Soluble CD163 from activated macrophages predicts mortality in acute liver failure.

Soluble CD163 (sCD163) is a scavenger receptor shed in serum during inflammatory activation of macrophages. We investigated if sCD163 was increased and predicted outcome in acute liver failure (ALF). Samples from 100 consecutive patients enrolled in the U.S. ALF Study Group for whom sera were available were collected on days 1 and 3, and clinical data were obtained prospectively. sCD163 levels were determined by ELISA. The median level of sCD163 was significantly increased in ALF (21.1mg/l (range 3.6-74.9)) as compared to healthy controls (2.3mg/l (0.65-5.6), p<0.0001) and patients with stable liver cirrhosis (9.8mg/l (3.6-16.9), p=0.0002). sCD163 on day 1 correlated significantly with ALT, AST, bilirubin, and creatinine. sCD163 concentrations on day 3 were elevated in patients with fatal outcome of disease compared to spontaneous survivors, 29.0mg/l (7.2-54.0) vs. 14.6mg/l (3.5-67.2), respectively (p=0.0025). Patients that were transplanted had intermediate levels. Sensitivity and specificity at a cut-off level of 26mg/l was 62% and 81%, respectively. Activated macrophages are involved in ALF resulting in a 10-fold increase in sCD163. A high level (>26mg/l) of sCD163 was significantly correlated with fatal outcome and might be used with other parameters to determine prognosis.