Thymopentin modulates Th1 and Th2 cytokine response and host survival in experimental injury

To investigate the impact of thymopentin (Thy) on mortality and in vivo cytokine release in an animal model of gut-derived sepsis which includes different combinations of allogeneic blood transfusion (T) and burn injury plus bacterial gavage (BG).

Randomly controlled experiments.

Two hundred sixteen Balb/c (H-2d) and 50 C3H/HeJ (H-2k) mice.

In the first study 60 Balb/c mice were given Thy (1 mg/kg). The same day of therapy onset, 40 mice were transfused with allogeneic blood (from C3H/HeJ mice). The remaining 20 mice received aliquots of saline. Five days post-T, 20 of the 40 transfused mice were subjected to a 20% TBSA thermal injury and simultaneous gavage with 1 x 10(9) Escherichia coli and the other 20 mice underwent a sham burn. The 20 nontransfused mice also received a 20% burn plus bacterial gavage. In all animals Thy was administered for 15 days. Three control groups (n = 20 each) entered the same protocol design, but they did not receive Thy. In the second study 96 animals were randomized to six groups (n = 16 each) according to the above experimental design. Animals were sacrificed by exsanguination after burn or 5 days post-T in nonburned mice to measure TNF-alpha, IL-2, and IL-4 plasma levels.

The highest mortality (70%) occurred when T was combined with BG. Thy significantly reduced mortality in both groups that underwent BG, regardless of the association with T. TNF-alpha was detectable in 30% of the tested samples, IL-2 in 50%, and IL-4 in 70%. Thy significantly reduced the levels of IL-4 and increased the production of IL-2.

The protective effect of Thy in this experimental model may be mediated by modulation of cytokine release.