HP and acute kidney injury: Haptoglobin was identified as a biomarker for uranium nephrotoxicity (Malard et al., 2009), membranous nephropathy (Ngai et al., 2007), acute kidney injury (Zager, Vijayan & Johnson, 2012), diabetic nephropathy (Rao et al., 2007), bladder carcinoma (Li et al., 2011), hepatic fibrosis (Van Swelm et al., 2013) and acute phase response (Piras et al., 2014).