MPO and viral hepatitis: Our data are in line with the hypothesis that not only reactive oxygen species but also neutrophil-derived proteases, such as MPO and NE, contribute to hepatocyte death29,30 as also neutrophil proteases mediate direct hepatotoxicity in co-culture experiments of hepatocytes with activated neutrophils.31,32 In particular, NE participates in the early steps of the inflammation cascade in viral acute hepatitis, and elastase inhibitors significantly reduced the expression of hepatic inflammatory mediators.29