Making sense of antigens and antibodies in pemphigus

Pemphigus group: overview, epidemiology, mortality, and comorbidities

Pemphigus forms a group of rare autoimmune bullous diseases that affect the skin and mucous membranes. This group has a chronic course leading to high morbidity and mortality. It is characterized by the production of pathogenic autoantibodies directed against different proteins of the desmosome, leading histologically to intraepidermal cleavage, and clinically to vesicles and erosions on the epithelium of the mucous membranes and/or the skin. The diagnosis of the subtype of pemphigus is based on clinical features, the level of histologic cleavage, and the identification of the antigens recognized by circulating autoantibodies by immunoserological analyses. The epidemiological features of pemphigus vary considerably in different regions of the world. Observational studies examining comorbidities and associations among patients with pemphigus are scarce and sometimes inconclusive. The prognosis, mortality, and clinical outcomes in pemphigus have undergone dramatic change throughout the years. This review provides a brief overview about the different subtypes of pemphigus: pemphigus vulgaris, pemphigus foliaceus, paraneoplastic pemphigus, pemphigus herpetiformis, and IgA pemphigus. In addition, it summarizes the most recent understanding of the epidemiology, mortality data, and comorbidities of this group of organ-specific autoimmune diseases.

Bullous diseases: Kids are not just little people

Bullous diseases may be rare; however, this does not preclude the clinician from being familiar with their manifestations and treatment. After ruling out infection, genetically inherited blistering diseases are more likely to be the cause of blistering or erosions in the neonatal period, whereas immunobullous diseases are more common in adults. Published literature on immunobullous disorders reflects information gleaned from case reports and open-label case series; prospective studies and evidence-based treatments are limited. Although there may be overlapping clinical features, significant clinical differences exist between adults and children. Evidence-based treatment guidelines are limited, and information from the adult literature cannot be readily generalized to the pediatric population. This paper reviews the approach to blistering conditions and the differences among bullous pemphigoid, linear immunoglobulin A disease, dermatitis herpetiformis, pemphigus foliaceus, pemphigus vulgaris, and paraneoplastic pemphigus in adult versus pediatric patients.

Paraneoplastic Pemphigus Associated with Pelvic Inflammatory Fibrosarcoma: A Case Report

A 36-year-old African-American woman presented with an extensive stomatitis and pigmented cutaneous macules on the neck, axillae and hands. Subsequently she developed violaceus papules on the dorsa of the hands, histologically consistent with an interface dermatitis. After 18 months of progressive disease, paraneoplastic pemphigus was suspected and a search for an underlying neoplasm was initiated. An exploratory laparotomy revealed a pelvic mass and the histologic examination showed an inflammatory fibrosarcoma. The evidence of acantholysis on new cutaneous lesions and the positivity of indirect immunofluorescence with rodent urinary bladder epithelium reinforced the diagnostic criteria for paraneoplastic pemphigus, which is confirmed by the identification of strong protein bands at 210, 190 and 170 kd by immunoprecipitation. Paraneoplastic pemphigus should be considered when investigating atypical mucocutaneous manifestations of pemphigus vulgaris and lichen planus. Diagnostic screening for paraneoplastic pemphigus and a search for an underlying tumor should be performed.

Pemphigus vulgaris in pregnancy: analysis of current data on the management and outcomes

OBJECTIVES

The occurrence of pemphigus vulgaris (PV) during pregnancy is rare. The purpose of this review was to describe management of PV in the mother, and report maternal and perinatal outcomes associated with the disease.

DATA SOURCES

A search of PubMed was conducted using the phrases "pemphigus and pregnancy" and "neonatal pemphigus." The bibliographies of retrieved articles were also searched for relevant reports. Only articles in English and in which the diagnosis of pemphigus had been made on the basis of histology or immunopathology were included.

TABULATION, INTEGRATION, AND RESULTS

In 38 reports, pregnancies from 49 women with PV were described. Among the 40 patients in whom clinical profiles were provided, 33 had active disease and 7 were disease free. Prednisone was used in 37 of 49 (75%) patients with doses ranging from 5 to 300 mg/day (mean 152.5 mg). Concomitant therapies included plasmapheresis, plasma exchange, and dapsone in 1 patient each, and azathioprine in 5. Of the 44 live births, 20 (45%) neonates had PV lesions at birth and 24 (55%) were lesion-free. Five stillbirths were reported. In all neonates, PV lesions resolved within 1 to 4 weeks, either spontaneously or with mild topical corticosteroids treatment. Of the 5 intrauterine deaths, 1 was due to umbilical cord prolapse, 1 attributed to placental dysfunction, and 1 to cytomegalovirus pneumonitis. In the remaining 2, the cause was unknown. One neonate died 2 days after delivery due to meconium aspiration syndrome. Thus the aggregate perinatal mortality rate was 12% (6/49).

CONCLUSIONS

The outcome of pregnancies complicated by pemphigus is generally good, but achieving good outcomes likely depends on the collaborative efforts of the dermatologist and obstetrician. The available data suggest that the rate of perinatal mortality is increased, but these data may be subject to publication bias.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this educational activity, the participant should be better able to describe appropriate medical therapies for pemphigus vulgaris complicating pregnancy, and plan the management of pregnancies complicated by pemphigus vulgaris.

Oesophageal involvement during attacks in pemphigus vulgaris patients

BACKGROUND

Pemphigus vulgaris (PV) is a rare autoimmune bullous skin disorder characterized by frequent involvement of the mucous membranes, usually beginning at the mouth.

AIMS

To investigate the oesophageal involvement in patients with PV and to explore the primary relationship of the disease with symptoms such as dysphagia, odynophagia and retrosternal burning.

METHODS

Oesophageal involvement was investigated by upper gastrointestinal endoscopy and biopsy during the early phase of the attacks in 26 patients with PV (12 men, 14 women, age range 24-63 years).

RESULTS

Histopathological examination and direct immunofluorescence of the oesophageal biopsy specimens revealed pemphigus involvement in 12 of 26 patients (46.15%).

CONCLUSION

The oesophagus is an important predilection zone for PV, thus care must be taken to detect these lesions at an early stage.

Oral and vulvar changes in pregnancy

The endocrinologic, immunological, and vascular changes that occur during pregnancy are far-reaching. These systemic factors produce profound local impact on the physiology and pathology of the oral cavity, vagina, and vulva. Physiological changes can be expected and tolerable or of such severity that they are viewed as pathological. Existing disease can be exacerbated and dermatoses specific to pregnancy can erupt. Each of these conditions can pose potentially challenging treatment considerations.

Neonatal pemphigus vulgaris in an infant born to a mother with pemphigus vulgaris in remission

Neonatal pemphigus vulgaris is a rare autoimmune disease that is caused by transplacental passage of pemphigus vulgaris autoantibodies. The association of maternal pemphigus vulgaris with neonatal disease pemphigus vulgaris has been only rarely reported. We describe an infant with pemphigus vulgaris born to a mother whose disease was in remission.

Paraneoplastic pemphigus: A brief update

First described in 1990, paraneoplastic pemphigus is an autoimmune condition that causes considerable morbidity, is resistant to therapy and is frequently fatal. Clinical heterogeneity is being recognized as more cases are reported and the documented auto-antigen profile is also increasing. Target antigens are now known to be not restricted to the skin, suggesting that this condition is part of a paraneoplastic autoimmune multiorgan syndrome.

Paraneoplastic pemphigus associated with uterine carcinoma

Paraneoplastic pemphigus (PNP) is an autoimmune blistering disease characterized by severe mucous membrane involvement, polymorphous skin eruptions, and underlying neoplasms, usually those of lymphoreticular system. Cases of PNP associated with solid cancer are extremely rare. A 46-year-old woman presented with severe stomatitis, pseudomembranous conjunctivitis, and polymorphous skin eruptions. Histologic, immunofluorescence, and immunoblot analyses confirmed the diagnosis of PNP. Whole-body examination revealed squamous cell carcinoma of the uterine cervix, but no hematologic tumors. Complete removal of the uterine tumor in addition to administration of betamethasone induced considerable improvement of cutaneous and mucous membrane lesions. To our knowledge, this is the first reported case of PNP associated with uterine carcinoma.

Neonatal pemphigus vulgaris: IgG4 autoantibodies to desmoglein 3 induce skin blisters in newborns

We report a case of neonatal pemphigus vulgaris presenting with skin lesions on the head, genital area, and right foot. Pemphigus vulgaris was diagnosed by the presence of circulating autoantibodies predominantly of the IgG4 subtype by indirect immunofluorescence microscopy and by enzyme-linked immunosorbent assay using recombinant desmoglein 3. This case demonstrates the pathogenic relevance of IgG4 autoantibodies to desmoglein 3 in the skin of neonates.

Unique role for the periplakin tail in intermediate filament association: specific binding to keratin 8 and vimentin

Plectin, desmoplakin, and the 230-kDa bullous pemphigoid antigen (BPAG1), members of the plakin family of proteins, are multifunctional cytolinkers, connecting the cytoskeletal structures to the cell adhesion complexes. Envoplakin and periplakin are components of the cornified envelope, but less is known about their role in tissues other than the stratified epithelium. Our tissue-wide survey utilizing RT-PCR revealed that periplakin, like plectin and desmoplakin, has a wide tissue distribution, but envoplakin expression is limited to certain tissues only, and BPAG1 is clearly specific for epidermal keratinocytes. Plectin, desmoplakin and BPAG1 are known to bind to the intermediate filaments through their C-terminal domains. The short C-terminal domain of periplakin is composed only of the linker domain, a region highly homologous between the plakin proteins. Here we demonstrate, through the use of yeast two-hybrid assay, a specific interaction of the periplakin linker domain with keratin 8 and vimentin. Co-expression of each plakin linker domain with keratin 8 revealed that periplakin and BPAG1 linkers co-localize with keratin signals in HaCaT cells, plectin and desmoplakin linkers were detected both in the nucleus and in cytoplasm together with the overexpressed keratin 8, while envoplakin linker localized independently into the nucleus. These results suggest that, in spite of its high homology and structural similarity with envoplakin, periplakin is functionally closer to the well-characterized plakin proteins plectin and desmoplakin, and thus may function tissue-wide as a scaffolding protein in intermediate filament assembly.

The molecular basis of hereditary palmoplantar keratodermas

In recent years, the gene defects causing many types of hereditary palmoplantar keratoderma have been discovered. These genes encode a variety of proteins involved in the terminal differentiation of keratinocytes and the formation of the cornified cell envelope. In this article, we review the molecular defects underlying various palmoplantar keratodermas with particular attention to the role of these molecules in the terminal differentiation of palmoplantar epidermis. Of the proteins involved in keratodermas, loricrin, keratins, and desmosomal proteins provide the protein structure of the cornified cell envelope. Connexins form intercellular gap junctions, which regulate ionic calcium signals necessary for the expression of the proteins that form the cornified cell envelope. Cathepsins likely mediate enzymatic processes necessary for the formation and dissolution of the cornified cell envelope. The clinical phenotypes produced by various mutations affecting these proteins are discussed vis-à-vis data from genetic, cellular, and molecular experiments.

Striated palmoplantar keratoderma of Brunauer-Fohs-Siemens

A 67-year-old African American man presented with callosities of his hands (which he had since adolescence) that were exacerbated by manual labor. His father suffered severe callosities of his feet, but no other family member was afflicted. Physical examination revealed symmetrically distributed linear hyperkeratotic plaques on the palms extending onto the full length of the volar aspect of his digits (Fig. 1). There was no personal or family history of hair, nail, or dental abnormalities. Histologic evaluation showed marked acanthosis, hypergranulosis, and hyperkeratosis of the lesions (Fig. 2). There was no evidence of epidermolytic hyperkeratosis.

Novel human alpha9 acetylcholine receptor regulating keratinocyte adhesion is targeted by Pemphigus vulgaris autoimmunity

Pemphigus vulgaris (PV) is a potentially fatal autoimmune mucocutaneous blistering disease. It was assumed that PV is caused by anti-desmoglein (Dsg) 3 autoimmunity because absorption of PV sera with a chimeric baculoprotein containing the Dsg 3 and IgG1 portions, rDsg3-Ig-His, eliminated disease-causing antibodies. In this study we demonstrate that rDsg3-Ig-His adsorbs out autoantibodies to different keratinocyte antigens, including a non-Dsg 3 130-kd polypeptide. Because the pool of disease-causing PV IgGs contains antibodies against the keratinocyte acetylcholine receptor (AChR), we sought to identify the targeted receptor(s). Preincubation of monkey esophagus with PV antibodies blocked specific staining of the keratinocyte cell membrane with rabbit monoepitopic antibody to alpha9 AChR, indicating that this first of its kind AChR with dual, muscarinic and nicotinic pharmacology is targeted by PV autoimmunity. Anti-alpha9 antibody stained keratinocytes in a fishnet-like intercellular pattern, and visualized a single band at approximately 50 kd in Western blots of keratinocyte membrane proteins. Using step-by-step reverse transcription polymerase chain reactions with primers based on known alpha9 sequence regions, we identified the complete reading frame of human alpha9. Its amino acid sequence showed 85% similarity with rat alpha9. Treatment of keratinocyte monolayers with anti-alpha9 antibody induced pemphigus-like acantholysis, which could be reversed either spontaneously or by using the cholinergic agonist carbachol. We conclude that alpha9 is coupled to physiological regulation of keratinocyte adhesion, and its interaction with PV IgG may lead to blister development.