Opposite Effects of Interleukin-2 on Normal and Transfusion-Suppressed Healing of Experimental Intestinal Anastomoses

Abstract

Objective This study was done to investigate whether administration of interleukin-2 (IL-2) can abrogate the negative effects of blood transfusions on anastomotic healing. Summary Background Data Recently, the authors showed that blood transfusion severely impairs anastomolic repair and significantly increases the susceptibility to intra-abdominal septic complications in rats. It has been reported that blood transfusions suppress IL-2 production and that IL-2 may stimulate wound healing. Methods Lewis rats underwent resection and anastomosis of both the ileum and colon. Subsequently, they received either 3 mL of saline (control and IL-2 groups) or 3 mL of blood from brown Norway donors (transfusion and transfusion/IL-2 groups) Intravenously. From the operation onward, the animals in the IL-2 and transfusion/IL-2 groups received daily injections of 5.4 X 105 IU of IL-2 in dextrose solution subcutaneously; the rats in the other groups received only the dextrose solution. The animals were killed 3 or 7 days after the operation and examined for septic complications and anastomolic repair. Results Transfusion led to an enhanced incidence of anastomotic abscesses, which was almost completely abrogated after IL-2 administration. The anastomotic strength was consistently and significantly reduced after transfusion. Seven days after surgery, the anastomotic strength was completely restored by IL-2 treatment. For instance, the average bursting pressures (± the standard deviation) of the ileal anastomoses in the control, transfusion, and transfusion/IL-2 groups were 86±15, 32±8,* and 63±10 mmHg*† on day 3 and 293±36,227±16,* and 299±19 mmHg† on day 7, respectively (where* = significant vs. control group and † = significant vs. transfusion group). In addition, IL-2 administration elevated the anastomotic hydroxyproline content, which was significantly decreased by transfusion alone, to the level found in the control group. The administration of IL-2 to control animals resulted unexpectedly in a significant reduction in anastomotic strength. Conclusions Exogenous IL-2 reverses the negative effects of blood transfusions on anastomotic repair, but it impairs healing under normal conditions.