MPO and bacterial urinary tract infection: One cohort study measured myeloperoxidase (MPO) to creatinine ratio (MCR) (measured in ng MPO to g creatinine) in 253 adult outpatients with suspected UTI.28 In samples which were culture positive for 1 or 2 pathogens, log2MCR values were higher than those in patients with sterile urine (mean 8.6 ng/g (SD 2.5) vs 5.4 (SD 1.5), P = .001).