Relationship between the Composition of Urinary Calculi and Protein Biomarkers in Serum and Urine.

Background: The present study aims to determine the relationship between the expression levels of serum and urine biomarkers, and the composition of urinary calculi, in order to provide additional background information on the disease.

Methods: A total of 80 patients with urinary calculi, who were admitted to our hospital from January 2022 to June 2023, were selected as the study objects. In addition, 80 healthy subjects, who were admitted to our hospital during the same period, were selected as the control group. Patients with urinary calculi were further divided into two groups: Calcium oxalate calculi group and uric acid carbonate calculi group. The serum and urine biomarker levels of subjects in each group were compared by enzyme-linked immunosorbent assay. The correlation among calculi composition, clinical indicators, and protein biomarker levels was determined by single-factor and multi-factor analyses. The value of protein biomarkers in predicting calculi composition was evaluated using the receiver operating characteristic curve.

Results: There were significant differences in the expression levels of Lipocalin-2, matrix metalloproteinase 8, matrix metalloproteinase 9, angiopoietin-like 3, Dickkopf-4, interleukin 10 receptor alpha, interleukin 1 receptor 5, interleukin 2 receptor subunit gamma chain, and interleukin 28 A between the experimental and control groups. Furthermore, serum and urine Dickkopf-4, urine interleukin 10 receptor alpha, and microscopic red blood cell levels in urine were higher in patients with calcium oxalate calculi, when compared to patients with uric acid carbonate calculi (p < 0.05). The receiver operating characteristic curve analysis revealed that the area under curve for the four indicators was 0.854, with a cut-off value of 0.742. Thus, this can be used to predict the calcium oxalate composition in calculi.

Conclusions: Serum and urine protein biomarkers Dickkopf-4 and urine interleukin 10 receptor alpha, and microscopic red blood cells in urine can be used to predict the calculi composition. Patients with calcium oxalate calculi are more likely to have hematuria, when compared to patients with calculi of other compositions.