BACKGROUND: The clinical advantages of laparoscopic procedures result from a minimized surgical trauma. The present study was performed to investigate immunosupression following laparoscopic operations as compared with open surgery. Our analysis focused on the T cell secretion of cytokines that regulate the critical balance of either T helper type-1 (Th1)- and Th2-mediated immune responses on pro- and antiinflammatory activities. METHODS: In a prospective study, immunological data of 26 patients submitted to laparoscopic cholecystectomy (LCE) and 17 patients undergoing conventional cholecystectomy (CCE) for symptomatic cholecystolithiasis were compared. Patients with acute cholecystitis and patients developing postoperative complications or receiving immunosuppressive medication were excluded. Production of interferon (IFN)-gamma, interleukin (IL)-2, IL-4, tumor necrosis factor (TNF)-alpha, and IL-10 by isolated T cells stimulated by cross-linking of CD3 and CD28 was evaluated preoperatively as well as on postoperative days 1 and 6 or 7. Cytokines were measured by immunoenzymometric assay. RESULTS: IFN-gamma, TNF-alpha, and IL-2 production by T cells decreased significantly by 48.3%, 36.6%, and 36.8%, respectively, on postoperative day 1 after CCE, but not after LCE. These results indicate severe suppression of Th1-type and proinflammatory cytokines after the open operation. In contrast, IL-4 and IL-10 did not show significant changes in either group suggesting that Th2 cell response and anti-inflammatory activity remained normal. CONCLUSIONS: The present study shows that open, but not laparoscopic cholecystectomy is associated with a marked suppression of T lymphocytes functions as indicated by deregulation of both the Th1/Th2 and the pro-/anti-inflammatory cytokine balance. The results therefore suggest that downregulation of Th1 cell-mediated immune response and pro-inflammatory activity of T cells is a hallmark of open, but not laparoscopic surgery.