IgA bullous pemphigoid: a distinct blistering disorder

We report a patient with an eccrine carcinoma who developed localized blistering which clinically resembled pemphigoid, histologically showed subepidermal blistering with features of both dermatitis herpetiformis and bullous pemphigoid, responded to dapsone and exhibited linear IgA deposition on direct immunofluorescence. The nosological position of patients with linear IgA deposition and subepidermal blistering is not clear. A review of the literature reveals that in adults linear IgA deposition may occur in three separate situations: dermatitis herpetiformis, bullous pemphigoid and a third condition of which our case is an example which is best termed IgA bullous pemphigoid. This condition is distinguished from cases of dermatitis herpetiformis with linear IgA by the clinical features and the site of IgA deposition on immunoelectronmicroscopy. It is distinguished from cases of bullous pemphigoid with linear IgA by the absence of circulating IgG antibasement membrane zone antibody, the therapeutic response to dapsone and the frequent occurrence of circulating IgA antibasement membrane zone antibody. IgA bullous pemphigoid has not previously been reported with a carcinoma but the association lends further support to the concept that this eruption represents a variant of pemphigoid.     

Polymorphic pemphigoid. Is it still worth using this terminology?

The term polymorphic pemphigoid has been used in the literature as a variant of bullous pemphigoid. But this term is imprecise and now obsolete, since patients with linear IgA dermatosis have been reported under this terminology. The patients who develop an atypical subepidermal bullous disease with clinical and histological features of both bullous pemphigoid and dermatitis herpetiformis may actually be classified into three groups: (1) vesicular variant of bullous pemphigoid; (2) linear IgA dermatosis, and (3) mixed subepidermal bullous disease.     

Subepidermal blasenbildende Autoimmundermatose mit linearen Ablagerungen von IgA und IgG

A 29-year-old female patient with an autoimmune subepidermal blistering disease had linear deposits of both IgA and IgG at the basement membrane zone. Clinically, the patient presented with tense blisters on the face, trunk, extremities and oral mucosa. Histologically, we found a subepidermal blister formation and a predominantly neutrophilic infiltrate. Direct immunofluorescence showed linear deposits of IgA along the basement membrane zone, as well as linear deposits of IgG and C3 as typically found in bullous pemphigoid. Indirect immunofluorescence demonstrated circulating IgA and IgG autoantibodies. This case extends previous reports on a subgroup of patients with subepidermal blistering diseases characterized by the presence of both IgA and IgG anti-basement membrane antibodies. These patients reveal clinical, histological and immunopathological features of linear IgA disease and bullous pemphigoid.     

U-serrated immunodeposition pattern differentiates type VII collagen targeting bullous diseases from other subepidermal bullous autoimmune diseases

BACKGROUND: Epidermolysis bullosa acquisita (EBA) can be differentiated from other subepidermal bullous diseases by sophisticated techniques such as immunoelectron microscopy, salt-split skin antigen mapping, fluorescence overlay antigen mapping, immunoblot and enzyme-linked immunosorbent assay. OBJECTIVES: To determine whether the diagnosis can also be made by routine direct immunofluorescence microscopy. METHODS: We studied frozen skin biopsies from 157 patients with various subepidermal immunobullous diseases. RESULTS: We found three distinct 'linear' fluorescence patterns at the basement membrane zone: true linear, n-serrated and u-serrated. The true linear pattern, often seen in conjunction with either the n- or the u-serrated pattern, was found in any subepidermal immunobullous disease with nongranular depositions. In bullous pemphigoid, mucous membrane pemphigoid, antiepiligrin cicatricial pemphigoid, p200 pemphigoid and linear IgA disease the n-serrated pattern was found, corresponding with depositions located in hemidesmosomes, lamina lucida or lamina densa. However, in EBA and bullous systemic lupus erythematosus the u-serrated staining pattern was seen, corresponding with the ultralocalization of type VII collagen in the sublamina densa zone. The diagnosis of EBA with IgG or IgA autoantibodies directed against type VII collagen was confirmed by immunoelectron microscopy, salt-split skin antigen mapping, fluorescence overlay antigen mapping or immunoblotting. CONCLUSIONS: Using this pattern recognition by direct immunofluorescence microscopy we discovered several cases of EBA which would otherwise have been erroneously diagnosed as a form of pemphigoid or linear IgA disease.     

自身免疫性表皮下大疱病诊疗共识（2022）

【摘要】 自身免疫性表皮下大疱病主要包括大疱性类天疱疮、黏膜类天疱疮、瘢痕性类天疱疮、妊娠类天疱疮、扁平苔藓类天疱疮、线状IgA大疱性皮病、获得性大疱性表皮松解症、抗p200/层黏连蛋白γ1类天疱疮及疱疹样皮炎,不同的疾病靶抗原和致病性自身抗体存在差异,临床表现有相似之处也有明显不同,诊断与鉴别诊断有赖临床、病理、免疫病理检查及血清抗体检测等。为规范此类疾病的临床诊疗,中华医学会皮肤性病学分会和中国医师协会皮肤科医师分会组织本领域专家,依据近年国内外临床研究数据和指南共识,制订本共识 。     

IgA linear dermatosis of childhood (chronic Bullous disease of childhood)

Of twenty-seven cases of subepidermal blistering disease of children twelve corresponded clinically, histologically and immunologically to dermatitis herpetiforms of adults, six to bullous pemphigoid, and eight to chronic bullous disease of childhood (CBDC), i.e. IgA linear dermatosis. This latter disease seems to be a distinct entity, different from both dermatitis herpetiformis and bullous pemphigoid, and is characterized immunopathologically by linear IgA deposits at the basement membrane zone. These cases usually do not show intestinal involvement and respond well to combined treatment with sulphones and corticosteroids, whereas sulphones or sulphapyridine alone are, even in very high doses, not sufficient for full control of the disease. CBDC or IgA linear dermatosis of childhood may be regarded as a counterpart of IgA linear dermatosis of adults.     

Drug-induced linear IgA bullous dermatosis

A 73-year-old man was admitted to the University of California Davis Medical Center for treatment of a pleural effusion and congestive heart failure. His hospital course was complicated by asymptomatic sustained ventricular tachycardia requiring placement of an implantable cardiac defibrillator. The patient was treated with vancomycin and cefazolin during the procedure. After 3 days he developed tense vesicles over the dorsal aspect of the hands. Perilesional skin biopsy showed subepidermal cleavage with a neutrophilic infiltrate. Direct immunofluorescence revealed granular IgA and C3 deposition along the dermal epidermal junction. A diagnosis of drug-induced linear IgA bullous dermatosis secondary to vancomycin was established. Linear IgA bullous dermatosis is a rare autoimmune blistering disorder with clinical features that can overlap with bullous pemphigoid and dermatitis herpetiformis. Drug-induced linear IgA bullous dermatosis is a less common variant that is correspondingly less well characterized. Although a variety of medications have been implicated, vancomycin is the most common associated drug.     

Linear IgA Bullous Dermatosis of Childhood with Autoantibodies to a 230 kDa Epidermal Antigen

Abstract: Linear IgA bullous dermatosis (LABD) is an autoimmune, subepidermal disease defined on the basis of direct immunofluorescence findings. However, more recent techniques used to study bullous dermatoses suggest that LABD may be heterogeneous. A patient with LABD of childhood (chronic benign disease of childhood, CBDC) was studied by indirect immunofluorescence on salt-split skin and by Western blot in an attempt to characterize the involved autoantigen. This young girl's periorificial (mouth, genitalia), erythematovesicular lesions were diagnosed initially as herpes simplex. Histologic examination revealed eosinophilic spongiosis, suggesting the diagnosis of an autoimmune blistering disease. Direct immunofluorescence showed an exclusive linear IgA deposit at the dermoepidermal junction. Indirect immunofluorescence revealed circulating IgA autoantibodies that reacted with the epidermal side of saltsplit skin; these reacted by Western blot with a 230 kDa epidermal antigen, as in bullous pemphigoid. This case, fulfilling the diagnostic clinical and direct immunofluorescence criteria for LABD/CBDC, seems to represent IgA bullous pemphigoid. It further underscores the nosologic heterogeneity of LABD, which probably includes, apart from bullous pemphigoid, epidermolysis bullosa acquisita and cicatricial pemphigoid.     

Autoantibodies in a subgroup of patients with linear IgA disease react with the NC16A domain of BP1801

Linear IgA disease is an autoimmune subepidermal blistering disease characterized by IgA deposits at the cutaneous basement membrane zone. IgA antibodies from linear IgA disease sera react with antigens of 97 kDa (LABD97) and 120 kDa (LAD-1), both of which appear to be fragments of the extracellular domain of bullous pemphigoid 180 (type XVII collagen). The aim of this study was to determine whether linear IgA disease sera react with the immunodominant region of BP180 (NC16A domain), which is a major target of IgG autoantibodies produced by patients with bullous pemphigoid. Indeed, 11 of 50 linear IgA disease sera were found to contain IgA autoantibodies that recognized a recombinant form of NC16A by immunoblotting. The same sera also reacted with NC16A by enzyme-linked immunosorbent assay. An epitope mapping analysis uncovered four linear IgA disease-associated epitopes located within the 45 amino acid N-terminal stretch of NC16A, all of which were previously identified as antigenic sites targeted by bullous pemphigoid autoantibodies. Eight of the linear IgA disease sera that were reactive with NC16A also recognized LAD-1 secreted by the SCC-25 cell line, and five sera recognized BP180 extracted from keratinocytes. Linear IgA disease sera depleted of reactivity to NC16A by immunoadsorption continued to react with both the LAD-1 antigen and BP180 by immunoblotting and with the basement membrane zone by indirect immunofluorescence microscopy. Our results demonstrate that IgA autoantibodies from a subset of linear IgA disease patients react with the same sites on BP180 that are targeted by IgG autoantibodies in bullous pemphigoid.     

Non‐paraneoplastic autoimmune subepidermal bullous disease associated with fatal bronchiolitis obliterans

Bronchiolitis obliterans is a small‐airway obstructive lung disease for which immunologically mediated pathogenesis is supposed. Frequent association of bronchiolitis obliterans with paraneoplastic pemphigus is well known, but its association with other autoimmune bullous diseases has not been reported except for a case of anti‐laminin‐332‐type mucous membrane pemphigoid in a patient with chronic graft‐versus‐host disease. We report a case of non‐paraneoplastic autoimmune subepidermal bullous disease associated with fatal bronchiolitis obliterans in a patient without transplantation. Although the patient's serum contained immunoglobulin (Ig)A antibodies to the 180‐kDa bullous pemphigoid antigen/type XVII collagen and IgG antibodies to laminin‐332, diagnosis of either linear IgA bullous dermatosis or mucous membrane pemphigoid could not be made because of the failure to detect linear IgA deposition at the basement membrane zone by direct immunofluorescence and the lack of mucous membrane lesions. Physicians should be aware that autoimmune bullous diseases other than paraneoplastic pemphigus can also associate with this rare but potentially fatal lung disease.     

The use of Michel's transport medium for immunofluorescence and immunoelectron microscopy in autoimmune bullous diseases

We report the use of Michel's solution, already a well established transport medium, in the combined use of direct immunofluorescence (IMF) and pre-embedding immunoelectron microscopy in 3 subepidermal bullous diseases - bullous pemphigoid (BP), epidermolysis bullosa acquisita (EBA) and dermal binding linear IgA disease (LABD). Our studies demonstrated that electron microscopy of normal skin maintained in Michel's medium for up to 28 clays showed remarkable preservation of all components of the basement membrane zone, including the ultrastructure of the basal keratinocytes, dermoepidermal junction and papillary dermis. However, epidermal cell cytolysis occurred after just 48 hours.
Immunoelectron microscopy using a gold probe has enabled us to localise the immunoreactants in bullous pemphigoid, epidermolysis bullosa acquisita and dermal-binding linear IgA bullous dermatoses. Our findings are comparable to and as equally reliable as those on immunoelectron microscopy of fresh skin biopsies with no loss of antigen deposition, and demonstrate an effective new use of a well established transport medium.     

Linear IgA dermatosis with IgA and IgG autoantibodies to the 180 kDa bullous pemphigoid antigen (BP180): evidence for a distinct subtype

BACKGROUND: Autoantibodies in linear immunoglobulin A (IgA) disease (LAD) are reported to be of IgA class and directed against a 97-120 kDa epidermal antigen. METHODS: We report a 39-year-old woman with clinical features of LAD and with circulating IgA and IgG autoantibodies to the 180 kDa bullous pemphigoid antigen (BP180). RESULTS: Histopathology of lesional skin revealed a subepidermal blister with mixed inflammatory cell infiltrate. Direct immunofluorescence of perilesional skin showed linear deposits of IgA along the dermal-epidermal junction. The antigen specificity of the patient's circulating antibodies was determined by Western blotting and enzyme-linked immunoabsorbent assay (ELISA) using various antigen sources, including cultured human keratinocytes, dermal protein lysates, and purified laminin-5, as well as proteins corresponding to BP180, the 230 kDa bullous pemphigoid antigen (BP230), laminin-5 subunits, and collagen IV alpha1-alpha6 chains. IgA and IgG antibodies in the patient's serum were directed against BP180, and no IgA or IgG reactivity was found against the other skin antigens. CONCLUSIONS: These data provide evidence for the presence of a subtype of LAD with dual IgA and IgG autoimmune response to BP180.     

Diagnosis of adult linear IgA dermatosis by immunoelectronmicroscopy in 16 patients with linear IgA deposits

Homogeneous linear IgA deposits at the dermo-epidermal junction (DEJ) shown by direct immunofluorescence are characteristic of what is termed linear IgA bullous dermatosis. However, it is not yet certain that this disease constitutes an entity distinct from other subepidermal blistering diseases, especially when IgG deposits are also present. Sixty-one cases of subepidermal blistering disease in adults were therefore investigated by immunoelectron microscopy (IEM), and the 16 patients observed to have homogeneous linear IgA deposits were compared with the 45 who had no IgA but had IgG and/or C3. In 11 of the 16 patients with IgA (four of whom also had IgG), the deposits were linear and formed a mirror image pattern on each side of the lamina densa from which they were separated by a clear space. In contrast to this monomorphic IEM pattern, clinical and other laboratory findings were very heterogeneous, making exact clinical diagnosis difficult. Of the remaining five patients in this group of sixteen, three (all with both IgA and IgG) had bullous pemphigoid, epidermolysis bullosa acquisita, and cicatricial pemphigoid, respectively, on IEM and clinical investigation. In the remaining two patients (one with both IgA and IgG, and one with IgA only) the deposits were located in the lamina lucida, making precise classification impossible. None of the 45 patients with isolated IgG and/or C3 deposition displayed the mirror image pattern. We conclude that this IEM pattern may constitute a specific diagnostic criterion of linear IgA dermatosis.     

Histology of linear IgA disease, dermatitis herpetiformis, and bullous pemphigoid

The histologic appearances of cutaneous biopsy specimens from 30 patients with linear IgA disease with a continuous band of IgA along the basement membrane, four patients with a linear pattern of granular IgA along the basement membrane, 26 patients with dermatitis herpetiformis who had IgA in the papillary dermis, and 23 patients with bullous pemphigoid who had IgG and/or C3 along the basement membrane were compared. Those with linear and granular IgA and dermatitis herpetiformis differed from those with bullous pemphigoid in five respects. Multiple microabscesses and fibrin at tips of papillae and leukocytoclasis were less common in bullous pemphigoid, whereas a dense infiltrate of eosinophils in and below bullae and a linear infiltrate of eosinophils along the basement membrane were more common in bullous pemphigoid. Also, multilocular bullae and acantholysis were more common in dermatitis herpetiformis than in bullous pemphigoid. Linear IgA disease differed from dermatitis herpetiformis in two respects. Acantholysis and fibrin at the tips of papillae and leukocytoclasis were more common in dermatitis herpetiformis. The specimens from patients with granular IgA did not differ significantly from those with linear IgA or dermatitis herpetiformis. The appearances of biopsy specimens of patch tests with potassium iodide taken from 11 patients with dermatitis herpetiformis and linear or granular IgA disease were similar to those taken from spontaneous lesions.     

Unusual clinicopathological and immunological presentation of chronic bullous dermatosis of childhood (linear IgA dermatosis)

Linear IgA bullous dermatosis is a rare sulfone-responsive subepidermal blistering disorder of unknown etiology in which smooth linear deposits of IgA are found in the basement membrane zone. Chronic bullous dermatosis of childhood is equivalent to linear IgA disease of adulthood and is characterized by an abrupt onset of large, widespread and tense bullae on a normal or erythematous base. In this case, we describe an unusual presentation of chronic bullous dermatosis in a 14-month-old Saudi girl. Histopathological examination revealed subepidermal cell poor blisters with linear deposition of IgA, IgG, IgM, and C3 along the dermoepidermal junction. The unusual clinical, histopathological and immunofluorescence findings in this patient are discussed, with an account on the differential diagnosis in such cases along with a detailed review of the relevant literature.     

Nutrition and bullous diseases

Although relatively uncommon, autoimmune bullous diseases carry the risk of increased mortality and can significantly impact quality of life. This group of diseases is broad and encompasses subepidermal conditions such as bullous pemphigoid, cicatricial pemphigoid, epidermolysis bullosa acquisita, dermatitis herpetiformis, and linear IgA bullous dermatosis, as well as intraepidermal conditions such as pemphigus and its variants. The pathophysiology of each condition is incompletely understood but broadly involves the formation of autoantibodies targeting skin adhesion proteins, a process that relies on a complex interplay between a dysregulated immune system, genetic predisposition, and environmental factors. We review the impact of nutrition on pathogenesis, clinical course, and treatment of various autoimmune bullous diseases.     

Autoimmune subepidermal blistering diseases in Uganda: correlation of autoantibody class with age of patients

BACKGROUND: No data are available on the incidence and immunoreactivity of autoimmune subepidermal blistering skin diseases in East Africa. METHODS: All patients with frank blisters/erosions on the skin and/or mucous membranes that attended the Department of Dermatology at Mbarara University, Uganda, from May 2000 to June 2002, were investigated. The diagnosis was based on the clinical presentation and on the presence of circulating autoantibodies detected by indirect immunofluorescence microscopy on 1 m NaCl-split human skin and by Western blotting of recombinant and cell-derived forms of BP180, BP230, and type VII collagen. RESULTS: Twenty-two patients with autoimmune subepidermal blistering skin disorders were identified, including nine with bullous pemphigoid (41%), four with linear immunoglobulin A (IgA) disease (18%), three with mucous membrane pemphigoid (14%), two with linear IgG/IgA bullous dermatosis (9%), and one each with cicatricial pemphigoid and epidermolysis bullosa acquisita (5%). In addition, two patients with immunoreactivity to both the epidermal and dermal side of salt-split skin by indirect immunofluorescence microscopy, who were unreactive to type VII collagen, were provisionally diagnosed as "mixed pemphigoid" (9%). In patients with subepidermal blistering diseases, IgG reactivity correlated significantly with old age, whereas younger patients preferentially developed IgA autoantibodies (P = 0.024). CONCLUSIONS: The age of patients with autoimmune subepidermal blistering diseases appears to influence the immunoglobulin class of autoantibodies. The high frequency of IgA autoantibodies in Ugandan patients may be explained by the age distribution of the Ugandan population.     

Childhood bullous pemphigoid treated by i.v. immunoglobulin

Bullous pemphigoid is an acquired autoimmune subepidermal blistering disorder mostly seen in the elderly. Childhood bullous pemphigoid is very rare. For the first time we report a case of childhood bullous pemphigoid associated with infantile eczema. Two weeks after a routine vaccination, a 3.5-month-old boy with infantile eczema developed a generalized blistering disorder. Histopathology revealed a subepidermal blister. Direct immunofluorescence showed linear depositions of C3 along the basement membrane zone. Indirect immunofluorescence studies demonstrated the presence of circulating immunoglobulin G antibodies directed against the epidermal side of salt-split skin. Enzyme-linked immunosorbent assay demonstrated serum level of anti-BP180 antibody elevated. The patient was successfully treated by high-dose i.v. immunoglobulin.     

False-negative results in immunoblot assay of serum IgA antibodies reactive with the 180-kDa bullous pemphigoid antigen: the importance of primary incubation temperature

BACKGROUND: Different subepidermal autoimmune blistering skin disorders are characterized by linear deposition of IgA, sometimes accompanied by linear IgG, along the epidermal basement membrane zone. Identification of the targeted autoantigen is usually attempted by immunoblotting. Although immunoblotting works well for human IgG, the method is less successful for IgA and often no or only faint signals are obtained. OBJECTIVES: To improve the method of immunoblotting for diagnosis of IgA-mediated bullous dermatoses. METHODS: Eleven sera, selected from patients with linear deposition of IgA along the epidermal basement membrane zone in vivo, were tested by immunoblotting for antigen specificity using different primary incubation temperatures. RESULTS: No reliable information regarding IgA antigen specificity was obtained when the primary incubation was undertaken at room temperature. In 10 of 11 sera, IgA bound to the 180-kDa bullous pemphigoid antigen (BP180) when the primary incubation temperature was increased to 37 degrees C. CONCLUSIONS: Primary incubation at room temperature may result in false-negative results in the IgA-BP180 immunoblot assay.     

Ultrastructural immunocytochemistry of autoimmune bullous diseases

Advanced immunopathological assays have been developed to elucidate the pathophysiology and provide more precise nosological definitions of the immunobullous diseases. Forty-seven patients suffering from autoimmune bullous diseases (intra- or subepidermal) were studied by immunoelectron microscopy (direct and indirect). Peroxidase staining was revealed by diaminobenzidine (determination of immune deposit location) in the majority of the cases of subepidermal bullous diseases, but in less than half of the cases of intraepidermal bullous diseases. Immunoelectron microscopy features contributed in verifying the diagnosis of rare entities such as cicatricial pemphigoid, paraneoplastic autoimmune bullous disease, linear IgA disease and epidermolysis bullosa acquisita.