Secretion of Soluble ST2 – Possible Explanation for Systemic Immunosuppression after Heart Surgery

Abstract

Background: Cardiopulmonary bypass is known to affect cytokine release leading to a generalized endogenous immune reaction similar to that described in sepsis, without having been explored in great detail. Therefore we evaluated the anti- and pro-inflammatory cytokine responses after heart surgery. Methods: 16 patients who underwent coronary artery bypass graft (CABG) surgery with extracorporeal circulation were included. ST2, IL-4 and IL-10 served as markers for TH2 cytokine response; IL-6, IL-8 and IFN-gamma as TH1 markers. Furthermore, total immunoglobulin subtype analysis (IgM, IgG, IgE) was performed. Results: Serum levels of soluble ST2 started to climb at 60 minutes (from 38 ± 14 preoperatively to 1 480 ± 890 pg/ml) and peaked 24 hours after surgery (13 360 ± 2 840 pg/ml, p < 0.001). IL-10 reached a maximum at 60 minutes and returned to baseline levels 24 hours later. IL-6 and IL-8 levels peaked 60 minutes after surgery. IL-4 and IFN-gamma did not change. Only IgM showed a significant peak on day eight (p < 0.001). Conclusion: Our results demonstrate that CABG surgery induces a massive long-lasting secretion of ST2, a protein related to immune suppression.

Key words

immunology - CABG - inflammation

References

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1 Szerafin, Niederpold and Mangold share the first authorship.