Circulating basement membrane zone antibodies are found in lichen sclerosus of the vulva

TLDR

These antibodies may reflect a tendency to produce autoantibodies or be relevant to pathogenesis. The study investigated the prevalence, subtypes, and clinical correlations of BMZ antibodies in 96 patients with vulvar lichen sclerosus. Serum IgG was screened for BMZ staining by indirect immunofluorescence on intact and split skin, and positive samples were further subclassified into IgG1, IgG2, IgG3, and IgG4. One‑third of LS patients had BMZ antibodies binding to the epidermal side of salt‑split skin; immunoblotting revealed BP180 antibodies in six of seven patients and BP230 in one, with IgG1 and IgG2 subclasses predominating, and no clinical correlation with erosions, scarring severity, age of onset, or treatment response.

Abstract

SUMMARY This study was undertaken to investigate the prevalence of basement membrane zone (BMZ) antibodies, their subtypes and clinical correlations in 96 patients attending the Oxford vulval clinic with lichen sclerosus (LS) of the vulva. Indirect immunofluorescence of serum (intact and split skin) to immunoglobulin (Ig)G was performed looking for the presence or absence of staining at the BMZ. Eighteen patients' sera (14 with positive indirect immunofluorescence to IgG) were examined for IgG antibodies of subclasses IgG1, 2 and 3, and 23 sera were examined for IgG4 subclass. Immunoblotting was performed in seven patients, and showed antibodies to BP180 in six patients and BP230 in one. One‐third of patients with vulval LS had BMZ antibodies binding to the epidermal side of salt split skin. Immunoblotting showed antibodies to BP180 collagen XVII (six of seven patients) and BP230 in one. The subclasses were chiefly IgG1 and 2, different from those seen in bullous pemphigoid. No clinical correlation was found between the presence of antibodies and the presence of erosions, severity of scarring, age of onset of disease or response to treatment. These antibodies may be a reflection of a tendency to produce autoantibodies or be relevant to pathogenesis.