Serum cachectin/tumor necrosis factor in critically ill patients with burns correlates with infection and mortality.

Serum cachectin/tumor necrosis factor (TNF), a cytokine implicated in the pathogenesis of septic shock, may appear in the circulation during serious infection, but the frequency of detection of elevated serum levels during protracted critical burn injury is unknown. Serial serum samples taken from 43 critically ill patients with burns with and without sepsis were analyzed for TNF using an enzyme-linked immunosorbent assay (ELISA). TNF was detectable (greater than 34 picograms per milliliter) at one or more time points in 69 per cent of the patients with sepsis versus 33 per cent of those without sepsis, in 71 per cent of the patients who died versus only 31 per cent of the survivors and in only one healthy normal control patient (n = 21). The frequency of the appearance of TNF correlated with both infection and mortality rate. Moreover, all three patients with TNF levels greater than 540 picograms per milliliter died. Neither the size of the burn nor injury from inhalation correlated with detection of TNF. A subset of 16 patients was studied longitudinally from admission until resolution of injury and these data demonstrate that TNF appears transiently and repetitively in the circulation of patients during infection and protracted critical burn injury. Also, serum cortisol levels were significantly higher during sepsis and death in the absence of serum TNF, compared with sepsis and death with detectable cachectin, suggesting that cortisol may interact with the production or detection of this cytokine during ongoing infection and lethal injury. In this study, we have demonstrated that serum TNF is detectable with greater frequency and in higher concentration in patients with sepsis and in those who ultimately succumb to the burn injury, that serum TNF appears transiently and repetitively in the circulation during injury and that higher serum cortisol levels are correlated with the absence of serum TNF during sepsis and lethal injury.