Linear IgA bullous dermatosis of childhood (chronic bullous dermatosis of childhood)

Antagonizing FcαR1 (CD89) as treatment in IgA-mediated chronic inflammation and autoimmunity

Introduction

Immunoglobulin A (IgA) is mostly considered as a non-inflammatory regulator at mucosal areas. However, previous work of our group showed that IgA can also be involved in disease pathology, because it provides a potent stimulus to activate neutrophils after crosslinking of surface CD89 (FcaRI), resulting in chronic inflammation and tissue damage. IgA (auto)antibodies and neutrophils are key players in various diseases, including blistering skin diseases and rheumatoid arthritis. Therefore, we generated an array of anti-CD89 monoclonal antibodies (mAbs) for therapeutic targeting of CD89. The biological activity of newly developed anti-human CD89 mAbs and their potential therapeutic capacity were investigated.

Methods

Human neutrophils were isolated from heparinized healthy donor blood. The ability of anti-CD89 mAbs to bind human neutrophils was investigated by flow cytometry. Furthermore, the capacity of these anti-CD89 mAbs to inhibit IgA-mediated phagocytosis, neutrophil extracellular trap (NET) release and migration was studied. To this end, neutrophils were pre-incubated with/without anti-CD89 mAbs after which they were stimulated with IgA-coated beads. The amount of phagocytosed beads, NET release and migrated neutrophils were subsequently analysed. In parallel, chemoattractant leukotriene B4 and lactoferrin (as a measure for degranulation) release were determined. Finally, the therapeutic potential of our prototypic anti-CD89 mAb clone 10E7 was in vivo tested in anti-mouse collagen XVII human IgA-treated transgenic CD89 mice, a preclinical model for autoimmune linear IgA bullous disease (LABD).

Results

Our results show that all generated anti-CD89 mAbs bound surface CD89 on neutrophils. Although these anti-CD89 mAbs bind to different epitopes on EC1 of CD89, they all have the capacity to inhibit IgA-mediated phagocytosis, neutrophil extracellular trap (NET) release and neutrophil migration. Moreover, IgA mediated leukotriene B4 and lactoferrin release are decreased in supernatant from anti-CD89 mAbs-treated neutrophils. Finally, anti-CD89 mAb clone 10E7, that was selected based on its selective binding profile on tissue micro arrays, reduced anti-mouse collagen XVII hIgA-induced neutrophil influx in an in vivo linear IgA bullous disease (LABD) mice model.

Conclusion

This study clearly indicates that our newly developed anti-CD89 mAbs inhibited IgA-induced neutrophil activation and reduced anti-autoantigen IgA-induced neutrophil influx in vivo, supporting further clinical development for the treatment of LABD.

Linear Immunoglobulin a Bullous Dermatosis in Children

Linear Immunoglobulin A Bullous Disease (LABD) is a rare dermatosis whose pathomechanisms are not yet completely understood. LABD has different features characterizing adults and children in terms of potential triggers, clinical manifestations, and prognosis. The aim of the present study is to review all neonatal and pediatric cases of LABD and summarize the major characteristics. Childhood LABD is mainly idiopathic with a benign prognosis. Neonatal cases are difficult to differentiate from infectious diseases and usually have a poor prognosis. Drugs are one of the possible triggers that can activate autoimmune responses through antigen mimicry and epitope spreading as well as different stimuli (e.g., infections, inflammatory diseases, trauma). The gold standard for the diagnosis is based on direct immunofluorescence. Prognosis is generally favorable but often depends on the prompt dermatological diagnosis, treatment and follow-up guaranteed by a multidisciplinary team, including pediatricians for this group of age.

A 62-year-old man with new-onset bullae

Cutaneous blisters and/or bullae can occur in autoimmune disorders, infections, genetic diseases, and drug hypersensitivity. We present the case of a 62-year-old man with two autoimmune conditions who was admitted for antibiotic treatment of a lower extremity infection and suddenly developed a bullous rash. His physical examination was significant for tense, bullous lesions that involved his chin, palms, and inner thighs. Narrowing the differential diagnosis for patients with blistering skin lesions is imperative for timely and appropriate management.

Bullous Diseases in Children: A Review of Clinical Features and Treatment Options

Bullous diseases are uncommon in children; however, as they have the potential to affect quality of life, occasionally have long-term side effects in the setting of scarring processes, and carry a rare risk of underlying malignancy [e.g., with paraneoplastic pemphigus (PNP)], knowledge of their clinical presentation and treatment options is essential. Given the rarity of these conditions, our current state of knowledge is largely derived from case reports and case series, with a paucity of evidence-based recommendations. In this review, we discuss the clinical presentation of and treatment options for linear immunoglobulin A disease, dermatitis herpetiformis, pemphigus vulgaris, pemphigus foliaceus, PNP, bullous pemphigoid, mucus membrane pemphigoid, epidermolysis bullosa acquisita, and inherited epidermolysis bullosa. In general, when these conditions, except for PNP, occur in childhood, they have a better prognosis than when they occur in adults. Clinical, histopathological, and immunologic features frequently overlap, but distinct differences have also been reported, most commonly in clinical presentation. Treatment is often similar to that in adults, although specific considerations are necessary for a pediatric population.

Linear IgA bullous dermatosis in adults and children: a clinical and immunopathological study of 38 patients

BACKGROUND

Linear IgA bullous dermatosis (LABD) is a rare autoimmune subepithelial vesiculobullous disease due to IgA autoantibodies directed against different antigens of the basement membrane zone (BMZ) of the skin and/or mucosae. It affects mainly preschool-aged children and adults, with only few studies on large series. The aim of this study was to assess possible differences between adults and children regarding clinical presentation, immunopathologic features, management and course of the disease.

METHODS

A retrospective review of 38 LABD patients, followed-up from November 2006 to September 2018, was performed.

RESULTS

Of 38 patients, 27 were adults and 11 children. Mean age at diagnosis was 5.4 years and 60.6 years in the pediatric and adult group, respectively. Considering both groups, limbs were the most commonly involved site (73.7%), followed by trunk (55.3%), head (36.8%) and buttocks (13.2%). Interestingly, head (p = 0.008), particularly perioral (p = 0.001), involvement, as well as "string of pearls" arrangement (p = 0.03), were more prevalent in children. Mucosal involvement was seen in 9 (23.7%) patients and was more frequent in children than adults (45.5% vs 14.8%, respectively, p = 0.09). Linear IgA deposits along the BMZ were observed in 30 patients (78.9%), while linear/granular IgA deposits in 8 patients (21.1%). Dapsone was the most commonly used drug (78.9%) and complete remission was achieved in most cases (81.6%).

CONCLUSIONS

Our epidemiological and clinicopathological findings relative to a large cohort of LABD patients are mostly consistent with the literature data. Interestingly, head, notably perioral, involvement and "string of pearls" arrangement occurred more frequently in the paediatric than adult group. The above clinical parameters may be regarded as diagnostic tools for LABD in children.

Ocular Manifestations and Management of Autoimmune Bullous Diseases

Autoimmune bullous diseases with ocular involvement consist of a group of systemic entities that are characterized by formation of autoantibodies against the proteins of the epithelial basement membrane zone of the conjunctiva. Mostly, the elderly are affected by these diseases. The characteristic patterns of mucocutaneous involvement and the specific tissue components targeted by these autoantibodies are differentiating features of these diseases. Ocular pemphigus vulgaris exhibits intraepithelial activity, whereas the autoimmune activity in linear immunoglobulin A disease, mucous membrane pemphigoid, and epidermolysis bullosa acquisita occurs at a subepithelial location. Given the increased risk for blindness with delays in diagnosis and management, early detection of ocular manifestations in these diseases is vital. The precise diagnosis of these autoimmune blistering diseases, which is essential for proper treatment, is based on clinical, histological, and immunological evaluation. Management usually includes anti-inflammatory and immunosuppressive medications. Inappropriate treatment results in high morbidity and even potential mortality.

Linear IgA bullous dermatosis

Aim: to present a clinical case of linear IgA bullous dermatosis.Materials and methods. A 44 years old patient complaining of skin rashes on the trunk and extremities, accompanied by severe itching was examined. We carried out a morphological investigation of biopsy samples derived from the lesion and apparently unaffected skin areas using the method of indirect immunofluorescence.Results. The patient having rashes in the form of multiple vesicles and small bubbles with a tight cover, which had been grouped into figures resembling pearl necklaces, demonstrated the presence of focal subepidermal cracks (subepidermal bubble in one location), as well as a linear deposition of IgA along the epidermal basement membrane. According to the clinical picture and following the histological and immunofluorescent investigation of skin biopsies, the patient was diagnosed with linear IgA bullous dermatosis. Lesion regression was achieved as a result of systemic therapy with prednisolone at a dose of 50 mg per day.Conclusion. The diagnosis of linear IgA bullous dermatosis should be made on the basis of skin biopsy investigation by the method of indirect immunofluorescence. Systemic glucocorticosteroids are seen as an effective approach to the treatment of such patients.

Idiopathic linear IgA bullous dermatosis: prognostic factors based on a case series of 72 adults

BACKGROUND

Linear IgA bullous dermatosis (LABD) is a clinically and immunologically heterogeneous, subepidermal, autoimmune bullous disease (AIBD), for which the long-term evolution is poorly described.

OBJECTIVES

To investigate the clinical and immunological characteristics, follow-up and prognostic factors of adult idiopathic LABD.

METHODS

This retrospective study, conducted in our AIBD referral centre, included adults, diagnosed between 1995 and 2012, with idiopathic LABD, defined as pure or predominant IgA deposits by direct immunofluorescence. Clinical, histological and immunological findings were collected from charts. Standard histology was systematically reviewed, and indirect immunofluorescence (IIF) on salt-split skin (SSS) and immunoblots (IBs) on amniotic membrane extracts using anti-IgA secondary antibodies were performed, when biopsies and sera obtained at diagnosis were available. Prognostic factors for complete remission (CR) were identified using univariate and multivariate analyses.

RESULTS

Of the 72 patients included (median age 54 years), 60% had mucous membrane (MM) involvement. IgA IIF on SSS was positive for 21 of 35 patients tested; 15 had epidermal and dermal labellings. Immunoelectron microscopy performed on the biopsies of 31 patients labelled lamina lucida (LL) (26%), lamina densa (23%), anchoring-fibril zone (AFz) (19%) and LL+AFz (23%). Of the 34 IgA IBs, 22 were positive, mostly for LAD-1/LABD97 (44%) and full-length BP180 (33%). The median follow-up was 39 months. Overall, 24 patients (36%) achieved sustained CR, 19 (29%) relapsed and 35% had chronic disease. CR was significantly associated with age > 70 years or no MM involvement. No prognostic immunological factor was identified.

CONCLUSIONS

Patients with LABD who are < 70 years old and have MM involvement are at risk for chronic evolution.

Diaminodiphenyl Sulfone-Induced Hemolytic Anemia and Alopecia in a Case of Linear IgA Bullous Dermatosis

Linear immunoglobulin A (IgA) bullous dermatosis (LABD) is an autoimmune mucocutaneous disease characterized by subepidermal blistering induced by IgA autoantibodies against several autoantigens in the basal membranous zone of the skin and mucosal tissue. Although diaminodiphenyl sulfone (DDS), also known as dapsone, is generally recognized as the first-line therapy for LABD, DDS can induce several severe side effects. We present a Japanese case of LABD with DDS-induced hemolytic anemia and alopecia. In the present case, the DDS-induced hemolytic anemia and hair loss made the DDS monotherapy difficult. When DDS is used in LABD patients with iron deficiency anemia (IDA), hemolytic anemia is concealed by IDA. It is thus necessary to carefully and frequently examine the laboratory data to find the signs of DDS-induced hemolytic anemia. Even though there is no literature on DDS-induced alopecia, alopecia was reported as one of the side effects of DDS in an FDA report, and, in our case, hair loss was improved after reducing its dosage. We have to recognize that alopecia is one of the side effects of DDS and that careful management is needed in order not to overlook the adverse side effects of DDS when treating LABD patients.

Antibiotics used in nonbacterial dermatologic conditions

The majority of nonbacterial dermatological conditions treated with antibiotics benefit from the anti-inflammatory properties of these medications, usually dapsone or tetracycline. Many other antimicrobials are used to treat noninfectious conditions. The following chapter is an overview of select noninfectious dermatological conditions for which antibiotics are used, with a focus on the most common antibiotics used for their nonantimicrobial properties.

Linear immunoglobulin A bullous dermatosis

Linear immunoglobulin A (IgA) bullous dermatosis, also known as linear IgA disease, is an autoimmune mucocutaneous disorder characterized by subepithelial bullae, with IgA autoantibodies directed against several different antigens in the basement membrane zone. Its immunopathologic characteristic resides in the presence of a continuous linear IgA deposit along the basement membrane zone, which is clearly visible on direct immunofluorescence. This disorder shows different clinical features and distribution when adult-onset of linear IgA disease is compared with childhood-onset. Diagnosis is achieved via clinical, histopathologic, and immunopathologic examinations. Two common therapies are dapsone and sulfapyridine, which reduce the inflammatory response and achieve disease remission in a variable period of time.

A Case of Chronic Bullous Disease of Childhood That Was Reactive to the Antigen of 120 kDa (LAD-1)

Chronic bullous disease of childhood (CBDC) is an autoimmune blistering disease that is characterized by Immunoglobulin A (IgA) deposits at the basement membrane zone. IgA autoantibodies (aAbs) from the serum of patients with CBDC react with antigens of 97 kDa (LABD97) and 120 kDa (LAD-1), and both of which are fragments of the extracellular domain of bullous pemphigoid 180 (BP180, type XVII collagen). The CBDC sera reacts with the immunodominant NC16a domain of BP180, which is the major region recognized by IgG aAbs in patients with bullous pemphigoid. A five-year-old boy presented with multiple pruritic tense blisters on the umbilical and inguinal areas for six weeks. The direct immunofluorescence of the perilesional area demonstrated linear deposits of IgA at the basement membrane zone. Using immunoblotting and an enzyme linked immunosorbent assay (ELISA), we identified the IgA aAbs reactive to antigens with a molecular weight of 120 kDa (LAD-1), which is a fragment of the extracellular domain of BP180.

Ocular manifestations of blistering diseases

Ocular manifestations are a comorbidity of a group of chronic autoimmune blistering diseases that includes mucous membrane pemphigoid, linear immunoglobulin A disease, epidermolysis bullosa acquisita, and ocular pemphigus vulgaris. Various diagnostic measures differentiate between the diseases and allow for appropriate treatment including a specific selection of immunomodulatory medications. New treatment modalities offer alternatives that may minimize disease severity and residual tissue damage and may reduce treatment-related complications.