Implications of serum TNF-β and IL-13 in the treatment response of childhood nephrotic syndrome

The cause of childhood nephrotic syndrome (NS) is unknown and whether it responds to steroid therapy remains unpredictable. In the present study, we measured the Th1/Th2 cytokines, serum tumor necrosis factor-β (TNF-β) and interleukin-13 (IL-13), levels in children with NS before and after prednisolone (60 mg/m²/day) treatment for 4 weeks, to evaluate their relationships with disease activity and treatment response. Patients with acute NS had higher serum TNF-β and IL-13 levels than normal controls. After 4 weeks of prednisolone treatment, patients with steroid-resistant NS (SRNS) presented a higher serum TNF-β level than that before treatment (p=0.008). In contrast, patients with steroid-sensitive NS (SSNS) presented a higher serum IL-13 level than that before treatment (p=0.027). This study demonstrates the significance of serum TNF-β and IL-13 levels in relation to the disease activity and treatment response of childhood NS. Patients with SRNS appeared to have elevated TNF-β after steroid therapy, while patients with SSNS tended to have elevated IL-13 after steroid therapy. Thus, an altered Th1/Th2 reaction as demonstrated by TNF-β/IL-13 imbalance may play a pathophysiologic role in childhood NS.