NORMAL T-LYMPHOCYTE AND MONOCYTE FUNCTION AFTER MINIMALLY INVASIVE SURGERY

Background: The aim of this study was to evaluate immune defense mecha nisms after laparoscopic (LCHE) and open cholecystectomy (CHE), partic ularly with regard to monocyte and T-lymphocyte function. Methods: In a prospective study, we evaluated the following immunological data fro m 27 patients (21 women, six men; mean age, 47.2 years) submitted to e lective LCHE and 14 patients (seven women, seven men; mean age, 60.8 y ears) undergoing elective CHE: T-lymphocyte proliferation (stimulated by SEA, SEE, TSST-1 with antigen presentation by patient monocytes), e xpression of cell surface molecules on monocytes (HLA-BR, CD80, L-Sele ctin), CD4(+) T lymphocytes (HLA-DR, CD25, ICAM-1, L-Selectin), and gr anulocytes (L-Selectin). Blood samples were collected preoperatively a nd 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 postoper ative course but returned to preoperative levels within 1 week. After CHE, significant downregulation of HLA-DR expression persisted through out the whole observation period. This decrease, however, did not alte r the antigen-presenting capacity of monocytes in both groups. Moreove r, the APC-independent proliferative capacity of T lymphocytes was uni mpaired. CD25 expression was significantly increased on postoperative day 1 after CHE but not after LCHE. Expression of HLA-DR, ICAM1, and L -Selectin on CD4+ T cells was not altered in either group. CD80 on mon ocytes and L-Selectin on monocytes and granulocytes remained unchanged after both procedures. Conclusions: HLA-DR surface molecules on monoc ytes that are required for antigen presentation were significantly dec reased in both groups; they returned to normal within 1 week after LCH E but not after CHE. However, the antigen-presenting capacity of monoc ytes 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 def ense than CHE; however, the clinical relevance of the changes noted af ter the open operation remains to be determined.