Abstract
Background: The pathogenesis of idiopathic nephrotic syndrome (INS) has not been fully explained. Among the likely factors, tumor necrosis factor - alpha (TNF-α) is considered. We aimed to evaluate the TNF-α (sTNF-α, uTNF-α) levels in the serum and urine of INS children, with the aim of determining its association with proteinuria, and of determining its usefulness as a marker of the disease severity. Methods: Fifty-one examined patients were divided into subgroups depending on the number of relapses as follows: group IA-first episode; group IB-more than two relapses, and according to treatment modality; group IIA-glucocorticosteroids (GS) alone; and group IIB-GS with immunosuppressants. Healthy age-matched children served as the control group. Results: sTNF-α and uTNF-α levels were significantly increased in active phases in the whole INS group compared to the control group. They decreased in remission, but remained significantly higher when compared to the control group. During remission in the IB group, sTNF-α levels were significantly higher than in IA, whereas, in the relapse phase, these values were similar. In the IA group, a positive correlation between proteinuria and sTNF-α was demonstrated. Conclusions: Our findings suggest that TNF-α plays a role in the development of INS, and may be used as a prognostic marker, as well as an indicator for the continuation of therapy. Additional research is required to verify this statement.