[Characterisation of Postoperative Immune Suppression by Validated Parameters in Visceral Surgery]

Abstract

Background: Surgical interventions induce changes in postoperative immune competence due to the surgical trauma. Consequently, the immune system cannot react sufficiently in case of septic complications. The dimension of postoperative immune suppression can be determined by HLA-DR surface expression on circulating monocytes.

Material and methods: In the present study relevant literature was researched and patients with visceral and thoracic surgery were included. 17 patients underwent minor surgery, i.e., cholecystectomy, thyroidectomy or hernia repair. 101 patients underwent major surgery, i.e., visceral or thoracic resections. Expression of HLA-DR on circulating monocytes (HLA-DR) was analysed by FACS, whereas gene expression of T-cells was determined by gene-array methods.

Results: Postoperative complications or postoperative acquired sepsis were predominantly seen in patients with significantly reduced HLA-DR. The postoperative immune suppression was influenced by the type of operation itself: following colon surgery there was a longer-lasting immune suppression compared to that after surgery on the thorax or rectum. In addition, postoperative immune suppression depends on preoperative existing risk factors: adipositas and further risk factors cause a decrease of HLA-DR. Gene expression analysis revealed a distinct down-regulation of transcriptional activity of T-cells following surgical intervention. This effect is much more pronounced in patients with septic complications.

Conclusion: The expression of HLA-DR is a useful parameter to describe postoperative immune suppression. Furthermore, regulation of transcriptional T-cell activity can provide additional information on the postoperative immune status.