Very late antigen (VLA) expression in various forms of epidermolysis bullosa simplex

The very late antigen (VLA) glycoproteins are a family of adhesion membrane receptors involved in cell-cell and cell-matrix interactions. In order to investigate the expression of these molecules in inherited epidermolysis bullosa (EB), we studied the reactivity of monoclonal antibodies directed against VLA-1, -2, -3, -4, -5, and -6, and VLA beta receptors in skin sections from patients affected by several types of EB simplex (EBs) using indirect immunofluorescence. Skin samples were obtained from six patients with generalized type (Koebner), one patient with localized type (Weber-Cockayne) and one patient with Dowling-Meara EBs type and also from two normal controls. No significant modification of the expression of these adhesion receptors was observed. Anti-VLA-2 and anti-VLA-3 stained the whole cytoplasmic membrane of basal keratinocytes and allowed the detection of focal areas of cytolysis in unblistered skin from the Koebner and Dowling-Meara type. In Koebner type blisters anti-VLA-3 stained the cell remnants at the roof of the blister with a linear staining along the epidermal basement membrane on the dermal side. In Dowling-Meara type blisters anti-VLA-3 also stained cell remnants at the bottom of the cavity. Anti-VLA-6 stained the bottom of the blister cavity with the same distribution of bullous pemphigoid serum but with a stronger and more constant reactivity. Our data show that anti-VLA-3 and anti-VLA-6 can usefully be utilized in diagnostic immunomapping studies of EBs.