Differentiating anti-lamina lucida and anti-sublamina densa anti-BMZ antibodies by indirect immunofluorescence on 1.0 M sodium chloride-separated skin

Abstract

Sixty-one bullous disease sera containing IgG anti-BMZ antibodies were examined by indirect immunofluorescence on intact skin and skin separated through the lamina lucida by incubation in 1.0 M NaCl. All sera produced an indistinguishable pattern of linear immunofluorescence on intact skin at dilutions of 1:10 or higher. On separated skin, antibodies bound to either the epidermal (epidermal pattern), dermal (dermal pattern), or epidermal and dermal (combined pattern) sides of the separation. The binding patterns were consistent on separated skin from several donors and titers of anti-basement membrane zone antibodies on separated skin were comparable to those on intact skin. Sera from 3 patients with herpes gestationis (HG), 36 patients with bullous pemphigoid (BP), and 1 patient with clinical and histologic features of epidermolysis bullosa acquisita (EBA) showed an epidermal pattern. Sera from 9 patients with BP showed a combined pattern and sera from 6 patients with EBA and 6 patients with clinical and histologic features of BP showed a dermal pattern. Indirect immunoelectron microscopy of selected sera showed antibodies producing the epidermal and combined patterns were anti-lamina lucida antibodies and those producing the dermal pattern were anti-sublamina densa antibodies. These results show indirect immunofluorescence on separated skin is a dependable method for differentiating bullous disease anti-lamina lucida and anti-sublamina densa antibodies and that differentiating between the antibodies is essential for accurate diagnosis in some patients. The results also suggest BP anti-lamina lucida antibodies may have more than one antigenic specificity.