Background: Anesthesia and surgical trauma are known to affect various functions of the immune system. Alterations reported in the immune system, such as imbalance of Th1 (IFN-gamma) and Th2 (IL-4, 5, 10) cytokines, may result from a number of factors, including pre-medication, type of anesthetic drug, and modality of anesthesia. In this study, we investigated the effects of spinal and general anesthesia with desflurane and bupivakain, respecttively, on Th1 (IFN-gamma) and Th2 (IL-10) cytokines, absolute lymphocyte and natural regulatory T cell numbers (Treg). 

Methods: Peripheral Blood Mononuclear cells from 24 patients with Benign Prostate Hyperplasia (BPH), undergoing transuretheral prostatectomy under spinal (n = 12) and general (n = 12) anesthesia were analyzed before and 24 hours after surgery. Intracellular cytokine production in response to mitogen stimulation and absolute numbers of Tregs and lymphocytes were determined by using flow cytometry. 

Results: In patients who received spinal anesthesia, while the frequency of IFN-gamma (1.68% +/- 0.74 vs. 1.03% +/- 0.74) and IL-10 producing CD4(+) T cells decreased (2.62% +/- 2.24 vs. 1.04% +/- 1.06; p < 0.05), the ratio of Th1/Th2 remained similar (1.14 +/- 0.7 vs. 1.52 +/- 1.02; p > 0.05) after surgery. In contrast, in the general anesthesia group the frequency of CD4(+)IFN-gamma(+) T cells increased (1.3% +/- 0.7 vs. 2.5% +/- 1.2; p < 0.05) and the frequency of CD4(+)IL-10(+) T cells decreased (1.1% +/- 0.68 vs. 0.67% +/- 0.47), resulting in an increased Th1/Th2 ratio (1.61 +/- 1.1 vs. 4.77 +/- 3.95; p < 0.05). Absolute lymphocyte and Treg numbers did not change significantly in both groups following surgery. 

Conclusions: Our results support the notion that general anesthesia, rather than spinal anesthesia, alters the balance of Th1 and Th2 in favor of Th1 responses. However, whether this has any effect on the susceptibility to post-surgery-related infections remains to be determined.