Abstract
Introduction: Vancomycin is widely used for treating serious gram-positive infections; however, its clinical utility can be limited by nephrotoxicity. Early detection of vancomycin-induced acute kidney injury (AKI) remains a clinical challenge, as traditional markers such as serum creatinine often rise only after significant renal damage has occurred.
Objectives: Urinary gamma-glutamyl transferase (GGT), an early tubular injury biomarker, may provide a sensitive indicator for detecting nephrotoxicity before overt renal impairment develops.
Materials and Methods: This prospective observational study was conducted between 2023 and 2024 at Loghman Hakim Hospital, Tehran, involving 14 patients receiving vancomycin who had no prior kidney disease. Demographic and clinical data were collected, and urinary GGT levels were measured on days 1, 3, and 6 after treatment initiation. The outcome was to compare urinary GGT levels between patients with and without AKI, to evaluate GGT as a potential biomarker for predicting vancomycin-associated AKI.
Results: The results demonstrated that urinary GGT in relation to the occurrence of vancomycin-induced AKI demonstrated no statistically significant associations across different time points of day 1, 3, and 3 after the administration of vancomycin. The area under the curve (AUC) values for predicting the occurrence of AKI were non-significant and were 0.633 on day 1, 0.556 on day 3, and 0.733 on day 6, respectively (P>0.05). The optimal urinary GGT cut-off values for AKI occurrence were 31 on day 1, 33.5 on day 3, and 47.35 on day 6, yielding sensitivities of 40%, 60%, and 60% and specificities of 56%, 67%, and 67%, respectively, suggesting only modest discriminative ability of urinary GGT for AKI.
Conclusion: In conclusion, urinary GGT showed no clinically meaningful or statistically significant ability to predict vancomycin-induced AKI at any evaluated time point and therefore cannot be recommended as a reliable standalone biomarker in this setting.