Ultrastructural immunocytochemistry of autoimmune bullous diseases

Paraneoplastic Pemphigus and Autoimmune Blistering Diseases Associated with Neoplasm: Characteristics, Diagnosis, Associated Neoplasms, Proposed Pathogenesis, Treatment

Autoimmune paraneoplastic and neoplasm-associated skin syndromes are characterized by autoimmune-mediated cutaneous lesions in the presence of a neoplasm. The identification of these syndromes provides information about the underlying tumor, systemic symptoms, and debilitating complications. The recognition of these syndromes is particularly helpful in cases of skin lesions presenting as the first sign of the malignancy, and the underlying malignancy can be treated in a timely manner. Autoimmune paraneoplastic and neoplasm-associated bullous skin syndromes are characterized by blister formation due to an autoimmune response to components of the epidermis or basement membrane in the context of a neoplasm. The clinical manifestations, histopathology and immunopathology findings, target antigens, associated neoplasm, current diagnostic criteria, current understanding of pathogenesis, and treatment options for a selection of four diseases are reviewed. Paraneoplastic pemphigus manifests with clinically distinct painful mucosal erosions and polymorphic cutaneous lesions, and is often associated with lymphoproliferative neoplasm. In contrast, bullous pemphigoid associated with neoplasm presents with large tense subepidermal bullae of the skin, and mild mucosal involvement, but without unique clinical features. Mucous membrane pemphigoid associated with neoplasm is a disorder of chronic subepithelial blisters that evolve into erosions and ulcerations that heal with scarring, and involves stratified squamous mucosal surfaces. Linear IgA dermatosis associated with neoplasm is characterized by annularly grouped pruritic papules, vesicles, and bullae along the extensor surfaces of elbows, knees, and buttocks. Physicians should be aware that these autoimmune paraneoplastic and neoplasm-associated syndromes can manifest distinct or similar clinical features as compared with the non-neoplastic counterparts.

Immunohistochemical localization of basement membrane laminin 5 and collagen IV in adult linear IgA disease

BACKGROUND

Linear immunoglobulin A disease (LAD), also known as linear IgA bullous dermatosis, is an autoimmune disorder characterized by subepidermal bullae caused by IgA autoantibodies directed against several antigens located in the basement membrane zone of the skin. Laminin 5 (laminin-332) is considered a key component of the lamina lucida/lamina densa interface, which provides stable attachment of the epidermis to the dermis. Meanwhile, collagen IV is a major component of the lamina densa. Laminin 5 and collagen IV bind to the cell membrane and induce cytoskeletal rearrangements, which contribute to the basement membrane's final mat-like structure. The study aimed to evaluate the immunohistochemical staining of laminin 5 and collagen IV and to identify the site of blister formation in formalin-fixed, paraffin-embedded skin biopsies from adults with LAD.

METHODS

Skin biopsies from 20 adult patients with LAD were subjected to routine hematoxylin-eosin as well as immunohistochemical staining of collagen IV and laminin 5.

RESULTS

Linear staining was positive on the floor of the blister for laminin 5 in 65% and collagen IV in 90% of biopsies denoting that the site of separation in most cases of LAD is above the lamina densa.

CONCLUSIONS

The use of laminin 5 and collagen IV immunohistochemistry can be considered as an adjuvant diagnostic tool and may aid in the identification of the site of blister formation in routine skin biopsies in adults with LAD.

Reliability of the autoimmune bullous disease quality of life (ABQOL) questionnaire in the USA

PURPOSE

To evaluate the reliability of the autoimmune bullous diseases quality of life (ABQOL) questionnaire in a North American patient cohort.

METHODS

Patients attending the dermatology clinics of the University of Pennsylvania with a histological diagnosis of an autoimmune bullous disease (AIBD) and self-reported proficiency in English were recruited to participate in the study. Patients completed the ABQOL questionnaire at Day 0 and Day 3. Internal consistency was calculated through Cronbach's alpha. Test-retest reliability was determined by the intraclass correlation coefficient.

RESULTS

Of the 45 patients enrolled in the study, 39 patients (87 %) participated to completion. The mean age was 60.7 years with an equal sex distribution observed. Patients had a range of AIBD including pemphigus vulgaris, bullous pemphigoid, pemphigus foliaceus, epidermolysis bullosa acquisita, mucous membrane pemphigoid and linear IgA disease. Cronbach's alpha was calculated to be 0.90. The intraclass correlation coefficient was calculated to be 0.93 (95 % confidence interval 0.88-0.94).

CONCLUSION

The ABQOL was found to be reliable tested by internal consistency and test-retest reliability in an American patient cohort. It represents a promising disease-specific outcome measure for patients with AIBD.

Number III Mucous membrane pemphigoid

Mucous membrane pemphigoid (MMP) is a sub-epithelial vesiculobullous disorder. It is now quite evident that a number of sub-epithelial vesiculobullous disorders may produce similar clinical pictures, and also that a range of variants of MMP exist, with antibodies directed against various hemidesmosomal components or components of the epithelial basement membrane. The term immune-mediated sub-epithelial blistering diseases (IMSEBD) has therefore been used. Immunological differences may account for the significant differences in their clinical presentation and responses to therapy, but unfortunately data on this are few. The diagnosis and management of IMSEBD on clinical grounds alone is impossible and a full history, general, and oral examination, and biopsy with immunostaining are now invariably required, sometimes supplemented with other investigations. No single treatment regimen reliably controls all these disorders, and it is not known if the specific subsets of MMP will respond to different drugs. Currently, apart from improving oral hygiene, immunomodulatory-especially immunosuppressive-therapy is typically used to control oral lesions. The present paper reviews pemphigoid, describing the present understanding of this fascinating clinical phenotype, summarising the increasing number of subsets with sometimes-different natural histories and immunological features, and outlining current clinical practice.