Linear IgA disease with IgA antibodies directed against 200- and 280-kDa epidermal antigens

Drug-Induced Linear IgA Bullous Dermatosis

We report the case of a 69-year-old Japanese woman with multiple blistering lesions covering almost her whole body. Linear IgA and C3 depositions were seen at the basement membrane zone on direct immunofluorescence (IF). Linear IgA bullous dermatosis (LABD) is one of the autoimmune diseases resulting in subepidermal blisters. It is clinically similar to bullous pemphigoid and IF is required to distinguish the two diseases. In this case, the blistering lesions appeared after vancomycin treatment. This drug was strongly suspected as a cause of LABD in light of the clinical course of the patient even though a drug-lymphocyte stimulating test was negative. Among the various implicated causative drugs, vancomycin is the most commonly associated with LABD.

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.

Childhood linear IgA bullous disease triggered by amoxicillin-clavulanic acid

Linear immunoglobulin A bullous disease is an autoimmune subepidermal blistering disease that has been described in both children and adults. Reports have shown that as many as two-thirds of occurrences may be drug-induced. The offending drugs include antibiotics, predominantly vancomycin, nonsteroidal anti-inflammatory agents and diuretics. We report childhood linear immunoglobulin A bullous dermatosis developing following amoxicillin-clavulanic acid administration. The patient presented with characteristic blisters in an annular fashion, likened to a ''crown of jewels.'' The diagnosis was confirmed by the presence of a linear band of immunoglobulin A at the dermoepidermal junction on direct immunofluorescence. The lesions resolved with withdrawal of the drug, and systemic therapy was not required. We review the current literature and concepts of drug-induced linear immunoglobulin A bullous disease.

Linear IgA disease: the IgA and IgG response to the epidermal antigens demonstrates that intermolecular epitope spreading is associated with IgA rather than IgG antibodies, and is more common in adults

BACKGROUND

Linear IgA disease (LAD; adult and childhood) is a dapsone-responsive, acquired immunobullous disorder mediated by IgA antibodies directed at target antigens within the epithelial basement membrane. These antigens have not been completely characterized.

OBJECTIVES

To identify the target antigens in LAD, and to correlate these with the antibody isotype.

METHODS

We used 101 LAD sera without IgG antibodies detected by indirect immunofluorescence. The sera were analysed by immunoblotting for IgA (65 adults and 36 children) and IgG (61 adults and 34 children) autoantibodies, on salt-split, urea-extracted epidermal tissue extracts.

RESULTS

Antigens were targeted in LAD by IgA antibodies (54 adults and 23 children), IgG antibodies (34 adults and 19 children), and both isotypes (30 adults and 16 children). Three major antigens were recognized by IgA antibodies: LAD285 (22 adults and three children), BP230 (30 adults and eight children) and BP180 (collagen XVII), including the 97-kDa ectodomain (52 adults and 20 children). Seven 'minor' antigens were occasionally detected (18 adults and 13 children). IgA antibodies bound multiple antigens (33 adults and nine children) more frequently than single antigens (21 adults and 14 children), but the binding to multiple antigens was more restricted in children than in adults. IgG antibodies mainly bound a single antigen (29 adults and 16 children), predominantly BP180.

CONCLUSIONS

There was variation in the autoantibody response within the disease and the patient, with regard to target molecules and autoantibody class. The finding that IgG as well as IgA autoantibodies predominantly target BP180 supports a pivotal role for collagen XVII in adult and childhood LAD. The IgG response was very restricted compared with IgA autoantibodies (P < 0.01). Autoantibodies from children had a more restricted antigen repertoire than from adults (P < 0.05). Epitope spreading is common in LAD and is affected by the class of autoantibody and age of the patient.

Two cases of linear IgA disease with clinical manifestations limited to the gingiva

Linear IgA disease (LAD) is a chronic, subepithelial blistering disease that is associated with the presence of linear deposits of IgA along the basement membrane zone. Etiopathogenic aspects of LAD are only partially known. LAD is clinically characterized by vesiculobullous skin and mucous lesions. Although more than half of LAD patients present oral mucosal lesions, there are only a few cases reported of oral lesions as the only manifestation of LAD. This study presents 2 of these uncommon cases.

Vancomycin-induced linear IgA disease with autoantibodies to BP180 and LAD285

Linear IgA disease (LAD) is an acquired autoimmune subepidermal bullous disease characterized by the linear deposition of IgA at the basement membrane zone. A minority of cases are induced by drugs, of which the most frequently implicated is vancomycin. The target antigens in idiopathic LAD are heterogeneous, but have not previously been reported in vancomycin-induced LAD. We report three cases, and in two of these we investigated the target antigens. In both we identified IgA antibodies to LAD285 and IgA and IgG antibodies (dual response) to BP180.