ROLE OF COMPLEMENT IN PORPHYRIN-INDUCED PHOTOSENSITIVITY

[摘要] Addition of porphyrins to sera of guinea pigs in vitro, followed by irradiation with 405 nm light, resulted in dose-dependent inhibitions of hemolytic activity of complement (CH50 [total hemolytic complement], C3 and C5). With guinea pig as an animal model, systematically administered porphyrins, followed by irradiation with 405 nm light, resulted in dose-dependent inhibition of CH50 in vivo. The erythrocytes from porphyrin-treated guinea pigs showed an increased susceptibility to hemolysis induced by 405 nm irradiation in vitro. Clinical changes in these animals were limited to light-exposed areas and consisted of erythema, crusting and delayed growth of hair. Histologically, dermal edema, dilation of blood vessels and infiltration of mononuclear and polymorphonuclear cells were observed. Guinea pigs irradiated with UV B developed erythema, but had no alteration of their C profiles. C products may play a specific role in the pathogenesis of the cutaneous lesions of some porphyrias.