Abstract: Objective To investigate the relationship between serum levels of soluble CD14 (sCD14), neutrophil gelatinase-associated lipocalin (NGAL), and bacterial infection in maintenance hemodialysis (MHD) patients.  Methods  MHD patients from Cangzhou People's Hospital were selected as the study group (n=106). Based on the presence or absence of respiratory bacterial infection, they were further divided into an infection group and a non-infection group. Additionally, 106 healthy individuals undergoing physical examinations were selected as the control group. Serum levels of sCD14 and NGAL were measured by ELISA. Their correlations with laboratory parameters were analyzed. Logistic regression was used to identify influencing factors. The diagnostic value of these markers for bacterial infection in MHD patients was analyzed.  Results  Serum levels of sCD14 and NGAL in the study group were higher than those in the control group (t=28.866, 7.963, both P ＜0.001). The infection group had higher serum levels of sCD14, NGAL, hematocrit (HCT), and procalcitonin (PCT) compared to the non-infection group (t=37.476, 8.740, 6.086, 7.944, all P＜0.001), and lower albumin (ALB) levels (t=37.298, P＜0.001). Pearson analysis showed a positive correlation between sCD14 and NGAL (r=0.594, P <0.001). Serum sCD14 and NGAL were positively correlated with HCT (r=0.501, 0.512, both P＜0.001) and PCT (r=0.510, 0.511, both P＜0.001), and negatively correlated with ALB (r=-0.524, -0.534, both P＜0.001). Logistic regression analysis indicated that sCD14 (OR=3.148, 95% CI: 1.590～6.076, P＜0.001), NGAL (OR=4.378, 95% CI: 2.011～9.533, P＜0.001), HCT (OR=2.058, 95% CI: 1.429～2.963, P＜0.001), and PCT (OR=3.420, 95% CI: 1.452～8.054, P=0.005) were risk factors for bacterial infection in MHD patients, while ALB was a protective factor (OR=0.521, 95% CI: 0.329～0.824, P=0.005). ROC curve analysis revealed that the combined application of serum sCD14 and NGAL had higher diagnostic value compared to either marker alone (Z=2.643, 2.664, P=0.024, 0.021).  Conclusion  Serum levels of sCD14 and NGAL are elevated in MHD patients and are associated with bacterial infection. Combined detection of their levels holds clinical value for diagnosing bacterial infection in these patients.

Key words: Maintenance hemodialysis, Bacterial infection, Soluble cluster of differentiation-14, Neutrophil gelatinase-associated lipocalin