MPO and acute kidney injury: In the setting of CVVH, a prospective randomized study of 20 critically ill patients with AKI, studied the effects of either heparin or citrate anticoagulation on oxidative stress, measuring myeloperoxidase (MPO) (polymorphonuclear (PMN) cell degranulation and release from endothelial cells), as well as inflammatory cytokine production [62].