The augmented neutrophil respiratory burst in response to Escherichia coli is reduced in liver cirrhosis during infection

Abstract

Summary Several functional abnormalities in phagocytes from patients with liver cirrhosis contribute to an increased risk of infection. An increased resting respiratory burst has been observed in neutrophils from cirrhotic patients. We investigated whether an infection in cirrhosis affects the respiratory burst capacity of neutrophils and monocytes in response to Escherichia coli. This study included 45 hospitalized patients with liver cirrhosis and clinical signs of infection, 39 patients with liver cirrhosis in the absence of infection and 29 healthy subjects. Respiratory burst, lipopolysaccharide-binding protein (LBP), and immunoglobulin (Ig)G-autoantibodies against oxidized low-density lipoproteins (ab-oxLDL) were measured. The fraction of neutrophils spontaneously producing reactive oxygen species (ROS) was elevated in liver cirrhosis (P < 0·01). The neutrophil resting burst increased with Child–Pugh stage (P = 0·02) and correlated with augmented ROS release in response to opsonized E. coli (P < 0·05). Although LBP was increased in patients with cirrhosis (P < 0·01), higher LBP levels correlated with a lower resting burst in neutrophils (rs = –0·395; P < 0·01). In the presence of infection, the resting burst was unaltered. However, neutrophil ROS release in response to E. coli was reduced markedly (P = 0·01), and it decreased as serum C-reactive protein (CRP) concentration rose (rs = −0·437; P < 0·01), indicating the development of a sepsis-like immune paralysis. A positive correlation between ab-oxLDL and ROS release was observed (P < 0·01). In conclusion, the respiratory burst increases with severity of liver cirrhosis but is restrained by increasing LBP levels. Augmented ROS release in response to E. coli is accompanied by elevated markers of oxidative damage and becomes exhausted in the presence of infection.