Soluble CD163 from activated macrophages predicts mortality in acute liver failure

Background/Aims: 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). Methods: 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. Results: The median level of sCD163 was significantly increased in ALF (21.1 mg/l (range 3.6-74.9)) as compared to healthy controls (2.3 mg/l (0.65-5.6), p < 0.0001) and patients with stable liver cirrhosis (9.8 mg/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, 29.0 mg/l (7.2-54.0) vs. 14.6 mg/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 26 mg/l was 62% and 81%, respectively. Conclusions: Activated macrophages are involved in ALF resulting in a 10-fold increase in sCD163. A high level (>26 mg/l) of sCD163 was significantly correlated with fatal outcome and might be used with other parameters to determine prognosis.