Updated S2 K guidelines for the management of bullous pemphigoid initiated by the European Academy of Dermatology and Venereology (EADV).

BACKGROUND: Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease of the skin and mucous membranes. This disease typically affects the elderly and presents with itch and localized or, most frequently, generalized bullous lesions. A subset of patients only develops excoriations, prurigo-like lesions, and eczematous and/or urticarial erythematous lesions. The disease, which is significantly associated with neurological disorders, has high morbidity and severely impacts the quality of life. OBJECTIVES AND METHODOLOGY: The Autoimmune blistering diseases Task Force of the European Academy of Dermatology and Venereology sought to update the guidelines for the management of BP based on new clinical information, and new evidence on diagnostic tools and interventions. The recommendations are either evidence-based or rely on expert opinion. The degree of consent among all task force members was included. RESULTS: Treatment depends on the severity of BP and patients' comorbidities. High-potency topical corticosteroids are recommended as the mainstay of treatment whenever possible. Oral prednisone at a dose of 0.5 mg/kg/day is a recommended alternative. In case of contraindications or resistance to corticosteroids, immunosuppressive therapies, such as methotrexate, azathioprine, mycophenolate mofetil or mycophenolate acid, may be recommended. The use of doxycycline and dapsone is controversial. They may be recommended, in particular, in patients with contraindications to oral corticosteroids. B-cell-depleting therapy and intravenous immunoglobulins may be considered in treatment-resistant cases. Omalizumab and dupilumab have recently shown promising results. The final version of the guideline was consented to by several patient organizations. CONCLUSIONS: The guidelines for the management of BP were updated. They summarize evidence- and expert-based recommendations useful in clinical practice.

S2k guidelines (consensus statement) for diagnosis and therapy of dermatitis herpetiformis initiated by the European Academy of Dermatology and Venereology (EADV).

INTRODUCTION: Dermatitis herpetiformis (DH) is a chronic, pruritic, gluten-induced skin disorder characterized by subepidermal granular IgA deposition and a variable degree of enteropathy identical to that seen in coeliac disease. So far, there has been no European consensus about the management of DH. METHODS: The guidelines were created by small subgroups of a guideline committee consisting of 26 specialists from various medical fields and one patients' representative. The members of the committee then discussed the guidelines and voted for the final version at two consensus meetings. The guidelines were developed under the support of the European Academy of Dermatology and Venereology (EADV) and in collaboration with the European Dermatology Forum (EDF). RESULTS: The guidelines summarize evidence-based and expert-based recommendations (S2 level) for the management of DH (see Appendix). CONCLUSION: These guidelines will improve the quality of management of DH and support dermatologists in their diagnostic and therapeutic decisions.

Updated S2K guidelines on the management of pemphigus vulgaris and foliaceus initiated by the european academy of dermatology and venereology (EADV).

BACKGROUND: Pemphigus encompasses a group of life-threatening autoimmune bullous diseases characterized by blisters and erosions of the mucous membranes and skin. Before the era of immunosuppressive treatment, pemphigus was almost always fatal. Due to its rarity, only few randomized controlled therapeutic trials are available. Recently, rituximab has been approved as first-line treatment for moderate and severe pemphigus vulgaris in Europe and the United States. OBJECTIVES: The Autoimmune blistering diseases Task Force of the European Academy of Dermatology and Venereology (EADV) has initiated a throughout update of the guideline for the management of patients with pemphigus. RESULTS: The guidelines for the management of pemphigus were updated, and the degree of consent among all task force members was included. The final version of the guideline was consented by the European Dermatology Forum (EDF) and several patient organizations.

Discordant expression of desmoglein 2 and 3 at the mRNA and protein levels in nodular and superficial basal cell carcinoma revealed by immunohistochemistry and fluorescent in situ hybridization.

BACKGROUND: Basal cell carcinoma (BCC) is the most common human cancer. It is thought that skewed expression of desmogleins (Dsgs) in BCC may promote tumourigenesis. AIM: To comparatively examine expression of Dsg2/Dsg3, using fluorescent in situ hybridization (FISH) and immunohistochemistry (IHC) in BCC subtypes. METHODS: In total, 84 frozen sections from patients with various clinical or histological subtypes of BCC were analyzed. Expressions of Dsg2/Dsg3 protein and Dsg2/Dsg3 mRNA were evaluated using IHC and FISH, respectively, in BCC nests and BCC-free epidermis, and then quantitatively measured. RESULTS: There was loss of correlation between Dsg2 and Dsg3 (IHC) in nodular and superficial BCC (nBCC, sBCC), and significant correlation between Dsg2 and Dsg3 (FISH) in BCC, but not nBCC and sBCC. CONCLUSIONS: Because more prominent aberrations of Dsg2/Dsg3 expression were seen at the protein than at the mRNA level in BCC, these comparative observations indicate greater importance of events at the proteome level than those at the genome level in tumour functional compartments. Different Dsg2/Dsg3 expression in sBCC and nBCC might corroborate the possibility that sBCC and nBCC are separate conditions. These results may contribute to better understanding of the biological behaviour of BCC.

Acroangiodermatitis in a leg amputee using a suction-socket prosthesis: clinical, histological as well as HHV-8 and CD34 immunohistochemical study.

Acroangiodermatitis (AAD) is a rare, vascular phenomenon of unclear pathogenesis. Itchy, lichenoid, purple/violaceous/yellowish/brownish papules/nodules, plaques/patches mainly on lower limbs occasionally evolve into verrucous lesions and recurrent painful ulcerations. Elevated vein and capillary pressure due to the sub-atmospheric suspension system seems to be the triggering factor for angioproliferation in the amputation stump. A middle-aged male amputee, a suction-socket prosthesis user, showing combined clinical, histological and immunohistochemical (HHV-8 negative; CD34 and CD31 expressed in endothelial, but not perivascular, cells) features of AAD is presented. Dermatologists, orthopedic surgeons, pathomorphologists, but also prosthesis makers and amputees themselves, should be aware of AAD as suction-socket prostheses become increasingly popular.

Desmocollins I and II are recognized by certain sera from patients with various types of pemphigus, particularly Brazilian pemphigus foliaceus.

Recently, it has been shown that desmoglein, pemphigus foliaceus target antigen, and a 130-kD pemphigus vulgaris antigen belong to the cadherin family of cell adhesion molecules. We tried to determine whether desmocollins I/II, other cadherin-like transmembranous glycoproteins present in desmosomes, are also recognized by pemphigus autoantibodies of the IgG class. We examined 16 pemphigus vulgaris sera, 15 pemphigus foliaceus sera, 15 Brazilian pemphigus foliaceus sera, five bullous pemphigoid sera, and 65 normal sera. Four (25%) pemphigus vulgaris sera, one (7%) pemphigus foliaceus serum, eight (53%) Brazilian pemphigus foliaceus sera, and three (5%) normal sera reacted with desmocollins I/II on immunoblots of bovine desmosome preparation. The affinity-purified desmocollins I/II pemphigus autoantibodies were shown to bind the epidermal cell surface by indirect immunofluorescence. Immunoblot analysis revealed one pemphigus vulgaris serum, one Brazilian pemphigus foliaceus serum, and one normal serum recognizing a recombinant protein produced by a desmocollin cDNA clone. Moreover, immunoblot analysis of reactivity of a Brazilian pemphigus foliaceus serum with recombinant proteins produced by deletion mutants of the desmocollin cDNA clone showed that the extracellular portion of desmocollin is immunogenic in this pemphigus patient. We conclude that desmocollins I/II are recognized by certain sera from patients with various types of pemphigus, particularly Brazilian pemphigus foliaceus. However, the significance of this reactivity remains to be defined.

The extracellular aminoterminal domain of bovine desmoglein 1 (Dsg1) is recognized only by certain pemphigus foliaceus sera, whereas its intracellular domain is recognized by both pemphigus vulgaris and pemphigus foliaceus sera.

The major antibody binding regions of desmoglein 1 (Dsg1) in pemphigus foliaceus and pemphigus vulgaris were examined using cDNA-encoded fusion proteins combining glutathione S-transferase with various domains of bovine Dsg1, namely, the extracellular regions EC1-2, EC3-5, EC1-5, and the entire intracellular region IC. In immunoblot analyses using these fusion proteins, EC1-2, as well as EC1-5, which comprises EC1-2, were recognized by 50% of the sporadic pemphigus foliaceus sera and 45% of Brazilian pemphigus foliaceus sera that reacted with Dsg1 in immunoblotting of bovine desmosome preparations. None of these fusion proteins reacted with any sera of pemphigus vulgaris. None of these sera showed reactivity with EC3-5. In contrast, the IC domain was recognized by 91% of pemphigus vulgaris sera reactive with Dsg1 in bovine desmosome preparations, and by certain pemphigus foliaceus and Brazilian pemphigus foliaceus sera. These results indicate that major epitopes of Dsg1 recognized by pemphigus foliaceus and Brazilian pemphigus foliaceus sera are located in the extracellular amino-terminal domain EC1-2, and that sera of the Dsg1-positive pemphigus vulgaris contain antibodies against the intracellular domain, which may not play a pathogenic role. Possible reasons for this selectivity of antigen binding site are discussed.

A case of pemphigus vulgaris showing reactivity with pemphigus antigens (Dsg1 and Dsg3) and desmocollins.

Both pemphigus vulgaris antigen (PVA; Dsg3) and pemphigus foliaceus antigen (PFA; Dsg1) are members of the desmoglein subfamily of the cadherin supergene family. Another desmosomal cadherin, desmocollin, is occasionally recognized by certain pemphigus sera. We present a 38-year-old Japanese male who showed clinically and histopathologically typical features of pemphigus vulgaris, whose sera reacted with all PVA, PFA, and desmocollins using immunoblotting of both human epidermis and bovine snout epidermis. Studies using domain-specific fusion proteins of PFA and PVA suggested that this patient's serum reacted with the intracellular domain of PFA and the extracellular domain of PVA, the latter of which seems to be responsible for initiating the skin lesion. The patient's serum showed reactivity with human desmocollin and was shown to react with bovine Dsc2 fusion protein, further suggesting the significance of anti-desmocollin autoantibodies in pemphigus. These results indicate that certain pemphigus cases may produce antibodies against multiple antigen molecules, although the complex mechanism of the production of autoantibodies remains to be elucidated.

97-kDa linear IgA bullous dermatosis (LAD) antigen localizes to the lamina lucida of the epidermal basement membrane.

Linear IgA bullous dermatosis (LAD) is an autoimmune blistering disease in which IgA autoantibodies develop against the epidermal basement membrane zone. Target antigens of the circulating autoantibodies are thought to be heterogeneous, and their ultrastructural localization has not been fully elucidated. Previous studies with immunoblotting have demonstrated that the 97-kDa autoantigen is detected most frequently in patients' sera and is thought to be a major LAD antigen. Although a recent report suggests that the 97-kDa antigen localized to the hemidesmosomal plaques and the adjacent lamina lucida, discrepancies still exist among previous immunoelectron microscopic findings. To identify the precise localization of the 97-kDa LAD antigen, we used two different low-temperature immunoelectron microscopic techniques. For immunolabeling, we selected five LAD sera that had a high titer of autoantibodies against the 97-kDa LAD antigen. A post-embedding method with cryofixation and freeze substitution failed to immunolabel the 97-kDa LAD antigen. Cryoultramicrotomy with immunoelectron microscopy succeeded in preserving the antigenicity of the 97-kDa LAD antigen. In all cases, the majority of labeling occurred in the lamina lucida beneath the hemidesmosomes. No specific labeling was observed in the hemidesmosomal attachment plaques or the lamina densa or sublamina densa region, including anchoring fibrils. These results indicate that the 97-kDa LAD antigen is a component of the lamina lucida.

Human desmocollin 1a transiently expressed in COS-7 cells and NIH 3T3-3 cells is reacted by IgG4 antibodies in a pemphigus foliaceus serum.

Human desmocollin (Dsc) 1 is an autoantigen in the subcorneal pustular dermatosis type of IgA pemphigus. Moreover, Dscs, particularly bovine Dscs, are recognized by IgG antibodies in certain sera of various types of pemphigus by immunoblotting. In this study, 10 pemphigus sera were examined by immunofluorescence for IgG antibodies to human Dsc1a, Dsc2a and Dsc3a transiently expressed in COS-7 and NIH 3T3-3 cells using two different transfection methods. IgG antibodies in a number of sera showed a strong background staining with untransfected COS-7 and NIH 3T3-3 cells. Using COS-7 cells, a pemphigus foliaceus serum, which did not stain untransfected COS-7 cells, was found to contain IgG antibodies reactive exclusively with Dsc1a. This serum showed the same reactivity in studies using NIH 3T3-3 cells. Moreover, this pemphigus foliaceus serum contained IgG4, but not IgG1 antibodies, to Dscla expressed in the NIH 3T3-3 cells. These results indicate that autoantibody response in pemphigus foliaceus might be more heterogenous than hitherto supposed.

Immunoblotting studies of linear IgA disease.

Patients with linear IgA deposits at the basement membrane zone (BMZ) detected by direct immunofluorescence (IF) may show diverse clinical and laboratory findings. The aim of this study was to investigate the issue of target antigens for linear IgA disease (LAD) antibodies. We examined sera from 46 adults and children with exclusive IgA deposits at the BMZ, by both indirect IF on 1 M NaCl split human skin and immunoblotting. IgA anti-BMZ antibodies binding to the epidermal side of the split were found in 31 LAD sera. IgA anti-BMZ antibodies binding to the dermal side of the split were detected only in 4 LAD sera. No sera contained IgA anti-BMZ antibodies binding to both sides of the split. Immunoblotting revealed that 12 epidermal side-positive LAD sera reacted with the 97 kDa protein in the human epidermal extracts. Moreover, we found that 2 dermal side-positive LAD sera reacted with a protein of approximately 255 kDa on immunoblotting of the dermal extract. We conclude that there are at least two types of LAD. However, the nature of target antigens for LAD antibodies remains to be determined.

IgA antikeratinocyte surface autoantibodies from two types of intercellular IgA vesiculopustular dermatosis recognize distinct isoforms of desmocollin.

We previously proposed the term intercellular IgA vesiculopustular dermatosis (IAVPD) for cases showing IgA antikeratinocyte surface autoantibodies. This condition is divided into two subtypes: intraepidermal neutrophilic IgA dermatosis (IEN), showing pustule formation in the entire epidermis, and subcorneal pustular dermatosis (SPD) showing pustule formation in the uppermost epidermis. We have previously reported that serum from certain IAVPD patients reacts with bovine desmocollin (Dsc), a desmosomal cadherin. In this study we showed that two Dsc isoforms with a slightly different molecular weight were recognized by the serum from these patients. Further analysis revealed that serum from patients with the SPD type, which stained the cell surface in the uppermost epidermis with immunofluorescence, seem to react with Dsc1. By contrast, serum from patients with the IEN type, which stained the cell surface at all levels of the epidermis with immunofluorescence, seemed to react with Dsc3. This difference of distribution between the two distinct Dsc molecules may contribute to the different clinicopathological features between the IEN and SPD type of IAVPD.

Evaluation of an avidin-biotin-peroxidase method with a monoclonal antibody to type IV collagen in the differential diagnosis of bullous pemphigoid and epidermolysis bullosa acquisita.

There are reports in which an immunohistochemical technique with a monoclonal antibody to type IV collagen has been employed for differentiating between bullous pemphigoid (BP) and epidermolysis bullosa acquisita (EBA). The aim of this study was to determine whether this method could be used routinely. Biopsies (paraffin-embedded lesional skin containing a blister) from currently diagnosed patients with clinical features suggesting BP or EBA were examined by an avidin-biotin-peroxidase (ABC) technique. Sera were tested by indirect immunofluorescence on salt-split skin (IF) and immunoblotting (IB). In all cases which exhibited clear type IV collagen staining, the results of the ABC technique agreed with results of both IF and IB. In one confirmed EBA case, it was impossible to unequivocally localize type IV collagen, because it stained very faintly. Taking into consideration the results of our study, data indicating that the level of blistering might not coincide with the localization of immunoreactants in EBA cases and the possibility of an enzymatic destruction of lamina densa, we conclude that the ABC method is unsuitable for differentiation between BP and EBA.

Concomitant occurrence of circulating IgA anti-intercellular and anti-basement membrane zone antibodies in autoimmune blistering diseases: immunofluorescence and immunoblot studies.

Recently, cases with circulating IgA anti-intercellular antibodies have been described. The objective of this study was to present immunofluorescence and immunoblot findings in three cases of bullous diseases with concomitant circulating IgA anti-intercellular and anti-basement membrane zone antibodies. Direct immunofluorescence, indirect immunofluorescence on intact and 1M NaCl-split skin, immunoblotting of epidermal extracts from dispase- and EDTA-separated (two different procedures) human skin, and immunoblotting of the bovine desmosome preparation were performed. All three cases had IgA anti-intercellular and anti-basement membrane zone antibodies. However, immunoblot results were divergent. Case 1 had antibodies against the 150 kD pemphigus foliaceus antigen (IgG), the 170 kD protein (IgG and IgA), and the 97 kD antigen (IgG and IgA). Case 2 had IgG antibodies reactive with the 230 kD and the 170 kD bullous pemphigoid antigens, while case 3 had IgA antibodies against the 97 kD antigen only. The results of immunofluorescence and immunoblot studies in our patients widen the spectrum of laboratory features in blistering skin diseases mediated, at least in part, by antibodies of the IgA class.

Identification of desmoglein 1 as autoantigen in a patient with intraepidermal neutrophilic IgA dermatosis type of IgA pemphigus.

In a 51-year-old female patient with intraepidermal neutrophilic IgA dermatosis (IEN) type of IgA pemphigus, circulating IgA, but not IgG, autoantibodies were detected to bind to the cell surface of the whole epidermis, being much stronger in the upper epidermis. In the patient's skin a heavy intraepidermal IgA staining was observed throughout the whole epidermis, accompanied by a weak IgG and a more prominent C3 staining. IgA from the patient's serum showed no reactivity either with epidermal proteins by immunoblot analysis, or with COS 7 cells transiently transfected with mammalian cell expression constructs containing full length human Dsc1, Dsc2 and Dsc3. Our patient's IgA specifically reacted with conformational epitopes of human desmoglein (Dsg) 1 but not Dsg 3, when studied in a previously established, here for IgA antibody detection modified enzyme-linked immunoabsorbent assay (ELISA) of baculovirus expression system. The immunoreactivity against keratinocyte cell surface was completely removed from the serum of the patient by pre-incubation with recombinant Dsg1 baculoprotein. This finding indicates that the sera possess only IgA antibodies against the extracellular domain of Dsg1 baculoprotein, but no antibodies against components of keratinocyte cell surface other than Dsg1. This is the first case of IgA pemphigus where Dsg1 has been identified as the autoantigen.

The occurrence of IgA pemphigus foliaceus without neutrophilic infiltration.

A 70-year-old woman with pemphigus foliaceus is reported. Direct immunofluorescence performed on perilesional skin revealed deposits of IgA, C3 and lambda chains in the intercellular substance of the upper stratum spinosum. Indirect immunofluorescence demonstrated serum antibodies of the IgA class against the intercellular region of the upper epidermis at an initial titre of 1:2560. Histological studies, performed together with immunofluorescence, revealed an absence of a distinct neutrophil infiltrate either in the epidermis or dermis, contrary to the findings in cases with intra-epidermal IgA deposits reported previously.

Unusual acantholytic bullous dermatosis associated with neoplasia and IgG and IgA antibodies against bovine desmocollins I and II.

There are unusual cases of pemphigus that have antibodies nonreactive with either pemphigus vulgaris or pemphigus foliaceus antigens. We describe a patient with an acantholytic bullous dermatosis and lung cancer with intercellular IgG and IgA antibodies that differed in specificity from those of pemphigus vulgaris and pemphigus foliaceus and reacted with bovine desmocollins I and II and recombinant desmocollin protein.

Demonstration of antibodies to bovine desmocollin isoforms in certain pemphigus sera.

We have shown previously that IgG antibodies in certain pemphigus sera, particularly endemic Brazilian pemphigus foliaceus (BPF) sera, react with bovine desmocollins (Dsc), which are transmembranous glycoproteins of desmosome junctions. Desmocollins occur as three different isoforms (Dsc 1, 2 and 3), all of which are represented in the epidermis. In this study, we examined sera of various pemphigus types by immunoblotting purified bovine desmosomes and bovine Dsc 1, 2 and 3 fusion proteins, expressed in pGEX expression vectors. Six of 15 (40.0%) BPF sera, two of 18 (11.1%) non-endemic pemphigus foliaceus sera, eight of 39 (20.5%) pemphigus vulgaris (PV) sera, and two of 11 (18.2%) normal sera, showed reactivity with Dsc from desmosomes. Experiments with fusion proteins showed that no Dsc isoform was specifically recognized by sera of any individual pemphigus type. Our results indicate that the pathogenesis of pemphigus might be more complex than previously believed.