An increase in macrophage migration inhibitory factor release in patients with cardiopulmonary bypass surgery.

To determine the macrophage migration inhibitory factor (MIF) responses to cardiopulmonary bypass (CPB) surgery as well as to investigate their roles in predicting patient outcome, a prospective, observational, pilot study was performed. Thirty patients undergoing cardiovascular surgery with CPB received 10mg/kg betamethasone immediately before the CPB. Ten normal healthy volunteers served as control subjects. Blood samples were serially obtained for 24h and assayed for MIF, cortisol, and tumor necrosis factor alpha (TNF-alpha). TNF-alpha release could not be detected during the study period. Compared with both the control and baseline values, the MIF and cortisol levels were elevated before CPB and peaked at the end of CPB (57.5 +/- 4.8 ng/ml, P < 0.0001), and at the end of the surgery (507.7 +/- 44.1 nmol/l, P < 0.0001), respectively. Peak MIF levels correlated with aortic cross-clamp time (r2 = 0.183, P = 0.0182, n = 30), but did not show a significant correlation with peak cortisol levels. The levels of MIF tended to be 40%-50% higher during CPB in patients with longer intensive care unit (ICU) stays and in those with organ dysfunction than in those with short ICU stays and no organ dysfunction. All patients were discharged from the ICU. In conclusion, our findings demonstrate that MIF production occurs in patients with CPB surgery. When high-dose steroids are administered, high MIF levels were found to only slightly affect the patient morbidity and outcome after CPB surgery.