The clinical transition between pemphigus foliaceus and pemphigus vulgaris correlates well with the changes in autoantibody profile assessed by an enzyme-linked immunosorbent assay

Is transition between subtypes of pemphigus possible? A series of pemphigus vulgaris patients showing the transition to pemphigus foliaceus

BACKGROUND

Pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are subtypes of pemphigus with distinct clinical and laboratory features. The transition between these two subtypes has rarely been reported previously.

METHODS

The data of PV patients who exhibited clinical and immunoserological transition to PF during the follow-up period were retrospectively evaluated regarding their demographical, clinical, and laboratory characteristics.

RESULTS

Among 453 patients diagnosed with PV, 13 (2.9%) patients exhibited clinical and immunoserological transition from PV to PF. The mean age of PV patients at the time of diagnosis was 39.8 ± 14.7 (19‒62) years and 7 (53.8%) of them were female. These patients showed clinical and immunoserological transition from PV to PF after a period ranging from 4 months to 13 years (mean 36.2 ± 41 months). In addition to typical clinical features of PF, all patients had positive anti-desmoglein-1 and negative anti-desmoglein-3 antibody levels after the clinical transition had occurred without any mucosal involvement. During a mean 7.8 ± 5.8 (2‒21) years of follow-up period after the transition from PV to PF, only one female patient had experienced a re-transition to PV characterized by a relapse of disease involving mucosal surfaces with positive anti-desmoglein-3 antibody levels following a 5-year period of remission period without treatment.

STUDY LIMITATIONS

Single-center study with a retrospective study design.

CONCLUSION

Our series is the largest group of patients reported to show the transition from PV to PF to date with a long follow-up period. The reason behind the disappearance of anti-desmoglein-3 antibodies and the pathogenesis of this phenomenon is not yet elucidated.

Histopathology of autoimmune bullous dermatoses: What's new?

Autoimmune bullous dermatoses are characterized by the presence of tissue-bound and often circulating pathogenic autoantibodies targeting structural components of the skin and/or mucous membranes. The diagnostic workup for this heterogeneous group of disorders consists of a multi-step process, of which the light microscopic examination is a crucial component. This review is organized following a classification scheme that is based on two main histopathologic features, namely level of intraepithelial split and composition of the inflammatory infiltrate. Overall, we aim to place emphasis on the histopathologic clues that can assist pathologists in differential diagnosis and review the updates in the literature.

Detection of circulating anti-skin antibodies by indirect immunofluorescence and by ELISA: a comparative systematic review and meta-analysis

Background Both enzyme-linked immunosorbent assays (ELISAs) and indirect immunofluorescence (IIF) are available for the diagnosis of autoimmune bullous diseases (AIBD). Many studies have reported on the performance of ELISAs and concluded that ELISAs could replace IIF. This study compares the diagnostic accuracy of ELISA and IIF for the detection of autoantibodies to desmoglein 1 (DSG1), desmoglein 3 (DSG3), bullous pemphigoid antigen 2 (BP180) and bullous pemphigoid antigen 1 (BP230) to support the diagnosis of pemphigus vulgaris (PV), pemphigus foliaceus (PF) and bullous pemphigoid (BP). Methods A literature search was performed in the PubMed database. The meta-analysis was performed using summary values and a bivariate random effect model. Results The five included studies on PV did not demonstrate significant differences between IIF and DSG3-ELISA (sensitivity 82.3% vs. 81.6%, p = 0.9284; specificity 95.6% vs. 93.9%, p = 0.5318; diagnostic odds ratio [DOR] 101.60 vs. 67.760, p = 0.6206). The three included studies on PF did not demonstrate significant differences between IIF and DSG1-ELISA (sensitivity 80.6% vs. 83.1%, p = 0.8501; specificity 97.5% vs. 93.9%, p = 0.3614; DOR 160.72 vs. 75.615, p = 0.5381). The eight included studies on BP showed that BP230-ELISA differed significantly from both IIF on monkey esophagus (MO) and BP180-ELISA with regard to DOR (11.384 vs. 68.349, p = 0.0008; 11.384 vs. 41.699, p = 0.0125, respectively) Conclusions Our meta-analysis shows that ELISA performs as well as IIF for diagnosing PV, PF and BP.

Rare Diseases of Larynx, Trachea and Thyroid

This review article covers data on rare diseases of the larynx, the trachea and the thyroid. In particular, congenital malformations, rare manifestations of inflammatory laryngeal disorders, benign and malignant epithelial as well as non-epithelial tumors, laryngeal and tracheal manifestations of general diseases and, finally, thyroid disorders are discussed. The individual chapters contain an overview of the data situation in the literature, the clinical appearance of each disorder, important key points for diagnosis and therapy and a statement on the prognosis of the disease. Finally, the authors indicate on study registers and self-help groups.

Clinical and immunological features of pemphigus relapse

BACKGROUND

More than half of patients with pemphigus experience relapse during the disease course. The risk factors and clinical and immunological characteristics of relapse remain largely unclear.

OBJECTIVES

To elucidate the risk factors and clinical features of pemphigus relapse.

METHODS

We carried out a retrospective review of the clinical records of 42 cases of pemphigus at a single centre.

RESULTS

Sixty-two per cent of patients experienced relapse, usually when oral prednisolone was tapered to around 0·1 mg kg^-1 . In mucocutaneous pemphigus vulgaris (mcPV), the initial doses (mean ± SD) of prednisolone were significantly lower in patients with relapse (0·78 ± 0·24 mg kg^-1 ) than in those without relapse (1·01 ± 0·01 mg kg^-1 ). At relapse, mcPV shifted to mucosal dominant PV (mPV; 40%), pemphigus foliaceus (PF) (20%) or 'other' (20%). In contrast, relapsing mPV and PF had the same clinical phenotypes as the initial phenotypes. Patients with both anti-desmoglein (Dsg)1 and anti-Dsg3 antibodies at onset had recurrence with anti-Dsg3 antibodies alone (40%), with both anti-Dsg1 and anti-Dsg3 antibodies (30%), with anti-Dsg1 antibody alone (20%) or were subthreshold (10%).

CONCLUSIONS

mcPV shows transitions in clinical phenotype and autoantibody profile at relapse. At least 1 mg kg^-1 daily of prednisolone, especially for patients with mcPV, and prudent tapering around 0·1 mg kg^-1 may lead to better outcomes.

Humoral Epitope Spreading in Autoimmune Bullous Diseases

Autoimmune blistering diseases are characterized by autoantibodies against structural adhesion proteins of the skin and mucous membranes. Extensive characterization of their autoantibody targets has improved understanding of pathogenesis and laid the basis for the study of antigens/epitopes diversification, a process termed epitope spreading (ES). In this review, we have reported and discussed ES phenomena in autoimmune bullous diseases and underlined their functional role in disease pathogenesis. A functional ES has been proposed: (1) in bullous pemphigoid patients and correlates with the initial phase of the disease, (2) in pemphigus vulgaris patients with mucosal involvement during the clinical transition to a mucocutaneous form, (3) in endemic pemphigus foliaceus, underlining its role in disease pathogenesis, and (4) in numerous cases of disease transition associated with an intermolecular diversification of immune response. All these findings could give useful information to better understand autoimmune disease pathogenesis and to design antigen/epitope specific therapeutic approaches.

New biochip immunofluorescence test for the serological diagnosis of pemphigus vulgaris and foliaceus: A review of the literature

The immunoassays that are available for the serological diagnosis of the more common subtypes of autoimmune blistering diseases such as pemphigus vulgaris (PV) and pemphigus foliaceus (PF) include enzyme-linked immunosorbent assay (ELISA) testing to specific antigens desmoglein (Dsg)1 and Dsg3, direct immunofluorescence (DIF), indirect immunofluorescence (IIF), and immunoblotting. A review of the literature on the biochip assay was conducted. Six studies investigated the validity of a new biochip, mosaic-based, IIF test in patients with pemphigus and demonstrated its relatively high sensitivity and specificity (Dsg3: 97.62-100%, 99.6-100%; Dsg1: 90%, 100%) in comparison with ELISA (Dsg3: 81-100%, 94-100%; Dsg1: 69-100%, 61.1-100%), and/or IIF (PV: 75-100%, 91.8-100%; PF: 67-100%) using suitable substrates. So far, validation studies of the biochip have been conducted in four countries (Germany, Italy, Turkey, and Poland) but none in the southern hemisphere. Caucasian patients were recruited as normal controls for these studies; thus, the diagnostic value of the biochip remains uncertain in population groups of other ethnicities. A range of disease control patients were recruited including patients with linear immunoglobulin A dermatosis, psoriasis, discoid lupus erythematosus, lichen planus, and noninflammatory skin diseases (e.g., squamous cell carcinoma, basal cell carcinoma, and vascular leg ulcers). Prospective studies with control patients from a diverse range of ethnicities are needed to better validate the biochip.

A Case of Concomitant Pemphigus Foliaceus and Oral Pemphigus Vulgaris

Pemphigus is a chronic autoimmune condition that can affect multiple areas of the body. The two main subtypes of pemphigus are pemphigus vulgaris (PV) and pemphigus foliaceus (PF) which can rarely occur concurrently or even transition from one to the other. The process of transition may be explained by qualitative changes in desmoglein autoantibody profile. We present a rare case of concomitant PF and oral PV and explore the literature on transitions between pemphigus subtypes and whether this case could represent a transition from PF to PV. Furthermore, the realities of multidisciplinary patient management are discussed.

[Transition from pemphigus vulgaris to pemphigus foliaceus: a case report]

BACKGROUND

Pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are the two main subtypes of auto-immune pemphigus, each having different clinical, histological and immunopathological features. We report the case of a patient initially with typical PV who relapsed within 2years, presenting clinically, histologically and immunologically typical PF.

PATIENTS AND METHODS

A 47-year old man presented in March 2008 with clinically, histologically and serologically typical PV and treated with systemic corticosteroids alone (prednisone: 1mg/kg per day) then combined with a cycle of rituximab, which resulted in complete remission. After discontinuation of therapy (duration: 26months), he relapsed 6 months later with PF presenting clinical, histological and serological characteristics typical of this condition.

DISCUSSION

This is a rare case of complete transition from PV to PF in clinical, histological and serological terms, and the first case occurring after initial treatment with rituximab.

Autoimmune bullous diseases associations

The presence of one autoimmune disorder helps lead to the discovery of other autoimmune conditions. It is thought that diseases in which autoimmunity is a feature tend to be associated together more often than one can ascribe to chance. A variety of diseases have been implicated in the onset of intraepidermal and subepidermal autoimmune diseases. The presence of one autoimmune disease should alert the physician to watch for a second immunologic disorder. A list of autoimmune bullous diseases associations includes autoimmune bullous diseases, pemphigus, pemphigoid, epidermolysis bullosa acquisita, dermatitis herpetiformis (Duhring), linear immunoglobulin A disease, and multiple autoimmune syndrome.

Urban legends: pemphigus vulgaris

Pemphigus vulgaris (PV) is the most common type of pemphigus. PV pathogenesis is still debated, and treatment remains challenging. We investigated five controversial topics: (1) What are the target antigens in PV? (2) Do desmogleins adequately address PV pathophysiology? (3) How does acantholysis occur in PV? (4) Is PV still a lethal disease? (5) What is the role of rituximab (RTX) in PV treatment? Results from extensive literature searches suggested the following: (1) Target antigens of PV include a variety of molecules and receptors that are not physically compartmentalized within the epidermis. (2) PV is caused by a variety of autoantibodies to keratinocyte self-antigens, which concur to cause blistering by acting synergistically. (3) The concept of apoptolysis distinguishes the unique mechanism of autoantibody-induced keratinocyte damage in PV from other known forms of cell death. (4) PV remains potentially life-threatening largely because of treatment side effects, but it is uncertain which therapies carry the highest likelihood of lethal risk. (5) RTX is a very promising treatment option in patients with widespread recalcitrant or life-threatening PV. RTX's cost is an issue, its long-term side effects are still unknown, and randomized controlled trials are needed to establish the optimal dosing regimen.

Mucocutaneous pemphigus vulgaris carrying high-titre antidesmoglein 1 antibodies with skin lesions resembling pemphigus erythematosus

Patients with pemphigus vulgaris (PV) who have both antidesmoglein (Dsg)1 and anti-Dsg3 antibodies usually develop flaccid blisters on skin and mucous membranes. We report a case of PV with crusting skin lesions resembling pemphigus erythematosus, the localized variant of pemphigus foliaceus (PF). Notably, the patient had high titres of anti-Dsg1 IgG, as assessed by ELISA. We then established an in vitro model of pemphigus, and found that patient's serum was able to induce suprabasilar acantholysis in mouse skin culture. However, epidermal splitting also occurred within the granular layer, suggesting that the pathogenic potential of such a high-titre anti-Dsg1 serum was intermediate between PV and PF. Thus, the levels of anti-Dsg1 antibodies could play a role in determining the clinical phenotype of pemphigus.

Case of pemphigus foliaceus that shifted into pemphigus vulgaris after adrenal tumor resection

A 79-year-old Japanese woman visited our hospital on 6 May 2003, who had suffered from erythema and crusted vesicles located on the head, face and trunk. The eruptions first appeared in February 2003. Histopathological findings included blister formation spreading from just below the horny layers to the upper squamous layers, where acantholytic cells were observed. Direct immunofluorescence disclosed immunoglobulin G depositions in the epidermal intercellular spaces. Enzyme-linked immunosorbent assay showed an elevated titer of anti-desmoglein (Dsg)1 autoantibodies (154 index value), but almost normal levels of anti-Dsg3 autoantibodies (8 index value in serum). The diagnosis at first was made as pemphigus foliaceus (PF). Topical use of corticosteroids alone could control the eruptions well. Systemic examinations on admission revealed a right adrenal tumor that had caused Cushing's syndrome. Its resection was performed on 24 July 2003. Histopathological diagnosis of the removed tumor was a functional adrenal adenoma. The symptoms had worsened after the resection. Topical use of corticosteroids alone could no longer control the symptoms. Additional p.o. medications of minocycline hydrochloride and nicotinic acid amides improved the symptoms to some extent. However, oral cavity erosions appeared in December 2004, and the titer of anti-Dsg3 autoantibodies in serum elevated, suggesting a transition from PF to pemphigus vulgaris (PV). p.o. administration of corticosteroids started, which improved the symptoms significantly. To date, there have been no reports of pemphigus complicated with an adrenal tumor that caused Cushing's syndrome in Japan. The present case is particularly interesting in that the symptoms became worse after the tumor resection and that the first diagnosis of PF shifted into PV after the operation.

Immunoadsorption in pemphigus

The principle of extracorporal immunoadsorption (IA) is based on affinity adsorption of pathogenic (auto-)antibodies and circulating immune complexes (CIC) which reversibly bind to an immobilized ligand of the adsorber. In pemphigus, a blistering autoimmune disease affecting skin and mucous membranes, autoantibodies, mainly of the IgG subclass are directed against desmosomal adhesion molecules and other non-desmosomal antigens on the surface of epidermal keratinocytes, such as acetylcholine receptors. The pathogenicity of these autoantibodies has been shown in various in vitro and in vivo systems. Recently, IA was applied in severe pemphigus demonstrating that a rapid and dramatic decline in desmoglein (Dsg)-reactive autoantibodies is accompanied by clinical remission of mucocutaneous blisters and erosions. As an adjuvant treatment, IA was combined with systemic immunosuppressive medication and current protocols initially apply treatment cycles of 3-4 IAs on consecutive days followed by immunoapheresis once a week or repeating the initial cycle in 4 week intervals depending on the disease activity. IA in pemphigus is generally safe and well tolerated.

Upregulation of c-Myc may contribute to the pathogenesis of canine pemphigus vulgaris

The pathomechanism in human pemphigus vulgaris (PV) has recently been described to rely on generalized c-Myc upregulation in skin and oral mucosa followed by hyperproliferation. Here we assessed whether dogs suffering from PV present the same pathological changes as described for human patients with PV. Using immunofluorescence analysis on patients' biopsy samples, we observed marked nuclear c-Myc accumulation in all layers of the epidermis and oral mucosa in all (3/3) dogs analysed. In addition, c-Myc upregulation was accompanied by an increased number of proliferating Ki67-positive cells. These molecular changes were further paralleled by deregulated expression of wound healing and terminal differentiation markers as observed in human PV. Together these findings suggest a common pathomechanism for both species which is of particular relevance in the light of the recently discussed novel therapeutic strategies aiming at targeting PV antibody-induced signalling cascades.

Detection of pemphigus desmoglein 1 and desmoglein 3 autoantibodies and pemphigoid BP180 autoantibodies in saliva and comparison with serum values

Although there is much literature on the detection of pemphigus and pemphigoid autoantibodies by enzyme-linked immunosorbent assay (ELISA) in serum, nothing is known about their presence in saliva. The aim of this study was to evaluate the salivary levels of these autoantibodies in pemphigus and pemphigoid patients. Autoantibodies against desmoglein3, desmoglein1, and BP180 were assayed, by ELISA, in serum and saliva samples of patients and healthy controls. The titres of autoantibodies against Dsg1/3 found in both serum and saliva of pemphigus patients showed a statistically significant correlation, suggesting that saliva may be a useful biological material for diagnostic purposes, in monitoring disease activity, as well as for the early detection of relapses. By contrast, the titres of autoantibodies against BP180 in the serum and saliva of bullous pemphigoid patients were not statistically related, and further study of the usefulness of the BP180 ELISA for saliva in this disease is needed. In addition, based on our results, the BP180 ELISA with a recombinant NC16a epitope failed to detect the autoantibodies against BP180 in the serum and saliva of mucous membrane pemphigoid patients.

Prevalence of Anti-Desmoglein-3 Antibodies in Endemic Regions of Fogo Selvagem in Brazil

Fogo selvagem (FS), the endemic form of pemphigus foliaceus (PF), is an autoimmune blistering disease characterized by autoantibodies against desmoglein 1. The Terena reservation of Limao Verde in Mato Grosso do Sul, Brazil, is a previously identified focus of disease. Autoantibodies against desmoglein 3 (Dsg3) have also been detected in sera from patients with FS. In an effort to further characterize the serological, geographical, and clinical epidemiology of the disease, we sought to determine the prevalence of anti-Dsg3 autoantibodies in sera from normal subjects living outside of and in an endemic area using an ELISA. Anti-Dsg3 antibodies were detected in 53 of 146 normal subjects from Limao Verde (36%), and in eight of 140 normal subjects from surrounding areas (6%). A significant trend was observed in the proportion of positive tests relative to distance from the endemic area (P < 0.001). Our seroepidemiological observations support the concept that the likely environmental trigger of the antibody response in FS is located in this endemic area, and that the population at risk to develop FS may also be at risk to develop an endemic form of pemphigus vulgaris as reported by our co-investigators from Brasilia.

Non-pathogenic anti-desmoglein 3 IgG autoantibodies in Fogo Selvagem

The endemic form of pemphigus foliaceus, fogo selvagem, is caused by IgG autoantibodies directed against desmoglein 1 (Dsg1). Hilario-Vargas and his colleagues describe a high prevalence of IgG autoantibodies against Dsg3, the target antigen of pemphigus vulgaris, in a Brazilian population where fogo selvagem is endemic, although those patients do not develop any apparent clinical phenotype of pemphigus vulgaris.

How does acantholysis occur in pemphigus vulgaris: a critical review

BACKGROUND

Pemphigus vulgaris is a life-threatening autoimmune blistering disease targeting skin and mucous membranes, characterized by disruption of keratinocytes' adhesion termed acantholysis. Today multiple classes of targets are considered to play a role in the genesis of the acantholysis; of these, the classical pemphigus antigens, desmosomal cadherins (desmoglein 1 and 3) are the best characterized and considered as the most important. Additional antigens include the novel epithelial acetylcholine receptors (alpha9 and pemphaxin). Thus, acantholysis in pemphigus seems to result from a cooperative action of antibodies to different keratinocyte self-antigens, but the mechanisms by which epithelial cleft occurs are not yet clearly understood. In fact, the binding of the autoantibodies to these targets generates a plethora of biological effects due, on one hand, to their direct interference with adhesive function and, on the other, to more complex events involving intracellular pathways that modify proteases activity or calcium metabolism, leading to loss of cell-cell adhesion.

Atypical pemphigus: discordance between clinicopathological findings and the antigenic profile in four cases

BACKGROUND

The diagnosis of pemphigus vulgaris and pemphigus foliaceus is usually based on clinical, histological, and immunofluorescence (IF) findings. In recent years, the antigenic profile of both diseases has been further defined by immunobiochemical techniques (ELISA, immunoblot, and immunoprecipitation).

METHODS

A retrospective study of 40 pemphigus patients was performed to determine the clinical, histological, and antigenic profile in patients with pemphigus followed at our Department. Charts review, clinical data, histological and IF findings, and antigenic analysis by ELISA were performed in all patients.

RESULTS

In most patients, there was a perfect correlation between the clinical and histological findings and their antigenic profile. In four patients (10%), clinicopathological features and antigenic findings were discordant.

CONCLUSIONS

The antigenic profiles in pemphigus do not always correlate with the clinical diagnosis. Therefore, clinical and histological features should be considered as the mainstay for the diagnosis of pemphigus.

Transition from pemphigus foliaceus to pemphigus vulgaris: case report with literature review

The transition between the main subtypes of pemphigus, pemphigus vulgaris (PV), and pemphigus foliaceus (PF) has rarely been reported. Moreover, the development of PV in a patient with PF is much more unusual than that of PF in a patient with PV. We report a 48-year-old man who presented with cutaneous lesions showing the typical clinical and histological features of PF. Five years later, his skin lesions became extensive and he developed oral erosions. His condition did not respond well to steroids and azathioprine. Histological examination of a vesicle disclosed suprabasal acantholysis in contrast to the subcorneal acantholysis discovered upon initial histological evaluation. Indirect immunofluorescence revealed IgG antikeratinocyte cell surface antibodies at a titer of 1:640. The titer was 1:160 at initial diagnosis. Upon immunoblotting, the patient's serum reacted with 130 kiloDalton (kDa) and 160 kDa proteins, suggesting desmoglein (Dsg) 3 and 1, respectively. We herein report an unusual case of PV that developed from PF during the disease's flare-up.

Three cases of transition from pemphigus vulgaris to pemphigus foliaceus confirmed by desmoglein ELISA

We report 3 cases of pemphigus vulgaris (PV) confirmed by histology and direct and indirect immunofluorescence that showed transition to pemphigus foliaceus (PF) 2-4 years from the time of disease onset. Desmoglein (Dsg) ELISA testing of the sera from these 3 patients in the later stages of their disease showed the presence of anti-Dsg1 antibodies and the absence of anti-Dsg3 antibodies. These patients were on prednisolone and immunosuppressives at the time the sera were tested, and it is unclear if the transition from PV to PF is a permanent one or whether it is due to preferential suppression of Dsg3 antibodies below a certain threshold. Previously reported cases of transition from PV to PF and PF to PV are summarized.

Pénfigo

Pemphigus is an infrequent, organ-specific, autoimmune bullous disease, which affects the skin, mucous membranes and appendages. Histopathologically, it is characterized by acantholysis. Pemphigus has classically been divided into two major groups, pemphigus vulgaris and pemphigus foliaceus, with their respective clinical variants pemphigus vegetans and pemphigus erythematosus. In recent years, new variants of pemphigus have been described: paraneoplastic pemphigus, IgA pemphigus and pemphigus herpetiformis. This article reviews the epidemiology, etiopathogenesis, clinical symptoms, diagnosis, treatment and prognosis of pemphigus. Advances in molecular biology techniques have made it possible to more precisely identify the different antigens against which antibodies are directed, and to fine-tune ELISA diagnostic techniques. Treating pemphigus vulgaris and foliaceus with general steroids has modified their prognosis; it is estimated that mortality in recent decades is less than 10 %. Managing the clinical complications that appear during the evolution of the pemphigus has contributed to reducing morbidity and mortality.

Desmosomes and disease: pemphigus and bullous impetigo

Desmosomal cadherins are the pathophysiologic targets of autoimmune or toxin-mediated disruption in the human diseases pemphigus and bullous impetigo (including its generalized form, called staphylococcal scalded skin syndrome). Experiments exploiting the production of both pathogenic and nonpathogenic antidesmoglein antibodies in pemphigus patients' sera have afforded data that make an invaluable contribution towards identifying the functional domains of the desmogleins involved in intercellular adhesion. Conformational epitopes of antidesmoglein autoantibodies in pemphigus patients' sera and the specific cleavage site of desmoglein 1 by exfoliative toxin have been identified, implicating the N-terminal extracellular domains of the desmogleins as critical regions for controlling intercellular adhesion. Furthermore, the development of active autoimmune mouse models for pemphigus allows in vivo characterization of the disease and its pathogenesis. These studies offer new insight into the potential mechanisms of acantholysis in pemphigus and staphylococcal-associated blistering disease, with implications for the role of desmogleins in desmosomal structure and function.

Paraneoplastic pemphigus secondary to fludarabine evolving into unusual oral pemphigus vegetans

We report a patient with chronic lymphocytic leukaemia who developed paraneoplastic pemphigus (PNP) soon after the initiation of fludarabine therapy. He presented with severe oral and cutaneous erosions. Initially, he had high titres of circulating autoantibodies as detected by indirect immunofluorescence (IF) on multiple epithelial substrates (normal human skin, monkey oesophagus, and rat bladder) and by desmoglein 1 and 3 enzyme-linked immunosorbent assays (ELISAs). His oral erosions have subsequently progressed into unusual hyperplastic papillomatous lesions affecting the inner aspect of lips and buccal mucosae, histologically consistent with pemphigus vegetans. Desmoglein 1 antibodies and IF on rat bladder substrate have become negative after 18 months of therapy. Several agents had been initiated to bring the disease under control originally, but a partial remission was achieved and maintained with mycophenolate mofetil and low-dose prednisolone.

Recent advances in the study of the pathophysiology of pemphigus

Recent rapid advances in the basic research into pemphigus have provided many insights into its pathophysiology. In particular, a recently developed enzyme-linked immunosorbent assay (ELISA) for desmogleins 1 and 3 (Dsg1 and Dsg3), antigens for pemphigus foliaceus (PF) and pemphigus vulgaris (PV), respectively, has led to great progress in the diagnosis and classification of pemphigus, as well as in understanding its pathomechanisms. Studies with the anti-Dsg1 and anti-Dsg3 antibodies have indicated that there are two types of PV, the mucosal dominant type and the mucocutaneous type. The same ELISA has identified the antigens in pemphigus herpetiformis. The autoantigens detected by this ELISA correlate well with the clinical features in pemphigus patients in showing the shift between PV and PF. In addition, the Dsg compensation theory proposed by Stanley and Amagai can reasonably explain the different depths of skin lesions and the different occurrences of skin and oral mucosal lesions between PV and PF. Furthermore, a complicated profile of autoantigens in paraneoplastic pemphigus (PNP) has been indicated in various biochemical studies, and IgG anti-Dsg1 and anti-Dsg3 antibodies have been detected in serum from all the PNP patients by the above ELISA. On the other hand, serum from subcorneal pustular dermatosis type IgA pemphigus patients have been shown to react with Dsc1, another type of desmosomal cadherin, by a novel cDNA transfection method. In addition, IgA anti-Dsg1 and anti-Dsg3 antibodies have been detected in a few patients with IgA pemphigus by an ELISA for IgA antibodies. Various autoimmune bullous diseases, including several types of pemphigus, are the only diseases in which the pathogenic role of circulating autoantibodies has been confirmed using the newborn mouse animal model. Therefore, studies of the pathophysiology of pemphigus are extremely important as a paradigm for research into various types of autoimmune diseases in other fields.