Childhood epidermolysis bullosa acquisita: a novel variant with reactivity to all three structural domains of type VII collagen

Investigation of comorbid autoimmune diseases in women with autoimmune bullous diseases: An interplay of autoimmunity and practical implications

Autoimmune bullous diseases are a group of skin disorders resulting from an autoimmune reaction against intercellular adhesion molecules or components of the basement membrane of skin and mucosa. Autoimmune disorders often occur in patients with a history of another autoimmune disease and most autoimmune diseases have a striking female predominance. In this review, we aim to analyze the different associations of autoimmune bullous diseases with other autoimmune diseases and highlight the distinctiveness of the female gender in these associations.

Pediatric epidermolysis bullosa acquisita: A review

Epidermolysis bullosa acquisita (EBA) is an acquired autoimmune blistering skin disorder that is rare in adults and even rarer in childhood. This review aims to identify cases of pediatric EBA and report their clinical features and course. Our literature review was conducted in MEDLINE^® using the search terms related to juvenile epidermolysis bullosa acquisita. We identified 40 cases of pediatric EBA. Mucosal tissues were affected in 29 out of 40 cases. Treatment mostly consisted of a systemic corticosteroid combined with dapsone. Prognosis is favorable with 17 of 40 cases achieving complete remission, 9 of 40 with complete control with therapy, 12 of 40 with partial control with therapy, 1 of 40 with no response to therapy, and 1 of 40 terminating treatment early. Though it is a rare condition, childhood EBA should still be included in the differential diagnosis of pediatric blistering diseases.

Thyroid diseases and skin autoimmunity

The skin is the largest organ of the body, at the boundary with the outside environment. Primarily, it provides a physical and chemical barrier against external insults, but it can act also as immune organ because it contains a whole host of immune-competent cells of both the innate and the adaptive immune systems, which cooperate in eliminating invading pathogens following tissue injury. On the other hand, improper skin immune responses lead to autoimmune skin diseases (AISD), such as pemphigus, bullous pemphigoid, vitiligo, and alopecia. Although the interplay among genetic, epigenetic, and environmental factors has been shown to play a major role in AISD etiology and progression, the molecular mechanisms underlying disease development are far from being fully elucidated. In this context, epidemiological studies aimed at defining the association of different AISD with other autoimmune pathologies revealed possible shared molecular mechanism(s) responsible for disease progression. In particular, over the last decades, a number of reports have highlighted a significant association between thyroid diseases (TD), mainly autoimmune ones (AITD), and AISD. Here, we will recapitulate the epidemiology, clinical manifestations, and pathogenesis of the main AISD, and we will summarize the epidemiological evidence showing the associations with TD as well as possible molecular mechanism(s) underlying TD and AISD pathological manifestations.

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.

Acquired bullous epidermolysis: complexity of diagnostics

The article describes the case of acquired bullous epidermolysis in a woman of 45 years old, suffering from a disease from 2.5 years. As a child, she was diagnosed with herpetiform dermatitis on the base of a clinical picture and histological data. After the period of puberty, when in addition to skin blistering a lesion of the oral mucosa, dystrophy and absence of nail plates, contracture of the 2 fingers of the hands arose, the diagnosis was changed to dystrophic congenital bullous epidermolysis, which did not contradict with re-histological examination of the skin. In order to clarify the diagnosis, another biopsy of the leg skin was performed in 2016. The light microscopy data corresponded to the herpetiform dermatitis or vesicular form of the bullous pemphigoid, the acquired bullous epidermolysis was not also excluded. Indirect RIF allowed to reject the diagnosis of herpetiform dermatitis. The possibility of bullous pemphigoid developing on the background of preexisting congenital bullous epidermolysis was investigated by immunofluorescence mapping with antibodies to 13 structural proteins of the dermo-epidermal junction. Expression of all the studied proteins corresponded to that of healthy individuals, which conflicted with the diagnosis of congenital bullous epidermolysis. Additional immunofluorescence study of the sites of spontaneous cleavage of the biopsy specimen, as well as of n- and u-patterns in the structure of the luminescence line, made possible to exclude the bullous pemphigoid. So, the use of a complex of immunomorphological methods helped to establish the correct diagnosis.

Clinical features and diagnosis of epidermolysis bullosa acquisita

INTRODUCTION

Epidermolysis bullosa acquisita (EBA) is a rare autoimmune blistering disease of skin and mucous membranes. EBA is caused by autoantibodies against type VII collagen, which is a major component of anchoring fibrils, attaching epidermis to dermis. Binding of autoantibodies to type VII collagen leads to skin fragility and, finally, blister formation. The clinical picture of EBA is polymorphic, with several distinct phenotypes being described. Despite recent progress in understanding the pathophysiology of EBA, its diagnosis is still challenging. Areas covered: This review provides an update on the clinical manifestations and diagnostic methods of EBA. We searched PubMed using the terms 'epidermolysis bullosa acquisita' covering articles in English between 1 January 2005 and 31 May 2016. Relevant older publications were retrieved form cited literature. Expert commentary: While the clinical picture is highly variable, diagnosis relies on direct immunofluorescence (IF) microscopy of a perilesional skin biopsy. Linear deposits of IgG, IgA and/or C3 along the dermal-epidermal junction with an u-serrated pattern are diagnostic for EBA alike the detection of serum autoantibodies against type VII collagen. Several test systems for the serological diagnosis of EBA have recently become widely available. In some patients, sophisticated diagnostic approaches only available in specialized centers are required.

Childhood Epidermolysis Bullosa Acquisita: Confirmation of Diagnosis by Skin Deficient in Type VII Collagen, Enzyme-linked Immunosorbent Assay, and Immunoblotting

Epidermolysis bullosa acquisita (EBA) is an acquired subepidermal bullous disorder characterized by autoantibodies against Type VII collagen. It usually affects adults; childhood EBA is rare. We describe a 10-year-old girl presenting with recurrent tense blisters predominantly on legs, dorsa of hands and feet accompanied by oral erosions since the age of 5 years. Direct immunofluorescence (IF) microscopy showed linear deposition of IgG and C3 along the basement membrane zone (BMZ); indirect IF microscopy on salt-split skin revealed staining of IgG to the dermal side of the split. The patient's serum did not show BMZ staining in recessive dystrophic epidermolysis bullosa skin deficient for Type VII collagen, thus confirming autoantibody reactivity against Type VII collagen. Circulating antibodies against the immunodominant noncollagenous 1 domain of Type VII collagen were detected by ELISA and immunoblotting studies. The patient was treated with oral corticosteroids and dapsone with good improvement.

Bullous diseases: Kids are not just little people

Bullous diseases may be rare; however, this does not preclude the clinician from being familiar with their manifestations and treatment. After ruling out infection, genetically inherited blistering diseases are more likely to be the cause of blistering or erosions in the neonatal period, whereas immunobullous diseases are more common in adults. Published literature on immunobullous disorders reflects information gleaned from case reports and open-label case series; prospective studies and evidence-based treatments are limited. Although there may be overlapping clinical features, significant clinical differences exist between adults and children. Evidence-based treatment guidelines are limited, and information from the adult literature cannot be readily generalized to the pediatric population. This paper reviews the approach to blistering conditions and the differences among bullous pemphigoid, linear immunoglobulin A disease, dermatitis herpetiformis, pemphigus foliaceus, pemphigus vulgaris, and paraneoplastic pemphigus in adult versus pediatric patients.

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.

Epidermolysis bullosa acquisita

Epidermolysis bullosa acquisita (EBA) is a chronic autoimmune subepidermal bullous disease with clinical features similar to the genetic form of dystrophic epidermolysis bullosa. EBA is characterized by the presence of autoantibodies against type VII collagen which is a major component of the anchoring fibrils at the dermal-epidermal junction. EBA can be divided into two main clinical types; mechanobullous and inflammatory EBA. Mechanobullous EBA, referred to as classic EBA, presents with skin fragility, blisters and dystrophic changes on trauma-prone areas. Inflammatory EBA resembles other autoimmune subepidermal bullous diseases. Compelling evidence from mouse models supports a pathogenic role of autoantibodies against type VII collagen in EBA. Treatment of EBA is often unsatisfactory. The most widely used systemic treatment is corticosteroids. Colchicine and dapsone have been reported to be good treatment modalities when combined with corticosteroids. Some intractable cases of EBA have successfully been treated with intravenous immunoglobulin or rituximab.

Childhood epidermolysis bullosa acquisita: report of a Chinese case

Epidermolysis bullosa acquisita (EBA) is a rare, acquired, subepidermal blistering disease characterized by autoantibodies directed against type VII collagen, the major component of anchoring fibrils. We report a 5-year-old Chinese boy who presented with extensive lesions consisting of disseminated pruritic vesicles and tense blisters. The diagnosis of EBA was confirmed by histopathology, immunofluorescence, and immunoblotting analysis. The disease was controlled with a combination of prednisone and dapsone.

Epidermolysis bullosa acquisita

Epidermolysis bullosa acquisita (EBA) is a rare, acquired, chronic subepidermal bullous disease of the skin and mucosa characterized by autoantibodies to type VII collagen (C7) structures, a major component of anchoring fibrils, which attach the epidermis to the dermis. EBA patients have tissue-bound and circulating antitype C7 autoantibodies that attack type C7 and result in a reduction or perturbation of normally functioning anchoring fibrils. Patients with EBA have skin fragility, blisters, erosions, scars, milia, and nail loss, all features reminiscent of genetic dystrophic epidermolysis bullosa. These immunoglobulin G antitype C7 antibodies are pathogenic, because when they are injected into mice, the mice develop an EBA-like blistering disease. In addition to the classical mechanobullous presentation, EBA also has several other distinct clinical syndromes similar to bullous pemphigoid, Brunsting-Perry pemphigoid, or cicatricial pemphigoid. Although treatment for EBA is often unsatisfactory, some therapeutic success has been achieved with colchicine, dapsone, plasmapheresis, photopheresis, infliximab, and intravenous immunoglobulin.

Erosive diseases of the vulva

Vesicobullous and inflammatory diseases produce vulvar erosions that may exhibit nonspecific morphology and represent a diagnostic challenge. An approach to arriving at the correct diagnosis is presented. Most common etiologies are reviewed.

Some epidermolysis bullosa acquisita sera react with epitopes within the triple-helical collagenous domain as indicated by immunoelectron microscopy

BACKGROUND

Epidermolysis bullosa acquisita (EBA) autoantibodies recognize epitopes predominantly within the N-terminal noncollagenous (NC)-1 domain of type VII collagen. Recently, some EBA cases with reactivity to other domains, i.e. the triple-helical (T-H) collagenous domain and the NC-2 domain, have been reported.

OBJECTIVES

To investigate the ultrastructural localization of epitopes for sera from five patients with EBA that were unreactive by immunoblotting with the NC-1, NC-2 and collagenous domains of type VII collagen.

METHODS

Immunogold postembedding indirect immunoelectron microscopy was performed using normal human skin and type VII collagen-deficient skin as substrates.

RESULTS

Postembedding indirect immunoelectron microscopy revealed that the five EBA sera showed immunoreactivity in the dermis, mainly located 0-400 nm below the lamina densa. IgG labelling was not observed in type VII collagen-deficient skin from a patient with recessive dystrophic epidermolysis bullosa. The distribution histogram found in this study was different from those of sera that reacted with the NC-1 and/or NC-2 domains, and was similar to those of sera reacting with the T-H collagenous domain.

CONCLUSIONS

Our results suggest that epitopes within the T-H collagenous domain of type VII collagen are recognized by IgG antibodies from some EBA sera. These antibodies appear to be found in patients with inflammatory-type EBA.

A case of epidermolysis bullosa acquisita with clinical features of Brunsting-Perry pemphigoid showing an excellent response to colchicine

BACKGROUND

Brunsting-Perry pemphigoid is a rare subepidermal blistering disease characterized by scarring blisters on the head and neck. However, the identity of the responsible autoantigens is still unresolved.

METHODS

We reported a patient with epidermolysis bullosa acquisita who had clinical features typical of Brunsting-Perry pemphigoid and investigated the involved type VII collagen epitopes. The patient was a 65-year-old Japanese woman with a 20-month history of recurrent subepidermal bullae on her head, face, and neck.

RESULTS

Immunoblot studies revealed that the serum of this patient reacted with type VII collagen, specifically with the noncollagenous domain 1 and the triple-helical domain. The patient responded completely to colchicine monotherapy.

LIMITATIONS

This study was performed on only one case.

CONCLUSION

This study suggests that Brunsting-Perry pemphigoid may be a clinical variant of epidermolysis bullosa acquisita.

[Epidermolysis bullosa acquisita of childhood]

BACKGROUND

Epidermolysis bullosa acquisita (EBA) is a subepidermal autoimmune blistering disease characterized immunologically by autoantibodies to type VII collagen. Its occurrence in childhood is rare. Thirty-five cases have been described to date in the literature.

PATIENTS AND METHODS

We report the case of an 8-year-old girl presenting blistering lesions on the cheeks, extremities and limb extension areas. The diagnosis of EBA was confirmed by histology, direct immunofluorescence of a perilesional skin biopsy specimen, indirect immunofluorescence on salt-split skin substrate and direct electron microscopy. The patient was controlled clinically under treatment with dapsone alone.

DISCUSSION

This 36th childhood case of EBA presented typical clinical features, a similar prognosis and comparable treatment response to other paediatric cases. Clinical presentation is inflammatory and affects the face. As in our case, in childhood, prognosis is often better than in adults without the need for immunosuppressive agents.

Complete Fixed Prostheses Over Implants in Patients With Oral Epidermolysis Bullosa

PURPOSE

This study was conducted to evaluate the feasibility of placing fixed prostheses over endosseous implants in edentulous patients with recessive dystrophic epidermolysis bullosa.

PATIENTS AND METHODS

Three cases of dental implants with fixed prostheses are presented. All 3 patients had marked oral involvement, with devastating alterations in the soft and hard tissues. The use of fixed prostheses avoids contact between the prosthesis itself and the oral mucosa, thus preventing the formation of blisters.

RESULTS

A total of 27 implants (15 maxillary and 12 mandibular) were placed. One maxillary implant failed; the rest integrated successfully, allowing crown placement. The average follow-up after implant placement was 3 years (range, 1 to 5 years).

CONCLUSIONS

Our findings suggest that endosseous implants are not contraindicated and can be placed successfully to improve these patients' quality of life. Implants can provide support for complete fixed prosthesis restoration in patients with epidermolysis bullosa. This procedure keeps the prosthesis from rubbing on the oral mucosa and prevents the development of ulcerations, improving mastication and esthetics.

Experimental models of epidermolysis bullosa acquisita

Epidermolysis bullosa acquisita (EBA) is an organ-specific autoimmune disease with a well-defined antigen-autoantibody system. Recently, mutually complementary ex vivo and animal models were developed for this disease. The blister formation of EBA can be reproduced by passively transferring antibodies against type VII collagen into mice. In addition, the Fc-dependent interaction of autoantibodies with granulocytes resulting in dermal-epidermal separation can be studied using patient autoantibodies and leukocytes from healthy donors in cryostat sections of normal human skin. Finally, the autoimmune response and the active blistering disease are replicated by immunizing mice with autologous type VII collagen. The results obtained using these experimental systems provided conclusive evidence that EBA is an antibody-mediated autoimmune disease. In addition, these models represent powerful new tools for understanding EBA pathophysiology and will likely offer unique opportunities to investigate the molecular mechanisms of antibody-mediated autoimmune diseases in general. Thus, due to improved disease modelling, EBA emerges as an exquisitely instructive model disease to study fundamental, biologically and clinically crucial aspects of antibody-mediated organ-specific autoimmune diseases that extend well beyond the limits of autoimmunity against type VII collagen. The new mechanistic insights gained from investigating EBA pathogenesis will facilitate the design of immunomodulatory interventions for this and other pathogenetically related organ-specific, antibody-dependent autoimmune diseases.

Immunopathology and molecular diagnosis of autoimmune bullous diseases

Autoimmune bullous diseases are associated with autoimmunity against structural components maintaining cell-cell and cell matrix adhesion in the skin and mucous membranes. Pemphigus diseases are characterized by autoantibodies against the intercellular junctions and intraepithelial blisters. In pemphigoid diseases and epidermolysis bullosa acquisita, sub-epidermal blistering is associated with autoantibodies targeting proteins of the hemidesmosomal anchoring complex. The autoantigens in autoimmune blistering diseases have been extensively characterized over the past three decades. In general, the pathogenicity of autoantibodies, already suggested by clinical observations, has been conclusively demonstrated experimentally. Detection of tissue-bound and circulating serum autoantibodies and characterization of their molecular specificity is mandatory for the diagnosis of autoimmune blistering diseases. For this purpose, various immunofluorescence methods as well as immunoassays, including immunoblotting, enzyme-linked immunosorbent assay and immunoprecipitation have been developed. This review article describes the immunopathological features of autoimmune bullous diseases and the immunological and molecular tests used for their diagnosis and monitoring.

Childhood epidermolysis bullosa acquisita with autoantibodies against the noncollagenous 1 and 2 domains of type VII collagen: case report and review of the literature

Epidermolysis bullosa acquisita (EBA) is an acquired subepidermal bullous disease characterized by IgG autoantibodies to type VII collagen, a major component of anchoring fibrils. Most patients with EBA are adult and develop autoantibodies to the noncollagenous (NC) 1 domain of type VII collagen. We describe a 4-year-old Japanese boy presenting pruritic vesicles and tense blisters over his whole body. Immunofluorescence studies revealed linear IgG/C3 deposits along the dermal-epidermal junction of the patient's skin, and circulating IgG autoantibodies mapping to the dermal side of 1 M NaCl-split skin. By immunoblotting analysis using dermal extracts as a substrate, the patient's IgG antibodies labelled a 290-kDa protein corresponding to type VII collagen. Immunoblotting studies using recombinant proteins demonstrated that the patient's circulating autoantibodies recognized not only the NC1 but also the NC2 domain of type VII procollagen. Review of the previously reported cases and the present case suggested that patients with EBA with autoantibodies to regions other than the NC1 domain are all children younger than 10 years of age with clinical features of an inflammatory phenotype.

Epidermolysis bullosa acquisita sera react with distinct epitopes on the NC1 and NC2 domains of type VII collagen: study using immunoblotting of domain-specific recombinant proteins and postembedding immunoelectron microscopy

BACKGROUND

The sera of epidermolysis bullosa acquisita (EBA) react with type VII collagen, a major component of anchoring fibrils, in which the major epitopes have been considered to be present in the N-terminal noncollagenous (NC) 1 domain.

OBJECTIVES

To determine whether there are also epitopes in the C-terminal NC2 domain, and to determine their ultrastructural localization.

METHODS

Immunoblotting using recombinant proteins of the NC1 and NC2 domains of type VII collagen, and postembedding immunoelectron microscopy.

RESULTS

Twenty of 28 EBA sera tested reacted with the NC1 domain and eight sera reacted with the NC2 domain. The sera that reacted with the NC1 domain showed immunoreactivity within the lamina densa and the sera that reacted with the NC2 domain showed immunoreactivity in the dermis 300-360 nm below the lamina densa.

CONCLUSIONS

This study clearly identified the presence of epitopes in the NC2 domain, and showed that the epitope in the NC1 domain is present in the lamina densa and that the epitope in the NC2 domain is in the dermis below the lamina densa.

[Blistering autoimmune diseases of childhood]

Autoimmune blistering skin diseases are exceedingly rare in children. In most cases, they are characterized by circulating autoantibodies directed against adhesion structures of the skin which subsequently induce blistering at the dermoepidermal junction or intraepidermally. The most frequent paediatric immunobullous disease is linear IgA dermatosis; all others such as pemphigoid, epidermolysis bullosa acquisita, dermatitis herpetiformis and pemphigus are less common than in adults. In children, mucous membranes are involved more frequently. Recent advances in the identification of the autoantigens have improved diagnostic approach and therapeutic management of blistering diseases. In most cases, treatment requires systemic immunosuppression. With respect to the chronic course of the diseases and potential complications of treatment, cooperation between dermatologists and paediatricians seems advisable.