Objectives: We have previously demonstrated associations between the macrophage activation marker soluble (s)CD163 and histology of nonalcoholic fatty liver disease (NAFLD) in adults, and elevated sCD163 levels in children with obesity with NAFLD. Macrophage activation has, however, not been investigated in children with biopsy-proven NAFLD, which was the objective of the present study.
Methods: We used in-house enzyme-linked immunosorbent assays to measure sCD163 and the novel macrophage marker soluble mannose receptor (sMR) in a cross-sectional (n = 155) pediatric NAFLD cohort, and a cohort of NAFLD children (n = 36) undergoing a randomized trial by the probiotic VSL#3. We included 56 healthy nonobese children for comparison.
Results: Levels of sCD163 and sMR were higher in both of the NAFLD cohorts compared with controls (P < 0.001). In the cross-sectional cohort, sCD163 only showed trends toward association with ballooning (rho = 0.14, P = 0.08) and portal inflammation (rho = 0.17, P = 0.08). sMR showed similar associations with liver histology. In the VSL#3 cohort, sCD163 correlated inversely with steatosis (rho = -0.35, P = 0.04), and lobular (rho = -0.57, P < 0.001) and portal inflammation (rho = -0.38, P = 0.02); sMR was not associated with any histological scores. Neither sCD163 nor sMR changed significantly during intervention, and without association with NAFLD resolution.
Conclusions: The macrophage activation markers sCD163 and sMR showed poor associations with liver histology in 2 different cohorts of children with biopsy-proven NAFLD, and none of the markers decreased during successful intervention. These results are in contrast with studies of adult NAFLD and may suggest a possibility of different roles for macrophages in the pathogenesis of adult and pediatric NAFLD.