History, Diagnosis, Pathogenesis, and Nomenclature in Sublamina Densa-Type Linear IgA Disease

An unusual case of linear IgA disease affecting only the oral gingiva: a case report

BACKGROUND

We present a case report on desquamative gingivitis diagnosed as linear IgA disease (LAD), which is a rare autoimmune bullous disease exclusively affecting the oral gingiva. The oral mucosa can be impacted by various autoimmune bullous diseases, and our report focuses on this particular manifestation of LAD.

CASE PRESENTATION

This patient presented with atypical symptoms, as frequent blister formation on the gingiva was the primary clinical manifestation. A combination of systemic and local treatment was administered to the patient. Following the treatment, there was a significant improvement observed in both the erythema and the bullous lesions on the gingiva.

CONCLUSIONS

A more suitable local treatment strategy should be formulated for patients presenting with oral topical lesions, which clinicians can employ effectively.

Classification and Antigen Molecules of Autoimmune Bullous Diseases

Autoimmune bullous diseases (AIBDs), which are a group of tissue-specific autoimmune diseases of the skin, present with various blistering lesions on the skin and mucous membranes, and show autoantibodies of IgG, IgA and IgM against epidermal cell surfaces and basement membrane zone. To date, AIBDs have been classified into a number of distinct subtypes by clinical and histopathological findings, and immunological characteristics. In addition, various biochemical and molecular biological studies have identified various novel autoantigens in AIBDs, which has resulted in proposals of new subtypes of AIBDs. In this article, we summarized various distinct AIBDs, and proposed the latest and most comprehensive classification of AIBDs with their autoantigen molecules.

A Case of Lamina Lucida-Type Linear IgA Disease Complicated by Colon Polyposis and Rectal Adenocarcinoma

Linear IgA disease (LAD) is a rare autoimmune bullous disease characterized by IgA deposition in the basement membrane zone (BMZ). A 66-year-old male was treated for myelodysplastic syndrome at our hospital for 5 years, during which his condition remained stable. He visited our department because of erythema with itching, which appeared 1 year ago and gradually exacerbated with the development of blisters and erosions. During the first visit, multiple erythemas with erosions and crusts on their periphery were observed on the trunk and lower limbs. Histopathological examination revealed subepidermal blisters with inflammatory cell infiltration, mainly constituting of neutrophils, eosinophils, and lymphocytes. Direct and indirect immunofluorescence showed linear IgA deposits in the BMZ and IgA anti-BMZ antibodies, respectively, while immunoblotting using a concentrated culture supernatant of HaCaT cells detected IgA antibodies reactive to 120-kDa LAD-1. Accordingly, the patient was diagnosed with lamina lucida-type LAD. Subsequent colonoscopy revealed multiple colorectal polyps and rectal adenocarcinoma (Tis, N0, and M0). Multigene panel test showed an ATM variant of unknown significance but did not detect any pathogenic variants associated with intestinal polyposis syndrome. The skin lesions quickly resolved with oral diaphenylsulfone 50 mg/day and resection of the colorectal polyps and adenocarcinoma. To our knowledge, this is the first reported case of LAD associated with multiple colorectal polyps and rectal adenocarcinoma. Additionally, we also analyzed reported cases of LAD associated with malignancy from the literature.

Diagnostics for Dermatologic Diseases with Autoantibodies

Background

Dermatologic diseases with autoantibodies were recognized early as autoimmunity became accepted as a pathogenic immunologic concept. Laboratory testing to identify disease-defining autoantibodies and investigate their role in pathophysiology has evolved since.

Content

Blistering dermatologic diseases, profiled by autoantibody production, target epithelial components critical in cell–cell and cell–matrix adhesion, resulting in epithelial separation and other characteristic features of the disorders. This review covers the clinical indications for dermatologic disease-related autoantibody testing, the specifics of procuring specimens to test, the available diagnostic tests, and information provided by the testing. Atypical, uncharacteristic, and less well-known clinical and autoantibody profiles as well as several of the many future prospects for expansion of the testing applications are elaborated on in the online Data Supplement.

Summary

Autoantibody-associated dermatologic diseases are acquired immunologic disorders that have considerable clinical implications affecting essential barrier functions of skin and mucous membranes and causing discomfort, including pain and pruritus. Certain of the diseases can have life-threatening manifestations, and treatments can have significant side-effects. The skin diseases may presage other clinical associations that are important to recognize and treat. Laboratory testing aids in the diagnosis of these diseases through identification of the autoantibodies and is essential for prompt and precise knowledge of the disease type for prognosis, further clinical evaluations, and treatment decisions.

Updates in the Diagnosis and Management of Linear IgA Disease: A Systematic Review

Background and Objectives: Linear IgA disease (LAD) is a rare autoimmune blistering disease with linear IgA deposits along the basement membrane zone. Direct immunofluorescence remains the gold standard for diagnosis, but other diagnostic measures reported in recent literature have proven useful in the setting of inconclusive preliminary results. Dapsone is a commonly used treatment, but many therapeutic agents have emerged in recent years. The objective of this study is to provide a comprehensive overview of updates on the diagnosis and management of LAD. Materials and Methods: A literature search was conducted from May to June of 2021 for articles published in the last 5 years that were related to the diagnosis and management of LAD. Results: False-negative results in cases of drug-induced LAD and the presence of IgG and IgM antibodies on immunofluorescence studies were reported. Serration pattern analysis has been reported to be useful in distinguishing LAD from sublamina densa-type LAD. Rituximab, omalizumab, etanercept, IVIg, sulfonamides, topical corticosteroids, and others have been used successfully in adult and pediatric patients with varying disease severity. Topical corticosteroids were preferred for pediatric patients while rituximab and IVIg were used in adults with recalcitrant LAD. Sulfonamides were utilized in places without access to dapsone. Conclusion: In cases where preliminary biopsy results are negative and clinical suspicion is high, repeat biopsy and additional diagnostic studies should be used. Patient factors such as age, medical comorbidities, and disease severity play a role in therapeutic selection.