The adaptive immune response to major surgery in the neonate.

The effect of major surgery on components of the adaptive immune response in babies has not previously been reported. In a prospective study, eight neonates undergoing uncomplicated surgery for repair of esophageal atresia were investigated. They were compared with ten age-matched normal babies not undergoing surgery. The parameters of the immune response investigated were: total leukocytes (WBC), lymphocytes and their subsets (T-helper, T-suppressor, natural killer [NK], B-lymphocytes), monocytes, immunoglobulins (Ig) G and M, the cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin 1-beta (Il-1beta), and C-reactive protein (CRP), an acute-phase protein. When compared to the normal controls, the operated group showed a fall in all types of WBC following surgery, but only the falls in B-lymphocytes and NK cells were significant on postoperative day 3 (P < 0.05). The suppression in WBC was temporary, and by day 7 the operated group had significantly higher numbers of total WBC and T-helper cells than the controls (P < 0.05), who were undergoing their physiological postpartum fall in WBC. Within the operated group, there was a significant fall in the numbers of total lymphocytes, T-suppressors, and B-lymphocytes compared to preoperative levels (P < 0.01). The ratio of T-helper/T-suppressor cells increased significantly following surgery. There was a vigorous immune response in terms of the humoral factors: CRP, TNF-alpha, and Il-1beta all rose significantly postoperatively (P < 0.02).