Release of interleukin-8 and calprotectin during and after paediatric cardiopulmonary bypass with and without ultrafiltration.

Release of calprotectin and interleukin-8 (IL-8), changes in leukocyte counts and subsets and influence of extracorporeal ultrafiltration were evaluated during and after cardiopulmonary bypass (CPB) in 18 children undergoing open-heart surgery for congenital heart anomalies. Ultrafiltration was used in nine cases and nine were controls. Calprotectin concentration rose after start of CPB, peaking 48 hours postoperatively, with no significant intergroup difference. Positive correlation was found between duration of CPB and calprotectin (peak level and accumulated total). Circulating IL-8 was detected in all patients perioperatively, peaking at wound closure in the ultrafiltration group and at termination of bypass in the controls. CPB duration correlated significantly to peak level and accumulated total of IL-8. Seven of nine ultrafiltrate samples contained IL-8 at levels similar to the plasma concentration. Changes in white cell counts were mainly attributable to neutrophils. The two subgroups did not differ significantly in neutrophil count's. Neutropenia found after 10 minutes of CPB was replaced by neutrophilia, with maximal values postoperatively. Calprotectin and IL-8 thus were released into the circulation during CPB in children. Ultrafiltration did not affect the plasma concentrations of these substances, and only IL-8 was detected in the ultrafiltrate.