Antinuclear antibody-keratinocyte interactions in photosensitive cutaneous lupus erythematosus

Abstract

Autoimmune diseases are characterized by various circulating autoantibodies, especially antinuclear antibodies (ANA). It has been a long-standing issue as to whether andlor how ANA interact with epidermal cells to produce skin lesions. Of these ANA, the anti-SS-AIR0 antibody is the most closely associated with photosensitivity in patients with systemic lupus erythematosus (SLE) and its subgroups, including subacute cutaneous lupus erythematosus (SCLE) and neonatal lupus erythematosus (NLE). SS-A/Ro antigens are present in the nucleus and cytoplasm, and interestingly, ultraviolet B (UVB) light translocates these antigens to the surface of the cultured keratinocytes. Thus, anti-SS-AIR0 antibodies in the sera can bind to the relevant antigens expressed on the UVB-irradiated keratinocyte surface, and have been speculated to be an important inducer of antibody-dependent keratinocyte damage. This interaction between the anti-SS-A/Ro antibodies and UVBirradiated keratinocytes may induce the skin lesions through a cytotoxic mechanism. This review will focus on the involvement of antibody-dependent cellular cytotoxicity in the pathogenesis of the skin lesions observed in photosensitive cutaneous lupus erythernatosus.