Search

Background The objective of the present study was to investigate the effects of isolated limb perfusion (ILP) with tumour necrosis factor α (TNF-α) and melphalan on circulating T cells from cancer patients using two different methods. Design Eight patients undergoing an ILP entered the study. At first, the number of T cells at several time points was determined using FACScan. Subsequently, production of interferon gamma (IFN-γ) (T-helper 1) and interleukin (IL) 4 (T-helper 2) was measured at the intracytoplasmic level after stimulation with phorbol 12-myristate 13-acetate (PMA) and ionomycin. IFN-γ, IL-4 and IL-2 (also T-helper 1) production in the whole-blood cell culture system was then determined after stimulation with a combination of anti-CD3/anti-CD28 monoclonal antibodies. Results An enormous decrease in the number of circulating T cells was observed. In the remaining T-cell population cytokine production (IL-2, IL-4, IFN-γ) was depressed, showing the same pattern in both methods. No difference could be detected between the effect of TNF-α and melphalan on Th1 cells and Th2 cells. Conclusions The results demonstrate that TNF-α and melphalan reduce the number of circulating T cells and at the single-cell level decrease cytokine production in the remaining circulating T cells. No selective effect of TNF-α on Th1 or Th2 cells could be detected. If the impaired T-cell function is representative of all T cells remaining in the systemic circulation, this could help to explain the tolerability of high TNF concentrations after ILP, perhaps by decreasing the synthesis and production of T-cell-derived cytokines. [ABSTRACT FROM AUTHOR]

BackgroundIn this study, we have evaluated hepatotoxicity, secondary cytokine production and hepatic acute-phase response (APR) in patients who underwent isolated hepatic perfusion (IHP) with tumour necrosis factor (TNF) α and melphalan for irresectable colorectal liver metastases. DesignAn extracorporeal veno-venous bypass was used to shunt blood from the lower body and intestines to the heart. Inflow catheters were placed in the hepatic artery and portal vein, and an outflow catheter in the inferior caval vein. The liver was perfused for 60 min with 0.4 mg of TNF-α plus 1 mg kg-1 melphalan (IHPTM group, n = 6) or 1 mg kg-1 melphalan (IHPM group, n = 3). The liver was washed with macrodex before restoring vascular continuity. ResultsAfter the washout procedure, a TNF-α peak (169 ± 38 pg mL-1) was demonstrated in the IHPTM group only. Both groups demonstrated peak levels of interleukin 6 (IL-6) in the perfusate as well as systemically. These were significantly higher in the IHPTM group. Acute-phase protein (APP) levels followed a similar pattern as has been demonstrated after major surgery, with no significant differences between both groups. The addition of TNF-α to the perfusate did not lead to a significant difference in APP levels and the time course between groups. ConclusionsIHP with TNF and melphalan is followed by a transient systemic peak of TNF directly after liver washout. Secondary IL-6 induction was seen in the present study after IHP with and without TNF, which was highest when TNF was added. This phenomenon cannot be extrapolated to APP induction, which appeared unaffected by the addition of TNF, presumably because the surgical procedure itself already causes maximal stimulation of APP production. [ABSTRACT FROM AUTHOR]