Clinical importance of thiol-disulfide balance in the diagnosis of chronic urticaria in children: Relationship with disease activity and immune markers

Abstract

To demonstrate the role of thiol–disulfide balance (TDB) in chronic urticaria (CU) in children and to examine their relationship with disease activity to find out its value as a diagnostic biomarker. Our study is a prospective, case-control, single-center cross-sectional study. A total of 78 individuals were included. Thirty-nine patients with CU were compared with 39 healthy children with similar demographic characteristics. Serum native thiol (-SH), disulfide (SS), total thiol (-SH + -S-S-) (TT), and derived indices that constitute the thiol–disulfide balance were measured. The relationship between these parameters and the urticaria activation score (UAS) was evaluated. Appropriate statistical methods were used in comparisons between the two groups. Correlations were analyzed using Spearman's ρ. Diagnostic performance was assessed using ROC analysis. There was no significant difference when both the patient group and the control group were evaluated in terms of age and gender.(p>0.05). -SH and TT were Considerably lower in the CU group (-SH: 535.69±51.90 vs 613.23±90.92 µmol/L; TT: 650.63±55.38 vs 746.51±137.93 µmol/L; both p<0.001). No group differences were found in SS and ratio-based indices (p>0.05). UAS was inversely associated with -SH (ρ=−0.389; p=0.009). IgE was positively correlated with TT (ρ=0.403; p=0.007) and SS (ρ=0.355; p=0.018); no significant association was observed with eosinophilia. ROC analysis revealed AUC=0.749 (SE=0.053; 95% CI 0.645–0.853; p<0.001), cut-off=676.38 µmol/L, sensitivity=0.717, and specificity=0.733 for TT; and AUC=0.729 (SE=0.055; 95% CI 0.622–0.837; p<0.001), cut-off=548.50 µmol/L, sensitivity=0.696, and specificity=0.689 for -SH. The remarkable decrease of the thiol pool (especially -SH and TT) in children with CU is consistent with an oxidative-antioxidative imbalance associated with disease activity and IgE levels. -SH and TT demonstrate statistically significant discrimination between CU and controls, and come forward as complementary biomarkers for clinical evaluation. However, a detailed comprehensive study including larger sample sizes and longitudinal analyses are needed to confirm the findings.