Division of Gastroenterology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
BACKGROUND & AIMS:
Microparticles released into the bloodstream upon activation or apoptosis of CD4+ and CD8+ T cells correlate with inflammation, determined by histologic analysis, in patients with chronic hepatitis C (CHC). Patients with nonalcoholic fatter liver (NAFL) or nonalcoholic steatohepatitis (NASH) can be differentiated from those with CHC based on activation of distinct sets of immune cells in the liver.
We compared profiles of circulating microparticles from patients with NAFL and NASH (n=67) to those with CHC (n=42), compared with healthy individuals (controls) using flow cytometry; the profiles were correlated with inflammation grade and fibrosis stage, based on histologic analyses. We assessed the ability of the profiles determine the severity of inflammation and fibrosis, based on serologic and histologic analyses.
Patients with CHC had increased levels of microparticles from CD4+ and CD8+ T cells; the levels correlated with disease severity, based on histologic analysis and levels of alanine aminotransferase (ALT). Patients with NAFL or NASH had significant increases in numbers of microparticles from invariant natural killer T (iNKT) cells and macrophages/monocytes (CD14+), which mediate pathogenesis of NASH. Microparticles from CD14+ and iNKT cells correlated with levels of ALT and severity of NASH (based on histology). Levels of microparticles could differentiate between patients with NAFL or NASH and those with CHC, or either group of patients and controls (area under the receiver operating characteristic curves ranging from 0.56 to 0.99).
Quantification of immune cell microparticles from serum samples can be used to assess the extent and characteristics of hepatic inflammation in patients with chronic liver disease.