Tumor necrosis factor, interleukin-6,and epinephrine are associated with hypermetabolism in AIDS patients with acute opportunistic infections

During a 9-day period we investigated body composition, resting energy expenditure (REE), IL-6, TNF, and sTNFR-55 and sTNFR-75 plasma concentrations during infectious complications in 12 patients with HIV disease. At study entry, IL-6 was detectable in 5 and TNF in 10 patients. TNF was closely correlated with sTNFR-75 concentration (r = 0.84, p < 0.001) whereas sTNFR/sTNFR-55 ratio increased throughout the study. TNF concentrations were significantly correlated with the 24-hour excretion of epinephrine and norepinephrine (r = 0.64 and 0.69; each p < 0.01). Compared to expected values REE was increased by 34%. Body cell mass was the single best predictor of REE and explained 72% of its variance. In contrast, the deviation of measured from predicted REE was correlated with TNF and IL-6 concentrations (r = 0.9). We conclude that increased plasma concentrations of cytokines in complicated HIV disease display little biologic variability and relate to hypermetabolism in these patients.