Different immune responses to abdominal surgery in men and women

Background: Animal experiments reveal significant gender differences in the immunological response to surgical trauma. This raises the possibility that gender differences may also exist in patients after major abdominal surgery. Patients and methods: This prospective study included 40 patients (20 men, 20 women) with colorectal diseases requiring surgical intervention. To evaluate the immune response to surgery circulating lymphocyte populations and natural killer cells were determined by flow-cytometry, and IL-6 serum levels were measured by enzyme-linked immunosorbent assay. Blood samples were taken before and on days 1, 2, and 5 after surgery. Results: Despite comparable preoperative cell counts we detected significant postoperative gender differences regarding B-lymphocyte, T-lymphocyte, T-helper cell counts, and NK cell counts. While only a short, insignificant depression of these immune competent cells was detected in women, men suffered long-lasting (5 days) depression of these cells. Furthermore, women showed a more pronounced immediate (day 1) proinflammatory response (circulating IL-6) after abdominal surgery. Conclusions: Significant immunological gender differences following major abdominal surgery were observed in this prospective clinical study. Our findings support the experimental observations of better posttraumatic immune competence in women than in men. These gender differences may be of relevance for short- and long-term results after surgery for colorectal diseases. Future studies will address the use of sex-steroids and/or their antagonists as a therapeutic option for the improvement in perioperative immune dysfunction in patients with major surgery.