The role of complement in UVB-induced inflammation.

To evaluate the role of the complement system in skin inflammation accompanying leukocyte infiltration induced by UVB irradiation, the response of guinea pigs decomplemented with cobra venom factor was compared with that in saline-treated animals. Complement-depleted animals showed a weaker clinical response in the late phase (12-48 h) of UVB-induced inflammation (p less than 0.05). However, complement activation, detectable as a decrease in CH50 and generation of chemotactic anaphylatoxin, did not occur after in vitro irradiation of guinea pig serum. These results suggest that although the complement system does not play a key role in initiating leukocyte chemotaxis to the UVB-induced inflammatory site, it contributes to the amplification of the late inflammatory reaction.