Passive transfer of photosensitivity by intradermal injection of vesiculobullous lupus erythematosus serum and ultraviolet light irradiation in the guinea pig.

To study the effect of ultraviolet light (UVL) exposure on the pathogenesis of vesiculobullous lupus erythematosus (VBLE), the back of depilated Strain 2 female guinea pigs was injected with sera from 2 patients with VBLE, 3 patients with non-bullous systemic lupus erythematosus (SLE) (disease control) and 4 normal human adults (normal control). Normal saline was also used as an additional control. Of the 20 injected areas, only half (10) were then irradiated with one minimal erythema dose of UVB (310 nm). The clinical and histologic features of the areas injected with VBLE sera and then irradiated showed significant differences from the areas only injected, as well as from the areas receiving injection and irradiation of the control sera (both disease and normal). Immunofluorescence studies, on the other hand, showed similar results in the areas injected with either VBLE or SLE sera. These results suggest that the most likely mechanism for induction of VBLE blisters is photoactivation of circulating factor(s) that damage the dermoepidermal junction of both sun-exposed and non-sun-exposed skin.