Epidermal basal membrane antibodies

These are autoantibodies directed against basal membrane proteins of the skin. They are a clinical and laboratory markers of bullous pemphigoid and are used to diagnose and monitor the treatment of this disease.

Basal membranes are formed as a result of the activity of epithelial cells and the underlying connective tissue. Basal membranes consist of two plates and are 1 µm thick. They perform mechanical, morphogenetic, trophic and barrier functions. Through the basal membrane, the epidermis can influence dermal cells to increase or decrease the synthesis of various substances.

The study of the epidermal basal membrane revealed the presence of immune complexes consisting of different classes of immunoglobulins - IgM, IgG, IgA. They are localized in the lower and sometimes anterior part of the follicle. Antibodies to the epidermal basal membrane are determined in pemphigoid. The change in antibody titer is independent of the activity of the disease.

Antibodies to the epithelial basal membrane are observed in 70% of cases of active bullous pemphigoid, in 50% of cases of vesicular pemphigoid and acquired forms of epidermolysis bullosa, and in 10% of cases of scarring pemphigoid. But antibody titers to the basal membrane usually show no correlation with disease activity. The analysis is used to confirm the diagnosis of the disease, differential diagnosis of vesicular bullous skin diseases. This analysis is included in the differential diagnosis of various autoimmune diseases due to deficiency of the cellular component of immunity, dysimmunoglobulinemia in peripheral blood, immunocomplex pathology.

Antibodies to the basal membrane of the multilayer squamous epithelium (BMZ) are found in 70% of cases of active bullous pemphigoid, in 50% of cases of vesicular pemphigoid and acquired forms of bullous epidermolysis, and in 10% of cases of scarring pemphigoid. Differentiation of anti-BMZ antibodies produced in epidermolysis and pemphigoid requires special additional analyses. The main autoantigens in pemphigoid are BP180 and BP230, two antigens of the basal membrane zone of the epithelium. Antibody titers to the basal membrane usually show no correlation with disease activity (unlike antibodies to the intercellular substance in pemphigoid).