Desmoglein 1 (DSG1) Antibodies, IgG

The Desmoglein 1 (DSG1) Antibodies, IgG test is used in the differential diagnosis of vesiculobullous skin disease, in particular for establishing pemphigus foliaceus. In conjunction with desmoglein 3 testing, the anti-desmoglein 1 antibody profile helps differentiate pemphigus variants based on their autoantibody patterns. It is also used to monitor pemphigus activity over time and to assess response to therapy, as desmoglein 1 antibodies (DSG1 IgG) typically fluctuate with clinical severity.

Desmoglein 1 (DSG1) and desmoglein 3 (DSG3) are calcium-dependent transmembrane glycoproteins that form part of desmosomes in epithelial cells and function as key autoantigens in pemphigus. Pemphigus represents a group of autoimmune blistering disorders of skin and mucous membranes characterized by acantholysis with intraepidermal blistering. Major clinical variants include vulgaris, vegetans, foliaceus (exfoliative), and erythematosus; the Nikolsky sign is frequently present across these forms. Isolated elevation of anti-DSG1 IgG is characteristic of pemphigus foliaceus and is reported in most affected individuals, whereas concurrent anti-DSG1 and anti-DSG3 positivity is typical of pemphigus vulgaris/vegetans. The tissue distribution of these antigens accounts for the clinical patterns observed: DSG1 is concentrated in the superficial epidermis and is largely absent in mucosal epithelium, while DSG3 is prominent in mucosal epithelia and deeper epidermal layers. Consequently, pemphigus foliaceus shows subcorneal blistering with relative sparing of mucosa, in contrast to pemphigus variants that involve DSG3. Anti-DSG1 IgG titers tend to parallel clinical disease activity and typically decline with effective treatment, supporting their role in ongoing monitoring.