The association between renal medullary and cortical fibrosis, stiffness, and concentrating capacity: an observational, single-center cross-sectional study.

Patients with disorders involving both renal medullary and cortical fibrosis had decreased maximum urine osmolality but had no abnormalities in the urinary concentrating capacities with either condition. Renal medullary and cortical fibrosis were positively correlated with urinary β2-MG, but not with urinary N-acetyl-beta-D-glucosaminidase.