Thymopentin increases the survival of mice after allogeneic blood transfusion, bacterial gavage, and burn injury

Objective: To investigate the effect of blood transfusion on mortality and the incidence of bacterial translocation in mice subjected to thermal burn or bacterial gavage, or both, and to assess the influence of thymopentin on mortality. Design: Randomly controlled experiments. Setting: University departments of surgery, immunology and nuclear medicine. Material: 235 Balb/c (H-2(d)) and C3H/HeJ (H-2(k)) mice. Interventions: 8 groups of 20 mice each received: saline infusion (controls), blood transfusion (BT) alone, 20% burn alone, gavage with 1 x 10¹⁰ Escherichia coli alone, BT and gavage, BT and burn, burn and gavage, or BT, burn, and gavage. A further 3 groups of 10 mice were all gavaged with ¹¹¹In-biotin labelled E coli and randomised to additional BT and burn, BT alone, or burn alone. 98 mice that had had BT, burn, and gavage, were then randomised to receive thymopentin 0, 0.1, 1, or 5 mg/kg/day for 15 days. The impact of the pretreatment with thymopentin on PGE₂ concentration was also evaluated in a separate group of 45 mice that received BT, burn, and gavage; or burn and gavage. Main outcome measures: Survival, degree of translocation. Results: The highest mortality (75%) was in the BT, burn, and gavage group. BT alone significantly reduced survival in burned mice, whereas BT alone or associated with gavage had no effect. Thermal injury had the most influence on bacterial translocation, whereas BT did not increase it. Thymopentin significantly improved survival, particularly in the higher doses. The pretreatment with thymopentin significantly reduced PGE₂ concentration after BT, burn and gavage. Conclusion: Burn injury significantly increased mortality in the presence of immune deficiency caused by BT. Thymopentin reduced mortality, possibly by immunomodulation.