Chronic bullous disease of childhood and linear IgA disease of adults are IgA1-mediated diseases

Ulcerative colitis complicated with linear immunoglobulin A bullous dermatosis

Linear immunoglobulin A (IgA) bullous dermatosis (LABD) is a rare disorder involving subepidermal blistering characterised by IgA deposition along the basement membrane. The clinical features of LABD are variable but can include bullae, vesicles and erythematous lesions. Histopathology reveals formation of subepidermal bullae and linearly deposition of IgA in the basement membrane of the epidermis. LABD has been reported as a rare complication of ulcerative colitis (UC). We report the case of a young woman with UC complicated by LABD. The latter manifested as vesicles with erythema on almost the entire body. A biopsy of the skin lesions revealed linear IgA deposits in the basement membrane according to a direct immunofluorescence assay. Prednisolone administration resulted in clinical remission of UC but poor improvement of skin lesions. Oral administration of diaminodiphenyl sulfone led to improvement of blisters. Thereafter, abdominal and skin symptoms did not recur and she was discharged from hospital.

Linear IgA bullous dermatosis associated with ulcerative colitis: A case report and literature review

We report the case of a 59-year-old Japanese woman who developed linear IgA bullous dermatosis during treatment for ulcerative colitis that manifested as pruritic vesicles with erythema on the trunk and scalp. Histopathological examination revealed subepidermal bulla with neutrophil and eosinophil infiltration in the upper dermis. Direct immunofluorescence revealed linear IgA deposits at the basement membrane zone, and indirect immunofluorescence using split skin revealed IgA reaction to the epidermal side (lamina lucida type). We reviewed 33 reported cases of linear IgA bullous dermatosis associated with ulcerative colitis and found that ulcerative colitis preceded the onset of linear IgA bullous dermatosis in 94% of the patients and that IgA-positive patients in split skin indirect immunofluorescence all showed the lamina lucida type, indicating that target antigens for serum IgA antibodies may reside in the lamina lucida. Regarding the pathogenetic association of ulcerative colitis and linear IgA bullous dermatosis, intestinal inflammation may induce the exposure and presentation of intestinal antigens that are cross-reactive to cutaneous antigens, stimulating autoimmune response to antigens of cutaneous basement membrane zones.

Consensus on the treatment of autoimmune bullous dermatoses: dermatitis herpetiformis and linear IgA bullous dermatosis - Brazilian Society of Dermatology

Dermatitis herpetiformis and linear IgA bullous dermatosis are autoimmune diseases that present with pruritic urticarial papules and plaques, with formation of vesicles and blisters of subepidermal location, mediated by IgA antibodies. Mucosal lesions are present only in linear IgA bullous dermatosis. The elaboration of this consensus consisted of a brief presentation of the different aspects of these dermatoses and, above all, of an updated literature review on the various therapeutic options that were discussed and compared with the authors' experience, aiming at the treatment orientation of these diseases in Brazil. Dermatitis herpetiformis is a cutaneous manifestation of celiac disease, and can be controlled with a gluten-free diet and dapsone. On the other hand, linear IgA bullous dermatosis arises spontaneously or is triggered by drugs, and can be controlled with dapsone, but often requires the association of systemic corticosteroids and eventually immunosuppressants.

Immunological methods for the diagnosis of oral mucosal diseases

Immunological methods, which have been widely used in autoimmune blistering diseases (AIBDs) of the oral mucosa, can also be adopted as auxiliary diagnostic tools in oral lichen planus (OLP) and discoid lupus erythematosus (DLE). AIBDs, characterized by autoantibodies against structural proteins of keratinocytes or the basement membrane zone, clinically present as blisters and erosions of the oral mucosa. When atypical lesions occur, OLP or DLE may be confused with AIBDs. The improvement of diagnostic accuracy is necessary due to the significant differences in treatment and prognosis among these diseases. A variety of immunological methods are used for qualitative and quantitative detection of target antigens and autoantibodies. These methods can evaluate efficacy of treatment, monitor diseases and guide treatment decisions. In this review, we discuss the application of immunofluorescence, biochemical tests, and protein microarrays for AIBDs, OLP and DLE, as well as the differential diagnostic methods using immunological tests.

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.

Immunofluorescence of Autoimmune Bullous Diseases

Autoimmmune bullous diseases of skin and mucosa are uncommon, disabling, and potentially lethal diseases. For a quick and reliable diagnosis immunofluorescence is essential. This article describes two variants of immunofluorescence. The direct method uses a skin or mucosal biopsy of the patient to detect in vivo bound antibodies. Indirect immunofluorescence uses patient's serum and a substrate to visualize circulating autoantibodies. These two methods supplemented with advanced techniques allow reliable classification of autoimmune bullous diseases; not only the main entities pemphigus and pemphigoid, but also subclasses within these groups. This is important because prognosis and therapy vary among different variants of autoimmune bullous diseases.

Linear IgA dermatosis associated with ulcerative colitis: complete and sustained remission after total colectomy

Linear IgA dermatosis has been increasingly associated with inflammatory bowel diseases, particularly ulcerative colitis. A 13-year-old male patient with an 11-month history of ulcerative colitis developed vesicles, pustules and erosions on the skin of the face, trunk and buttocks and in the oral mucosa. The work-up revealed a neutrophil-rich sub-epidermal bullous disease and linear deposition of IgA along the dermoepidermal junction, establishing the diagnosis of linear IgA dermatosis. The patient experienced unsatisfactory partial control of skin and intestinal symptoms despite the use of adalimumab, mesalazine, prednisone and dapsone for some months. After total colectomy, he presented complete remission of skin lesions, with no need of medications during two years of follow-up. A review of previously reported cases of the association is provided here and the role of ulcerative colitis in triggering linear IgA dermatosis is discussed.

[Chronic bullous disease of childhood. Long-term therapy over 8 years with 4,4'-diaminodiphenylsulfone]

A 3-year-old boy presented with a generalized bullous disease, clinically strongly indicative of chronic bullous disease of childhood (CBDC). The diagnosis was confirmed by histopathology and further verified by several immunological and biochemical examinations. Direct immunofluorescence (IF) of perilesional skin revealed in vivo bound IgA-autoantibodies (aabs) in a linear pattern along the basement membrane zone; indirect IF revealed circulating IgA-aabs bound to the roof of "split skin" preparations of healthy human skin; immunoblotting of epidermal protein extracts showed that the aabs bound to a 97KD/120KD protein. Therapy with 4,4'-diaminodiphenylsulfone (DADPS, 2 mg/kg /daily), combined with prednisolone for the first month, was initiated, and promptly led to complete remission. Two attempts to stop DADPS treatment after 3 and 5 years of continuous therapy were followed by prompt recurrences. The boy is now 8 years old; with continuous DADPS therapy (1 mg/kg body weight/d), he displays regular physical and intellectual development.

Linear immunoglobulin A bullous dermatosis

Linear immunoglobulin A (IgA) bullous dermatosis, also known as linear IgA disease, is an autoimmune mucocutaneous disorder characterized by subepithelial bullae, with IgA autoantibodies directed against several different antigens in the basement membrane zone. Its immunopathologic characteristic resides in the presence of a continuous linear IgA deposit along the basement membrane zone, which is clearly visible on direct immunofluorescence. This disorder shows different clinical features and distribution when adult-onset of linear IgA disease is compared with childhood-onset. Diagnosis is achieved via clinical, histopathologic, and immunopathologic examinations. Two common therapies are dapsone and sulfapyridine, which reduce the inflammatory response and achieve disease remission in a variable period of time.

Clinical features, diagnosis, and pathogenesis of chronic bullous disease of childhood

Chronic bullous disease of childhood (CBDC) is the most common acquired autoimmune blistering disorder of childhood and is characterized by linear IgA staining of the basement membrane zone on direct immunofluorescence. This autoimmune attack on structural proteins, usually proteolytic fragments of collagen XVII, renders the dermal-epidermal junction prone to blistering. Diagnosis is confirmed by characteristic histology and direct immunofluorescence. Prognosis is generally favorable, with spontaneous remission usually occurring by puberty; however, cases with severe morbidity and cases persisting into adulthood have been reported. This article discusses the clinical features, diagnosis, and pathogenesis of CBDC in more detail.

About linear igA/igG bullous dermatosis

A case study of linear IgA/IgG bullous dermatosis has been described, and issues related to classification as well as clinical, histological and immunopathological signs of the disease have been discussed.

Chronic bullous disease of childhood in a patient with acute lymphoblastic leukemia: possible induction by a drug

Linear IgA disease is characterized by the presence of linear IgA deposits in the basement membrane zone of the skin, and circulating basement membrane zone antibodies are detected in 80% of cases. The disease occurs in both adults and children, and is designated adult linear IgA disease in the former and chronic bullous disease of childhood (CBDC) in the latter. We describe a 5-year-old boy with acute lymphoblastic leukemia in remission, in whom CBDC developed after treatment with trimethoprim/sulfamethoxazole (cotrimoxazole). To our knowledge, this is the first reported case of possible drug-induced CBDC.

Linear IgA dermatosis induced by a new angiotensin-converting enzyme inhibitor

A 68-year-old female patient treated with benazepril for arterial hypertension developed oral and cutaneous blistering. Biopsy of the oral and cutaneous lesions showed neutrophilic microabscesses in the mesenchymal papillae, with epitheliomesenchymal separation. Direct immunofluorescence revealed linear immunoglobulin deposits at the epithelial basement membrane zone, consisting predominantly of IgA. The histologic results supported the clinical diagnosis of drug-induced linear IgA disease. The substitution of benazepril with a beta blocker resulted in complete resolution of all mucocutaneous lesions.

Autoimmune responses in patients with linear IgA bullous dermatosis: both autoantibodies and T lymphocytes recognize the NC16A domain of the BP180 molecule

Linear IgA bullous disease (LABD) is an autoimmune skin disease characterized by subepidermal blisters and IgA autoantibodies directed against the epidermal basement membrane zone (BMZ) of the skin. Various antigens have been identified as targets of IgA autoantibodies including BP180, a type II glycoprotein that spans the BMZ and lamina lucida. Previously, we have identified a subset of LABD patients whose sera contained IgA antibodies against the 16th noncollagenous (NC16A) domain of BP180. NC16A was previously shown to harbor epitopes that are recognized by both autoantibodies and T cells from patients with bullous pemphigoid and herpes gestationis and is thought to be associated with the development of these immunobullous diseases. The aim of this study was to determine whether T lymphocytes from LABD patients with anti-NC16A IgA autoantibodies respond to epitopes in the same region of the BP180 protein. Indeed, of the four LABD patients in our study, all had T cells that specifically proliferated in response to NC16A. Moreover, two subfragments of NC16A were identified as the predominant targets of LABD T cells. Further analysis of T cell lines and clones derived from these patients revealed that these cells express a CD4 memory T cell phenotype and secrete a Th1/Th2 mixed-cytokine profile, characteristics similar to those of T cells in bullous pemphigoid patients. Our data suggest that the BP180 protein, typically the NC16A region, is the common target of both cellular and humoral immune responses in some LABD patients. This information helps to further elucidate the autoimmune mechanisms in this disease.

Assessment of skin basement membrane zone antibodies in the urine of patients with acquired subepidermal immunobullous diseases

BACKGROUND

In bullous pemphigoid (BP), cicatricial pemphigoid (CP) and linear IgA disease (LAD), autoantibodies to the basement membrane zone (BMZ) are found in skin and mucosa, blood and blister fluid.

OBJECTIVES

To assess whether BMZ antibodies might also be detected in urine.

METHODS

Urine and serum samples from 62 patients (32 with BP, 17 with CP and 13 with LAD) were analysed for antibody isotypes and subclasses by indirect immunofluorescence, and urine and serum samples from 40 patients (25 with BP, eight with CP and seven with LAD) were screened for target antigens using immunoblotting.

RESULTS

Fourteen of 32 patients with BP had detectable levels of IgG BMZ autoantibodies in their urine, and all 32 had positive sera. Of these 14 BP patients, 13 had epidermal-binding serum autoantibodies at a titre > 1 : 160, and one had dermal-binding serum antibodies at a titre of 1 : 40. BMZ autoantibodies were not detected in the urine of the CP or LAD patients, but the corresponding sera were of low titre or negative. IgG subclasses (IgG1-4) were less frequently detected in urine than in serum. IgG4 was the predominant subgroup found (10 urine samples and all 14 sera), followed by IgG1 (two urine samples and 12 sera); IgG2 was detected in a single urine sample and three sera, and IgG3 was not detected. Eight of 25 BP and one of eight CP urine samples were positive on immunoblotting, and bound BP230 and/or BP180 with IgA and/or IgG autoantibodies. IgA autoantibodies were not detected in the urine of the seven LAD patients. The corresponding sera were often more positive, with 21 of 25 BP, five of eight CP and six of seven LAD sera immunoblotting the major BP antigens.

CONCLUSIONS

The detection of IgG autoantibodies from urine samples using indirect immunofluorescence correlated with a high titre of IgG autoantibodies in the serum. IgG and IgA autoantibodies in the urine were detected by immunoblotting, although less frequently than in serum. The finding of BMZ antibodies in the urine of many BP patients may have clinical relevance, and may have a restricted application in the diagnosis of immunobullous disease.

Induction of keratinocyte IL-8 expression and secretion by IgG autoantibodies as a novel mechanism of epidermal neutrophil recruitment in a pemphigus variant

A subset of pemphigus herpetiformis, a rare pemphigus variant, is characterized histopathologically by subcorneal acantholysis and neutrophilic infiltration. The mechanism of neutrophil infiltration is unknown, but chemokines such as IL-8 may play a role. We investigated the possible role of IL-8 in two such cases. Direct and indirect immunofluorescence studies demonstrated in vivo-bound and circulating IgG epithelial cell surface-binding autoantibodies, both predominated by IgG4 subclass. ELISA and immunoblotting studies revealed that the patients' IgG autoantibodies recognized recombinant desmoglein 1 but not desmoglein 3. Preadsorption of the patients' sera with recombinant desmoglein 1 completely removed the epidermal cell surface immunostaining. Significantly, immunohistochemistry demonstrated intense expression of IL-8, co-localized with in vivo-bound IgG, in the upper epidermis, where the acantholysis took place. Affinity-purified sera IgG from these two patients, a normal individual, and a pemphigus vulgaris patient containing desmoglein 1 autoantibodies, were incubated with normal human keratinocytes in vitro. Cells treated with these patients' IgG secreted a seven-to-nine-fold increase of IL-8 (30-37 pg/ml) compared with the controls (2-4 pg/ml) and expressed a higher intensity of cytoplasmic IL-8 staining. These data demonstrate a novel functional role for IL-8 in the pathogenesis of the neutrophil-dominant subset of pemphigus herpetiformis. The autoantibody-induced epidermal cell IL-8 expression may represent a novel mechanism of epidermal neutrophil recruitment.

The role of lymphocytes, granulocytes, mast cells and their related cytokines in lesional skin of linear IgA bullous dermatosis

Linear IgA bullous dermatosis (LAD) is an acquired, heterogeneous, subepidermal blistering disease characterized by linear IgA deposits at the dermoepidermal basement membrane zone (BMZ), often with circulating IgA antibodies to the BMZ. The pathogenetic mechanism, possibly related to the immunophenotype of infiltrating cells, as well as the potential role of cytokines in determining bullous lesions, have not yet been elucidated. An immunohistochemical study was performed with a large panel of monoclonal antibodies [to CD3, CD4, CD8, CD25, CD1a, CD30, CD54, CD50, endothelial leucocyte adhesion molecule-1, vascular cell adhesion molecule-1, myeloperoxidase (MPO), eosinophil cationic protein EG1 and EG2, tryptase, HLA-DR, human interleukin (IL)-3, human IL-5, human IL-8, human IL-4, tumour necrosis factor (TNF)-alpha, interferon (IFN)-gamma and granulocyte/macrophage colony-stimulating factor] using the alkaline phosphatase-antialkaline phosphatase procedure on lesional and perilesional skin of nine patients (one male, eight female; age range 8 months-80 years) with clinical, histological and immunofluorescent proven LAD. The predominant infiltrating cells, distributed mostly inside and below the bullae, were neutrophils and eosinophils which showed intense activation (MPO +, EG1 +, EG2 +). The lymphocytic infiltrate, consisting principally of CD4 +, HLA-DR + and CD30 + T cells, had a predominantly perivascular distribution. Proinflammatory cytokines, such as TNF-alpha and IFN-gamma, showed a moderate focal expression on the dermal perivascular sites; IL-8 was found to have a particularly intense staining on all the epidermal cell layers and at perivascular and vascular sites. Other cytokines, such as IL-4 and IL-5, showed a prevalent intracytoplasmic staining on some cells of the dermal infiltrate (probably mastocytes and lymphocytes), and at the dermal-epidermal separation sites there was also an intense scattered distribution of IL-5. The specific tissue lesions of LAD may be the consequence of the IgA deposits at the BMZ and also of the release of these cytokines together with tissue damage enzymes derived from neutrophils or eosinophils.

[Autoimmune bullous skin diseases]

INTRODUCTION

Important advances have been made in the pathogenesis of autoimmune bullous skin diseases during the last 10 years. The aim of this review is to describe new types of autoimmune bullous skin diseases and to summarize progresses in the pathogenesis and treatment of these diseases.

CURRENT KNOWLEDGE AND KEY POINTS

Paraneoplastic pemphigus (PNP) is a new type of pemphigus, distinct from pemphigus vulgaris (PV) and pemphigus foliaceus (PF). It has both clinical and histological features of pemphigus, bullous pemphigoid (BP), erythema multiforme, and lichen planus, in patients with lymphoma. Numerous clinical types of autoimmune bullous skin diseases of the dermal epidermal junction have also been described. Analysis of patients' serum by immunoblotting and immunoprecipitation allowed the identification of target antigens of most of these diseases: PV and PF are due to the production of autoantibodies directed against adhesion molecules (desmoglein 1 and 3) that belong to the cadherin family. In PNP, autoantibodies are directed against plakins, a new family of desmosomal plaque proteins. BP, CP and pemphigoid gestationis are characterized by the production of autoantibodies mainly directed against two hemidesmosomal proteins: BPAG1 and BPAG2. The mortality rate of autoimmune bullous skin diseases is estimated between 10 and 40%, mainly due to infections and cardiovascular diseases. The potential interest of the first use of adjuvant therapies in addition to corticosteroids has not been demonstrated yet.

FUTURE PROSPECTS AND PROJECTS

Due to the numerous side-effects of oral corticosteroids, many therapeutic trials are aimed at finding other treatments for the management of these diseases. Topical corticosteroids could be effective in BP, and even in some cases of pemphigus. New treatments using specific immunoadsorption of pathogenic autoantibodies with recombinant proteins will probably be available in the future.

Analysis of desquamative gingivitis using direct immunofluorescence in conjunction with histology

Chronic desquamative gingivitis (DG) is a common condition often first recognized by periodontists. DG is characterized clinically by erythema with epithelial desquamation, ulceration, and/or the presence of vesiculobullous lesions of the free and attached gingiva. However, DG is actually a clinical manifestation of several different disease processes, particularly lichen planus and benign mucous membrane pemphigoid. Correct diagnosis in DG is critical since proper treatment and follow-up will depend on which disease is involved. However, the diseases that cause DG frequently present diagnostic problems because their lesions often resemble each other clinically and routine histological examination sometimes cannot differentiate between them. Thus, immunohistology, particularly immunofluorescence, is increasingly being used with routine histology to more accurately diagnose DG diseases. This article reviews our experience over the past 10 years in the diagnosis of 72 cases of DG using direct immunofluorescent (DIF) in conjunction with histology and clinical evaluation. Of the 72 DG cases in this study, 30 cases were diagnosed as erosive lichen planus or lichenoid mucositis; 29 cases were diagnosed as benign mucous membrane pemphigoid; 2 cases each of linear IgA disease and pemphigus vulgaris were diagnosed; there was 1 case of bullous pemphigoid; and 1 suspected case of paraneoplastic pemphigus. Even with DIF analysis, 7 cases could not be definitively assigned a particular cause. DIF analysis is not only proving very useful for differential diagnosis, but also adds insight into possible pathogenic mechanisms of DG.

Misdiagnosis, treatments, and outcomes in the immunobullous diseases in children

As a group, the immunobullous diseases are very uncommon in childhood. We analyzed all cases of immunobullous diseases in individuals under age 18 years which we had evaluated at the University of Colorado and examined their age of onset, diagnostic difficulties, treatments, and outcomes. This was considered to be a representative North American population within a single referral area which contained a diverse ethnic population mixture. Further, we believe this study to be uniquely uniform in that all the patients were examined by us using the same diagnostic strategy and the immunofluorescent (IF) diagnostic tests were performed by the same individual (J.C. Huff) using uniform diagnostic criteria and consistent IF techniques.