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

Clinical Features of Paediatric Inflammatory Epidermolysis Bullosa Acquisita: A Case Series Study

Epidermolysis bullosa acquisita (EBA) rarely develops in childhood. This study retrospectively recruited paediatric patients with EBA (age ≤ 16 years), diagnosed by clinical and histopathological features and results of immunofluorescence, immunoblotting and enzyme-linked immunosorbent assay (ELISA), and reviews their clinical manifestations, histopathology, immunological features, and responses to various treatments. All 7 included patients presented with inflammatory EBA. Among them, 3 had a bullous pemphigoid-like phenotype. Pathologically, in addition to dermal-epidermal blistering, in all patients, the distribution of neutrophils was superficial perivascular or interstitial, or in the dermal papilla. Mixed neutrophils and eosinophils were detected in 2 of the 3 patients with bullous pemphigoid-like phenotypes. In addition to treatment with glucocorticoids, dapsone was administered in 4 patients, while thalidomide and sulfasalazine were administered in 1 patient. All patients responded to the these therapies. Relapse was mainly due to reduction and cessation of glucocorticoids. In conclusion, EBA in childhood may be unique, and thus distinct from its adult counterpart. Specific treatment and follow-up protocols are required for therapy of this rare autoimmune skin disease in children.

Spontaneous autoimmune subepidermal blistering diseases in animals: a comprehensive review

Autoimmune subepidermal blistering diseases (AISBDs) are rare skin disorders of animals that were first identified in dogs but several AISBDs are now recognised in other companion animal species. Most AISBDs in animals are homologues of the human diseases and are thought to share similar pathomechanisms of epidermal and/or mucosal blister formation caused by autoantibodies targeting structural proteins of the basement membrane zone (BMZ). Disruption of their structural function by the autoantibodies and/or recruited inflammation leads to BMZ fragility, which presents clinically as vesicles, bullae and, later, deep erosions and ulcers. Canine AISBDs are the best characterised, particularly the more common variants such as mucous membrane pemphigoid (48%), epidermolysis bullosa acquisita (EBA) (26%), and bullous pemphigoid (10%). Exceedingly rare AISBDs in the dog are junctional EBA, mixed AISBD, type-1 bullous systemic lupus erythematosus, linear IgA dermatosis, and pemphigus gestationis. The diagnosis of a specific AISBD is made by combining the clinical features (breed, age, lesion distribution) with histological evidence of subepithelial clefting, but not all AISBDs can be differentiated in this manner and specialised immunological testing is required. This latter, unfortunately, is not readily available and, therefore, the specific AISBD diagnosis often remains unconfirmed. While this limits further understanding of these diseases, it does not prevent clinicians from treating their patients, as the treatment approaches are similar for the different AISBDs in dogs. This review primarily focuses on canine AISBDs, the species for which these diseases have been best characterised, and shorter descriptions of variants in other species are also provided.

Pediatric Autoimmune Bullous Disease: A Literature Review and Update on Management

Pediatric autoimmune bullous disease is a rare group of blistering skin disorders in children that result from autoimmunity against intercellular and basement membrane antigens in the skin and mucous membranes. Most pediatric cases are treated with oral corticosteroids or longer-term immunosuppressants such as azathioprine or mycophenolate mofetil. Immunomodulating drugs such as rituximab are increasingly being considered as options for refractory disease.

Epidermolysis bullosa acquisita: a case series of three paediatric patients

Epidermolysis bullosa acquisita (EBA) is an acquired, subepidermal blistering skin disease characterized by autoantibodies against type VII collagen, which links the epidermis to the dermis at the dermo-epidermal junction. EBA is exceptionally rare in children. The diagnosis can be challenging as it shares clinical and histopathological features with other immunobullous diseases. We report three children diagnosed with EBA. The main clinical features were blisters (n=3), milia (n=3), scarring (n=2), oral erosions (n=2) and onychodystrophy (n=1). Histological findings were non-specific, showing a subepidermal blister with various inflammatory infiltrates. On direct immunofluorescence a bright deposit of IgG was seen, and the antibodies adhered to the dermal side of the salt-split in two cases. ELISA analysis confirmed circulating autoantibodies against type VII collagen in one patient. All of them received a course of oral corticosteroids alongside steroid-sparing agents such as dapsone, azathioprine, and rituximab depending on clinical response and shared favorable prognosis.

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.

Multiple milia formation in blistering diseases

BACKGROUND

Milia are superficial keratinous cysts seen as pearly white, dome-shaped lesions 1-2 mm in diameter. Milia are associated with diseases that cause subepidermal blistering, such as hereditary forms of epidermolysis bullosa, epidermolysis bullosa acquisita, bullous pemphigoid, bullous lichen planus, and porphyria cutanea tarda. Multiple eruptive milia are rare and more extensive in number than primary milia.

OBJECTIVE

The aim of this study was to search the literature for cases of blistering diseases with multiple milia formation, especially in areas of the skin where there was no evidence of blistering or trauma, and review the interpretations of their pathogenesis.

METHODS

We performed a literature search with the terms multiple milia and bullous diseases, pemphigoid, and pemphigus.

RESULTS

Very few studies have investigated the origin of milia. Primary milia are thought to originate from the sebaceous collar of vellus hairs, and secondary milia are believed to derive from eccrine ducts more commonly than from overlying epidermis, hair follicles, or sebaceous ducts. Milia secondary to blisters or trauma are speculated to be produced through the regeneration process of disrupted sweat glands or hair follicles. Immunological predisposition, aberrant interaction between the hemidesmosomes, and the extracellular matrix components beneath the hemidesmosomes have been described with regard to the formation of numerous milia during recovery. Multiple milia could be a primary manifestation of dystrophic epidermolysis bullosa in skin areas without evidence of blistering.

CONCLUSION

The exact etiology of multiple milia remains unknown. Immunological predisposition and improper interaction between hemidesmosomes and extracellular matrix components are speculated to play a role in the formation of milia during recovery of bullous lesions in blistering diseases. Still, further studies on the triggering mechanisms of keratinocyte dysfunction in cases of multiple milia formation without evidence of prior blistering are needed.

Bullous Diseases in Children: A Review of Clinical Features and Treatment Options

Bullous diseases are uncommon in children; however, as they have the potential to affect quality of life, occasionally have long-term side effects in the setting of scarring processes, and carry a rare risk of underlying malignancy [e.g., with paraneoplastic pemphigus (PNP)], knowledge of their clinical presentation and treatment options is essential. Given the rarity of these conditions, our current state of knowledge is largely derived from case reports and case series, with a paucity of evidence-based recommendations. In this review, we discuss the clinical presentation of and treatment options for linear immunoglobulin A disease, dermatitis herpetiformis, pemphigus vulgaris, pemphigus foliaceus, PNP, bullous pemphigoid, mucus membrane pemphigoid, epidermolysis bullosa acquisita, and inherited epidermolysis bullosa. In general, when these conditions, except for PNP, occur in childhood, they have a better prognosis than when they occur in adults. Clinical, histopathological, and immunologic features frequently overlap, but distinct differences have also been reported, most commonly in clinical presentation. Treatment is often similar to that in adults, although specific considerations are necessary for a pediatric population.

Unique mouse monoclonal antibodies reactive with maturation-related epitopes on type VII collagen

In this study, we generated a new set of monoclonal antibodies (mAbs) to bovine and human type VII collagen (COL7) by immunizing mice with bovine cornea-derived basement membrane zone (BMZ) fraction. The four mAbs, tentatively named as COL7-like mAbs, showed speckled subepidermal staining in addition to linear BMZ staining of normal human skin and bovine cornea, a characteristic immunofluorescence feature of COL7, but showed no reactivity with COL7 by in vitro biochemical analyses. Taking advantage of the phenomenon that COL7-like mAbs did not react with mouse BMZ, we compared immunofluorescence reactivity between wild-type and COL7-rescued humanized mice and found that COL7-like mAbs reacted with BMZ of COL7-rescued humanized mice. In ELISAs, COL7-like mAbs reacted with intact triple-helical mammalian recombinant protein (RP) of COL7 but not with bacterial RP. Furthermore, COL7-like mAbs did not react with COL7 within either cultured DJM-1 cells or basal cells of skin of a bullous dermolysis of the newborn patient. These results confirmed that COL7-like mAbs reacted with human and bovine COL7. The epitopes for COL7-like mAbs were considered to be present only on mature COL7 after secretion from keratinocytes and deposition to BMZ and to be easily destroyed during immunoblotting procedure. Additional studies indicated association of the speckled subepidermal staining with both type IV collagen and elastin. These unique anti-COL7 mAbs should be useful in studies of both normal and diseased conditions, particularly dystrophic epidermolysis bullosa, which produces only immature COL7.

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.

Liver Transplant in a Patient With Acquired Epidermolysis Bullosa and Associated End-Stage Liver Disease

We report the first case of a liver transplant in a patient with epidermolysis bullosa acquisita and associated hepatitis B virus-hepatitis D virus cirrhosis and its inherent technical issues. Epidermolysis bullosa acquisita is an autoimmune multisystem disorder involving skin and mucosa characterized by the appearing of blisters and erosions. The more severe forms may result in nutritional compromise, anemia, osteopenia, dilated cardiomyopathy, laryngeal mucosal involvement, esophageal strictures, bladder, and kidney involvement requiring surgical intervention. Epidermolysis bullosa acquisita has become recognized as a multisystem disorder that poses several surgical challenges. This case shows that liver transplant is a feasible procedure in patients affected by epidermolysis bullosa acquisita. Patients with epidermolysis bullosa acquisita require a particular pretransplant assessment and a dedicated intra- and postoperative management of every invasive procedure that can traumatize the skin and mucosal epithelium to achieve an uneventful liver transplant. Epidermolysis bullosa acquisita does not represent a contraindication to liver transplant, and immunosuppression after transplant may favor a good systemic control of this immunologic disorder.

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.

A case of recalcitrant epidermolysis bullosa acquisita responsive to rituximab therapy

Epidermolysis bullosa acquisita (EBA) is an autoimmune blistering disorder that occurs infrequently in children. Although typically associated with a good prognosis in children, there are rare cases that are refractory to treatment with conventional immunosuppressive therapy. Rituximab, an anti-CD20 monoclonal antibody, has been reported to be effective in the adult form of EBA. We report a case of a child with severe and recalcitrant EBA exhibiting a sustained response to treatment with rituximab.

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: autoimmunity to anchoring fibril collagen

Epidermolysis bullosa acquisita (EBA) is a rare and acquired autoimmune subepidermal bullous disease of skin and mucosa. EBA includes various distinct clinical manifestations resembling genetic dystrophic epidermolysis bullosa (DEB), Bullous pemphigus, Brunsting-Perry pemphigoid, or cicatricial pemphigoid. These patients have autoantibodies against type VII collagen (C7), an integral component of anchoring fibrils (AFs), which are responsible for attaching the dermis to the epidermis. Destruction or perturbation of the normal functioning AFs clinically results in skin fragility, blisters, erosions, scars, milia, and nail loss, all features reminiscent of genetic dystrophic epidermolysis bullosa. These anti-C7 antibodies are "pathogenic" because when injected into a mouse, the mouse develops an EBA-like blistering disease. Currently, treatment is often unsatisfactory; however, some success has been achieved with colchicine, dapsone, photopheresis, plasmapheresis, infliximab, rituximab, and IVIG.

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.

Epidermolysis bullosa acquisita: current diagnosis and therapy

Epidermolysis bullosa acquisita (EBA) is an acquired, autoimmune subepidermal blistering disease with an approximate prevalence of 0,2/million people. The hallmark of EBA is the presence of autoantibodies (mainly IgG class) to anchoring fibril collagen (type VII collagen) located at the dermal-epidermal junction. Clinically EBA is subdivided into the inflammatory and the non-inflammatory phenotypes, depending on the level of the cleavage in the basal membrane. A recent addition to the diagnostic techniques is the analysis of the serration pattern of the autoantibody deposits at the basal membrane in the direct immunofluorescence. EBA and the closely related bullous systemic lupus erythematosus are the only diseases presenting with the so-called u-serration pattern which distinguishes them from many other autoimmune subepidermal blistering diseases. We also discuss the recent advances in therapy, including the experience with Rituximab.

Clinical and immunopathological evaluation of epidermolysis bullosa acquisita

BACKGROUND

Epidermolysis bullosa acquisita (EBA) is a subepidermal blistering disease with IgG antibodies against collagen VII. The disease is heterogeneous and can lead to significant morbidity.

AIM

To characterize the clinical and laboratory profile of patients with EBA from Sao Paulo, Brazil.

METHODS

In total, 12 patients (mean age 24 years) were analysed for cutaneous and mucosal involvement, laboratory data and response to treatment.

RESULTS

Mucosal involvement occurred in 11 of the 12 patients (eyes in 4/12, nose in 4/9, pharynx-larynx in 5/9 and oesophagus in 4/10; 3 patients did not undergo nasopharyngeal examination and 2 paediatric patients did not undergo endoscopy). Using direct immunofluorescence, different patterns of deposits were found at the basement membrane zone: IgG (12/12), IgA (6/12), IgM (4/12), C3 (11/12). Indirect immunofluorescence (IIF) was positive in 6 of 12 patients, and IIF on salt-split skin detected dermal deposition in 10 of 12 patients. Antinuclear antibodies were found in 3 of 12 patients, but none of them fulfilled the criteria for systemic lupus erythematosus. After treatment, total remission was achieved in three patients and partial remission in five (three were maintained on minimal treatment, one on the full treatment and one was able to come off treatment). Two patients were lost to follow-up and the remaining two had disease flares. Complications were mainly mucosal (oesophageal stenosis, laryngeal synechia, symblephara and trichiasis).

CONCLUSIONS

Mucosal involvement in EBA is a determining factor for disease morbidity. Complete evaluation of the patient, focusing on both cutaneous and extracutaneous sites is essential, as EBA may evolve to refractory disease, severely compromising its outcome.

Autoimmune blistering diseases in children

Autoimmune blistering disorders comprise a series of conditions in which autoantibodies target components of the skin and mucous membranes, leading to blister and bullae formation. Most conditions in the spectrum of autoimmune blistering disorders are uncommonly seen in the pediatric population, even the most common ones, such as chronic bullous disease of childhood and dermatitis herpetiformis; however, they often come into the differential diagnosis of other more common pediatric entities. In addition, prompt recognition and treatment avoids unnecessary morbidity and improves ultimate outcome.

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.

[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.

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.