To investigate the predictive value of urinary Tamm-Horsfall protein (THP) and 24-hour urine osmotic pressure in patients with calcium oxalate stones.

A retrospective analysis was conducted on the clinical data of 120 patients hospitalized for upper urinary tract stones in Songjiang Hospital Affiliated to Shanghai Jiaotong University school of Medicine from January 2020 to December 2021. The patients were divided into a recurrence group (53 cases) and a non-recurrence group (67 cases) based on whether stone recurrence occurred during follow-up. The levels of urinary THP and 24-hour urine osmotic pressure were compared between the two groups, and ROC curves were used to evaluate the predictive value of urinary THP and 24-hour urine osmotic pressure for stone recurrence.

The urinary THP and 24-hour urine osmotic pressure were significantly higher in the recurrence group than in the non-recurrence group (P<0.05). The ROC curve showed that the optimal cut-off points for predicting stone recurrence were ≥27.01 mg/L for urinary THP and ≥577.69 mOsm/(kg·H₂O) for 24-hour urine osmotic pressure. The accuracy, sensitivity, and negative predictive value of 24-hour urine osmotic pressure and urinary THP alone for predicting kidney stone recurrence were significantly lower than those of their combined detection (P<0.05).

Urinary THP and 24-hour urine osmotic pressure are higher in patients with recurrent calcium oxalate stones. Combined detection of the two methods has good predictive value for stone recurrence.