An unusual presentation of painless penile erosions of pemphigus vulgaris: A case report

Introduction@#Pemphigus vulgaris is a life-threatening, autoimmune bullous disease caused by desmogleins (Dsg) 1 and 3 au- toantibodies. It is a rare disease with an incidence rate of 0.5 to 3.2 per 100,000 per year. It typically presents as painful, flaccid blisters and erosions on both the skin and mucous membranes.@*Case report@#We present a 43-year-old male with painless penile erosions of 1-month duration. He was evaluated for sexually transmitted infections, but laboratory tests yielded negative results. Subsequently, vesicles and bullae on the back and hyper- keratotic lesions on the malar area appeared, leading to the differential diagnoses of bullous diseases. Skin biopsy was done revealing intraepidermal suprabasal blisters with acantholytic cells. Direct Immunofluorescence demonstrated positive inter- cellular deposits of IgG and C3. ELISA Dsg 1 and Dsg 3 were positive (ratio of 1.857 and 4.580, respectively). A final diagnosis of pem- phigus vulgaris (PV) was made. The patient has remained in remission after a 3-month course of prednisone and azathioprine.@*Conclusion@#This is a unique case of PV presenting with an unusual manifestation of painless penile erosions. There have been limited reports of PV with penile skin involvement and all cases presented with painful lesions. Because painless penile lesions as presenting feature is rare, the diagnosis may be easily missed. This case demonstrates that thorough dermatologic examination and early diagnosis despite atypical findings are crucial to provide timely and appropriate treatment as this determines the clinical outcome of the disease.

Fogo selvagem: endemic pemphigus foliaceus

Abstract: Fogo selvagem or endemic pemphigus foliaceus is an autoimmune acantholytic anti-cadherin bullous disease that primarily affects seborrheic areas, which might disseminate. Brazil has the world's largest number of patients, mainly in the Central-West region, but the disease has also been reported in other South American countries. It affects young people and adults who have been exposed to rural areas, with occurrence of familial cases. Anti-desmoglein-1 autoantibodies are directed against desmosomal structures, with loss of adhesion of the upper layers of the epidermis, causing superficial blisters. The etiology is multifactorial and includes genetic, immune, and environmental factors, highlighting hematophagous insect bites; drug-related factors are occasionally involved. Flaccid blisters readily rupture to yield erosive-crusty lesions that sometimes resemble seborrheic dermatitis, actinic keratosis, and chronic cutaneous lupus erythematosus. The clinical presentation varies from localized to disseminated lesions. Clinical suspicion should be confirmed with histopathological and immunofluorescence tests, among others. The progression is usually chronic, and therapy varies according to clinical presentation, but generally requires systemic corticosteroid therapy associated with adjuvant immunosuppressive treatment to decrease the adverse effects of corticosteroids. Once the disease is under control, many patients remain stable on low-dose medication, and a significant proportion achieve remission.

Bullous pemphigoid associated with milia, increased serum IgE, autoantibodies against desmogleins, and refractory treatment in a young patient

Abstract: Bullous pemphigoid is a blistering autoimmune disease characterized by two hemidesmosomal proteins (anti-BP180 and 230). Pemphigus, by contrast, is characterized by two autoantibodies (anti-desmoglein 1 and 3). Coexistence of autoantibodies of bullous pemphigoid and pemphigus in a patient is rare. A 25-year-old male patient was admitted to our hospital, reporting a 3-month history of multiple papules, vesicles, and erosions over an extensive erythema on the entire body. Laboratory tests showed high levels of serum IgE, anti-BP180 antibodies, and anti-desmoglein 1 and 3. Histopathologic and immunopathologic features were characterized by bullous pemphigoid. No improvement was seen with systemic corticosteroid therapy, however, pulse corticosteriod therapy combined with methylprednisolone, immunosuppressants, immunomodulators, and plasmapheresis led to the recovery of his condition with numerous milia.

Intragenic deletion mutation in the gene desmoglein 4 underlies autosomal recessive hypotrichosis in six consanguineous families

Objectives: Localized autosomal recessive hypotrichosis is a non-syndromic human hair loss disorder, affecting scalp, eyebrows and eyelashes, and other parts of the body. Six consanguineous families with this form of hair loss disorder were investigated at both the clinical and molecular levels

Methods: Linkage in six families with twenty-one affected members was tested by genotyping microsatellite markers linked to autosomal recessive hypotrichosis loci including localized autosomal recessive hypotrichosis [LAH] 1, 2 and 3. Sequence analysis of the entire coding and splice sites of the gene DSG4 was performed to search for the disease-causing mutation

Results: Genotyping established linkage in families to the DSG4 gene at LAH1 locus on chromosome 18q21.1. Sequence analysis detected an intragenic deletion mutation [Ex5_8 del] in affected members of all six families

Conclusion: Identification of recurrent mutation in six additional Pakistani families strengthens the body of evidence that this is an ancestral mutation that is widespread among different Pakistani ethnic groups

A Case of Pemphigus Herpetiformis with Only Immunoglobulin G Anti-Desmocollin 3 Antibodies

Pemphigus represents a group of autoimmune blistering diseases caused by autoantibodies against desmogleins (Dsgs), a class of desmosomal cadherins. Recently, several pemphigus patients only with desmocollin (Dsc) 3-specific antibodies have been reported. Here, we report a case of pemphigus herpetiformis (PH), where only anti-Dsc3-specific antibodies but not anti-Dsg antibodies were detected. A 76-year-old woman presented with a 3-year history of blister formation. Physical examination revealed pruritic erythemas with vesicles on the trunk and legs, but no lesions of the oral mucosa. A skin biopsy specimen revealed intraepidermal blister containing neutrophils, eosinophils, and lymphocytes. Direct immunofluorescence (IF) showed immunoglobulin G (IgG) and complement 3 (C3) depositions on the keratinocyte cell surfaces. Indirect IF showed IgG anti-keratinocyte cell surface antibodies. These findings hinted at a diagnosis of pemphigus. However, repeated enzyme-linked immunosorbent assays (ELISAs) for both anti-Dsg1 and 3 antibodies proved to be negative. Immunoblotting of normal human epidermal extracts revealed Dsc antibodies, and recently established ELISAs using human Dsc1-Dsc3 recombinantly expressed in mammalian cells detected anti-Dsc3 antibodies. Based on these clinical, histopathological, and immunological findings, the patient was diagnosed as PH with only anti-Dsc3 antibodies. Treatment with corticosteroid prednisolone and steroid-sparing agent dapsone accomplished complete clinical remission of the patient.

Quality of Life Assessment in Korean Patients with Pemphigus

BACKGROUND: Measuring the quality of life (QOL) is important in the evaluation of nonclinical aspects of diseases, for the discovery of functional and psychological limitations, and in choosing treatment in the initial phase of the disease. Pemphigus is a potentially fatal autoimmune bullous disease caused by autoantibodies against desmogleins (cadherin family proteins in desmosomes). Thus far, there has been no published study on QOL in Korean patients with pemphigus. OBJECTIVE: To study the impact of pemphigus on the QOL in a large number of Korean patients. METHODS: Sixty-six patients enrolled at the Gangnam Severance Hospital from March 2012 to March 2013 were assessed for QOL by using the Dermatology Life Quality Index (DLQI), and for anxiety and depression by using the General Health Questionnaire (GHQ). Spearman's rank-order correlation, t-test, and ANOVA were used to identify the relations between the DLQI score and other clinical variables. RESULTS: Pemphigus vulgaris and pemphigus foliaceus significantly reduced the QOL of patients. The average DLQI score for all patients was 10.18. The mean DLQI score was 13.45 in patients in the active state and 5.15 in the patients in the remission state. The DLQI score highly correlated with disease severity, titer of anti-desmoglein 1 in enzyme-linked immunosorbent assay, and the corticosteroid dose. However, the QOL was not affected by sex, age, subtype of pemphigus, duration of disease, or comorbidities. Forty-two percent of the patients showed a positive result in the GHQ, reflecting probable minor psychiatric nonpsychotic conditions, and the GHQ score positively correlated to the DLQI score. CONCLUSION: Pemphigus significantly impairs the QOL of patients. The QOL of Korean pemphigus patients significantly correlates with clinical severity. Therefore, considerable attention should be paid to the patients' QOL and psychological states as well as clinical status.

Selective Elevation of Antibodies to Desmoglein 1 during the Transition from Mucocutaneous to Cutaneous Type Pemphigus Vulgaris

No abstract available.

Inmunopatogenia del pénfigo vulgar y el pénfigo foliáceo / Immunopathogenesis of pemphigus vulgaris and pemphigus foliaceus

El pénfigo vulgar y el pénfigo foliáceo son enfermedades ampollosas autoinmunes mediadas por autoanticuerpos dirigidos contra proteínas de los desmosomas, las desmogleínas 1 y 3. Están asociadas con moléculas del complejo mayor de histocompatibilidad (HLA) que por su estructura tienen la capacidad de presentar péptidos antigénicos de las desmogleínas. En los individuos afectados se han descrito la presencia de linfocitos T y B autorreactivos y alteraciones en la regulación del sistema inmune con desequilibrio de las respuestas Th1/Th2. No se conocen con precisión los mecanismos de daño pero la investigación actual indica que los anticuerpos tienen un papel patogénico, inician diferentes cascadas de señalización que provocan la acantólisis y apoptosis de los queratinocitos. El conocimiento de la inmunopatogenia de las enfermedades ampollosas autoinmunes ha permitido el desarrollo y la puesta en práctica de nuevas alternativas terapéuticas.

Pemphigus vulgaris and pemphigus foliaceus are autoimmune blistering diseases mediated by antibodies against desmosomal proteins. They are strongly associated with major histocompatibility complex alleles with the ability to present antigenic peptides of desmogleins. In the affected individuals the presence of auto-reactive T and B lymphocytes, and alterations in the immune system regulation with imbalance of the Th1/Th2 responses have been described. Damage mechanisms are not yet precisely known but current investigation indicates that antibodies play an important pathogenic role: they start different signaling cascades that lead to acantholysis and apoptosis of keratinocytes. Better knowledge of the pathogenesis of autoimmune blistering diseases has been the basis for the development and implementation of new therapeutic approaches.

Retinoid Induces the Degradation of Corneodesmosomes and Downregulation of Corneodesmosomal Cadherins: Implications on the Mechanism of Retinoid-induced Desquamation

BACKGROUND: Topical retinoids induce skin fragility. As corneodesmosomes are important adhesion structures in the epidermal cohesion, an effect of retinoids on corneodesmosomes has been suspected. OBJECTIVE: The aim of this study was to investigate the effect of retinoid on the expression of corneodesmosomal components including desmoglein (DSG) 1, desmocollin (DSC) 1, corneodesmosin (CDSN) and kallikrein (KLK)s. METHODS: 2% all-trans-retinol or ethanol was applied to the back of hairless mice for five days, and the structure of the stratum corneum was examined by transmission electron microscopy. The cultured human keratinocytes were treated with all-trans-retinoic acid (RA) in low or high calcium media for 24 hours. RESULTS: Topical retinol increased corneocyte detachment and degradation of corneodesmosomes. RA significantly decreased DSG1 and DSC1 expression at the mRNA and protein levels in keratinocytes that were cultured in both low- and high-calcium media. On the other hand, CDSN mRNA levels did not decrease in low-calcium media or increase in high-calcium media after RA treatment. KLK5 and KLK7 expression did not increase after RA treatment. CONCLUSION: Our results indicate that DSG1 and DSC1 downregulation by RA could be related to the increased degradation of corneodesmosomes and consequent desquamation induced by retinoids.

Expression of Desmoglein-1 in Fetal Skin Development / 대한피부과학회지

BACKGROUND: Desmosomes are cell-cell adhesion complexes that provide mechanical integrity to keratinocytes by linking them to keratin intermediate filaments. Desmosomes are composed of two major transmembrane proteins, desmoglein and desmocollin. In humans, four desmoglein isoforms have been identified: Dsg1, Dsg2, Dsg3, and Dsg4. Desmogleins are Ca2+-dependent adhesion molecules and play important parts in the formation and maintenance of desmosomes. Desmoglein-1 is the main skin-associated desmosomal cadherin. It is expressed throughout the epidermis, but most prominently in the differentiated layers. OBJECTIVE: The purpose of this study was to observe the distribution pattern of desmoglein-1 in the skin and oral mucosa during fetal development. METHODS: Skin was obtained from the sole and scalp of 35 fetuses, ranging from 10 to 37 weeks of gestational age. Immunohistochemical staining was performed on paraffin embedded tissue using anti-human monoclonal antibody against desmoglein-1. RESULTS: Expression of desmoglein-1 in the epidermis appeared in the upper layer of the sole, but the basal layer was negative at the 10th gestational age. Thereafter, stratification began with stronger expression in the middle layer than in the basal layer of the sole and scalp epidermis. Expression in the middle spinous layer is stronger in the fetal period than in other layers of the epidermis. Expression in the superficial layer seemed to increase in later stages. Expression of desmoglein-1 in hair was strong in the infundibulum, inner root sheath, sebaceous glandular epithelium, and eccrine duct epithelium. Expression of desmoglein-1 in oral lip mucosa was very weak or negative in the upper half of the mucosal epithelium, though the lower half was strongly positive, while the skin side of the mucosa was similar with the sole skin. CONCLUSION: Desmoglein-1 may play a complementary role in the maintenance of epithelial integrity along with other desmogleins, because desmoglein-1 distribution is slightly different from that of desmoglein-3 in epidermis, hair and mucosa in fetal skin development.

Pemphigus Erythematosus / 대한피부과학회지

Pemphigus is a group of blistering autoimmune diseases that affect the skin and mucous membranes with autoantibodies against desmoglein. Among the pemphigus subtypes, pemphigus erythematosus is one of the rare lupus-like variant subtypes of pemphigus that shares common clinical and histopathological manifestations with systemic lupus erythematosus. The lesions appear clinically as erythematous erosive patches on the face in a butterfly distribution, and they manifest subcorneal acantholysis histopathologically. There is concomitant basement membrane zone deposition of immunoglobulin and complement in lesional skin in addition to intercellular space staining in the epidermis. Two cases of pemphigus erythematosus have been reported domestically. Here, we report a case of pemphigus erythematosus in an 18-year old woman.

Immunohistochemical Study on the Expression of Desmoglein-3 in Fetal Skin Development / 대한피부과학회지

BACKGROUND: Desmogleins are calcium-dependent transmembrane glycoproteins of the desmosome that form an import component of the junction complexes of epithelial cells. Desmogleins are involved in maintaining the structural integrity of tissues. So far, four different desmogleins (Dsg1, Dsg2, Dsg3 and Dsg4) have been identified. OBJECTIVE: The purpose of this study was to observe the distribution pattern of desmoglein-3 in the fetal skin during development. METHODS: Skin was obtained from the sole, scalp and lip of 34 fetuses that ranged in age from 10 to 39 weeks of gestational age. Immunohistochemical staining was performed on the paraffin embedded tissue using anti-human monoclonal antibody against the desmoglein-3. RESULTS: The expression of desmoglein-3 in the epidermis appeared in the basal layer of the sole at the 10th week of gestation age. Thereafter, a stronger expression was noted in the middle layer of the sole and scalp epidermis. The basal layer had a stronger expression than did the other layers of the epidermis, followed by the middle and superficial layers. A stronger expression of desmoglein-3 in hair was noted in the outer root sheath, the bulge cells and the eccrine duct cells. The expression of desmoglein-3 in the lip mucosa was strong in both the basal and middle layers, while the skin side of the mucosa showed a stronger expression in basal layer. CONCLUSION: These results suggested that desmoglein-3 plays an important role in the development and differentiation of the epidermis and skin adnexa in the fetal stage, and especially in basal and suprabasal layers.

Desmoglein ELISA in the diagnosis of pemphigus and its correlation with the severity of pemphigus vulgaris

Anti-desmoglein 3 and 1 autoantibodies are involved in the pathogenesis of pemphigus diseases. Our objective was to assess the value of ELISA in the diagnosis of pemphigus and its correlation with the severity of pemphigus vulgaris. Based on clinical presentation and histopathologic confirmation for the diagnosis of the pemphigus, 38 patients took part in the study. Sera of the patients were tested by desmoglein 1 and desmoglein 3 ELISA. Also, direct immunofluorescence was performed for all patients which revealed positive results in 36 patients [94.7%]. ELISA was positive in 37 of 38 pemphigus patients [Sensitivity: 97.3%]. The relationship between desmoglein 1 index values and skin severity was statistically significant [p<0.05]. Desmoglein 3 index values increased with oral severity although this was not statistically significant. Iranian patients similar to Indian patients had higher positive anti-desmoglein 1 autoantibodies. Desmoglein-ELISA test is appropriate in the diagnosis of pemphigus. Desmoglein 1 index value is statistically correlated with the severity of pemphigus vulgaris

Effect of Anti-CD20 Monoclonal Antibody (Rituximab) on Recalcitrant Pemphigus Vulgaris / 대한피부과학회지

BACKGROUND: Pemphigus is a severe blistering disorder caused by autoantibodies to desmogleins 1 and 3. Because some patients with pemphigus never enter into remission, new immunosuppressants are warranted. Rituximab is a chimeric monoclonal antibody binding to the CD20 antigen on B cells, which proved to be effective in recalcitrant pemphigus. OBJECTIVE: The purpose of this study was to evaluate the efficacy and safety of Rituximab in the treatment of refractory pemphigus vulgaris. METHODS: A retrospective analysis was conducted of six patients with recalcitrant pemphigus vulgaris in Yongdong Severance Hospital. Rituximab was administered intravenously at a dosage of 375 mg/m(2) body surface area. Five patient received 2 cycles of Rituximab treatment with an interval of 7 days. One patient received 5 cycles of treatment. The mean follow-up after treatment was 9.3 months (range, 2 months to 16 months). RESULTS: All the patients presented clinical improvements. The average pemphigus vulgaris severity score decreased from 12.2 to 2.5 after treatment. No adverse effects were observed. CONCLUSION: Rituximab has been proved as an effective and safe treatment for refractory pemphigus vulgaris.

The Expressions of Desmoglein 1 and 3 according to Chronologic Skin Aging / 대한피부과학회지

BACKGROUND: Desmogleins are transmembrane glycoproteins of the desmosome which provide mechanical strength to epithelial tissue. Desmogleins have so far, been implicated in several diseases such as pemphigus, striate palmoplantar keratoderma, 4S and squamous cell carcinomas. Skin cancer usually occurs in old age. And there are reports that the expression of desmogleins are increased in squamous cell carcinoma. However the role of desmogleins in skin aging has not yet been reported. OBJECTIVE: The purpose of this study was to investigate the expression of desmoglein 1 and 3 according to chronologic skin aging. METHODS: A total of 6 normal tissue samples from sun-protected skin of different age groups (from 34-year-old to an 84-year-old) and 1 squamous cell carcinoma tissue from a 72-year-old patient were taken. Western blotting and immunohistochemical staining were performed with anti desmoglein 1 and 3 antibodies. The expression of desmoglein 1 and 3 by Western blotting were calculated semiquantitatively by a densitometer. RESULTS: The expression of desmoglein 1 was 0.382 in the 34-year-old, 0.450 in the 45-year-old, 0.369 in the 56-year-old, 0.761 in the 65-year-old, 1.035 in the 77-year-old and 1.329 ODu/mm2 in the 84-year-old. The expression of desmoglein 3 was 0.830 in the 34-year-old, 0.984 in the 45-year-old, 1.029 in the 56-year-old, 1.534 in the 65-year-old, 1.714 in the 77-year-old and 1.878 ODu/mm2 in the 84-year-old. In immunohistochemical staining, the expression of Dsg1 increased from the basal layer to the granular layer and Dsg3 was expressed in the basal and suprabasal layers. CONCLUSION: The expression of desmoglein 1 and 3 were increased according to chronologic skin aging.

Endemic pemphigus foliaceus (fogo selvagem) and pemphigus vulgaris: immunoglobulin G heterogeneity detected by indirect immunofluorescence

Pênfigos são enfermidades auto-imunes bolhosas intraepidérmicas, onde auto-anticorpos IgG se dirigem contra glicoproteínas desmossomais. O objetivo deste estudo foi determinar o perfil de subclasses de imunoglubulina G no pênfigo foliáceo endêmico (fogo selvagem) e no pênfigo vulgar através da imunofluorescência indireta. MÉTODOS: Vinte e cinco doentes de pênfigo foliáceo endêmico (fogo selvagem), 25 de pênfigo vulgar e 25 controles sadios foram analisados através da imunofluorescência indireta, com respeito aos auto-anticorpos circulantes (imunoglobulina G total e subclasses). RESULTADOS: Nossos dados mostram uma correlação estatisticamente significativa (p<0.05) entre atividade da doença e títulos de auto-anticorpos circulantes em ambas as formas de pênfigo, ou seja, títulos negativos relacionaram-se com remissão clínica, enquanto resultados positivos correlacionaram-se com doença em atividade. A análise de subclasses de IgG mostrou que 56% dos doentes de fogo selvagem em remissão apresentaram apenas IgG4 positiva; na doença ativa, IgG4 foi a subclasse predominante, sendo positiva em 100% dos casos. Nos doentes de pênfigo vulgar, apenas 10% dos doentes em remissão apresentaram positividade exclusiva para IgG4; na doença em atividade, IgG4 esteve presente em 78-83,3% dos casos. CONCLUSÕES: A caracterização de subclasses de imunoglobulina G consiste em um instrumento de grande valia no seguimento de doentes de pênfigo, uma vez que a IgG4 é a subclasse intimamente relacionada com o reconhecimento de epítopos patogênicos, e consequentemente com atividade da enfermidade. No fogo selvagem em remissão com uma resposta homogênea 'as custas de IgG4, uma monitoração cuidadosa deve ser realizada, uma vez que isto pode significar uma maior chance de reativação.

Immunolocalization of Desmoglein in Autoimmune Pemphigus

BACKGROUND: Pemphigus foliaceus(PF) and pemphigus vulgaris(PV) have different target antigens which belong to the desmoglein(DG) subfamily of the desmosomal cadherins; DG in the case of PF and PV antigen(PVA) in the case of PV. OBJECTIVE: Because DG is also a normal major component of the intercellular adhesive core, we investigated the immunohistochemical distribution of DG in PF to compare and contrast the findings with those of PV. METHODS: Immunohistochemical analysis using streptavidin-biotin complex method with anti-DG monoclonal antibody was done in six cases of PF and six cases of PV, as well as two samples of normal skin as control. RESULTS: Both disorders showed abnormal intense diffuse cytoplasmic staining patterns in the lesional skin. Contrary to PF, showing complete loss of normal, rim-like, membranous staining, two of six cases of PV showed the relatively well preserved normal staining pat-terns in the upper epidermis. CONCLUSION: The differences in the expression of DG in the lesional skins between PF and PV suggest that PVA is distinct from DG, although an overlapping of antigens between PF and PV could exist.

The Effects of Calcium and Retinoic Acid on Epidermal Desmosomes / 대한피부과학회지

BACKGROUND: Desmosomes are adhesive intercellular junctions that form an important component of the junction complexes of epithelial cells. They provide intercellular links between the intermediate filament cytoskeletons of adjacent cells and are thus involved in maintaining the structural integrity of tissues. OBJECTIVE: Calcium and retinoids are major regulators of epidermal differentiation and their role on keratin proteins are well known. However, their effects on desmosome moleucles are unknown. To address this question we initiated a study of the effects of these epidermal differentiation regulators on desmosomal components, i.e., desmoplakin, desmoglein, and pemphigus antigens. METHODS: We used monoclonal antibodies against desmoplakin(DP) and desmoglein(DG), and sera from patients with pemphigus vulgaris(PV), pemphigus foliaceus(PF) and paraneoplastic pemphigus (PNP) to study the effects of calcium and retinoic acids, which are major regulators of epidermal differentation, on desmosomal protein formation in human cultured deratinocytes. We performed immunofluorescence, immunoblotting and immunoprecipitation study using human keratinocytes cultured in high calcium media with or without retinoic acid and in low calcium media with or without retinoic acid. RESULTS: 1. In low calcium (0.15mM) media, PV antigen and DG were produced in a small amount and it appeared that these desmosomal proteins were located in cytosol. Whereas in high calcium (1.8mM) media, production of these desmosomal proteins was increased not they were assembled at the desmosomal structures located in cell-cell contact margins. 2. PF antigen, which was identical to the DG, were not produced or expressed in cultured keratinocytes even when cultured in high calcium media. 3. PNP antigen and DP were produced in cultured keratinocytes grown in both high low calcium media but their production was increased in high calcium media and only in high calcium media they were assembled at the desmosomal structures. 4. Retinoic acids induced loosening of cell-cell contacts of cultured keratinocytes and decreased the production of desmosomal proteins. CONCLUSION: Our results suggests calcium is a major regulator of the production and assembly of desmosomal proteins including pemphigus antigens, but PF sera and monoclonal antibodies against DG show different antigen binding characteristics. It appears that retinoic acids inhibit production of desmosomal proteins.