Opsonic glycoprotein (plasma fibronectin) levels after burn injury. Relationship to extent of burn and development of sepsis.

The time course of immunoreactive and bioassayable opsonic alpha 2-SB glycoprotein (plasma fibronectin), as well as its relationship to both the extent of injury and development of postburn sepsis, was evaluated following burn injury. Immunoreactive opsonic fibronectin was depleted acutely within hours following burn; its maximal depletion occurring 12 hours postburn injury. The magnitude of depletion was correlated with the body surface area burned, and normal levels were restored at 24 hours postinjury. There was a tendency toward rebound hyperopsonemia at two weeks postburn, with a slow return to normal over the ensuing weeks. Bioassayable opsonic protein levels, in general, paralleled those of immunoreactive protein. Following restoration of opsonic protein levels, a secondary phase of opsonic fibronectin deficiency (p equal to 0.05) developed in those burn patients that became septic. Moreover, this opsonic fibronectin deficiency actually became apparent prior to the onset of clinical sepsis, although it was maximal during sepsis. The resolution of the septic episode was associated with the return of plasma opsonic fibronectin levels to normal. The possibility that secondary deficiency in immunoreactive opsonic fibronectin may be a reliable index of impending sepsis following burn warrants further investigation.