Abstract: Objective  To investigate the predictive value of serum chitinase-3-like protein-1 (CHI3L1) and syndecan 4 (SDC4) levels for the prognosis of patients with acute renal failure (AKI) undergoing hemodialysis.  Methods  AKI patients who received hemodialysis treatment in Qinhuangdao integrated traditional Chinese and Western medicine hospital of Hebei Port Group Co., Ltd, from January 2019 to August 2021 were selected as the study group. Based on 1-year follow-up results, patients were divided into a survival group and a death group. Additionally, healthy individuals undergoing physical examinations during the same period were selected as the control group. Serum levels of CHI3L1 and SDC4 were measured using enzyme-linked immunosorbent assay (ELISA). Cox regression was used to analyze the factors influencing the prognosis of AKI patients undergoing hemodialysis. Receiver operating characteristic (ROC) curve was used to evaluate the predictive value of serum CHI3L1 and SDC4 for prognosis of these AKI patients. Survival analysis was performed using the Kaplan-Meier method.   Results   The study group included 150 patients, and the control group included 150 individuals. The serum levels of CHI3L1 [(82.33±10.19) vs. (51.85±8.34) ng/L] and SDC4 [(6.89±1.65) vs. (3.40±1.05) ng/L] in the study group were higher than those in the control group (t=28.350, 21.855, P＜0.001). The creatinine (t=3.722, P＜0.001), uric acid (t=3.627, P＜0.001), tumor necrosis factor-α (TNF-α) (t=3.557, P=0.001), CHI3L1 (t=6.299, P＜0.001), and SDC4 (t=7.277, P＜0.001) in the death group were higher than those in the survival group (P＜0.05). COX regression analysis showed that serum creatinine (HR=4.625, 95% CI:2.027～10.555, P＜0.001), uric acid (HR=4.334, 95% CI:2.038～9.217, P＜0.001), TNF-α (HR=3.160, 95% CI:1.642～6.081, P＜0.001), CHI3L1 (HR=5.227, 95% CI:1.950～14.009, P=0.001), and SDC4 (HR=4.816, 95% CI:1.947～11.911, P＜0.001) were all factors affecting the prognosis of AKI patients undergoing hemodialysis . ROC curves revealed that the  area under the curve (AUC) of CHI3L1, SDC4, and their combination in predicting poor prognosis in AKI patients undergoing hemodialysis was 0.770 (95% CI: 0.694～0.835), 0.766 (95% CI: 0.690～0.831), and 0.870 (95% CI: 0.806～0.920), respectively.  The AUC for the combination was greater than that for CHI3L1 alone (Z=3.129, P=0.002) and for SDC4 alone (Z=2.600, P=0.009). Kaplan-Meier curves showed that the overall survival rate of the high CHI3L1 group was lower than that of the low CHI3L1 group (Log-rank χ²=62.729, P＜0.001); the overall survival rate of the high SDC4 group was lower than that of the low SDC4 group (Log-rank χ²=52.709, P＜0.001).  Conclusion  Serum levels of CHI3L1 and SDC4 are elevated in AKI patients and are factors influencing the prognosis of AKI patients undergoing hemodialysis. The combined detection of CHI3L1 and SDC4 has high predictive value for poor prognosis in these patients.

Key words: Acute kidney injury, Hemodialysis, Chitinase-3-like protein-1, Syndecan 4, Prognosis