Comparison of Supersaturation Outputs from Different Programs and Their Application in Testing Correspondence with...

Area of Science:

• Nephrology
• Urology
• Biochemistry

Background:

• Urinary stone formation is influenced by mineral supersaturation.
• Relative supersaturation (SS) is a key metric for assessing crystallization risk.
• Several computational programs estimate urinary SS, including EQUIL, JESS, and Lithorisk.

Purpose of the Study:

• To compare the outputs of EQUIL, JESS, and Lithorisk for calculating SS of calcium oxalate (CaOx), calcium phosphate (CaP), and uric acid (UA).
• To evaluate the correspondence between these SS estimations and the actual mineral composition of urinary stones.
• To assess the clinical applicability of SS in managing stone-forming patients.

Main Methods:

• SS for CaOx, CaP, and UA was calculated using EQUIL, JESS, and Lithorisk for 211 stone-forming patients.
• Pearson correlation coefficients were used to compare program outputs and their relation to stone composition.
• Fractional regression models assessed the relationship between SS and the percentage of specific compounds in stones.

Main Results:

• All three programs demonstrated high correspondence in SS calculations for CaOx (r ≥ 0.96), CaP (r ≥ 0.99), and UA (r ≥ 0.99).
• Significant correlations were found between CaOx SS and CaOx dihydrate percentage, and between CaP SS and brushite/apatite percentages in stones.
• Uric acid SS showed the strongest correlation with the percentage of UA in urinary stones (p < 0.001).

Conclusions:

• The study confirms good agreement among EQUIL, JESS, and Lithorisk in estimating urinary SS.
• The strong correspondence between estimated SS and stone composition supports the clinical utility of these calculations.
• These findings advocate for the application of SS estimations in routine clinical practice for stone management.