Inhibiteur de rejet de greffe alpha2-macroglobulin in burn injury: a suppressive activity on complement

A subform of alpha2-macroglobulin, (inhibiteur de rejet de greffe (IRG), present at a low rate in healthy rat, increased with rate-related suppressive activity on complement during inflammatory processes. In human serum, a molecule with such properties was described. Serum and blister IRG from burn patients belonging to a selected population was purified under gentle conditions. Serum IRG increased quickly within the first day after hospitalization and continued to increase until day 6. Although absent in whole serum, the rate-related activity of IRG varied according to the surface area and the degree of burns. A rate-related activity was also revealed in whole blister fluid and in purified blister IRG. We report a new site and a new suppressive activity of IRG in its native form from serum and blister fluid during inflammatory processes of burned patients. The suppressive activity of IRG on complement is discussed, and it appears to play a role in the development of inflammatory processes.