Autoimmunity against type VII collagen in inflammatory bowel disease

Breaking Down Barriers: Epithelial Contributors to Monogenic IBD Pathogenesis

Monogenic causes of inflammatory bowel diseases (IBD) are increasingly being discovered. To date, much attention has been placed in those resulting from inborn errors of immunity. Therapeutic efforts have been largely focused on offering personalized immune modulation or curative bone marrow transplant for patients with IBD and underlying immune disorders. To date, less emphasis has been placed on monogenic causes of IBD that pertain to impairment of the intestinal epithelial barrier. Here, we provide a comprehensive review of monogenic causes of IBD that result in impaired intestinal epithelial barrier that are categorized into 6 important functions: (1) epithelial cell organization, (2) epithelial cell intrinsic functions, (3) epithelial cell apoptosis and necroptosis, (4) complement activation, (5) epithelial cell signaling, and (6) control of RNA degradation products. We illustrate how impairment of any of these categories can result in IBD. This work reviews the current understanding of the genes involved in maintaining the intestinal barrier, the inheritance patterns that result in dysfunction, features of IBD resulting from these disorders, and pertinent translational work in this field.

Case Report: Biological treatment of epidermolysis bullosa acquisita: report on four cases and literature review

Epidermolysis bullosa acquisita (EBA) is a chronic, recurrent autoimmune subepidermal bullous disease characterized by the presence of autoantibodies targeting type VII collagen -- basement membrane zone antigen. Standard therapy for EBA includes a combination of systemic corticosteroids and dapsone; however, severe cases may require advanced treatment. The current article reports on four EBA cases in which biologics: infliximab, rituximab (Rtx), and intravenous immunoglobulin (IVIG) were applied. All patients fulfilled the clinical and immunological criteria of EBA: they presented tense blisters healing with atrophic scars on the skin on traumatized areas and in mucous membranes. The diagnosis of EBA was established using numerous techniques: direct and indirect immunofluorescence, salt split skin, ELISA, Fluorescence Overlay Antigen Mapping using Laser Scanning Confocal Microscopy. Since all the patients did not achieve long-term remission on standard treatment (prednisone, dapsone) due to ineffectiveness or side effects of drugs, they eventually were treated with biologics leading to extraordinary skin improvement and stopping the disease for 1-3 years. Biologics in all patients were tolerated very well. No side effects were observed during application as well as multi-month follow-up. The presented cases provide a premise that biological drugs can be a valuable component of EBA therapy.

Epidermolysis bullosa acquisita treated with ustekinumab: A case report

Epidermolysis bullosa acquisita is a rare autoimmune disease involving cutaneous blistering and scarring associated with collagen VII autoantibodies. Similarly, collagen VII autoantibodies are present in the majority of Crohn’s disease patients and approximately a quarter of epidermolysis bullosa acquisita patients have coexisting Crohn’s disease. Treatment options for epidermolysis bullosa acquisita are limited and are largely ineffective. Here, we describe a 36-year-old female with a history of Crohn’s disease presenting with a 7-year history of severe blistering and scarring of acral surfaces. Diagnostic workup revealed subepidermal cleavage on skin biopsy and elevated serum collagen VII autoantibodies, indicative of epidermolysis bullosa acquisita. She was given ustekinumab for her coexisting Crohn’s disease and, afterwards, her epidermolysis bullosa acquisita resolved as evidenced by a lack of new blisters or scarring. Further studies are required to evaluate the effects of ustekinumab on epidermolysis bullosa acquisita.

Dermatological Manifestations in Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBDs) may be associated with extra-intestinal manifestations. Among these, mucocutaneous manifestations are relatively frequent, often difficult to diagnose and treat, and may complicate the course of the underlying disease. In the present review, a summary of the most relevant literature on the dermatologic manifestations occurring in patients with inflammatory bowel diseases has been reviewed. The following dermatological manifestations associated with IBDs have been identified: (i) specific manifestations with the same histological features of the underlying IBD (occurring only in Crohn's disease); (ii) cutaneous disorders associated with IBDs (such as aphthous stomatitis, erythema nodosum, psoriasis, epidermolysis bullosa acquisita); (iii) reactive mucocutaneous manifestations of IBDs (such as pyoderma gangrenosum, Sweet's syndrome, bowel-associated dermatosis-arthritis syndrome, aseptic abscess ulcers, pyodermatitis-pyostomatitis vegetans, etc.); (iv) mucocutaneous conditions secondary to treatment (including injection site reactions, infusion reactions, paradoxical reactions, eczematous and psoriasis-like reactions, cutaneous infections, and cutaneous malignancies); (v) manifestations due to nutritional malabsorption (such as stomatitis, glossitis, angular cheilitis, pellagra, scurvy, purpura, acrodermatitis enteropathica, phrynoderma, seborrheic-type dermatitis, hair and nail abnormalities). An accurate dermatological examination is essential in all IBD patients, especially in candidates to biologic therapies, in whom drug-induced cutaneous reactions may assume marked clinical relevance.

The intestinal tissue homeostasis - the role of extracellular matrix remodeling in inflammatory bowel disease

Introduction: Extracellular matrix (ECM) remodeling of the intestinal tissue is important in inflammatory bowel disease (IBD) due to the extensive mucosal remodeling. There are still gaps in our knowledge as to how ECM remodeling is related to intestinal epithelium homeostasis and healing of the intestinal mucosa.Areas covered: The aim of this review is to highlight the importance of the ECM in relation to the pathogenesis of IBD, while addressing basement membrane and interstitial matrix remodeling, and the processes of wound healing of the intestinal tissue in IBD.Expert opinion: In IBD, basement membrane remodeling may reflect the integrity of the intestinal epithelial-cell homeostasis. The interstitial matrix remodeling is associated with deep inflammation such as the transmural inflammation as seen in fistulas and intestinal fibrosis leading to fibrostenotic strictures, in patients with CD. The interplay between wound healing processes and ECM remodeling also affects the tissue homeostasis in IBD. The interstitial matrix, produced by fibroblasts, holds a very different biology as compared to the epithelial basement membrane in IBD. In combination with integration of wound healing, quantifying the interplay between damage and repair to these sub compartments may provide essential information in IBD patient profiling, mucosal healing and disease management.

Subepidermal autoimmune bullous diseases: overview, epidemiology, and associations

Subepidermal autoimmune bullous diseases of the skin and mucosae comprise a large group of chronic diseases, including bullous pemphigoid, pemphigoid gestationis, mucous membrane pemphigoid, linear IgA bullous dermatosis, epidermolysis bullosa acquisita, and anti-p200 pemphigoid. These diseases are characterized by an antibody response toward structural components of the basement membrane zone, resulting in subepidermal blistering. The epidemiological features of these diseases vary substantially in different regions of the world. Observational studies investigating comorbidities and associations among patients with these diseases are inconsistent and sometimes inconclusive. This review provides a brief overview regarding each one of the subepidermal autoimmune bullous diseases. In addition, it summarizes the most recent understanding of the epidemiological features and associations of this group of organ-specific autoimmune diseases.

Short article: Crohn's disease and pemphigus: is there an association?: a population-based study

BACKGROUND

Although the coexistence of Crohn's disease (CD) and pemphigus has been reported in several individuals, the association between the two conditions was not investigated systematically in the past. A recent association between pemphigus and ulcerative colitis has been reported. The study aims to estimate the association between pemphigus and CD using a large-scale real-life computerized database.

PATIENTS AND METHODS

A cross-sectional study was carried out comparing pemphigus patients with age-matched, sex-matched, and ethnicity-matched control participants in terms of the prevalence of CD. χ-Test and t-test were used for univariate analysis and a logistic regression model was used for multivariate analysis. The study was carried out utilizing the computerized database of Clalit Health Services ensuring 4.5 million patients.

RESULTS

A total of 1985 pemphigus patients and 9874 controls were included in the study. The prevalence of CD was comparable in patients with pemphigus and controls [0.4 vs. 0.3%, respectively; odds ratio (OR): 1.2; 95% confidence interval (CI): 0.5-2.5; P=0.688]. In an age-stratified analysis, a significant association was observed between pemphigus and CD in patients younger than 40 years (2.1 vs. 0.4%, respectively; OR: 5.1; 95% CI: 1.0-25.7; P=0.027). In a multivariate analysis adjusting for potential confounding factors, no independent association between the two conditions was found (OR: 0.9; 95% CI: 0.4-2.0; P=0.828). Study findings were robust to sensitivity analysis that included patients under pemphigus-specific treatments.

CONCLUSION

Unlike ulcerative colitis, CD was not associated with pemphigus. Further research is warranted to understand the pathophysiology of these observations better.

Diagnostic Markers for Nonspecific Inflammatory Bowel Diseases

The nonspecific inflammatory bowel diseases (IBD) represent a heterogeneous group of chronic inflammatory disorders of the gastrointestinal tract, and Leśniowski-Crohn's disease (CD) and ulcerative colitis (UC) are among the two major clinical forms. Despite the great progress in understanding the pathogenesis of these diseases, their etiology remains unclear. Genetic, immune, and environmental factors are thought to play a key role. The correct diagnosis of nonspecific inflammatory bowel diseases as well as the determination of disease activity, risk stratification, and prediction of response to therapy still relies on a multidisciplinary approach based on clinical, laboratory, endoscopic, and histologic examination. However, considerable effort has been devoted to the development of an accurate panel of noninvasive biomarkers that have increased diagnostic sensitivity and specificity. Laboratory biomarkers useful in differentiating IBD with functional disorders and in evaluating disease activity, prognosis, and treatment selection for IBD are presented in this study.

Development of a Neo-Epitope Specific Assay for Serological Assessment of Type VII Collagen Turnover and Its Relevance in Fibroproliferative Disorders

Type VII collagen is the main component of the anchoring fibrils connecting the basement membrane to the underlying interstitial matrix. Mutations in the type VII collagen gene cause dystrophic epidermolysis bullosa. Increased levels of type VII collagen in the skin have been reported in patients with systemic sclerosis (SSc), whereas reduced levels in the airways have been related to asthma. This indicates that type VII collagen plays an important part in upholding tissue integrity and that its remodeling may lead to pathological states. The aim of this study was to investigate the role of type VII collagen remodeling in fibroproliferative disorders. We produced monoclonal antibody targeting a specific fragment of type VII collagen (C7M) released to the systemic circulation and developed a neo-epitope specific competitive enzyme-linked immunosorbent assay (ELISA). Biological relevance was evaluated in serum from patients with SSc or chronic obstructive pulmonary disease (COPD). The C7M ELISA was technically robust and specific for the C7M neo-epitope. Serum C7M levels were significantly elevated in two cohorts of patients with SSc and in patients with COPD as compared with healthy individuals (P < 0.0001). The C7M ELISA enabled quantification of type VII collagen turnover in serum. Elevated serum C7M levels indicated that the turnover rate of type VII collagen was significantly increased in patients with SSc or COPD, suggesting a pathological role. Thus, the C7M ELISA may become useful in future investigations of type VII collagen turnover in fibroproliferative disorders, and it may prove a valuable tool for evaluating novel anti-fibrotic drugs.

[Cutaneous involvement in chronic inflammatory bowel disease : Crohn's disease and ulcerative colitis]

BACKGROUND

Over recent decades, both the incidence and prevalence of chronic inflammatory bowel disease have continued to rise in industrialized countries; the disease is frequently associated with extracutaneous involvement and comorbidity.

OBJECTIVES

The purpose of this work was to investigate the frequency and specificity of mucocutaneous manifestations in Crohn's disease (CD) and ulcerative colitis (UC).

MATERIALS AND METHODS

An extensive search in peer-reviewed journals via PubMed was performed; presented is a summary and analysis of various studies and data, including data of patients treated at our department.

RESULTS

CD and UC are frequently associated with mucocutaneous symptoms; however, primary/specific disease-associations are exclusively seen in CD patients. These include peri-anal and -stomal fistulas and ulcerations, "metastatic" Crohn's disease as well as oral granulomatous disease. Moreover, in both CD and UC, there occur several other inflammatory skin conditions such as erythema nodosum, pyoderma gangrenosum, hidradenitis suppurativa, chronic oral aphthous disease, Sweet syndrome, pyostomatitis vegetans, and bowel-associated dermatosis-arthritis syndrome. Malnutrition syndromes (zinc and vitamin deficiencies) are only rarely observed.

CONCLUSION

On skin and oral/genital mucous membranes various different inflammatory manifestations may be observed during the course of CD or UC. However, most data about a direct pathogenic relationship of the gastrointestinal and dermatologic disorders are quite heterogeneous or even contradictory. Nevertheless, knowledge of these conditions and their possible association with CD and UC could be crucial for early diagnosis and initiation of an appropriate therapy and thus be essential to prevent secondary tissue damage.

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.

Epidermolysis bullosa acquisita in a 17-year-old boy with Crohn's disease

Epidermolysis bullosa acquisita is a rare, acquired, autoimmune subepidermal blistering disease of the skin, characterised by blisters and erosions, especially in trauma-prone sites and extensor skin surface, scarring with formation of milia, skin fragility and nail dystrophy. Epidermolysis bullosa acquisita is extremely rare in childhood and it has been reported to be frequently associated with Crohn's disease. Furthermore, autoantibodies against type VII collagen have been found in a large number of patients with Crohn's disease without epidermolysis bullosa acquisita. We report a case of a 17-year-old boy affected by Crohn's disease who presented with milia on infiltrated erythematous plaques over the back of the hands. The diagnosis of epidermolysis bullosa acquisita was confirmed by histopathology, direct and indirect immunofluorescence analysis and ELISA.

Blister-inducing antibodies target multiple epitopes on collagen VII in mice

Epidermolysis bullosa acquisita (EBA) is an autoimmune subepidermal blistering disease of mucous membranes and the skin caused by autoantibodies against collagen VII. In silico and wet laboratory epitope mapping studies revealed numerous distinct epitopes recognized by EBA patients' autoantibodies within the non-collagenous (NC)1 and NC2 domains of collagen VII. However, the distribution of pathogenic epitopes on collagen VII has not yet been described. In this study, we therefore performed an in vivo functional epitope mapping of pathogenic autoantibodies in experimental EBA. Animals (n = 10/group) immunized against fragments of the NC1 and NC2 domains of collagen VII or injected with antibodies generated against the same fragments developed to different extent experimental EBA. Our results demonstrate that antibodies targeting multiple, distinct epitopes distributed over the entire NC1, but not NC2 domain of collagen VII induce blistering skin disease in vivo. Our present findings have crucial implications for the development of antigen-specific B- and T cell-targeted therapies in EBA.

Genome-wide mapping of gene-microbiota interactions in susceptibility to autoimmune skin blistering

Susceptibility to chronic inflammatory diseases is determined by immunogenetic and environmental risk factors. Resident microbial communities often differ between healthy and diseased states, but whether these differences are of primary aetiological importance or secondary to the altered inflammatory environment remains largely unknown. Here we provide evidence for host gene–microbiota interactions contributing to disease risk in a mouse model of epidermolysis bullosa acquisita, an autoantibody-induced inflammatory skin disease. Using an advanced intercross, we identify genetic loci contributing to skin microbiota variability, susceptibility to skin blistering and their overlap. Furthermore, by treating bacterial species abundances as covariates with disease we reveal a novel disease locus. The majority of the identified covariate taxa are characterized by reduced abundance being associated with increased disease risk, providing evidence of a primary role in protection from disease. Further characterization of these putative probiotic species or species assemblages offers promising potential for preventative and therapeutic treatment development.

The pathogenesis of inflammatory disorders afflicting the skin is multifactorial. Srinivas et al. show that diversity of the skin microbiota is a critical factor determining the susceptibility to epidermolysis bullosa acquisita, a chronic mucocutaneous autoimmune skin blistering disease.

Molecular diagnosis in autoimmune skin blistering conditions

Blister formation in skin and mucous membranes results from a loss of cell-cell or cell-matrix adhesion and is a common outcome of pathological events in a variety of conditions, including autoimmune and genetic diseases, viral and bacterial infections, or injury by physical and chemical factors. Autoantibodies against structural components maintaining cell-cell and cell-matrix adhesion induce tissue damage in autoimmune blistering diseases. Detection of these autoantibodies either tissue-bound or circulating in serum is essential to diagnose the autoimmune nature of disease. Various immunofluorescence methods as well as molecular immunoassays, including enzyme-linked immunosorbent assay and immunoblotting, belong to the modern diagnostic algorithms for these disorders. There is still a considerable need to increase awareness of the rare autoimmune blistering diseases, which often show a severe, chronic-relapsing course, among physicians and the public. This review article describes the immunopathological features of autoimmune bullous diseases and the molecular immunoassays currently available for their diagnosis and monitoring.

Cutaneous manifestations in patients with inflammatory bowel diseases: pathophysiology, clinical features, and therapy

The skin is one of the most common extraintestinal organ system affected in patients with inflammatory bowel disease (IBD), including both Crohn's disease and ulcerative colitis. The skin manifestations associated with IBD are polymorphic and can be classified into 4 categories according to their pathophysiology: (1) specific, (2) reactive, (3) associated, and (4) induced by IBD treatment. Cutaneous manifestations are regarded as specific if they share with IBD the same granulomatous histopathological pattern: perianal or metastatic Crohn's disease (commonly presenting with abscesses, fistulas or hidradenitis suppurativa-like features) is the prototype of this setting. Reactive cutaneous manifestations are different from IBD in the histopathology but have close physiopathological links: pyoderma gangrenosum, a neutrophil-mediated autoinflammatory skin disease typically manifesting as painful ulcers, is the paradigm of this group. Among the cutaneous diseases associated with IBD, the most commonly seen are erythema nodosum, a form of panniculitis most commonly involving bilateral pretibial areas, and psoriasis, a T helper 1/T helper 17-mediated erythematous squamous inflammatory disease. Finally, the number of cutaneous adverse reactions because of IBD therapies is progressively increasing. The most frequent drug-induced cutaneous manifestations are psoriasis-like, eczema-like, and lichenoid eruptions, as well as cutaneous lupus erythematosus for biologics, and nonmelanoma skin cancer, mainly basal cell and squamous cell carcinomas for thiopurines.

Prevalence of specific anti-skin autoantibodies in a cohort of patients with inherited epidermolysis bullosa

Background

Inherited epidermolysis bullosa (EB) is a group of skin diseases characterized by blistering of the skin and mucous membranes.

There are four major types of EB (EB simplex, junctional EB, dystrophic EB and Kindler syndrome) caused by different gene mutations. Dystrophic EB is derived from mutations in the type VII collagen gene (COL7A1), encoding a protein which is the predominant component of the anchoring fibrils at the dermal-epidermal junction.

For the first time in literature, we have evaluated the presence of anti-skin autoantibodies in a wider cohort of patients suffering from inherited EB and ascertained whether they may be a marker of disease activity.

Methods

Sera from patients with inherited EB, 17 with recessive dystrophic EB (RDEB), 10 with EB simplex (EBS) were analysed. As much as 20 patients with pemphigus vulgaris, 21 patients with bullous pemphigoid and 20 healthy subjects were used as controls.

Anti-skin autoantibodies were tested in all samples with the Indirect Immunofluorescence (IIF) method and the currently available ELISA method in order to detect anti-type VII collagen, anti-BP180 and anti-BP230 autoantibodies.

Results

The mean concentrations of anti-type VII collagen autoantibodies titres, anti-BP180 and anti-BP230 autoantibodies were statistically higher in RDEB patients than in EBS patients.

The sensitivity and specificity of the anti-type VII collagen ELISA test were 88.2% and 96.7%. The Birmingham Epidermolysis Bullosa Severity score, which is used to evaluate the severity of the disease, correlated with anti-skin autoantibodies titres.

Conclusions

The precise pathogenic role of circulating anti-skin autoantibodies in RDEB is unclear. There is a higher prevalence of both anti-type VII collagen and other autoantibodies in patients with RDEB, but their presence can be interpreted as an epiphenomenon.

Clinical presentation, pathogenesis, diagnosis, and treatment of epidermolysis bullosa acquisita

Epidermolysis bullosa acquisita (EBA) is a chronic mucocutaneous autoimmune skin blistering disease. The pathogenic relevance of autoantibodies targeting type VII collagen (COL7) has been well-documented. Therefore, EBA is a prototypical autoimmune disease with a well-characterized pathogenic relevance of autoantibody binding to the target antigen. EBA is a rare disease with an incidence of 0.2 new cases per million and per year. The current treatment of EBA relies on general immunosuppressive therapy, which does not lead to remission in all cases. Therefore, there is a high, so far unmet medical need for the development of novel therapeutic options. During the last 10 years, several novel in vitro and in vivo models of EBA have been established. These models demonstrated a critical role of the genetic background, T cells, and cytokines for mediating the loss of tolerance towards COL7. Neutrophils, complement activation, Fc gamma receptor engagement, cytokines, several molecules involved in cell signaling, release of reactive oxygen species, and matrix metalloproteinases are crucial for autoantibody-induced tissue injury in EBA. Based on this growing understanding of the diseases' pathogenesis, several potential novel therapeutic targets have emerged. In this review, the clinical presentation, pathogenesis, diagnosis, and current treatment options for EBA are discussed in detail.

Prevalence of collagen VII-specific autoantibodies in patients with autoimmune and inflammatory diseases

Background

Autoimmunity to collagen VII is typically associated with the skin blistering disease epidermolysis bullosa acquisita (EBA), but also occurs occasionally in patients with systemic lupus erythematosus or inflammatory bowel disease. The aim of our present study was to develop an accurate immunoassay for assessing the presence of autoantibodies against collagen VII in large cohorts of patients and healthy donors.

Methods

Based on in silico antigenic analysis and previous wetlab epitope mapping data, we designed a chimeric collagen VII construct containing all collagen VII epitopes with higher antigenicity. ELISA was performed with sera from patients with EBA (n = 50), Crohn's disease (CD, n = 50), ulcerative colitis (UC, n = 50), bullous pemphigoid (BP, n = 76), and pemphigus vulgaris (PV, n = 42) and healthy donors (n = 245).

Results

By ELISA, the receiver operating characteristics analysis yielded an area under the curve of 0.98 (95% CI: 0.9638-1.005), allowing to set the cut-off at 0.32 OD at a calculated specificity of 98% and a sensitivity of 94%. Running the optimized test showed that serum IgG autoantibodies from 47 EBA (94%; 95% CI: 87.41%-100%), 2 CD (4%; 95% CI: 0%-9.43%), 8 UC (16%; 95% CI: 5.8%-26%), 2 BP (2.63%; 95% CI: 0%-6.23%), and 4 PV (9.52%; 95% CI: 0%-18.4%) patients as well as from 4 (1.63%; 95% CI: 0%-3.21%) healthy donors reacted with the chimeric protein. Further analysis revealed that in 34%, 37%, 16% and 100% of sera autoantibodies of IgG1, IgG2, IgG3, and IgG4 isotype, respectively, recognized the recombinant autoantigen.

Conclusions

Using a chimeric protein, we developed a new sensitive and specific ELISA to detect collagen specific antibodies. Our results show a low prevalence of collagen VII-specific autoantibodies in inflammatory bowel disease, pemphigus and bullous pemphigoid. Furthermore, we show that the autoimmune response against collagen VII is dominated by IgG4 autoantibodies. The new immunoassay should prove a useful tool for clinical and translational research and should improve the routine diagnosis and disease monitoring in diseases associated with collagen VII-specific autoimmunity.

Autoimmune bullous diseases associations

The presence of one autoimmune disorder helps lead to the discovery of other autoimmune conditions. It is thought that diseases in which autoimmunity is a feature tend to be associated together more often than one can ascribe to chance. A variety of diseases have been implicated in the onset of intraepidermal and subepidermal autoimmune diseases. The presence of one autoimmune disease should alert the physician to watch for a second immunologic disorder. A list of autoimmune bullous diseases associations includes autoimmune bullous diseases, pemphigus, pemphigoid, epidermolysis bullosa acquisita, dermatitis herpetiformis (Duhring), linear immunoglobulin A disease, and multiple autoimmune syndrome.

Skin manifestations of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a disease that affects the intestinal tract via an inflammatory process. Patients who suffer from IBD often have diseases that affect multiple other organ systems as well. These are called extraintestinal manifestations and can be just as, if not more debilitating than the intestinal inflammation itself. The skin is one of the most commonly affected organ systems in patients who suffer from IBD. The scientific literature suggests that a disturbance of the equilibrium between host defense and tolerance, and the subsequent over-activity of certain immune pathways are responsible for the cutaneous disorders seen so frequently in IBD patients. The purpose of this review article is to give an overview of the types of skin diseases that are typically seen with IBD and their respective pathogenesis, proposed mechanisms, and treatments. These cutaneous disorders can manifest as metastatic lesions, reactive processes to the intestinal inflammation, complications of IBD itself, or side effects from IBD treatments; these can be associated with IBD via genetic linkage, common autoimmune processes, or other mechanisms that will be discussed in this article. Ultimately, it is important for healthcare providers to understand that skin manifestations should always be checked and evaluated for in patients with IBD. Furthermore, skin disorders can predate gastrointestinal symptoms and thus may serve as important clinical indicators leading physicians to earlier diagnosis of IBD.

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.