Unveiling the role of sTLR2: A novel biomarker for predicting septic-associated AKI

Acute kidney injury (AKI) is common in septic patients and strongly associated with adverse outcomes. The pathophysiology of AKI in septic patients remains elusive, and detection of patients at risk of AKI or at risk of progression to severe and persistent AKI is critical for timely and adequate support measures, including mitigating further renal damage. Therefore, identification of biomarkers associated with septic-associated AKI that contribute to improve septic AKI is an area of intensive research.

A total of 116 consecutive patients with sepsis were categorized into two groups (AKI and non-AKI) based on the occurrence of AKI within 24 h of admission to the intensive care unit (ICU). Serum levels of soluble TLR2 (sTLR2), as well as biomarkers such as interleukin(IL)-6, IL-22, IL-10, creatinine, urea, procalcitonin, hypersensitive C-reactive protein (hs-CRP), and D-Dimer (D2), were measured within 24 h after ICU admission. Demographic and clinical characteristics including sequential organ failure assessment (SOFA) scores and acute physiology and chronic health evaluation II (APACHE II) scores were recorded. Logistic regression analysis was conducted to identify potential predictive biomarkers. Receiver operating characteristic (ROC) curve analysis was employed to determine the optimal model for predicting septic-associated AKI.

Patients in the AKI group exhibited significantly higher serum concentrations of IL-6, IL-10, sTLR2, creatinine, urea, hs-CRP, procalcitonin, D2 and lower serum albumin concentrations as well as higher APACHE II scores compared to those in the non-AKI group. Logistic regression analysis revealed that APACHE II scores, log10-transformed sTLR2 concentration, creatinine and D2 concentration were valuable predictors of AKI among septic patients. ROC curves demonstrated that log10-transformed sTLR2 concentration exhibited comparable predictive value to creatinine in determining the incidence of sepsis-associated AKI. The model with variables of APACHE II score, Log10-transformed serum TLR2 concentration, creatinine and D2 concentration yielded the greatest area under the curve of 0.863.

Elevated levels of sTLR2 in early-stage of septic patients may serve as a promising novel biomarker for predicting sepsis-associated AKI.