From anti‐p200 pemphigoid to anti‐laminin γ1 pemphigoid

Abstract

Anti-laminin c1 pemphigoid is an autoimmune subepidermal bullous disease first described in 1996, and has been distinct from previously known subepidermal blistering diseases, such as bullous pemphigoid and epidermolysis bullosa acquisita. Circulating autoantibodies of the patients do not react to any known autoantigen of the skin, but react to a 200-kDa molecule (p200) from dermal extracts. The identity of p200 was unmasked as laminin c1, an extracellular matrix glycoprotein composing several forms of laminin heterotrimers. We renamed this disease from the previously used anti-p200 pemphigoid to anti-laminin c1 pemphigoid, a new entity of an autoimmune bullous disease. In this decade, we have experienced over 70 cases of this disease. Although the number of the cases of anti-laminin c1 pemphigoid is half as many as the number of definitely diagnosed cases of epidermolysis bullosa acquisita in the same duration, a considerable number of the cases could be clinically misdiagnosed as epidermolysis bullosa acquisita. Unveiling the pathogenicity and development of a useful diagnostic method is necessary for appropriate management of this new disease.

IgA Anti-p200 Pemphigoid

“…[1][2][3][4][5][6][7][8][9][10][11][12] Herein, we describe the first case, to our knowledge, of anti-p200 pemphigoid associated exclusively with IgA antibodies. The patient presented with erythematous plaques forming an annular arrangement with vesicles on the edge and resembling DH or annular erythema.…”

“…6 Immunologically, anti-p200 pemphigoid is characterized by the development of IgG antibodies directed against a unique basement membrane zone (BMZ) protein with a molecular weight of 200 kDa. 1,2 Immunoelectron microscopic studies have disclosed that the 200-kDa protein is localized on the lower part of the lamina lucida. 4 This explains the dermal binding of circulating antibodies on the salt-split skin.…”

“…1 Approximately 70 cases have been published so far. 2 Clinically, it may resemble bullous pemphigoid (BP), 1,2 linear IgA bullous dermatosis (LABD), 2 or dermatitis herpetiformis (DH). 3 Some cases coexisted with psoriasis.…”

“…7 Until now, all published cases with anti-p200 pemphigoid were mediated exclusively by IgG antibodies. [1][2][3][4][5][6][7][8][9][10][11][12] Then, in 2009, Dainichi et al 13 identified p200 as laminin ␥1 and renamed it anti-laminin γ1 pemphigoid. Herein, we report the first case, to our knowledge, of anti-p200 pemphigoid associated with IgA antibodies and having clinical features resembling DH localized on traumatized areas, that is, on the dorsal part of the hands and feet, ankles, and buttocks.…”

Identification of Epitopes Within Integrin β4 for Binding of Auto-Antibodies in Ocular Cicatricial and Mucous Membrane Pemphigoid: Preliminary Report

“…24,25 Recently, another subset, formerly known as anti-p200 pemphigoid and now known as antilaminin pemphigoid, has been described. 26 These subsets are not included in this study.…”