A patient with both bullous pemphigoid and epidermolysis bullosa acquisita: an example of intermolecular epitope spreading

Pityriasis lichenoides acuta (PLEVA) pemphigoides: A rare bullous variant of PLEVA

Although the clinical presentations of patients with pityriasis lichenoides et varioliformis acuta (PLEVA) may vary, bullae are not usually part of the clinical spectrum. To date, only two other cases of a bullous variant of PLEVA with evidence of autoantibodies against hemidesmosomal antigens have been reported. The term PLEVA pemphigoides was suggested for this unique clinical, pathological and serological combination of both PLEVA and bullous pemphigoid.

Brunsting-Perry Type Pemphigoid Causing Secondary Cicatricial Alopecia in 2 Patients

Brunsting-Perry type pemphigoid (BPP) is a rare subepidermal blistering disease and a cause of secondary cicatricial alopecia. It was originally described by Brunsting and Perry in 1957 as a rare variant of cicatricial pemphigoid, characterized by bullous lesions limited to the head, neck, scalp, and upper trunk with mild or no mucosal involvement. We report 2 cases of BPP cicatricial alopecia with histopathology of subepidermal blister formation, different clinical presentation, and different salt-split test results. One patient had features of bullous pemphigoid (BP) with important oral mucosal involvement (not yet reported in the literature), and the second patient had typical features of epidermolysis bullosa acquisita (EBA). The secondary cicatricial alopecia may be due to different antigens associated with either BP or EBA. The phenomenon of epitope spreading could explain the association between 2 distinctive bullous diseases in the same patient, justifying the divergent findings of the immunofluorescence. The specific target antigen of BPP is yet to be defined.

International Bullous Diseases Group: consensus on diagnostic criteria for epidermolysis bullosa acquisita

BACKGROUND

Epidermolysis bullosa acquisita (EBA) is a complex autoimmune bullous disease disease with variable clinical presentations and multiple possible diagnostic tests, making an international consensus on the diagnosis of EBA essential.

OBJECTIVES

To obtain an international consensus on the clinical and diagnostic criteria for EBA.

METHODS

The International Bullous Diseases Group (IBDG) met three times to discuss the clinical and diagnostic criteria for EBA. For the final voting exercise, 22 experts from 14 different countries voted on 50 different items. When > 30% disagreed with a proposal, a discussion was held and re-voting carried out.

RESULTS

In total, 48 of 50 proposals achieved consensus after discussion. This included nine diagnostic criteria, which are summarized in a flow chart. The IBDG was unable to determine one procedure that would be applicable worldwide. A limitation of the study is that differential diagnosis of bullous systemic lupus erythematosus has not been addressed.

CONCLUSIONS

This first international consensus conference established generally agreed-upon clinical and laboratory criteria defining the clinical classification of and diagnostic testing for EBA. Holding these voting exercises in person with the possibility of discussion prior to voting has advantages in reaching consensus over Delphi exercises with remote voting.

Clinical and immunological studies for 105 Japanese seropositive patients of epidermolysis bullosa acquisita examined at Kurume University

OBJECTIVES

Using our serological diagnostic criteria, we selected 105 Japanese patients with epidermolysis bullosa acquisita (EBA), an autoimmune bullous disease (AIBD) reacting with type VII collagen, from our cohort of 5063 AIBD patients.

METHODS

We examined the patients clinically and immunologically.

RESULTS

We found diversity of clinical manifestations in both cutaneous and oral mucosal lesions and a high rate of inflammatory-type EBA patients in Japan. Common treatments were systemic steroids, followed by immunosuppressives, DDS, tetracycline/minocycline and colchicine. Immunological studies revealed that indirect immunofluorescence of 1M-NaCl-split skin, immunoblotting of dermal extract, and type VII collagen ELISA were sensitive methods, with possible multiplicity of circulating autoantibodies against other basement membrane autoantigens.

CONCLUSION

The present study analyzed the largest cohort of EBA patients, confirming the scarcity of EBA (only 105 of the 5063 AIBD patients), and showed that the three serological tests are useful for the diagnosis of EBA.

Pseudopemphigoid as caused by topical drugs and pemphigus disease

Pseudopemphigoid can cause a chronic cicatricial conjunctivitis that is clinically identical to the manifestations seen in mucous membrane pemphigoid, a disorder with a common clinical phenotype and multiple autoimmune links. For the purpose of this review, we will describe pseudopemphigoid as caused by topical drugs, the most common etiology with ocular manifestations, and as caused by the pemphigus disease, a more rare etiology. Specifically, we will discuss the ophthalmological features of drug-induced cicatricial conjunctivitis, pemphigus vulgaris, and paraneoplastic pemphigus. Other etiologies of pseudopemphigoid exist that will not be described in this review including autoimmune or inflammatory conditions such as lichen planus, sarcoidosis, granulomatosis with polyangiitis (Wegener’s granulomatosis), erythema multiforme (minor, major, and Stevens-Johnson syndrome), bullous pemphigoid, skin-dominated linear IgA bullous dermatosis, and skin-dominated epidermolysis bullosa acquisita. Prompt diagnosis of the underlying etiology in pseudopemphigoid is paramount to the patient’s outcome as certain diseases are associated with a more severe clinical course, increased ocular involvement, and differential response to treatment. A complete history and ocular examination may find early cicatricial changes in the conjunctiva that are important to note and evaluate to avoid progression to more severe disease manifestations. When such cicatricial changes are noted, proper diagnostic techniques are needed to help elucidate a diagnosis. Lastly, collaboration between ophthalmologists and subspecialists such as dermatologists, pathologists, immunologists, and others involved in the care of the patient is needed to ensure optimal management of disease.

B cell epitope spreading: mechanisms and contribution to autoimmune diseases

While a variety of factors act to trigger or initiate autoimmune diseases, the process of epitope spreading is an important contributor in their development. Epitope spreading is a diversification of the epitopes recognized by the immune system. This process happens to both T and B cells, with this review focusing on B cells. Such spreading can progress among multiple epitopes on a single antigen, or from one antigenic molecule to another. Systemic lupus erythematosus, multiple sclerosis, pemphigus, bullous pemphigoid and other autoimmune diseases, are all influenced by intermolecular and intramolecular B cell epitope spreading. Endocytic processing, antigen presentation, and somatic hypermutation act as molecular mechanisms that assist in driving epitope spreading and broadening the immune response in autoimmune diseases. The purpose of this review is to summarize our current understanding of B cell epitope spreading with regard to autoimmunity, how it contributes during the progression of various autoimmune diseases, and treatment options available.

A case of pemphigoid gestationis with concurrent IgG antibodies to BP180, BP230 and type VII collagen

A 22-year-old primigravida had a pruritic, erythematous, bullous eruption on the skin during the 26th week of gestation. After delivery the eruption flared up. The diagnosis of pemphigoid gestationis was confirmed based on histopathological and immunofluorescence findings. The result of immunoblotting showed IgG autoantibodies which reacted against BP230 in epidermal extracts and 290 kDa type VII collagen in dermal extracts. The BP180 antibodies were also detected by an enzyme-linked immunosorbent assay BP180NC16a diagnosis kit. Pulsed corticosteroid and cyclophosphamide resulted in a favourable response at the acute stage. The patient was cured in 2 years. The analysis of the patient's autoantibodies provides strong evidence for the involvement of epitope spreading in her autoimmune disease.

Missing the target: characterization of bullous pemphigoid patients who are negative using the BP180 enzyme-linked immunosorbant assay

BACKGROUND

Bullous pemphigoid (BP) is an autoimmune blistering disease characterized by autoantibodies specific for the 180-kd BP antigen-2 (BP180) (also termed "type XVII collagen") protein. The BP180 enzyme-linked immunosorbent assay (ELISA) is specific for the immunodominant NC16A domain of the protein. However, we and others have observed patients whose reactivity to BP180 is exclusive of the NC16A domain (referred to henceforth as non-NC16A BP).

OBJECTIVE

We sought to determine the incidence of non-NC16A BP and identify regions of reactivity within the BP180 protein.

METHODS

Sera from 51 patients who met the clinical and histologic criteria for BP were screened for NC16A reactivity by ELISA. Sera that were negative by ELISA were screened for IgG reactivity to an epidermal extract, recombinant BP180 protein, and subregions of BP180, by immunoblot. Demographic and clinical data were also collected on all patients.

RESULTS

Four sera (7.8%) were negative using the BP180 ELISA but positive for IgG reactivity to the extracellular domain of BP180. Further mapping identified 4 regions outside of NC16A recognized by these sera: amino acid (AA) 1280 to 1315, AA 1080 to 1107, AA 1331 to 1404, and AA 1365 to 1413. One of these sera also had IgE specific for NC16A. One patient had an atypical presentation with lesions limited to the lower aspect of the legs and scarring of the nail beds.

LIMITATIONS

The small total number of patients with non-NC16A BP limits the identification of demographic or clinical correlates.

CONCLUSION

It is significant that 7.8% of sera from patients with new BP react to regions of BP180 exclusively outside of NC16A and, thus, would not be identified using the currently available BP180 ELISA.

Untethering the nuclear envelope and cytoskeleton: biologically distinct dystonias arising from a common cellular dysfunction

Most cases of early onset DYT1 dystonia in humans are caused by a GAG deletion in the TOR1A gene leading to loss of a glutamic acid (ΔE) in the torsinA protein, which underlies a movement disorder associated with neuronal dysfunction without apparent neurodegeneration. Mutation/deletion of the gene (Dst) encoding dystonin in mice results in a dystonic movement disorder termed dystonia musculorum, which resembles aspects of dystonia in humans. While torsinA and dystonin proteins do not share modular domain architecture, they participate in a similar function by modulating a structural link between the nuclear envelope and the cytoskeleton in neuronal cells. We suggest that through a shared interaction with the nuclear envelope protein nesprin-3α, torsinA and the neuronal dystonin-a2 isoform comprise a bridge complex between the outer nuclear membrane and the cytoskeleton, which is critical for some aspects of neuronal development and function. Elucidation of the overlapping roles of torsinA and dystonin-a2 in nuclear/endoplasmic reticulum dynamics should provide insights into the cellular mechanisms underlying the dystonic phenotype.

Bullous pemphigoid in a patient with suspected non-Herlitz junctional epidermolysis bullosa

A 56-year-old man with lifelong trauma-induced blisters, nail dystrophy and dental enamel hypoplasia presented with a new spontaneous blistering eruption. Clinicopathologically, he had evidence of both an inherited and an acquired blistering disorder: non-Herlitz junctional epidermolysis bullosa (nHJEB) and bullous pemphigoid (BP). HIstological examination of a skin biopsy found reduced (but not absent) collagen XVII in nonlesional skin, in vivo bound anticollagen XVII antibodies in perilesional skin, and prominent eosinophils in perilesional and lesional skin, with subepidermal blistering. Circulating anticollagen XVII antibodies were also present. Treatment with oral corticosteroids and mycophenolate mofetil led to clinical control of the BP but had no effect on the mechanobullous blistering. Our patient is unusual in that his skin retains some labelling for collagen XVII rather than having the complete absence of immunoreactivity expected in patients with generalized nHJEB. Moreover, we were unable to identify any pathogenic mutations in the COL17A1 gene encoding collagen XVII (or in other EB-associated basement membrane genes). It is plausible that the long-term consequences of basement membrane disruption in our patient, perhaps associated with atypical inherited COL17A1 pathology, might result in a conformationally altered and more immunogenic protein with the subsequent development of anticollagen XVII antibodies and BP as a secondary pathology.

A case of epidermolysis bullosa acquisita with clinical features of Brunsting-Perry pemphigoid showing an excellent response to colchicine

BACKGROUND

Brunsting-Perry pemphigoid is a rare subepidermal blistering disease characterized by scarring blisters on the head and neck. However, the identity of the responsible autoantigens is still unresolved.

METHODS

We reported a patient with epidermolysis bullosa acquisita who had clinical features typical of Brunsting-Perry pemphigoid and investigated the involved type VII collagen epitopes. The patient was a 65-year-old Japanese woman with a 20-month history of recurrent subepidermal bullae on her head, face, and neck.

RESULTS

Immunoblot studies revealed that the serum of this patient reacted with type VII collagen, specifically with the noncollagenous domain 1 and the triple-helical domain. The patient responded completely to colchicine monotherapy.

LIMITATIONS

This study was performed on only one case.

CONCLUSION

This study suggests that Brunsting-Perry pemphigoid may be a clinical variant of epidermolysis bullosa acquisita.

Inflammatory epidermolysis bullosa acquisita mimicking toxic epidermal necrolysis and dermatitis herpetiformis

We report a patient with a spectrum of clinical features simulating toxic epidermal necrolysis, bullous erythema multiforme and later, dermatitis herpetiformis (DH). The histological features were suggestive of DH, bullous pemphigoid (BP) and epidermolysis bullosa acquisita (EBA). Direct immunofluorescence results suggested BP or EBA. Indirect immunofluorescence on salt-split skin and immunoblotting analysis on normal human dermal extracts gave results that were diagnostic for EBA.

FLT3 inhibitors for the treatment of autoimmune disease

BACKGROUND

Autoimmune diseases encompass a broad range of illnesses with a variety of underlying causes, some of which are known and some of which remain elusive.

OBJECTIVE

The focus of this review will be on describing the development of a new type of therapy that could potentially treat T cell-mediated autoimmune diseases. Unlike traditional therapies, which have primarily focused on suppressing T cells directly, targeting the step of antigen presentation may allow a less toxic therapy in which autoimmunity is lessened without compromising the entire immune system. This review will outline the science behind the development of the therapy, the roles of dendritic cells in generating autoimmune disease, and the function of the FLT3 receptor in this process.

Epidermolysis Bullosa Acquisita following Bullous Pemphigoid, Successfully Treated with the Anti-CD20 Monoclonal Antibody Rituximab

Epidermolysis bullosa acquisita is a rare autoimmune subepidermal blistering disease, often resisting current treatments, especially systemic corticosteroids. We report a patient having a bullous pemphigoid who relapsed with clinical and immunological features of inflammatory epidermolysis bullosa acquisita. An anti-CD20 monoclonal antibody (rituximab) was proposed because of resistance to high-dose steroids and other immunosuppressive agents. The disease dramatically improved within a few weeks following rituximab infusion allowing the decrease in steroid therapy. Our case illustrates also the possible evolution from bullous pemphigoid to epidermolysis bullosa acquisita that should be suspected when clinical atypia occurs or in case of corticosteroid resistance.

Spreading of antibody reactivity to non-thyroid antigens during experimental immunization with human thyroglobulin

Intermolecular spreading of antibody reactivity has been implicated in the evolution of autoimmune disease. In this study, spreading of antibody reactivity to non-thyroid autoantigens after experimental immunization with thyroglobulin (Tg) was investigated. For this purpose, two rabbits were injected with human Tg six times (stages 1-6) every 3 weeks. Animals were also bled before priming. Antisera were tested by enzyme-linked immunosorbent assay (ELISA) for reactivity to several non-thyroid antigens: bovine serum albumin (BSA), native DNA (nDNA), human myosin, human globular (G) and filamentous (F) actin and porcine tubulin. Tg-immunized animals developed the following serological reactivity pattern: (a) high reactivity to myosin from stage 2 onward, (b) significant reactivity to F-actin, remaining high up to stage 6, (c) reactivity to BSA with a peak at stage 3, (d) a small increase of reactivity to G-actin at stage 3 and (e) no increase of reactivity to nDNA and tubulin. The study of affinity-purified anti-Tg antibodies and the use of competitive assays revealed that reactivity to F-actin was not due to cross-reaction with Tg. On the contrary, reactivity to myosin during the first stages of immunization was due to cross-reaction with Tg, while at stage 6 it became myosin-specific. Reactivity to BSA at stage 3 was also due to cross-reaction with Tg. We conclude that at least part of the induced anti-Tg antibodies may result from the expansion of B cell clones producing polyreactive natural autoantibodies, and polyreactivity of anti-Tg antibodies during the first stages of Tg-immunization may be responsible for the intermolecular spreading of antibody response.

Corrélation entre présence d’anticorps anti-antigène de type 2 de la pemphigoïde et démence chez les sujets âgés sans manifestation clinique de pemphigoïde

BACKGROUND

Pemphigoid is a form of auto-immune bullous dermatosis characterised by the production of antibodies directed against components of hemidesmosomes in the basal membrane. The physiopathological process responsible for unmasking of these antigens is unknown. Pemphigoid is more common in elderly subjects and is most often seen in debilitated subjects. The prevalence of pemphigoid anti-pemphigoid antibodies (anti-PB) is not known in the elderly population presenting no dermatological signs evocative of the disease. We studied the prevalence of anti-PBAg2 antibodies in elderly subjects with no signs of pemphigoid as well as in the correlation between the presence of these antibodies and diagnosis of dementia.

PATIENTS AND METHODS

Elderly subjects (aged over 69 years) with no signs of pemphigoid were recruited consecutively in dermatology and geriatrics departments (138 subjects). Details of concomitant medication were recorded for all subjects and clinical examination was performed with calculation of MMS (Mini Mental Score). The subjects were then divided into two groups based on MMS score. The first group comprised subjects without dementia (MMS > 24) while the second comprised subjects with dementia. Serum anti-PBAg2 antibodies were determined by ELISA and indirect immunofluorescence with confirmation by Western blot. Antinuclear antibodies, used as a control for non-specific immune response, were assayed in all serum samples. The prevalence of these antibodies was compared between the two groups.

RESULTS

The two groups were comparable in terms of age, sex and presence of dermatological diseases (ulcers, bedsores, erysipelas). Each group comprised 69 subjects. The overall presence of anti-PBAg2 antibodies in subjects with no signs are suggestive of pemphigoid was 3.6%. Presence of anti-PBAg2 antibodies was associated with diagnosis of dementia (p=0.04; 0% and 7% in groups 1 and 2, respectively). No correlation was seen between the presence of anti-PBAg2 antibodies and concomitant medication or dermatological disease. The overall prevalence of antinuclear antibodies was 14.5% and the figure was similar between the two groups.

DISCUSSION

The presence of anti-PBAg2 could be associated with the diagnosis of dementia in elderly subjects.