Lymphocytic subpopulation changes after open and laparoscopic cholecystectomy: a prospective and comparative study on 38 patients

Up to now it has been unclear whether laparoscopic surgery has fewer immunosuppressive effects than traditional laparotomic procedures. In a series of 38 patients affected by symptomatic gallstone disease and operated on either by laparoscopy (group 1) or by traditional open surgery (group 2), we determined the postoperative changes in lymphocyte subpopulations up to postoperative day (POD) 30. We collected 15 ml of venous blood from all patients in both groups on the day before surgery and on POD 1, 7, 15, and 30. A control group (group 3) comprised 56 healthy volunteers; the control group was used only to ensure that baseline values were totally comparable with a normal population; only one blood sample was obtained from the subjects in group 3. Patients undergoing open cholecystectomy had a significant decrease in total lymphocyte count on POD 1. Basal levels of lymphocyte subpopulations did not differ significantly in the study and control groups. No differences were found in the preoperative lymphocyte cell counts in the two groups who underwent cholecystectomy. Pan-T cells (CD3) showed a statistically significant marked reduction throughout the observation period. The counts of helper (CD4), suppressor (CD8), and natural killer NK (CD16) T cells were reduced on POD 1; the NK cell (CD16) count remained low until POD 30, B lymphocytes showed no postoperative reduction. In patients who underwent laparoscopic cholecystectomy, a significant postoperative decrease in total lymphocyte count, and in CD3, CD4, and CD8 subpopulations was observed on day 1 only. There was no reduction in CD16 and CD19 subpopulations. A comparative statistical analysis of lymphocyte subpopulations in the two groups was carried out: In the open cholecystectomy group, compared with the laparoscopy group, CD3, CD4, CD8, and CD16 lymphocyte subpopulations showed marked reductions at different time points. In particular, statistically significant differences were found in CD3 levels from POD 1 through POD 30, in CD4 from day 1 through day 7, and in CD8 and CD16 only on day 1.