Abstract: Objective  To investigate the value of serum Toll-like receptor 4 (TLR4) and high mobility group protein B1 (HMGB1) in the early diagnosis of acute kidney injury (AKI) in severely burned patients.  Methods The clinical data of 45 patients with severe burn treated in Taizhou Hospital of Zhejiang Province from August 2019 to August 2021 were retrospectively analyzed. According to the presence or absence of AKI within one week after burn, they were divided into AKI group (n=20) and non-AKI group (n=25). Their basic data, acute physiology, age and chronic health evaluation II (APACHE II) and sequential organ failure estimation score (SOFA) were collected. Serum TLR4 and HMGB1 were detected by enzyme-linked immunosorbent assay at 24, 48 and 72 days after burn. The working characteristic curve (ROC) and area under the curve (AUC) were used to evaluate the value of serum TLR4 and HMGB1 in the early diagnosis of AKI in severely burned patients. Multivariate logistic regression was used to explore the risk factors for the occurrence of AKI in severely burned patients.  Results  SOFA score, APACHE Ⅱ score and serum Scr were higher in AKI group than in non-AKI group (t=16.839, 4.643 and 7.287 respectively; P＜0.001). Comparing between AKI group and non- AKI group, serum TLR4 levels were 4.12±0.36 vs. 2.33±0.25, 6.22±0.96 vs. 4.02±0.30, and 8.06±1.24 vs. 6.14±1.02 ng/ml after severe burn for 24, 48 and 72h respectively (t=8.076, 9.203 and 5.339 respectively; P＜0.001); serum HMGB1 levels were 9.63±2.28 vs. 6.23±1.20, 12.47±3.16 vs. 8.64±2.36, and 15.20±3.47 vs. 11.15±3.6 pg/ml after severe burn for 24, 48 and 72h respectively (t=4.951, 6.036 and 5.618 respectively; P＜0.001). Serum TLR4 and HMGB1 levels reached the highest at 72 hours after severe burn. ROC analysis showed that the AUC, cut-off value, sensitivity and specificity for serum TLR4 were 0.862, 4.50 ng/ml, 86.5% and 85.4%, respectively, and those for serum HMGB1 were 0.845, 6.22 ng/ml, 83.7% and 80.6%, respectively. The sensitivity and specificity of TLR4 (86.5% and 85.4%) and HMGB1 (83.7% and 80.6%) were higher than those of SOFA score (70.8% and 75.4%) and Scr (72.6% and 77.0%). SOFA score ≥4 points [OR (95% CI)=2.62 (1.40～4.91), P＜0.001], Scr≥133.00 μmol/L [OR (95% CI)=3.45 (1.52-7.89), P＜0.001], TLR4≥4.50 ng/ml [OR (95% CI)=3.87 (1.70～8.80), P＜0.001] and HMGB1≥6.22 pg/ml [OR (95% CI)=4.27 (2.10～8.70), P＜0.001] were the risk factors for AKI in severely burned patients.  Conclusion Serum TLR4 and HMGB1 levels increased in severely burned patients, and increased more in the severely burned patients with AKI. Both can predict AKI in severely burned patients. The two serum levels are expected to be used as biomarkers for the prediction of AKI in severely burned patients.

Key words: Toll-like receptor 4, High mobility group protein B1, Severe burn, Acute kidney injury