OBSERVATIONS: We describe a patient with
epidermolysis bullosa acquisita who has developed mutilating acral involvement with early
syndactyly and extensive
scarring lesions of the scalp. The patient's serum contains
IgG autoantibodies that bind the dermal side of 1-mol/L
sodium chloride-separated human skin (at a titer up to 5120), as determined by indirect immunofluorescence microscopy, and
type VII collagen, as determined by immunoblot. The severity of this patient's disease and the height of his immune response to
type VII collagen prompted us to assess the pathogenicity of his
autoantibodies in a murine model. Purified
IgG from our patient (or that from a healthy volunteer who served as a control) was administered subcutaneously to BALB/c mice (10 mg/g of
body weight) on 2 consecutive days. Light microscopy of normal-appearing skin showed pronounced dermal
edema and a dense granulocyte-rich infiltrate in the superficial dermis. Deposits of human
IgG, murine C3, and the
membrane attack complex of
complement were found in the epidermal basement membrane of all experimental mice. Immunogold electron microscopy demonstrated that deposits of human
IgG in an experimental subject were localized to anchoring fibrils. Serum samples from mice receiving
IgG antibodies from our patient had high titers of circulating
antibodies directed against the dermal side of 1-mol/L
sodium chloride-separated human skin (titer, 640 to 1280). Light, immunofluorescence, and immunogold electron microscopic studies did not detect such specific alterations in any control mice.
CONCLUSIONS: