[Pax2 expression in children with steroid-resistant primary nephrotic syndrome]

To investigate the difference of Pax2 and P53 expressions in children with primary nephritic syndrome (PNS) and the effect of Pax2 on glucocorsteroid (GC)-resistance.

Renal Pax2 and P53 expressions in children with PNS (40 patients) were detected by immunohistochemistry. A semiquantitative score was used to evaluate the injury degree of the glomeruli and the tubulointerstitium, and correlation analysis was done among Pax2, P53 and pathologic score.

Pax2 and P53 expressions were not found in the control group. Pax2 expression of renal tubule epithelia exsisted in children with PNS and there was weak or no expression of Pax2 in the podocytes. Pax2 expressions in the proximal tubule and the distal tubule in the GC-resistant group were more intense than those in the GC-intensive group (P <0.01). The more the Pax2 expression in the tubule, the more abnormal structure such as dilation and atrophy. Pax2 expression in the tubule epithelia was positively correlated with pathologic score of tubulointerstitium (P < 0.01). There was no P53 expression in the GC-intensive group, but there exsisted P53 expression in parts of the patients from the GC-resistant group, mainly distributing in the renal tubular epithelia. P53 expression was positively correlated with P53 expression and the pathologic score of tubulointerstitium (P < 0.01).

Over-expression of Pax2 in the renal tubule epithelia may improve P53 expression to a certain degree, which may aggravate the lesion of the renal tubule. It may be one of the mechanisms resulting in GC-resistant in children with PNS.