Pemphigoid with antibodies to laminin γ1, BP180 and BP230, associated with psoriasis vulgaris: Successful disease control with cyclosporin

Both anti‐laminin γ1 pemphigoid and bullous pemphigoid are autoimmune subepidermal blistering diseases. The former is rare and characterized by autoantibodies to laminin γ1, a 200‐kDa dermal protein, while the latter is common among the elderly and characterized by autoantibodies to BP180 and BP230, both of which are hemidesmosomal proteins. We experienced a 69‐year‐old Japanese male patient with blister formation secondary to erythrodermic psoriasis, which was successfully treated with cyclosporin. The histopathology of erythema corresponded with psoriasis and that of a blistering lesion showed infiltration of neutrophils and eosinophils in and around the subepidermal blisters. Patient immunoglobulin G antibodies labeled both the epidermal and dermal sides of 1 mol/L NaCl‐split human skin by indirect immunofluorescent microscopy and recognized laminin γ1, BP180 and BP230 by immunoblotting. To the best of our knowledge, this is the first report of coexistence of psoriasis and atypical pemphigoid with these three autoantibodies.     

180-kDa bullous pemphigoid antigen defective generalized atrophic benign epidermolysis bullosa: report of four cases with an unusually mild phenotype

Generalized atrophic benign epidermolysis bullosa (GABEB) is a rare variant of non-lethal junctional epidermolysis bullosa characterized by generalized skin blistering healing with atrophy and by atrophic alopecia with onset in childhood. Other features include mild mucosal blistering, dental abnormalities and nail dystrophy. We report four additional cases of GABEB from two families originating from the same isolated village. The patients shared an unusually mild clinical phenotype with cutaneous blisters strictly limited to trauma sites and rare occurrence of oral mucosal lesions. Scalp, eyelash and eyebrow alopecia was present in only two cases. Immunofluorescence studies showed a markedly reduced expression of the 180-kDa bullous pemphigoid antigen (BP180), and northern analysis of cultured keratinocytes indicated that the gene encoding for BP180 is affected in these GABEB patients.     

Case of subepidermal autoimmune bullous disease with psoriasis vulgaris reacting to both BP180 C‐terminal domain and laminin gamma‐1

A number of cases of psoriasis vulgaris developing bullous skin lesions have been diagnosed as either bullous pemphigoid with antibodies to the 180‐kDa bullous pemphigoid antigen (BP180) non‐collagenous 16a (NC16a) domain or anti‐laminin‐γ1 (p200) pemphigoid. We report a case of subepidermal bullous disease with psoriasis vulgaris, showing antibodies to both BP180 C‐terminal domain and laminin‐γ1. A 64‐year‐old Japanese man with psoriasis vulgaris developed exudative erythemas and tense bullae on the whole body but he did not have mucosal involvement. The blistering lesion showed subepidermal blisters histopathologically. In indirect immunofluorescence of 1 mol/L NaCl‐split skin, immunoglobulin (Ig)G antibodies reacted with both the epidermal and dermal side. Immunoblotting showed positive IgG with recombinant protein of BP180 C‐terminal domain and 200‐kDa laminin‐γ1 in normal human dermal extract.     

Bullous pemphigoid: role of complement and mechanisms for blister formation within the lamina lucida

Bullous pemphigoid (BP), an autoimmune subepidermal blistering skin disease, demonstrates tense blisters with or without widespread erythema, blistering along the lamina lucida, immunoglobulin G and/or complement deposits at the basement membrane zone, and the presence of circulating autoantibodies against hemidesmosomal molecules. These autoantibodies usually react against 180‐kDa and/or 230‐kDa proteins, designated as BP180 and BP230, respectively. The precise blistering mechanisms after autoantibodies bind to antigens are not fully understood. Immune complexes are thought to initially activate the complement cascade, which may induce activation of proteases and/or cytokines and cause dermal–epidermal separation. However, why does separation run specifically within the lamina lucida in a space as narrow as 500 nm wide? This review mainly focuses on the possible mechanisms of BP‐specific blistering and how separation occurs along the lamina lucida, based on existing evidence.     

Memory B cells specific for the NC16A domain of the 180 kDa bullous pemphigoid autoantigen can be detected in peripheral blood of bullous pemphigoid patients and induced in vitro to synthesize autoantibodies

Bullous pemphigoid is a subepidermal blistering disease characterized by the synthesis of autoantibodies against the 180 kDa and the 230 kDa bullous pemphigoid antigens. Whether autoimmunity is also reflected by the presence of circulating autoantigen-specific memory B cells is still a matter of debate. We used a new assay combining two-step immunomagnetic enrichment with multiparameter flow cytometry to detect and characterize bullous pemphigoid 180 kDa-specific IgG+ B cells in blood of bullous pemphigoid patients. In a first magnetic separation, B cells were isolated from peripheral blood mononuclear cells using releasable microbeads conjugated to a CD19 antibody. From pre-enriched B cells, bullous pemphigoid 180 kDa-specific cells were then positively selected using microbeads directly conjugated with a recombinant N-terminal fragment of the bullous pemphigoid 180 kDa ectodomain, containing the noncollagenous 16A domain, which was recently shown to harbor major epitopes of autoantibodies in bullous pemphigoid sera. Noncollagenous 16A domain-specific IgG+ B cells were detectable in blood of most, if not all patients with serum autoantibodies against the noncollagenous 16A domain. The specificity of the cells was confirmed by in vitro differentiation into antibody-forming cells and analysis of the culture supernatant for the presence of noncollagenous 16A domain-specific IgG antibodies. All noncollagenous 16A domain-specific IgG+ B cells showed a clear memory immunophenotype. Noncollagenous 16A domain-specific IgG+ memory B cells may be crucial for continuous noncollagenous 16A domain-specific autoantibody production and/or play a part as antigen-presenting cells for priming and restimulation of bullous pemphigoid 180 kDa-specific T helper cells.     

Erythrodermic bullous pemphigoid is a clinical variant of bullous pemphigoid

Bullous pemphigoid (BP) is an autoimmune blistering disease of the skin. Several variants olBP have been described but until recently the relationship of these variants to generalized BP was unclear. Several studies have shown that pemphigoid nodularis, pemphigoid vegetans, localized BP and vesicular pemphigoid are true variants of BP as the circulating antibodies in these patients recognize the same 230kDa BP antigen as found in patients with generalized BP. Erythrodermic BP is a very unusual variant characterized by an erythroderma along with blister formation. We describe the third known patient to develop erythrodermic BP and characterize the antigenic specificity of the circulating antibodies in both our newly reported patient with erythrodermic BP and in one of the two other previously reported cases of erythrodermic BP. Both patients with erythrodermic BP had circulating IgG antibodies which bound to the epidermal side of salt-split human skin in a pattern identical to two patients with immunopathologically proven generalized BP. Sera from four erythrodermic patients without blisters and from a healthy normal volunteer, as controls, failed to demonstrate detectable circulating IgG autoantibodies. Immunoprecipitation studies revealed that both patients with erythrodermic BP had circulating IgG autoantibodies which recognized, to varying degrees, the same 230 and 180kDa BP antigens as recognized by sera from two patients with immunopathologically proven generalized BP. Sera from four erythrodermic patients without blisters and from a healthy normal volunteer, as controls, failed to recognize any specific polypeptides. These observations demonstrate that erythrodermic BP is a distinct clinical variant of BP.     

Changes in the autoimmune blistering response: a clinical and immunopathological shift from pemphigus foliaceus to bullous pemphigoid

We describe a 64-year-old Brazilian man who developed bullous pemphigoid (BP) 12 years after pemphigus foliaceus (PF) was diagnosed. On his first presentation in 1992, histological examination revealed intraepidermal blistering and acantholysis at the granular layer, direct immunofluorescence (DIF) demonstrated intercellular deposits of C3 in the epidermis, and indirect immunofluorescence showed the presence of IgG antibodies against the intercellular spaces. In 2004, laboratory findings revealed a subepidermal blister with neutrophils and eosinophils (by histology), DIF demonstrated deposition of IgG and C3 along the basement membrane zone, salt-split skin showed IgG deposition in the epidermal side of the blister, and immunoblotting showed reactivity against BP180. The occurrence of two autoimmune blistering conditions in the same patient is a rare event, and may suggest an intermolecular epitope-spreading phenomenon.     

Autoreactivity to bullous pemphigoid 180: is this the link between subepidermal blistering diseases and oral lichen planus?

Subepidermal blistering diseases are antibody‐mediated diseases. The antigens differ between disease type, but bullous pemphigoid (BP)180 (collagen XVII) is a common finding in several clinical conditions. We report four patients with autoimmune blistering disease [linear Ig A disease (n = 2), bullous pemphigoid (n = 1), and epidermolysis bullosa acquisita (n = 1)], all of whom also developed oral lichen planus (LP). In all cases, the diagnosis of the blistering disease predated the development of the oral lesions. All patients were under the care of dermatologists and of oral medicine/surgery doctors for the diagnosis and management of the oral LP. All had circulating antibodies to BP180 protein. To our knowledge, the association between blistering diseases and oral LP has not been reported previously, and may reflect autoimmunity to BP180.     

Drug-induced bullous pemphigoid with dermal fluorescence on salt-split skin

The immunological features of drug-induced bullous pemphigoid appear to be similar to those of idiopathic bullous pemphigoid (BP), with presence of circulating and tissue-bound antibodies showing anti-basement membrane zone specificity. We describe a 28-year-old woman who developed a widespread blistering eruption with marked involvement of the mucous membranes shortly after commencing treatment with oral flucloxacillin. The eruption gradually cleared following drug withdrawal and treatment with oral corticosteroids. Indirect immunofluorescence showed circulating IgG anti-basement membrane zone (BMZ) antibody and C3 which bound to the dermal aspect of salt-split skin, and direct immunofluorescence (IMF) of perilesional skin showed a linear band of C3 at the BMZ. Western immunoblotting of the patient's serum showed positive reactivity with a 180 kDa antigen in epidermal extracts and no reactivity with dermal extracts. The dermal-binding pattern on indirect IMF with salt-split skin only occurs in a minority of patients with BP and has not been described previously in a drug-induced case.     

Respective contribution of neutrophil elastase and matrix metalloproteinase 9 in the degradation of BP180 (type XVII collagen) in human bullous pemphigoid.

Bullous pemphigoid is a blistering disorder associated with autoantibodies directed against two components of hemidesmosomes, BP180 and BP230. Autoantibodies to the extracellular collagenous domain of BP180 are thought to play a key role in the pathogenesis of the disease. In a murine model of bullous pemphigoid, neutrophil elastase and 92 kDa gelatinase (matrix metalloproteinase 9) have been implicated in subepidermal blister formation via proteolytic degradation of BP180. In this study we sought to elucidate the contribution of these two enzymes to subepidermal blister formation by assessing the expression, localization, and activity of the two proteases in lesional skin, serum samples, and blister fluids obtained from 17 patients with bullous pemphigoid. The results indicate that (i) neutrophil elastase is found in skin biopsy specimens from bullous pemphigoid lesions and is recovered as active enzyme in blister fluids, and (ii) although proform of matrix metalloproteinase 9 is present in lesional skin, it is present only as proenzyme in blister fluids, which also contain high levels of tissue inhibitor of metalloproteinase-1. Next, the capacity of matrix metalloproteinase 9 and neutrophil elastase to degrade a recombinant protein corresponding to the extracellular collagenous domain of the BP180 was studied. Our data illustrate that (i) recombinant matrix metalloproteinase 9, neutrophil elastase, and blister fluid from bullous pemphigoid patients are all able to hydrolyze recombinant BP180; (ii) the pattern of recombinant BP180 proteolysis with blister fluid was similar to that obtained with neutrophil elastase; and (iii) recombinant BP180 degradation by blister fluid could be inhibited by chloromethylketone, a specific elastase inhibitor, but not by batimastat, a wide spectrum matrix metalloproteinase inhibitor. Our results confirm the importance of neutrophil elastase but not matrix metalloproteinase 9 in the direct cleavage of BP180 autoantigen and subepidermal blister formation in human bullous pemphigoid.     

Concomitant psoriasis and bullous pemphigoid: coincidence or pathogenic relationship?

Psoriasis vulgaris and bullous pemphigoid represent two clinically well-characterized, chronic, inflammatory skin diseases. The concomitant occurrence of these two entities in a patient is rare, and the pathogenic implications of this phenomenon are unknown. We describe a 55-year-old woman with a 25-year history of plaque-type psoriasis who presented with disseminated tense bullae. Skin biopsies showed the typical histologic and immunohistochemical traits of bullous pemphigoid, and she had circulating immunoglobulin G (IgG) antibodies against the basement membrane zone, specifically the BP180 antigen. The bullous eruption was successfully treated with oral methylprednisolone and dapsone. Bullous pemphigoid is the autoimmune blistering disease that has most often been associated with psoriasis. Forty cases have been described in the literature. Classical psoriasis and psoriasis associated with bullous pemphigoid are identical. The pathogenic relationship between psoriasis and bullous pemphigoid is unclear. It has been postulated that the autoimmune process responsible for bullous pemphigoid lesions may be induced by ultraviolet light therapy, topical corticosteroids, and/or the inflammatory processes that occur in psoriasis. Immunomodulatory therapy may positively influence shared as well as distinct inflammatory mechanisms in patients who have psoriasis and bullous pemphigoid.     

Bullous pemphigoid arising in a patient with acquired perforating dermatosis

A middle‐aged Japanese man who had been on haemodialysis treatment for diabetic nephropathy developed multiple itchy papules and nodules, which were histopathologically diagnosed as acquired perforating dermatosis. Two years later he developed oral lesions and subsequently numerous erosive plaques with necrotic crusts on the trunk and extremities. Histopathology of a papule showed a parakeratotic plug intermingled with basophilic, necrotic debris and collagen bundles, along with penetration of collagen bundles across the epidermis and subepidermal blister. Immunoblotting studies revealed IgG autoantibodies in the patient's serum, which reacted with the C‐terminal and the NC16a domains of bullous pemphigoid (BP)180, indicating presence of BP. We searched the literature and found no other cases of an autoimmune blistering disease occurring in association with a perforating disorder. Possible injury to the basement membrane zone induced during the process of transepidermal elimination might be involved in the pathogenesis of the pemphigoid disease.     

Two cases of subepidermal blistering disease with anti-p200 or 180-kD bullous pemphigoid antigen associated with psoriasis

We describe two patients with psoriasis vulgaris who subsequently developed a subepidermal blistering disease which disclosed IgG and C3 at the basement membrane zone in direct immunofluorescence. The first case was a 75-year-old Japanese man with herpetiform lesions. Histopathology showed neutrophil infiltration. IgG antibodies bound to the dermal side of the salt-split skin. Immunoblot analysis identified a 200-kD antigen in dermal extracts. The second case was a 70-year-old Japanese man. Histopathology showed eosinophil infiltration. IgG antibodies bound to the epidermal side of salt-split skin. Immunoblot analysis identified a 180-kD bullous pemphigoid (BP) antigen in epidermal extracts. We review the clinical and pathological features of psoriatic patients who presented a subepidermal blistering disease in which antigens were detected by immunoblot analysis; i.e., anti-p200 pemphigoid (14 cases) or BP (12 cases). There were few distinct clinical differences between two diseases. However, neutrophils were predominant in anti-p200 pemphigoid, while eosinophils were predominant in BP. After blister formation, ciclosporin was used effectively in addition to systemic steroids in the treatment of anti-p200 pemphigoid. On the other hand, ciclosporin was not used in the treatment of BP with psoriasis.     

A Case of Chronic Bullous Disease of Childhood That Was Reactive to the Antigen of 120 kDa (LAD-1)

Chronic bullous disease of childhood (CBDC) is an autoimmune blistering disease that is characterized by Immunoglobulin A (IgA) deposits at the basement membrane zone. IgA autoantibodies (aAbs) from the serum of patients with CBDC react with antigens of 97 kDa (LABD97) and 120 kDa (LAD-1), and both of which are fragments of the extracellular domain of bullous pemphigoid 180 (BP180, type XVII collagen). The CBDC sera reacts with the immunodominant NC16a domain of BP180, which is the major region recognized by IgG aAbs in patients with bullous pemphigoid. A five-year-old boy presented with multiple pruritic tense blisters on the umbilical and inguinal areas for six weeks. The direct immunofluorescence of the perilesional area demonstrated linear deposits of IgA at the basement membrane zone. Using immunoblotting and an enzyme linked immunosorbent assay (ELISA), we identified the IgA aAbs reactive to antigens with a molecular weight of 120 kDa (LAD-1), which is a fragment of the extracellular domain of BP180.     

Lichen planus pemphigoides: its relationship to bullous pemphigoid

Clinical and immunopathological studies of three patients with lichen planus pemphigoides (LPP) were carried out to investigate the relationship between LPP and bullous pemphigoid (BP) and to determine whether the antigen in LPP is the classical BP antigen. LPP is usually considered to be the coexistence of lichen planus with BP. The bullae in LPP were subepidermal and indistinguishable from BP. Indirect immunofluorescence demonstrated antibody binding to the epidermal surface of 1 M NaCl-split skin and mucosae, as in BP. The tissue distribution of the LPP antigen mirrored the distribution of BP in stratified squamous epithelia but was absent from transitional epithelia (pig bladder). Immunoelectron microscopy, both direct (two cases) and indirect (one case), showed binding to the lamina lucida as with BP antigen. Western blotting of epidermal extracts using the patients' sera showed that instead of reacting with the classical bullous pemphigoid antigen (220 kDa in our series), the antisera reacted with a unique band of 200 kDa in addition to the band of 180 kDa found as a minor antigen in bullous pemphigoid, but more commonly in pemphigoid gestationis. The relationship between these antigens awaits molecular characterization. These findings suggest that the target antigen in LPP may be unique.     

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.     

Childhood bullous pemphigoid: a clinicopathologic study and review of the literature

Bullous pemphigoid (BP) is an acquired bullous disorder that predominantly affects the elderly. It is rare in children but when it occurs, there is considerable clinical and histologic overlap with other acquired or congenital blistering disorders. A definitive diagnosis of childhood BP requires direct immunofluorescence and, in some cases, characterization of the target antigen. Three cases of childhood BP are presented, with their histologic and immunofluorescence findings. The first was a 5-month-old male infant who presented with erythema and bullae of the palms and soles and was found to have linear deposition of IgG and C3 along the dermoepidermal junction on direct immunofluorescence (DIF). Histopathologic examination revealed a subepidermal blister containing eosinophils. Type IV collagen was demonstrated along the floor of the blister cavity by a direct immunoperoxidase technique. The second case was an 8-month-old female infant who presented with a blistering eruption of her palms and soles that then became widespread. Direct immunofluorescence showed linear IgG and C3 at the dermoepidermal junction, with laminin deposition at the base of the blister. The third case was a 7-year-old female with bullae and erosions on the vulva and vaginal mucosa. A subepidermal blister was seen on microscopic examination whereas immunofluorescence demonstrated linear IgG and C3 deposition at the basement membrane zone (BMZ). A literature review uncovered 50 cases of childhood BP confirmed by direct or indirect immunofluorescence, or both, and often with evidence of autoantibodies against either the 180 kD or the 230 kD human bullous pemphigoid antigens (BP180 or BP230). This review was used to delineate characteristics of childhood BP, including the newly proposed subtypes: infantile BP and childhood localized vulval BP. Infantile BP presents within the first year of life and is characterized by BP-like lesions on erythematous or normal acral skin. Localized vulval BP is a self-limited, nonscarring BP-like process that involves only the vulva. Both subtypes are normally self-limited and respond well to either topical or systemic steroids, if treatment is initiated before the disease becomes widespread.     

Experimental models for the autoimmune and inflammatory blistering disease,Bullous pemphigoid

Bullous pemphigoid (BP) is a subepidermal skin blistering disease characterized immunohistologically by dermal-epidermal junction (DEJ) separation, an inflammatory cell infiltrate in the upper dermis, and autoantibodies targeted toward the hemidesmosomal proteins BP230 and BP180. Development of an IgG passive transfer mouse model of BP that reproduces these key features of human BP has demonstrated that subepidermal blistering is initiated by anti-BP180 antibodies and mediated by complement activation, mast cell degranulation, neutrophil infiltration, and proteinase secretion. This model is not compatible with study of human pathogenic antibodies, as the human and murine antigenic epitopes are not cross-reactive. The development of two novel humanized mouse models for the first time has enabled study of disease mechanisms caused by BP autoantibodies, and presents an ideal in vivo system to test novel therapeutic strategies for disease management.     

Immune phenotyping of mononuclear infiltrate in bullous pemphigoid]

In bullous pemphigoid, autoantibodies alone are not capable of blister formation. In addition, they need complement and various inflammatory cells. The role of mononuclear cells, however, is poorly understood. Therefore, we studied the inflammatory infiltrate in 21 patients with bullous pemphigoid and 11 controls (normal skin, n = 5; eczematous skin, n = 6) using a panel of monoclonal antibodies. In bullous pemphigoid, 60% of the mononuclear infiltrate consists of CD3+ T-lymphocytes, while 25% represents monocytes/macrophages (MOMA); B-lymphocytes are absent. In the area of the basement zone (BMZ), which was studied separately, MOMA predominate. In 30% of bullous pemphigoid biopsies we found a close, almost linear attachment of MOMA to the BMZ. Along the BMZ, lymphocytes belong to the CD3+, CD4+ T-helper subset. CD8+ T-cytotoxic-suppressor cells, however, are rarely encountered there, and other cytotoxic lymphocytes are not found at all. All lymphocytes along the BMZ are memory cells. In small, early bullous pemphigoid lesions, MOMA are frequently the only effector cells. Eosinophilic granulocytes are rare in these lesions. Our findings suggest that mononuclear cells, and particularly MOMA, may be more important than believed hitherto in the inflammatory process resulting in separation of the BMZ.     

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.