Dysregulation of immune response following neurosurgical operations.

Background: Postoperative infections are common and potentially fatal complications in neurosurgical intensive care medicine. An impairment of immune function has been described after central nervous system surgery and in patients harboring malignant brain tumors. The aim of our study was to investigate whether differences in cell-mediated immunity can be found in patients undergoing craniotomy for surgery of glioblastoma or clipping of an intracerebral aneurysm. Methods: In order to determine the influence of the underlying disease on the immune system, we measured changes in cytokine concentrations (IL-6, IL-10, TGF-beta1) and lymphocyte-subsets (CD3+, CD3+HLA-DR+, CD4+, CD8+, CD19+, and CD16+56+) in 8 patients with glioblastoma and in 8 patients with an intracerebral aneurysm before, during and after the neurosurgical procedure. Results: In the comparison of glioblastoma and aneurysm patients, we could show that IL-6 plasma levels were pre- and intraoperatively higher in the aneurysm-group (P<0.05), and the plasma concentrations of IL-10 and TGF-β were significantly elevated in the glioma-group. The lymphocyte-subsets showed a significantly lower percentage of NK-cells and activated T-cells in the glioma-group. Conclusion: Our results document a significant dysregulation of immune response in glioma patients. This may be induced by elevated plasma concentrations of immunoinhibiting cytokines IL-10 and transforming growth factor-beta 1.