The interplay of oxidative stress and inflammation in pediatric patients with nephrotic syndrome

Abstract

Summary Background: The pathophysiological mechanisms crucial in the development of nephrotic syndrome (NS) in the pediatric population are still not fully understood. This study aims to investigate the synergistic interaction of oxidative stress and inflammation in the pathogenesis of NS. Additionally, one of the objectives of this study is to examine the relationship between hypertension and the degree of oxidative stress and inflammation in patients during the acute phase of the disease. Methods: The study included 33 children, aged 2 to 9 years, with NS. Blood samples were collected during the acute phase and remission. Parameters of oxidative status were determined, including total oxidative status (TOS), advanced oxidation protein products (AOPP), prooxidant-antioxidant balance (PAB), sulfhydryl groups (-SH), paraoxonase 1 (PON1), and total antioxidant status (TAS) in serum, measured spectrophotometrically. Inflammatory parameters such as pentraxin 3 (PTX3), leptin, programmed cell death ligand 1 (PD-L1), and E-cadherin were determined using enzyme-linked immunosorbent assay (ELISA). Results: Patients with NS and hypertension had significantly higher levels of AOPP and TOS (p=0.029 and p=0.003, respectively). During the acute phase of the disease, lower activity of -SH and PON1 was observed compared to remission (p<0.001, for both). PTX3 levels were higher, while leptin levels were lower during the acute phase (p<0.001, for both). PTX3 correlated with AOPP and TAS during the acute phase but not in remission (rs=0.42, p=0.027 and rs=0.43, p=0.025, respectively). A negative correlation between AOPP and leptin was observed during the acute phase, which disappeared in remission (rs=-0.42, p=0.028).   Conclusions: Results of this study show that hypertension influences oxidative stress markers, and decreased antioxidant capacity may contribute to NS development. PTX 3 appears as a potential disease activity marker, indicating a dynamic connection between inflammation and oxidative stress. Leptin may also play a role in oxidative stress in NS.  List of abbreviations: AOPP, advanced oxidation protein products; BMI, body mass index; DBP, diastolic blood pressure; ELISA, enzyme-linked immunosorbent assay; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol;  total antioxidant status; PAB, prooxidant-antioxidant balance; -SH, sulfhydryl group; SBP, systolic blood pressure; PON 1, paraoxonase; PTX 3, pentraxin 3; PD-L1, programmed cell death ligand 1; TC, total cholesterol; TG, triglyceride; TAS, total antioxidant status; TOS, total oxidation status.