Predictive Value of 5-Methoxytryptophan on Clinical Outcome in Patients with Sepsis Associated Acute Kidney Injury.

Purpose: Our study aims to investigate specific changes in serological 5-MTP expression in sepsis-associated acute kidney injury (SA-AKI) patients and assess its potential as a biomarker for SA-AKI occurrence. Additionally, we seek to evaluate the predictive value of 5-MTP in long-term clinical prognosis following SA-AKI.

Patients and methods: A prospective cohort study included 31 healthy controls and 78 patients diagnosed with sepsis at the Affiliated Hospital of Qinghai University. Following the collection of serological samples, 5-MTP levels were determined using targeted metabolomics.Additionally, we collected clinical data, including blood routine, biochemical, inflammatory indicators and severity of disease. Spearman correlation, COX regression analysis and Kaplan-Meier curves were used to evaluate the correlation between serum 5-MTP and renal function and the value of prognosis.

Results: The findings revealed that serum 5-MTP levels were significantly elevated in SA-AKI patients compared to both the healthy control and sepsis groups(P<0.05), and were associated with Scr, BUN, and eGFR levels(P<0.05). Additionally, 5-MTP was identified as an independent influencing factor for all-cause mortality in patients with sepsis and SA-AKI. Higher levels of 5-MTP were linked to faster recovery of kidney function, while lower levels were associated with increased 90-day all-cause mortality in SA-AKI patients.

Conclusion: 5-MTP may have a protective role in the development of SA-AKI, and an early increase in serological expression of 5-MTP could positively impact the prognosis of sepsis and SA-AKI.