IL-6 plasma concentration by ELISA. Plasma levels of IL-6 in peripheral artery* (A), coronary sinus* (CS), and superior vena cava* (SVC) in 14 patients undergoing uncomplicated CPB. Data are mean ± SD (error bars). BH, before heparinization; 5 minutes after crossclamping; 60 minutes after crossclamping; End, at the end of CPB, prior to reperfusion. *The level of IL-6 was significantly increased after CPB (p < .05).