Background and Aim: The present study was designed to compare the cell death, circulating levels of tumor necrosis factor-α and tumor necrosis factor type-I receptor in Iranian patients with sepsis and normal controls.

Materials and methods: Twenty-two patients with sepsis were included in this study. After blood collection, the serum circulating levels of TNF- and TNFRI measured with ELISA kits. The PBMCs isolated from blood samples and proportion of apoptotic cells measured by flowcytometry at the time of blood draws (0 time) and after 24-h incubation. PBMCs incubated at 37°C in culture (spontaneous apoptosis) and in the presence of rTNF that is capable of inducing apoptosis in activated T cells expressing the TNF family of receptors.

Results: PBMCs obtained from the patients showed significantly higher (P<0.001) proportion of apoptotic cells than PBMCs of controls at 0 time, indicated that a higher fraction of PBMCs were undergoing apoptosis in vivo in patients but not in controls. After 24-h incubation, spontaneous ex vivo apoptosis of PBMCs was nearly as high as that of TNF-  induced apoptosis, indicating that activated T cells had been preprogrammed in vivo to die.

Discussion and Conclusion: The circulating levels of both TNF- and TNFRI showed significantly higher in patients (P<0.001) than controls and this increase is proportional (r=0.908) in both indicating that TNFRI may have a protective effect in the early stage of sepsis.