Mycophenolate mofetil (MMF) in the treatment of epidermolysis bullosa acquisita (EBA) long-term follow-up

Epidermolysis Bullosa Acquisita-Current and Emerging Treatments

Epidermolysis bullosa acquisita (EBA) is a rare chronic autoimmune subepidermal blistering disease of the skin and mucous membranes, usually beginning in adulthood. EBA is induced by autoantibodies to type VII collagen, a major component of anchoring fibrils in the dermal-epidermal junction (DEJ). The binding of autoantibodies to type-VII collagen subsequently leads to the detachment of the epidermis and the formation of mucocutaneous blisters. EBA has two major clinical subtypes: the mechanobullous and inflammatory variants. The classic mechanobullous variant presentation consists of skin fragility, bullae with minimal clinical or histological inflammation, erosions in acral distribution that heal with scarring, and milia formation. The inflammatory variant is challenging to differentiate from other autoimmune bullous diseases, most commonly bullous pemphigoid (BP) but also mucous membrane pemphigoid (MMP), Brunsting-Perry pemphigoid, and linear IgA dermatosis. Due to its recalcitrance conventional treatment of epidermolysis bullosa acquisita is shown to be demanding. Here we discuss novel therapeutic strategies that have emerged and which could potentially improve the quality of life in patients with EBA.

Epidermolysis bullosa acquisita

Epidermolysis bullosa acquisita is a rare autoimmune disease, characterized by the synthesis of anti-collagen VII autoantibodies, the main component of hemidesmosome anchoring fibrils. The antigen-antibody binding elicits a complex inflammatory response, which culminates in the loss of dermo-epidermal adhesion of the skin and/or mucous membranes. Skin fragility with bullae, erosions, and milia in areas of trauma characterizes the mechanobullous form of the disease. In the inflammatory form of epidermolysis bullosa acquisita, urticarial inflammatory plaques with tense bullae, similar to bullous pemphigoid, or mucosal lesions can determine permanent scars and loss of functionality in the ocular, oral, esophageal, and urogenital regions. Due to the similarity of the clinical findings of epidermolysis bullosa acquisita with other diseases of the pemphigoid group and with porphyria cutanea tarda, the diagnosis is currently confirmed mainly based on the clinical correlation with histopathological findings (pauci-inflammatory subepidermal cleavage or with a neutrophilic infiltrate) and the demonstration of the presence of anti-collagen VII IgG in situ by direct immunofluorescence, or circulating anti-collagen VII IgG through indirect immunofluorescence and/or ELISA. There is no specific therapy for epidermolysis bullosa acquisita and the response to treatment is variable, usually with complete remission in children and a worse prognosis in adults with mucosal involvement. Systemic corticosteroids and immunomodulators (colchicine and dapsone) are alternatives for the treatment of mild forms of the disease, while severe forms require the use of corticosteroid therapy associated with immunosuppressants, intravenous immunoglobulin, and rituximab.

Current and Innovated Managements for Autoimmune Bullous Skin Disorders: An Overview

Autoimmune bullous skin disorders are a group of disorders characterized by the formation of numerous blisters and erosions on the skin and/or the mucosal membrane, arising from autoantibodies against the intercellular adhesion molecules and the structural proteins. They can be classified into intraepithelial or subepithelial autoimmune bullous dermatoses based on the location of the targeted antigens. These dermatoses are extremely debilitating and fatal in certain cases, depending on the degree of cutaneous and mucosal involvement. Effective treatments should be implemented promptly. Glucocorticoids serve as the first-line approach due to their rapid onset of therapeutic effects and remission of the acute phase. Nonetheless, long-term applications may lead to major adverse effects that outweigh the benefits. Hence, other adjuvant therapies are mandatory to minimize the potential harm and ameliorate the quality of life. Herein, we summarize the current therapeutic strategies and introduce promising therapies for intractable autoimmune bullous diseases.

Therapeutic approaches and targets for treatment of autoimmune bullous diseases

Autoimmune bullous diseases are a heterogeneous group of diseases characterized by the development of cutaneous and mucosal vesicles, blisters, and finally erosions. The common pathogenetic mechanism is the presence of autoantibodies targeting structural proteins of the skin and mucous membranes (demosomes and hemidesmosomes): in the case of pemphigus, the antigens are intraepidermal, whereas in the case of pemphigoid, dermatitis herpetiformis, and epidermolysis bullosa acquisita they are subepidermal. Mucosal involvement typically affects the oral and ocular mucosa, but in some cases, the upper airways or the upper digestive tract are affected. The burden on patients' lives could be severe due to the impairment of normal feeding or breathing. In other cases, they may represent paraneoplastic syndromes. Since autoimmune bullous diseases may result in significant morbidity and mortality, depending on the grade of cutaneous and mucosal involvement, a prompt therapeutic approach is mandatory and, in recalcitrant cases, may be challenging. The first line therapy consists of corticosteroids, both topical and systemic. Once remission or control of the acute phase is obtained, adjuvant therapies need to be introduced in order to spare the corticosteroid load and minimize side effects such as iatrogenic diabetes or osteoporosis. Herein, we describe all current therapeutic approaches to autoimmune bullous diseases, also including emerging therapies.

Consensus on the treatment of autoimmune bullous dermatoses: bullous pemphigoid, mucous membrane pemphigoid and epidermolysis bullosa acquisita - Brazilian Society of Dermatology

Bullous pemphigoid, mucous membrane pemphigoid and epidermolysis bullosa acquisita are subepidermal autoimmune blistering diseases whose antigenic target is located at the basement membrane zone. Mucous membrane pemphigoid and epidermolysis bullosa acquisita can evolve with cicatricial mucosal involvement, leading to respiratory, ocular and/or digestive sequelae with important morbidity. For each of these dermatoses, a literature review covering all therapeutic options was performed. A flowchart, based on the experience and joint discussion among the authors of this consensus, was constructed to provide treatment orientation for these diseases in Brazil. In summary, in the localized, low-risk or non-severe forms, drugs that have immunomodulatory action such as dapsone, doxycycline among others may be a therapeutic option. Topical treatment with corticosteroids or immunomodulators may also be used. Systemic corticosteroid therapy continues to be the treatment of choice for severe forms, especially those involving ocular, laryngeal-pharyngeal and/or esophageal mucosal involvement, as may occur in mucous membrane pemphigoid and epidermolysis bullosa acquisita. Several immunosuppressants are used as adjuvant alternatives. In severe and recalcitrant cases, intravenous immunoglobulin is an alternative that, while expensive, may be used. Immunobiological drugs such as rituximab are promising drugs in this area. Omalizumab has been used in bullous pemphigoid.

Epidermolysis Bullosa Acquisita: The 2019 Update

Epidermolysis bullosa acquisita (EBA) is an orphan autoimmune disease. Patients with EBA suffer from chronic inflammation as well as blistering and scarring of the skin and mucous membranes. Current treatment options rely on non-specific immunosuppression, which in many cases, does not lead to a remission of treatment. Hence, novel treatment options are urgently needed for the care of EBA patients. During the past decade, decisive clinical observations, and frequent use of pre-clinical model systems have tremendously increased our understanding of EBA pathogenesis. Herein, we review all of the aspects of EBA, starting with a detailed description of epidemiology, clinical presentation, diagnosis, and current treatment options. Of note, pattern analysis via direct immunofluorescence microscopy of a perilesional skin lesion and novel serological test systems have significantly facilitated diagnosis of the disease. Next, a state-of the art review of the current understanding of EBA pathogenesis, emerging treatments and future perspectives is provided. Based on pre-clinical model systems, cytokines and kinases are among the most promising therapeutic targets, whereas high doses of IgG (IVIG) and the anti-CD20 antibody rituximab are among the most promising "established" EBA therapeutics. We also aim to raise awareness of EBA, as well as initiate basic and clinical research in this field, to further improve the already improved but still unsatisfactory conditions for those diagnosed with this condition.

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.