Immunological suppression after surgery in scoliosis patients

This is a prospective study to analyze the postoperative immunological changes in scoliosis surgery. Twenty-eight patients who underwent Harrington instrumentation were analyzed. Seven patients who underwent arthroscopic surgery were analyzed as a control group. The objective of this study is to determine whether surgery and surgical stress (minor versus major surgery) changed the immune capability of patients as indicated by the ratio of lymphocyte cell types and interferon induction. Pre- and postoperative blood from scoliosis and knee arthroscopy patients was analyzed at various times using antisera and two-color flow cytometry with monoclonal antibodies. Both scoliosis and knee arthroscopy patients had a postoperative decrease in the population of B-lymphocytes (Leu 12+) and a transient increase in the natural killer cells (Leu 4-/Leu 19+) and the cytotoxic T-lymphocytes (Leu 2a++/Leu 15-). These changes were significantly greater in the scoliosis patients, who also experienced a prolonged decrease in the inducer T-lymphocytes (Leu 8+/Leu 3a+) for 3 weeks following surgery. Production of interferon-α and interferon-γ by lymphocytes was suppressed postoperatively and returned to preoperative levels within 3 weeks. Immunological depressive changes occurred postoperatively and lasted at least 1 week. These effects are more pronounced with longer surgeries, suggesting greater postoperative vigilance for infections in these cases.