Immunofluorescence mapping of antigenic determinants within the dermal-epidermal junction in the mechanobullous diseases

The classification of mechanobullous diseases often depends on the electron microscopic distinction of intradermal (dermolytic), junctional and intraepidermal sites of cleavage. Electron microscopy is tedious and time consuming. In this report we describe a different approach to the determination of the cleavage plane by using a method which recognizes subtle differences in the localization of antigenic structures relative to the cleavage plane. Cryostat sections of lesional and extralesional skin of 3 patients with dermolytic epidermolysis bullosa, 3 with epidermolytic epidermolysis bullosa and 8 with junctional epidermolysis bullosa were examined by immunofluorescence, with specific antisera against type IV collagen (localized within the basal lamina); against laminin (noncollagenous protein, localized in the lamina lucida); and with bullous pemphigoid antibodies (directed against the bullous pemphigoid antigen localized in the lamina lucida). All specimens were also examined by electron microscopy. In dermolytic epidermolysis bullosa (where cleft formation occurs intradermally) type IV collagen, laminin and the bullous pemphigoid antigen were consistently found in the roof of the blister, whereas in junctional epidermolysis bullosa (where the cleft occurs in the lamina lucida) type IV collagen and laminin were found on the floor of the blister whereas bullous pemphigoid antigen was present mainly on the roof, but focally also on the floor, of the blister. In epidermolytic epidermolysis bullosa (where the cleft is intraepidermal) all antigens were localized below the cleavage plane. In all cases electron microscopy confirmed the level of cleft formation predicted from the immunofluorescence mapping of the antigenic sites. The described method equals electron microscopy in accuracy but it is more rapid and simpler to perform.     

Three new cases of transient bullous dermolysis of the newborn

We present 3 new patients with transient bullous dermolysis of the newborn (TBDN), which is a form of dystrophic epidermolysis bullosa. TBDN may be diagnosed by electron microscopy showing a sublamina densa cleavage; immunofluorescence antigenic mapping demonstrating bullous pemphigoid antigen, laminin- 1, and type IV collagen along the epidermal roof of subepidermal clefts; and indirect immunofluorescence with monoclonal antibodies revealing intraepidermal type VII collagen. Although intraepidermal type VII collagen has been reported in other forms of dystrophic epidermolysis bullosa, we believe that the presence of type VII collagen in a striking intraepidermal granular array is a finding unique to TBDN. Our cases demonstrate the importance of immunodermatologic studies in the diagnosis of bullous disorders that are seen at birth because accurate diagnosis carries prognostic implications. This variant of epidermolysis bullosa, in contrast to other forms of dystrophic epidermolysis bullosa, is a benign, self-limited disease.     

Coexistence of pemphigus foliaceus and bullous pemphigoid. Demonstration of autoantibodies that bind to both the pemphigus foliaceus antigen complex and the bullous pemphigoid antigen

Pemphigus and bullous pemphigoid are autoimmune blistering diseases of the skin characterized by circulating autoantibodies directed against the keratinocyte cell surface and the epidermal basement membrane zone, respectively. The coexistence of pemphigus and bullous pemphigoid is very uncommon. We describe a patient with pemphigus foliaceus who later developed bullous pemphigoid and show, by means of immunoprecipitation studies utilizing both cultured keratinocytes and suction blister epidermis, that our patient had circulating autoantibodies directed against both the pemphigus foliaceus antigen complex and the bullous pemphigoid antigen. This report is the first to demonstrate the coexistence of pemphigus foliaceus and bullous pemphigoid at the molecular level.     

The sensitivity and specificity of "caterpillar bodies" in the differential diagnosis of subepidermal blistering disorders

Caterpillar bodies are eosinophilic, elongated, segmented bodies located within the roofs of blisters and are considered to represent a specific histopathologic feature of porphyric bullous eruptions, including porphyria cutanea tarda and erythropoietic protoporphyria. The possibility that similar or identical bodies may be present in other disorders prompted further study exploring the specificity of caterpillar bodies in the differential diagnosis of subepidermal vesiculobullous disorders. Seventy-six cases exhibiting subepidermal clefting were reviewed by light microscopy. "Classic" caterpillar bodies were present in porphyria cutanea tarda (6 of 14) and 1 case representing either venous stasis-associated bulla or possibly bullosis diabeticorum. Caterpillar body-like clusters were present in porphyria cutanea tarda (5 of 14), erythropoietic protoporphyria (1 of 3), bullous pemphigoid (7 of 24), and junctional or dystrophic epidermolysis bullosa (3 of 5). In some cases, classic caterpillar body and caterpillar body-like clusters coexisted in a blister roof. Caterpillar bodies or caterpillar body-like clusters were not identified in any cases of dermatitis herpetiformis, linear IgA bullous dermatosis, bullous erythema multiforme, epidermolysis bullosa acquisita, or wound-healing reactions. In contrast to caterpillar bodies, caterpillar body-like clusters were negative for PAS or Type IV collagen stains. In conclusion, caterpillar bodies appear to represent a specific feature of porphyria cutanea tarda (specificity, 98%) but were present in less than half of those cases in this study (sensitivity, 43%). Caterpillar body-like clusters are less specific and may be present in porphyria cutanea tarda, erythropoietic protoporphyria, pseudoporphyria, bullous pemphigoid, epidermolysis bullosa, and epidermolysis bullosa acquisita.     

Acantholysis and spongiosis are associated with loss of syndecan-1 expression

BACKGROUND: Syndecan-1, a heparan sulfate proteoglycan present on the membrane of keratinocytes, functions in intercellular adhesion. Acantholysis and spongiosis are both characterized by diminished intercellular adhesion that may lead to blister formation. In spongiotic conditions, desmosomal stretching occurs prior to cell separation while in acantholytic conditions, cell separation occurs without stretching. While many of the structural relationships have been described, the molecular interactions regulating keratinocyte to keratinocyte adhesion are not yet fully understood. METHODS: Sections from ten cases of Grover's disease, two pemphigus vulgaris, one pemphigus foliaceus, one bullous pemphigoid, two herpes simplex, and ten spongiotic dermatitis were stained with BB-4, a monoclonal anti-syndecan-1 antibody. RESULTS: Nine of ten Grover's, all three pemphigus, and both herpes cases showed absent or markedly decreased syndecan-1 expression by acantholytic keratinocytes, with a sharp delineation from adjacent unaffected skin. The remaining Grover's case showed moderate loss of syndecan-1 expression. The pemphigus foliaceus case showed retention of staining along the basal cell layer, but expression was lost in the mid stratum spinosum. All ten spongiotic cases showed a diffuse mild decrease in staining, with loss of syndecan-1 expression surrounding microvesicles. Bullous pemphigoid, as expected, did not show loss of syndecan expression. CONCLUSIONS: The loss of syndecan-1 expression evident in acantholytic conditions and, to a lesser extent in spongiotic conditions, may contribute to the decreased intercellular adhesion characteristic of these lesions.     

Location of basement membrane Type IV collagen beneath subepidermal bullous diseases

Using standard immunohistochemical methods, routinely processed sections, and a polyclonal antibody to Type IV collagen, we have determined the location of Type IV collagen, a substance located in the lamina densa of basement membrane, in a spectrum of acquired subepidermal bullous diseases. Type IV collagen was attached to the blister roof in five cases of well-established epidermolysis bullosa acquisita and to the blister base in 25 cases of bullous pemphigoid, four cases of dermatitis herpetiformis and 12 cases of porphyria cutanea tarda. Immunohistochemical localization of Type IV collagen in epidermal-dermal basement membrane is a simple, rapid and reliable technique which can be utilized to exclude and possibly to confirm the diagnosis of epidermolysis bullosa acquisita in routinely fixed paraffin-embedded tissues.     

Occult Herpes Simplex Virus Colonization of Bullous Dermatitides

Background: Acantholytic disorders, including pemphigus vulgaris, chronic benign familial pemphigus (Hailey-Hailey disease, superficial pemphigus), Darier disease, and Grover transient acantholytic dermatosis, as well as other vesiculo-bullous disorders, including bullous pemphigoid, epidermolysis bullosa, and atopic dermatitis, are prone to florid infections by herpes simplex virus (HSV)-I and -II, and, more rarely, by varicellazoster virus (VZV). As these infections are difficult to recognize clinically and histologically, their frequency remains unknown. A possible occult viral colonization has never been documented in these disorders. The manner in which the primary bullous disorders are contaminated by herpesviridae remains unclear. Objective: To retrospectively assess the possible presence of HSV and VZV in a series of biopsies of acantholytic disorders and bullous pemphigoid. Method: The typical α-herpesviridae-related cytopathic signs were searched for by conventional microscopy in skin biopsies of patients with bullous pemphigoid (n = 20), pemphigus vulgaris (n = 19), Darier disease (n = 18), chronic benign familial pemphigus (n = 3), and Grover transient acantholytic dermatosis (n = 3). Immunohistochemistry (IHC) targeted specific HSV-I, HSV-II, and VZV antigens. Polymerase chain reaction (PCR) was used for detecting HSV- and VZV-specific DNA sequences. Results: No cytopathic signs suggestive of HSV or VZV infection were detected. However, IHC revealed HSV antigens in Darier disease (1/18, HSV-I), Grover transient acantholytic dermatosis (1/3, HSV-I), pemphigus vulgaris (1/19, HSV-I), and bullous pemphigoid (2/20, HSV-I and HSV-II). In these IHC-positive cases, PCR amplified specific HSV primers in Darier disease (1/18), pemphigus vulgaris (1/19), and bullous pemphigoid (1/20). VZV antigens and nucleic acids were never identified. The HSV antigens were nearly always restricted to the upper part of the granular layer and thus differed from the usual HSV distribution during cutaneous infection. Negative and positive controls yielded consistently positive and negative results, respectively. Conclusion: This report shows for the first time that clinically and histologically occult HSV colonization may occur in Darier disease, Grover transient acantholytic disease, pemphigus vulgaris, and bullous pemphigoid. Given the frequent use of immunosuppressive treatments for primary bullous disorders, greater awareness of HSV colonization and infection is recommended in these patients.     

Acquired epidermolysis bullosa with the clinical feature of Brunsting-Perry cicatricial bullous pemphigoid

A 56-year-old woman with the typical clinical feature of cicatricial bullous pemphigoid of the Brunsting-Perry type was studied. Histologic examination of a lesion skin biopsy specimen demonstrated a subepidermal blister. Direct immunofluorescence microscopy revealed linear deposits of IgG, IgM, and C3 located on both the roof and the floor of the blister. Immunofluorescence antigen mapping using cryostat sections of a spontaneous blister and antisera against defined basement membrane components localized the bullous pemphigoid antigen and type IV collagen in the roof of the blister. This dermal type of blister formation was confirmed by electron microscopy, which showed the cleavage level below the lamina densa. In direct immunoelectron microscopy, granular deposits of C3 and IgG were found attached to and just beneath the lamina densa in a pattern identical to the distribution of anchoring fibrils. These findings are diagnostic of acquired epidermolysis bullosa, a blistering disease that has much more clinical heterogeneity than previously suggested.     

A review of high-dose intravenous immunoglobulin (hdIVIg) in the treatment of the autoimmune blistering disorders

High-dose intravenous immunoglobulin (hdIVIg) is being used increasingly for dermatological indications. Its mode of action is via a number of proposed mechanisms and it is not associated with the many side-effects of steroids and other immunosuppressive agents. The evidence for using hdIVIg in the treatment of autoimmune bullous disorders is based on uncontrolled trials and case reports. However, there are now 62 reported patients and this review aims to make a critical assessment of the current data. This has been obtained from a Medline search of the English literature from 1966 to 2000 for pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, pemphigoid gestationis, cicatricial pemphigoid, epidermolysis bullosa acquisita and linear IgA disease. Taken together hdIVIg was effective in 81% of the patients with blistering disease. Patients appear to be more likely to respond when hdIVIg is used as adjunctive therapy (91% response rate) than as monotherapy (56% response rate). hdIVIg may offer a safe potential therapeutic avenue for resistant cases of the autoimmune bullous disorders but should be further assessed using double-blind placebo-controlled trials.     

Scanning electron microscopy of acantholysis in pemphigus foliaceus

We performed scanning electron microscopy of an inverted blister roof in a case of pemphigus foliaceus. The loss of intercellular adherence could be easily seen with low magnification. The acantholytic keratinocytes displayed an irregular and sometimes polygonal contour. Round cells, typically seen in light microscopy, were also observed. The examination of a blister roof allows ultrastructural documentation of the acantholytic changes.     

Blistering diseases in the mature patient

Autoimmune blistering diseases (AIBD) are a group of chronic diseases affecting the skin and mucous membranes, with different presentation, clinical course, histologic and immunopathologic findings, and different therapeutic approach. Blisters develop as a result of autoantibodies directed against distinct adhesion structures within desmosomes or within the basement membrane zone. The most common AIBD that develops in the elderly is bullous pemphigoid (previously also named “pemphigoid senilis”), but mature patients can also present with other AIBD as mucous membrane pemphigoid, epidermolysis bullosa acquisita, paraneoplastic pemphigus, pemphigus vulgaris, pemphigus foliaceus, linear IgA dermatosis, and dermatitis herpetiformis. There are no differences in treatment approach to mature patients with AIBD, but due to more common comorbidities, systemic therapy should be given with more caution and control, and due to distorted skin integrity in the aged skin, the safety concerns are increased with the long-term use of any topical medication.     

Epidermolysis bullosa acquisita and associated symptomatic esophageal webs

Epidermolysis bullosa acquisita (EBA) is a well-characterized, subepidermal blistering disorder associated with autoimmunity to type VII collagen, which is the collagen localized to anchoring fibrils within the dermoepidermal junction of skin. Although the full clinical spectrum of EBA is still being defined, it is known that the clinical features of EBA may be reminiscent of hereditary dystrophic epidermolysis bullosa, a scarring blistering disease of children that is commonly associated with esophageal stenosis. We describe a patient with EBA who had both an acral-predominant mechanobullous disease akin to dystrophic epidermolysis bullosa and an inflammatory, widespread bullous eruption reminiscent of bullous pemphigoid in association with esophageal webs and dysphagia. Although esophageal involvement is common in dystrophic epidermolysis bullosa, a review of the literature shows that this is the first bonafide case of EBA with symptomatic esophageal disease.     

Scanning electron microscopy of a blister roof in dystrophic epidermolysis bullosa

In dystrophic epidermolysis bullosa the genetic defect of anchoring fibrils leads to cleavage beneath the basement membrane, with its consequent loss. We performed scanning electron microscopy of an inverted blister roof of a case of dystrophic epidermolysis bullosa, confirmed by immunomapping and gene sequencing. With a magnification of 2000 times a net attached to the blister roof could be easily identified. This net was composed of intertwined flat fibers. With higher magnifications, different fiber sizes could be observed, some thin fibers measuring around 80 nm and thicker ones measuring between 200 and 300 nm.     

Antibody deposits in Tzanck smears in pemphigus vulgaris

Forty-three patients, including 24 males and 19 females between 5 and 62 years of age, having pemphigus vulgaris (27), pemphigus foliaceus (1), bullous pemphigoid (3), chronic benign bullous dermatosis of childhood (2) and herpes zoster (10) were included in this study. Tzanck smears were prepared from the floor of the blisters in these patients by deroofing the bullae, and the slides were stored without fixation at room temperature for 1 to 10 days. Immunofluorescence staining was done with FITC-conjugated anti-human IgG. Twenty-one cases having pemphigus vulgaris and 1 case having pemphigus foliaceus showed bright green fluorescence on the membrane of acantholytic cells. No epithelial cells were seen in smears from bullous pemphigoid and chronic benign bullous dermatosis of childhood, whereas epithelial cells were seen in 10 cases of herpes zoster. These stained negative with anti-IgG. Storage of the prepared smears for 1–10 days did not seem to affect the results of immunofluorescence. Tzanck smears can be used as an easy substitute for skin/mucosal biopsy for the direct immunofluorescence test.     

Clinical variability in dystrophic epidermolysis bullosa and findings with scanning electron microscopy

In dystrophic epidermolysis bullosa, the genetic defect of anchoring fibrils leads to cleavage beneath the basement membrane and its consequent loss. A 46 year-old female patient presented blisters with a pretibial distribution associated with nail dystrophy. Her two children had hyponychia and anonychia, which affected all toe nails and the thumb, forefinger and middle finger. DNA sequencing identified in exon 75 of COL7A1 gene a pathologic mutation: c.6235G>A (p.Gly2079Arg). Immunomapping of a blister demonstrated collagen IV (basal membrane) in the blister roof and collagen VII in its floor, confirming dystrophic epidermolysis bullosa. Scanning electron microscopy of an inverted blister showed net-forming collagen attached to the blister roof . The variability found in this family has already been reported and confirms, on a clinical basis, the nail subtype as a dystrophic variant.     

Spectrum of autoimmune bullous diseases in Iran: a 10-year review

Background Autoimmune bullous diseases (ABDs) are potentially devastating bullous dermatoses of the skin and mucosae characterized by the presence of tissue‐bound and circulating antibodies directed against disease‐specific target antigens. These diseases comprise two major subgroups of subepidermal autoimmune bullous disorders and pemphigus, based on the level of blister formation. Although they occur worldwide, the relative frequencies of different ABDs show wide geographical variation. Most epidemiological studies on ABDs have focused on single diseases or a group of diseases; published surveys studying the whole spectrum of diseases are scarce. Objectives This study aimed to assess the relative frequencies of different ABDs in patients presenting to the Bullous Diseases Research Center, Tehran, Iran. Methods Medical files for all newly diagnosed patients with ABD presenting to the Center between March 1997 and February 2006 were examined. Patients with dermatitis herpetiformis were not included. Results A total of 1402 patients were diagnosed with ABD during the study period. Pemphigus vulgaris (PV) was the most common ABD (81.2%), followed by bullous pemphigoid (BP) (11.6%), pemphigus foliaceus (PF) (4.4%), pemphigoid gestationis (0.7%), mucous membrane pemphigoid (0.7%), epidermolysis bullosa acquisita (0.5%), linear immunoglobulin A (IgA) disease (0.4%), paraneoplastic pemphigus (0.2%), IgA pemphigus (0.2%), and pemphigus erythematosus (0.1%). The mean age at diagnosis and male : female ratio were 43.4 years and 1 : 1.39, 42.2 years and 1 : 1.34, and 59.4 years and 1 : 1.36 for PV, BP, and PF, respectively. Conclusions Pemphigus vulgaris was the most frequent ABD according to our study; cases of PV outnumbered those of BP by a ratio of almost 8 : 1. This finding contrasts with those of studies conducted in Western European countries, in which BP predominates. There was a female predominance in most subtypes of ABD. Mean age at onset of PV and BP was lower than in Europe. In view of its large population of PV patients, Iran should be considered a suitable field for future clinical trials.     

An extract of cultured A431 cells contains major tissue antigens of autoimmune bullous diseases

BACKGROUND: Autoantibodies that are characteristic of autoimmune bullous diseases (AIBDs) can be detected by immunoblot assay using epidermal or dermal extracts. However, none of the substrates obtained by ordinary methods seems to contain a sufficient amount of all of the autoantigens involved in AIBDs, and diagnosis may require the use of several different substrates. OBJECTIVES: To examine the potential of A431 cell extracts as a substrate for immunoblotting. METHODS: Fourteen sera obtained from patients with major AIBDs (pemphigus vulgaris, pemphigus foliaceus, paraneoplastic pemphigus, bullous pemphigoid and epidermolysis bullosa acquisita) were tested using this substrate. RESULTS: Bands corresponding to desmoglein 1 and 3, desmoplakin 1 and 2, periplakin, BPAG1, BPAG2 and type VII collagen were identified distinctly with these sera. CONCLUSIONS: This finding suggests that culture extracts of A431 cells provide an effective substrate for the diagnosis and differential diagnosis of major AIBDs.     

The spectrum of epidermolysis bullosa acquisita.

A patient has an acquired, scarring, bullous eruption. The severity of the cutaneous, ocular, esophageal, and laryngeal scarring was suggestive of cicatricial pemphigoid or the severely dystrophic forms of epidermolysis bullosa. Clinical features and histologic and immunofluorescence and electron microscopic study led to the diagnosis of epidermolysis bullosa acquisita. The spectrum of epidermolysis bullosa acquisita includes cases that closely approximate the severity of disease previously recognized only for the recessive form of epidermolysis bullosa dystrophica.     

A subepidermal blistering disease with histopathological features of dermatitis herpetiformis and immunofluorescence characteristcs of bullous pemphigoid: a novel subepidermal blistering disease or a variant of bullous pemphigoid?

A 64-year-old man presented with a bullous eruption which clinically and histopathologically resembled dermatitis herpetiformis. However, direct immunofluorescence analysis showed IgG deposits at the basement membrane zone, indicating a relationship with bullous pemphigoid or epidermolysis bullosa acquisita. Indirect immunofluorescence studies on salt-split skin showed binding of IgG mainly on the dermal side of the blister. Immunoblot analysis revealed a novel 200 kDa dermal antigen that could be associated with a major pathogen in this blistering a disease. The histopathological similarity to dermatitis herpetiformis and the immunofluorescence findings indicating bullous pemphigoid or epidermolysis bullosa acquisita seem typical of a distinct subepidermal blistering disease characterized by this 200 kDa antigen. However, the pathogenetic role of autoantibodies against this antigen should be further elucidated before confirming whether this case represents a novel subepidermal blistering disease or a special variant of bullous pemphigoid.     

Schleimhautbeteiligung bei blasenbildenden Autoimmunerkrankungen

Autoimmune bullous diseases are characterized by intraepidermal or subepidermal autoantibody deposition that leads to blisters and secondary erosion. Mucous membranes are frequently affected in pemphigus vulgaris and always involved in cicatricial and mucosal pemphigoid. Mucosal lesions are detected less frequently in patients with bullous pemphigoid or epidermolysis bullosa acquisita. The diagnosis of autoimmune bullous disorders is based on determination of the subtype of autoantibodies bound in the skin and the clinical picture. Treatment is based on immunosuppression related to the type of disease and severity of the mucosal symptoms. Ocular involvement in mucosal pemphigoid and pemphigus vulgaris requires systemic treatment.