Normal T lymphocyte and monocyte function after minimally invasive surgery.

BACKGROUND

The aim of this study was to evaluate immune defense mechanisms after laparoscopic (LCHE) and open cholecystectomy (CHE), particularly with regard to monocyte and T-lymphocyte function.

METHODS

In a prospective study, we evaluated the following immunological data from 27 patients (21 women, six men; mean age, 47.2 years) submitted to elective LCHE and 14 patients (seven women, seven men; mean age, 60.8 years) undergoing elective CHE: T-lymphocyte proliferation (stimulated by SEA, SEB, TSST-1 with antigen presentation by patient monocytes), expression of cell surface molecules on monocytes (HLA-DR, CD80, L-Selectin), CD4+ T lymphocytes (HLA-DR, CD25, ICAM-1, L-Selectin), and granulocytes (L-Selectin). Blood samples were collected preoperatively and on postoperative days 1 and 6-7. Statistical analysis was performed using the Mann-Whitney U test for paired samples.

RESULTS

HLA-DR on monocytes significantly decreased after LCHE during the early postoperative course but returned to preoperative levels within 1 week. After CHE, significant downregulation of HLA-DR expression persisted throughout the whole observation period. This decrease, however, did not alter the antigen-presenting capacity of monocytes in both groups. Moreover, the APC-independent proliferative capacity of T lymphocytes was unimpaired. CD25 expression was significantly increased on postoperative day 1 after CHE but not after LCHE. Expression of HLA-DR, ICAM1, and L-Selection on CD4+ T cells was not altered in either group. CD80 on monocytes and L-Selection on monocytes and granulocytes remained unchanged after both procedures.

CONCLUSIONS

HLA-DR surface molecules on monocytes that are required for antigen presentation were significantly decreased in both groups; they returned to normal within 1 week after LCHE but not after CHE. However, the antigen-presenting capacity for monocytes remained normal in both groups. T-cell stimulation, reflected by an increase of CD25 expression, was observed only after CHE, not after LCHE. We therefore conclude that LCHE interferes less with immune defense than CHE; however, the clinical relevance of the changes noted after the open operation remains to be determined.