MMP9 and acute kidney injury: Han et al. (2008) also reported that levels of urinary MMP-9 are significantly higher in UTI compared to AKI and healthy controls. In the study of Han et al. (2008) UTI was defined as present in patients without evidence of previous renal disease or AKI, positive leukocyturia and urine culture greater than 105 UFC. While our definition of UTI differs from that of Han et al. (2008), and our study was focused on subjects with T2DM with and without renal impairment, in whom GFR was measured on a single occasion, we found differences in the levels of MMP-9 between subjects with and without UTI.