Approaches to the urine lithogenicity assessment in patients with oxalate urolithiasis

We have investigated the crystal-forming activity of the urine in 111 patients (age 23-67 years) with oxalate urolithiasis, among them - 68 patients with non-recurrent form (39 male and 29 female patients) and 43 patients with recurrent form (27 men and 16 women). Eighty-six healthy patients without urological diseases were used as control (38 male and 48 female patients) with the age 21-62 years. The speed of crystal formation of calcium oxalate was calculated based on the dynamics of calcium concentration decrease. The initial speed of crystal formation (ISKF) was estimated when urine from healthy patients or from patients with oxalate urolithiasis was added into the model system. Index of the relative oversaturation of the urine - ROS (CaOx), as surrogate of the calcium oxalate lithogenesis, -was 2.52 times more in patients compared to healthy individuals. Diagnostic specificity of the ROS (CaOx) index was high - 87.5% with the sensitivity of 67.8% (p