, 3, 5, and 10 years was 3.2%, 18.2%, 27.4% and 51.9%, respectively. Multivariate model results showed that the risk of death was significantly higher in patients older than 78 years, in presence of multimorbidity, anti-BP180 autoantibodies >72 U/mL, or anti-BP230 > 3 U/mL at diagnosis. The variables jointly included provided an accuracy (Harrel's Index) of 77% for predicting mortality. CONCLUSION: This study represents the first nationwide Italian study to have retrospectively investigated the mortality rates and prognostic factors in patients with bullous pemphigoid. A novel finding emerged in our study is that a risk prediction rule based on simple risk factors (age, multimorbidity, steroid-sparing drugs, prednisone use, and disease severity) jointly considered with two biomarkers routinely measured in clinical practice (anti-BP230 and anti-BP180 autoantibodies) provided about 80% accuracy for predicting mortality in large series of patients with this disease.

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

BACKGROUND: 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. OBJECTIVES AND METHODOLOGY: 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. RESULTS: 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. CONCLUSIONS: The guidelines for the management of BP were updated. They summarize evidence- and expert-based recommendations useful in clinical practice.

European guidelines (S3) on diagnosis and management of mucous membrane pemphigoid, initiated by the European Academy of Dermatology and Venereology - Part I.

This guideline on mucous membrane pemphigoid (MMP) has been elaborated by the Task Force for Autoimmune Blistering Diseases of the European Academy of Dermatology and Venereology (EADV) with a contribution of physicians from all relevant disciplines and patient organizations. It is a S3 consensus-based guideline encompassing a systematic review of the literature until June 2019 in the MEDLINE and EMBASE databases. This first part covers methodology, the clinical definition of MMP, epidemiology, MMP subtypes, immunopathological characteristics, disease assessment and outcome scores. MMP describes a group of autoimmune skin and mucous membrane blistering diseases, characterized by a chronic course and by predominant involvement of the mucous membranes, such as the oral, ocular, nasal, nasopharyngeal, anogenital, laryngeal and oesophageal mucosa. MMP patients may present with mono- or multisite involvement. Patients' autoantibodies have been shown to be predominantly directed against BP180 (also called BPAG2, type XVII collagen), BP230, laminin 332 and type VII collagen, components of junctional adhesion complexes promoting epithelial stromal attachment in stratified epithelia. Various disease assessment scores are available, including the Mucous Membrane Pemphigoid Disease Area Index (MMPDAI), the Autoimmune Bullous Skin disorder Intensity Score (ABSIS), the 'Cicatrising Conjunctivitis Assessment Tool' and the Oral Disease Severity Score (ODSS). Patient-reported outcome measurements (PROMs), including DLQI, ABQOL and TABQOL, can be used for assessment of quality of life to evaluate the effectiveness of therapeutic interventions and monitor disease course.

European Guidelines (S3) on diagnosis and management of mucous membrane pemphigoid, initiated by the European Academy of Dermatology and Venereology - Part II.

This guideline has been initiated by the task force Autoimmune Blistering Diseases of the European Academy of Dermatology and Venereology, including physicians from all relevant disciplines and patient organizations. It is a S3 consensus-based guideline that systematically reviewed the literature on mucous membrane pemphigoid (MMP) in the MEDLINE and EMBASE databases until June 2019, with no limitations on language. While the first part of this guideline addressed methodology, as well as epidemiology, terminology, aetiology, clinical presentation and outcome measures in MMP, the second part presents the diagnostics and management of MMP. MMP should be suspected in cases with predominant mucosal lesions. Direct immunofluorescence microscopy to detect tissue-bound IgG, IgA and/or complement C3, combined with serological testing for circulating autoantibodies are recommended. In most patients, serum autoantibodies are present only in low levels and in variable proportions, depending on the clinical sites involved. Circulating autoantibodies are determined by indirect IF assays using tissue substrates, or ELISA using different recombinant forms of the target antigens or immunoblotting using different substrates. The major target antigen in MMP is type XVII collagen (BP180), although in 10-25% of patients laminin 332 is recognized. In 25-30% of MMP patients with anti-laminin 332 reactivity, malignancies have been associated. As first-line treatment of mild/moderate MMP, dapsone, methotrexate or tetracyclines and/or topical corticosteroids are recommended. For severe MMP, dapsone and oral or intravenous cyclophosphamide and/or oral corticosteroids are recommended as first-line regimens. Additional recommendations are given, tailored to treatment of single-site MMP such as oral, ocular, laryngeal, oesophageal and genital MMP, as well as the diagnosis of ocular MMP. Treatment recommendations are limited by the complete lack of high-quality randomized controlled trials.

IgE autoantibodies in serum and skin of non-bullous and bullous pemphigoid patients.

BACKGROUND: Non-bullous pemphigoid (NBP) is a pemphigoid variant which frequently resembles other pruritic skin diseases. In contrast with bullous pemphigoid (BP), blisters are absent. In BP, previous studies showed that IgE autoantibodies may be involved in its pathogenesis. IgE-activated mast cells, basophils and eosinophils may participate in BP by inducing pruritus and possibly blister formation, although the differential role of IgE in NBP compared with BP has not yet been described. OBJECTIVE: To assess IgE in serum and skin of NBP and BP patients. METHODS: We examined total IgE and pemphigoid-specific IgE in the serum of 68 NBP and 50 BP patients by enzyme-linked immunosorbent assay (ELISA). Sera of 25 pemphigus patients and 25 elderly patients with pruritus were included as controls. Skin biopsies of 14 NBP and 14 BP patients with the highest IgE titres to NC16A were stained for IgE by immunofluorescence techniques. RESULTS: Total IgE was elevated in 63% of NBP and 60% of BP patients, and in 20% of pemphigus controls, as well as 60% of elderly controls. IgE ELISAs were more frequently positive in BP than in NBP (NC16A 18% vs. 9%, P = 0.139; BP230 34% vs. 22%, P = 0.149). IgE ELISAs for NC16A and BP230 were positive in 8% and 20% of elderly controls, respectively, while all pemphigus controls were negative. Two of 28 biopsies (7%; one NBP, one BP) showed linear IgE along the basement membrane zone, while in most biopsies (71% NBP; 86% BP) IgE was bound to dermal cells. CONCLUSION: Since IgE was present in the serum and skin of both NBP and BP patients, this supports IgE-dependent mechanisms common to both diseases, such as pruritus. However, it remains to be elucidated whether IgE contributes to blister formation in BP.

Inter-rater reliability of the BIOCHIP indirect immunofluorescence dermatology mosaic in bullous pemphigoid and pemphigus patients.

BACKGROUND: The BIOCHIP (Dermatology Mosaic 7; EUROIMMUN, Lubeck, Germany) is a novel multiplex indirect immunofluorescence (IIF) technique used in the serological diagnosis of bullous pemphigoid (BP) and pemphigus. OBJECTIVE: To validate the accuracy and inter-rater reliability (IRR) of the BIOCHIP in the diagnosis of BP, pemphigus foliaceus (PF) and pemphigus vulgaris (PV). METHODS: Sera from patients with BP (n = 38), PF (n = 8), PV (n = 23), control patients (n = 64) and healthy control volunteers (n = 39) were tested. Sera were collected and analysed during the course of the disease at 1-5 different time points. The BIOCHIP was performed for all patients, digital images were captured of each incubated field, and the images were shared with 10 dermatologists experienced in reading IF from around the world to report. There were 312 BIOCHIP slides consisting of 1872 photos in total. All patients were de-identified. Fleiss Kappa was used to estimate the IRR. RESULTS: Fleiss Kappa was computed for each category (Oesophagus, Oesophagus immunofluorescence pattern, Salt-Split Skin (SSS), SSS immunofluorescence location, BP180, BP230, Dsg 1 and Ds3). The inter-rater agreement between the 10 raters varied between fair and moderate for all categories. Those that demonstrated fair concordance included monkey oesophagus (k = 0.257, P < 0.0001), oesophagus pattern (k = 0.357, P < 0.0001), Dsg1 (k = 0.390, P < 0.0001) and BP230 (k = 0.281, P < 0.0001). Moderate agreement was demonstrated for SSS (k = 0.416, P < 0.0001), SSS immunofluorescence location (k = 0.505, P < 0.0001), Dsg3 (k = 0.437, P < 0.0001) and BP180 (k = 0.559, P < 0.0001). CONCLUSION: The BIOCHIP mosaic-based immunofluorescence test is a simple, time and effort saving test that can aid in the diagnosis and screening of BP, PV and PF. However, the level of agreement was relatively low. The authors found the most common causes to be variable levels of training, indicating the presence of a learning curve in the interpretation of the results and ambiguous staining patterns leading to incongruent results.

A sensitive and specific assay for the serological diagnosis of antilaminin 332 mucous membrane pemphigoid.

BACKGROUND: Antilaminin 332 mucous membrane pemphigoid (MMP) is an autoimmune subepidermal blistering disease with predominant mucosal involvement and autoantibodies against laminin 332. Malignancies have been associated with this disease; however, no standardized detection system for antilaminin 332 serum antibodies is widely available. OBJECTIVES: Development of a sensitive and specific assay for the detection of antilaminin 332 antibodies. METHODS: An indirect immunofluorescence (IF) assay using recombinant laminin 332 was developed and probed with a large number of antilaminin 332 MMP patient sera (n = 93), as well as sera from patients with antilaminin 332-negative MMP (n = 153), bullous pemphigoid (n = 20), pemphigus vulgaris (n = 20) and noninflammatory dermatoses (n = 22), and healthy blood donors (n = 100). RESULTS: In the novel IF assay, sensitivities with the laminin 332 heterotrimer and the individual α3, ß3 and γ2 chains were 77%, 43%, 41% and 13%, respectively, with specificities of 100% for each substrate. The sensitivity for the heterotrimer increased when an anti-IgG4 enriched antitotal IgG conjugate was applied. Antilaminin 332 reactivity paralleled disease activity and was associated with malignancies in 25% of patients with antilaminin 332 MMP. CONCLUSIONS: The novel IF-based assay will facilitate the serological diagnosis of antilaminin 332 MMP and may help to identify patients at risk of a malignancy.

Lack of K140 immunoreactivity in junctional epidermolysis bullosa skin and keratinocytes associates with misfolded laminin epidermal growth factor-like motif 2 of the ß3 short arm.

Recessive mutations in the LAMA3, LAMB3 and LAMC2 genes that encode laminin-332 (LM332) (α3a, ß3 and γ2 chains, respectively) cause different junctional epidermolysis bullosa (JEB) subtypes. Biallelic truncating mutations in any of these three genes usually lead to lack of protein expression resulting in the severe generalized JEB subtype, while missense or splice-site mutations in at least one allele lead to reduced expression typical of JEB generalized intermediate (JEB-gen intermed) or localized. Here, we molecularly characterized an adult patient with JEB showing negative skin staining for the anti-ß3 chain monoclonal antibody K140. This antibody recognizes an as yet unidentified epitope within the laminin ß3 short arm. The patient harbours a homozygous splice-site mutation resulting in highly aberrant transcripts with partial skipping of the LAMB3 exon that encodes the laminin epidermal growth factor-like motif 2 of the ß3 short arm (ß3-LE2). At the protein level, mutation consequences predict a misfolded ß3-LE2 motif and, indeed, we found that LM332 is correctly assembled but retained in the endoplasmic reticulum (ER) where it colocalizes with the lumenal ER chaperone protein BiP, leading to dramatically reduced secretion. Lack of K140 reactivity to mutant LM332 was confirmed by immunoprecipitation and Western blot analyses. Our findings not only identify the ß3-LE2 subdomain as the region recognized by K140, but also show that misfolding of LM332 structural motifs and subsequent protein retention in the ER is a common pathomechanism in JEB-gen intermed. In addition to its usefulness in antigen mapping diagnosis of JEB subtypes, this knowledge is relevant to the design of therapeutic strategies aimed at releasing ER-retained LM332 in JEB.

Serological diagnostics in the detection of IgG autoantibodies against human collagen VII in epidermolysis bullosa acquisita: a multicentre analysis.

BACKGROUND: Epidermolysis bullosa acquisita (EBA) is a rare, potentially devastating autoimmune disease of the skin. IgG autoantibodies directed against type VII collagen (Col7), the major component of anchoring fibrils, induce skin fragility leading to cutaneous and mucocutaneous blister formation, which is mostly of a scarring phenotype. Thus, powerful and reproducible diagnostic assays are critical to establish the diagnosis of EBA early to avoid irreversible sequelae. OBJECTIVES: The present international, retrospective multicentre study included a large cohort of patients with EBA and evaluated the diagnostic power of four different diagnostic assays for the detection of anti-Col7 IgG autoantibodies. METHODS: Overall, 95 EBA sera and 200 control sera consisting of 100 bullous pemphigoid sera, 50 pemphigus vulgaris sera and 50 sera of healthy controls were tested for anti-Col7 IgG autoantibodies using indirect immunofluorescence (IIF), two commercial enzyme-linked immunosorbent assay (ELISA) systems and Western blot (WB) analysis. EBA sera were taken from patients with positive direct immunofluorescence and IgG reactivity in at least one of the immunoserological assays (IIF, ELISA, WB). RESULTS: A Col7-NC1/NC2 ELISA (MBL, Nagoya, Japan) showed the highest sensitivity (97·9%), followed by a Col7-NC1 ELISA (Euroimmun, Lübeck, Germany) (89·5%), WB with Col7-NC1 (85·3%), and IIF on saline-split human skin (74·7%). The specificities of both ELISA systems were comparable (NC1 98·7%, NC1/NC2 99·3%). Furthermore, WB was more sensitive than IIF, which was more specific. CONCLUSIONS: The two commercially available ELISA systems allow for a highly sensitive and specific diagnosis of EBA. The sensitivity of the Col7-NC1/NC2 ELISA is significantly higher compared with the ELISA based on the Col7-NC1 domain only.

Childhood epidermolysis bullosa acquisita during squaric acid dibutyl ester immunotherapy for alopecia areata.

Epidermolysis bullosa acquisita (EBA) is a rare acquired subepidermal blistering disease associated with autoantibodies against type VII collagen. Although EBA manifests more frequently in adults, it can occur in childhood. We describe a 6-year-old boy who developed the inflammatory variant of EBA shortly after initiation of immunotherapy with squaric acid dibutyl ester (SADBE) for scalp alopecia areata. The disease rapidly regressed following SADBE discontinuation and starting combined steroid and dapsone therapy, and never recurred after treatment tapering and withdrawal. The association of EBA with other autoimmune diseases is common, but EBA occurring during alopecia areata has not been described previously. The development of EBA during SADBE treatment is also notable: the clinical history and therapeutic response in our patient point to a possible role of SADBE in EBA onset.

A truncating mutation in the laminin-332α chain highlights the role of the LG45 proteolytic domain in regulating keratinocyte adhesion and migration.

BACKGROUND: Altered function of laminin-332 (α3ß3γ2) consequent to mutations in the LAMA3, LAMB3 and LAMC2 genes causes junctional epidermolysis bullosa non-Herlitz (JEB-nH). JEB-nH patients suffer from skin blistering and have an increased risk of developing aggressive skin carcinomas in adulthood. Laminin-332 is proteolytically processed and its extracellular mature form lacks the α3 chain C-terminal globules 4 and 5 (LG45). The LG45 tandem has cell adhesion and protumorigenic properties. However, mutations that affect this domain are very rare and their functional effects in patients have not been explored to date. OBJECTIVE: To characterize molecularly an adult patient with JEB-nH and altered laminin-332 expression presenting multiple skin carcinomas, and to analyse LG45-mediated biological functions using keratinocytes from the patient. METHODS: A mutational search in laminin-332 genes was performed by hetero-duplex analysis. LAMA3 mRNA and laminin-332 protein levels in patient keratinocytes were investigated by real-time reverse transcriptase polymerase chain reaction and radioimmunoprecipitation assay, respectively. Keratinocyte migration was examined by scratch and Boyden chamber assays. RESULTS: We identified a homozygous LAMA3 mutation, p.Leu1648TrpfsX32, which truncates the last 45 amino acids of the carboxyl terminal LG5 subdomain. Gene expression studies revealed that the mutant transcripts were stable and even increased, precursor laminin-332 molecules were retained intracellularly and the amount of mature extracellular heterotrimers was reduced to about 50%. Finally, the patient's keratinocytes migrated faster than normal keratinocytes. CONCLUSIONS: Structural disruption of LG5 highlights the critical functions of the LG45 proteolytic region in precursor laminin-332 secretion and keratinocyte adhesion and migration. Perturbation of LG45 function might explain the non-aggressive behaviour of carcinomas in this patient.

Urban legend series: mucous membrane pemphigoid.

Mucous membrane pemphigoid (MMP) is a heterogeneous group of autoimmune subepithelial blistering diseases affecting primarily mucous membranes showing marked degree of clinical and immunological variability. We investigated four controversial topics: (i) Does oral pemphigoid (OP) really exist as a separate entity? (ii) Is mucous membrane pemphigoid curable? (iii) What is the best therapeutic option for MMP? (iv) Does exclusive oral IgA dermatitis exist as a distinct entity from MMP? Results from extensive literature searches suggested that (i) it is still unclear whether patients with OP could be considered as a distinct subset of MMP with specific clinical and immunological features; (ii) it is uncertain whether treatment regimens that get MMP under control can be eliminated to allow patients to be in drug-free remission or they should be continuously administered in some capacities; (iii) there is a concerning paucity of good-quality trials on MMP and available recommendations are solely based on generally small patients' cohorts or case series. Some of the 2002 consensus experts' opinions should be possibly updated, particularly regarding the safety of sulfa drugs; (iv) we did not find any strong evidence to support an exclusive oral (and perhaps also mucosal) form of LAD as a separate entity.

Sensitivity of different assays for the serological diagnosis of epidermolysis bullosa acquisita: analysis of a cohort of 24 Italian patients.

BACKGROUND: Epidermolysis bullosa acquisita (EBA) is an autoimmune blistering disease characterized by tissue-bound and circulating autoantibodies to the dermal-epidermal junction. The autoantibody target is type VII collagen (Col VII) which is involved in dermal-epidermal adhesion. Diagnosis is made by clinical and histopathological findings, linear deposition of autoantibodies at the dermal-epidermal junction detected by direct immunofluorescence, and binding to the dermal side of salt-split skin by indirect immunofluorescence (IIF). However, the detection of specific anti-Col VII reactivity has an important confirmatory value. METHODS: The humoral immune response in EBA sera was analysed by (i) IIF on human skin, (ii) a commercial Col VII ELISA, and (iii) immunoblotting on Col VII produced by an epithelial cell line. OBJECTIVE: The aim of this study was to compare the sensitivity of different approaches for the serological diagnosis of EBA. RESULTS: The vast majority of EBA sera (79.2%) bound to the Col VII non-collagenous domains by a commercial ELISA, while a small proportion of patients (12.5%) exclusively reacted to the collagenous domain by immunoblotting. Of note, the autoantibodies reactivity to Col VII was more frequently detected by IB (91.7%) than by IIF (83.3%) and ELISA (79.2%). Interestingly, 2 out of 24 sera recognized Col VII epitopes undetectable in the native secreted protein but present in the context of extracellular matrix proteins, as assessed by immunomapping on Col VII-deficient skin. CONCLUSION: Our findings show that the use of multiple assays allows to improve diagnostic performance. An algorithm for efficient serological diagnosis of EBA is proposed.

Induction of senescence pathways in Kindler syndrome primary keratinocytes.

BACKGROUND: Individuals with Kindler syndrome (KS) have loss-of-function mutations in the FERMT1 gene that encodes the focal adhesion component kindlin-1. The major clinical manifestation of KS is epidermal atrophy (premature skin ageing). This phenotypic feature is thought to be related to the decreased proliferation rate of KS keratinocytes; nevertheless, molecular mediators of such abnormal behaviour have not been fully elucidated. OBJECTIVES: To investigate how kindlin-1 deficiency affects the proliferative potential of primary human keratinocytes. METHODS: We serially cultivated nine primary KS keratinocyte strains until senescence and determined their lifespan and colony-forming efficiency (CFE) at each serial passage. The expression of molecular markers of stemness and cellular senescence were investigated by immunoblotting using cell extracts of primary keratinocyte cultures from patients with KS and healthy donors. In another set of experiments, kindlin-1 downregulation in normal keratinocytes was obtained by small interfering RNA (siRNA) technology. RESULTS: We found that KS keratinocytes exhibited a precocious senescence and strongly reduced clonogenic potential. Moreover, KS cultures showed a strikingly increased percentage of aborted colonies (paraclones) already at early passages indicating an early depletion of stem cells. Immunoblotting analysis of KS keratinocyte extracts showed reduced levels of the stemness markers p63 and Bmi-1, upregulation of p16 and scant amounts of hypophosphorylated Rb protein, which indicated cell cycle-arrested status. Treatment of normal human primary keratinocytes with siRNA targeting kindlin-1 proved that its deficiency was directly responsible for p63, Bmi-1 and pRb downregulation and p16 induction. CONCLUSIONS: Our data directly implicate kindlin-1 in preventing premature senescence of keratinocytes.