Bullous pemphigoid

Bullous pemphigoid is the most frequent autoimmune bullous disease and mainly affects elderly individuals. Increase in incidence rates in the past decades has been attributed to population aging, drug-induced cases and improvement in the diagnosis of the nonbullous presentations of the disease. A dysregulated T cell immune response and synthesis of IgG and IgE autoantibodies against hemidesmosomal proteins (BP180 and BP230) lead to neutrophil chemotaxis and degradation of the basement membrane zone. Bullous pemphigoid classically manifests with tense blisters over urticarial plaques on the trunk and extremities accompanied by intense pruritus. Mucosal involvement is rarely reported. Diagnosis relies on (1) the histopathological evaluation demonstrating eosinophilic spongiosis or a subepidermal detachment with eosinophils; (2) the detection of IgG and/or C3 deposition at the basement membrane zone using direct or indirect immunofluorescence assays; and (3) quantification of circulating autoantibodies against BP180 and/or BP230 using ELISA. Bullous pemphigoid is often associated with multiple comorbidities in elderly individuals, especially neurological disorders and increased thrombotic risk, reaching a 1-year mortality rate of 23%. Treatment has to be tailored according to the patient's clinical conditions and disease severity. High potency topical steroids and systemic steroids are the current mainstay of therapy. Recent randomized controlled studies have demonstrated the benefit and safety of adjuvant treatment with doxycycline, dapsone and immunosuppressants aiming a reduction in the cumulative steroid dose and mortality.

[Bullous pemphigoid: diagnostics and new therapeutic strategies]

Bullous pemphigoid, the most frequent bullous autoimmune dermatosis of the adult, typically presents as disseminated tense blisters on normal or erythematous skin. The diagnosis can be confirmed by direct and indirect immunofluorescence, the detection of circulating autoantibodies against the basement membrane proteins collagen XVII/BP180 and BP230, and histopathology. Autoantibody reactivity against collagen XVII can be measured by ELISA and correlates with disease activity. The ELISA therefore provides a useful tool for monitoring disease activity. Treatment of bullous pemphigoid usually consists of topical and / or systemic steroids in combination with immunosuppressive agents. The intensity of skin involvement and the concurrent diseases and medications of the patient must be considered when selecting a certain treatment. Interdisciplinary cooperation between general practitioners, internists and other specialists facilitates the optimal adaptation of the medication and the early discovery of potential side effects.

A very mild form of non-Herlitz junctional epidermolysis bullosa: BP180 rescue by outsplicing of mutated exon 30 coding for the COL15 domain

Mutations in the gene COL17A1 cause non-Herlitz junctional epidermolysis bullosa. Here, we describe a patient who, despite two heterozygous mutations in COL17A1, has an extremely mild form of the disease missing most of the characteristic clinical features. DNA analysis revealed a frame-shift mutation 3432delT and a nonsense mutation 2356C-->T (Q751X). cDNA analysis showed that the deleterious effect of the latter mutation was skirted by deleting the premature termination codon containing exon 30. In this way, the reading frame was restored, resulting in a 36 nucleotides shorter mRNA transcript. Immunoblot analysis showed expression of the 180-kDa bullous pemphigoid antigen (BP180) with a slightly higher SDS-PAGE mobility, in line with the deletion of 12 amino acids from the COL15 domain. Immunofluorescence of skin sections showed diminished, but correctly localised expression of BP180, and this, in concert with the mild clinical phenotype, suggests that this COL15 mutated BP180 is still partly functional.

A comparison of oral and topical corticosteroids in patients with bullous pemphigoid

BACKGROUND

Bullous pemphigoid is the most common autoimmune blistering skin disease of the elderly. Because elderly people have low tolerance for standard regimens of oral corticosteroids, we studied whether highly potent topical corticosteroids could decrease mortality while controlling disease.

METHODS

A total of 341 patients with bullous pemphigoid were enrolled in a randomized, multicenter trial and stratified according to the severity of their disease (moderate or extensive). Patients were randomly assigned to receive either topical clobetasol propionate cream (40 g per day) or oral prednisone (0.5 mg per kilogram of body weight per day for those with moderate disease and 1 mg per kilogram per day for those with extensive disease). The primary end point was overall survival.

RESULTS

Among the 188 patients with extensive bullous pemphigoid, topical corticosteroids were superior to oral prednisone (P=0.02). The one-year survival rate was 76 percent in the topical-corticosteroid group and 58 percent in the oral-prednisone group. Disease was controlled at three weeks in 92 of the 93 patients in the topical-corticosteroid group (99 percent) and 86 of the 95 patients in the oral-prednisone group (91 percent, P=0.02). Severe complications occurred in 27 of the 93 patients in the topical-corticosteroid group (29 percent) and in 51 of the 95 patients in the oral-prednisone group (54 percent, P=0.006). Among the 153 patients with moderate bullous pemphigoid, there were no significant differences between the topical-corticosteroid group and the oral-prednisone group in terms of overall survival, the rate of control at three weeks, or the incidence of severe complications.

CONCLUSIONS

Topical corticosteroid therapy is effective for both moderate and severe bullous pemphigoid and is superior to oral corticosteroid therapy for extensive disease.

[The mosaic of pemphigus]

Pemphigus is an autoimmune blistering disease of skin and mucous membranes. The classic types of pemphigus are pemphigus vulgaris and pemphigus foliaceus. In this review we summarize recent advancement in the etiology and the pathogenesis of pemphigus. Desmogleins--transmembrane glycoproteins involved in intracellular adhesion--were recognized as targets of pemphigus antibodies. It was found that the distribution and the expression of desmogleins can explain the difference in the localization of lesions in pemphigus vulgaris and pemphigus foliaceus. Pemphigus develops in a two-step process. The first step leads to the presence of a low titer of autoantibody, the second step results in a significant increase in the antibody titer which causes the clinical stage of the disease. Selective presentation of self peptides can explain the Major Histocompatibility Complex (MHC)--linked susceptibility to autoimmune diseases including pemphigus and rheumatoid arthritis. Peptides selective for the disease-associated molecules can be identified and used to search for microbiologic factors that can take part in the pathogenesis of pemphigus.

[Profile of bullous pemphigoid. A report of 47 cases]

We report forty-seven cases of bullous pemphigoid recorded in the dermatology department of Charles Nicolle hospital in Tunis during 16 years. In Tunisia, bullous pemphigoid is at the second rank of acquired autoimmune bullous skin diseases, after pemphigus. The profile of bullous pemphigoid in our series differ from that reported in the literature by the more young age (67.2 years) and the male predilection but don't present any clinical an epidemiological particularity. Three atypicals forms were observed: a vesicular form, a localized form and a infantile form. Systemic corticosteroids were choice treatment for our patients.

A subepidermal blistering disease with histopathological features of dermatitis herpetiformis and immunofluorescence characteristics 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 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.

Nonbullous pemphigoid: prodrome of bullous pemphigoid or a distinct pemphigoid variant?

We describe two patients with pruritic, mainly urticarial or eczematous lesions associated with peripheral blood eosinophilia. No vesicles or blisters developed in either patient throughout the course of the disease (29 and 38 months, respectively). To characterize the clinicopathologic features of these patients we performed histopathologic studies, direct and indirect immunofluorescence, immunoelectron microscopy (patient 2), and immunoprecipitation of both patients' serum. Histopathologic examination revealed a moderate eosinophilic infiltrate partly arranged along the basement membrane zone and focally invading the epidermis. Linear deposits of immunoglobulin and C3 along the dermoepidermal junction were localized within the lamina lucida and over the hemidesmosomal plaques. Immunoprecipitation revealed the presence of circulating autoantibodies against the 230 kd bullous pemphigoid antigen. These findings suggest that our patients had a distinct, nonbullous variant of the pemphigoid spectrum.

Immune-mediated subepithelial blistering diseases of mucous membranes. Pure ocular cicatricial pemphigoid is a unique clinical and immunopathological entity distinct from bullous pemphigoid and other subsets identified by antigenic specificity of autoantibodies

BACKGROUND AND DESIGN

There is much confusion in the clinical classification of immune-mediated subepithelial blistering diseases of mucous membranes. We conducted a 6-year comprehensive study to better classify this heterogeneous disease group. Indirect immunofluorescence was performed on a salt-split-skin substrate to detect circulating antibasement membrane antibodies (n = 47). Serologic reactivity against cultured keratinocyte antigens was examined by immunoblots (n = 38) and immunoprecipitation (n = 15). The results were correlated with the clinical features and direct immunofluorescence data of the entire patient group (n = 87) without preassignment of clinical diagnoses. chi 2 Statistical analyses compared these results with those of the classic bullous pemphigoid group (n = 36).

RESULTS

When compared with the bullous pemphigoid patients, a subset of patients with combined oral mucosal and skin lesions demonstrated marked similarity in direct and indirect immunofluorescence findings and in serologic reactivity to bullous pemphigoid antigens. By contrast, a subset of patients with only ocular lesions exhibited significantly lower in vivo deposits of IgG and C3, higher deposits of fibrin, virtual absence of circulating antibodies, and negative serologic reactivity to bullous pemphigoid antigens.

CONCLUSIONS

Ocular patients without skin or mouth lesions, in particular those with negative indirect immunofluorescence, should be distinctively classified as ocular cicatricial pemphigoid, a unique clinical and immunopathologic entity. Patients with mucous membrane involvement who also demonstrate skin lesions and antibodies to the root of salt-split-skin substrate should be classified as anti-BP Ag mucosal pemphigoid, even though they may exhibit severe oral and/or ocular diseases. The remaining mucous membrane patients are heterogeneous. Some can be classified on the basis of autoantibodies to other basement membrane determinants, or if serum autoantibody negative, on the basis of clinical features (ie, pure oral mucosal pemphigoid or overlapping mucosal involvement).

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.

[Parapemphigus and variants; clinical and immunological aspects]

The clinical, histopathological and immunological findings and therapeutic data of 29 patients with different variants of pemphigoid seen by us in the period 1981-1988 are summarized. All 29 patients: disseminated or bullous pemphigoid (20 cases), localized pemphigoid (3 cases), cicatricial pemphigoid (2 cases), juvenile pemphigoid (2 cases), papular pemphigoid (1 case) and pemphigus vegetans (1 case) showed as common denominators subepidermal blister formation and linear deposition of Ig (IgG) and complement in the basement membrane zone. In nearly all the cases with disseminated pemphigoid treatment with immunosuppressive drugs orally was indicated. With particular reference to the age of patients in this subgroup (mean age greater than 70 years) aspects inherent to the treatment are briefly discussed. In contrast to the (relatively) benign course of the disease in localized pemphigoid and in juvenile pemphigoid, cicatricial pemphigoid with mucosal localization appears to be a variant within the spectrum of pemphigoid with severe complications due to tissue retraction and loss of local function.