Cytokines in plasma and ultrafiltrate during continuous arteriovenous haemofiltration.

Cytokines are considered to be important mediators in the pathophysiology of sepsis and septic shock. We investigated if continuous arteriovenous haemofiltration (CAVH) could be used to remove excessive amounts of the cytokines tumour necrosis factor-alpha (TNF alpha), interleukin (IL)-1 alpha and IL-6 from peripheral blood in critically ill patients. Nine septic patients with renal failure were treated with CAVH. Ultrafiltrate and plasma were tested for cytokines by ELISA. All patients had detectable TNF alpha and IL-6 plasma levels, ranging from 10-750 pg/ml and 50-4,575 pg/ml, respectively. TNF alpha was removed by the ultrafiltrate with concentrations ranging from 10-1,000 pg/ml. The TNF alpha levels were significantly higher in the ultrafiltrate samples than in the corresponding plasma samples (P < 0.003). IL-6 was undetectable in the ultrafiltrate from five of the patients despite concomitant high plasma levels. IL-1 alpha was detectable in both plasma and ultrafiltrate in four patients. All patients developed multi-organ failure and septic shock and seven died. It is concluded that TNF alpha and IL-1 alpha but not IL-6 can be removed by CAVH in patients with sepsis.