Background and Objective: Information about the type of kidney stones is important for informed therapeutic decisions and the prevention of urolithiasis. Urinary stones are heterogeneous, and their elemental composition and crystal structure vary between patients. The formation of urinary stone deposits depends, among other things, on physiological conditions, the concentration of promoters and inhibitors of crystallization, and proteins found in the urine. The aim of this study was to determine differences in urine osteopontin (OPN) levels between groups of different stone-formers. Methods: Urinary stone specimens (n = 44) were acquired during elective endoscopic procedures. Specimens were divided into subgroups by k-means cluster analysis depending on calcium and phosphorus concentrations. The concentration of urine OPN was determined and compared for each subgroup and the control group. Results: Cluster analysis divided the deposits into three clusters. Cluster 1 contained mainly calcium oxalate deposits; Cluster 2 contained uric acid deposits; Cluster 3 contained deposits with a high content of calcium phosphate. Urine OPN concentration in CaP stone-formers (5.77 ng/mL) differed significantly from those of controls (17.05 ng/mL, p = 0.013) and CaOx stone-formers (15.31 ng/mL, p = 0.048). Conclusions: The concentration of urine OPN varies depending on the elemental composition of renal calculi. The lowest concentration of OPN was determined in the group of patients with a high content of calcium phosphate in the deposits.
Journal of clinical medicine. 2025 Sep 04*** epublish ***
Maciej Jaromin, Piotr Kutwin, Tomasz Konecki, Hanna Jerczyńska, Piotr Wysocki, Magdalena Gajek, Waldemar Maniukiewicz, Małgorzata Iwona Szynkowska-Józwik, Dariusz Moczulski
1st Department of Urology, Medical University of Lodz, 90-549 Lodz, Poland., Research Laboratory CoreLab, Medical University of Lodz, 92-215 Lodz, Poland., Faculty of Chemistry, Institute of General and Ecological Chemistry, Lodz University of Technology, 90-534 Lodz, Poland., Department of Internal Medicine and Nephrodiabetology, University Clinical Hospital No. 2 of the Medical University of Lodz, 90-549 Lodz, Poland.