RESUMEN
<p><b>OBJECTIVE</b>To investigate the clinical significance of transforming growth factor-beta 1 (TGF-β1) in children with primary IgA nephropathy (IgAN).</p><p><b>METHODS</b>Thirty children who were diagnosed with primary IgAN by renal biopsy between May 2008 and October 2012 were included in the study. Thirty healthy children were used as the control group. Urinary and blood TGF-β1 levels were measured using enzyme-linked immunosorbent assay, and the protein expression of TGF-β1 in the renal tissue was measured by immunohistochemistry. The correlation between TGF-β1 levels in blood, urine, and renal tissue and their relationship with clinical indices were analyzed.</p><p><b>RESULTS</b>Children with primary IgAN had significantly higher urinary and blood TGF-β1 levels than the control group (P<0.01). Urinary TGF-β1 level was positively correlated with the pathological grade of renal tissue (r=0.557, P=0.001), and a significant positive correlation was also found between the TGF-β1 expression in the renal tissue and the pathological grade of renal tissue (r=0.682, P<0.01). There was no correlation between TGF-β1 levels in blood and renal tissue (r=0.038, P=0.844).</p><p><b>CONCLUSIONS</b>Urinary TGF-β1 level is significantly positively correlated with the pathological severity of disease in children with primary IgAN. Clinical measurement of urinary TGF-β1 may be of great practical value in predicting the progression and prognosis of chronic nephropathy.</p>