Korean Journal of Nephrology (대한신장학회지), Vol.20(5) : 890~897, 2001
Purpose : Proteinuria is the hallmark of glomerular injury and results from alterations in glomerular permeability. The permeability of diseased glomerulus has been estimated by selectivity of proteinuria. Recently, some authors showed a significant relationship between selectivity of proteinuria and tubulointerstial damage. The present study examines the role of protein selectivity as a prognostic marker in patients with IgA nephropathy and its correlation with other prognostic indices.
Methods : The selective proteiuria index of 81 cases with IgA nephropathy diagnosed between 1990 and 2000 were reviewed, and each case was subclassifted using the following : highly selective(SPI50.1), moderately selective(0.102). The mean age of the patients was 27±15 years with a follow-up period of 38±24 months. Six patients had highly selective proteinuria, thirty three patients had moderately selective proteinuria, and forty two patients had nonselective proteinuria.
Results = 1) A significant relationship was found between the SPI and Haas subclasess(p=0.01). With respect to clinical presentation, hypertension(0, 4, 11 cases, p<0.05), proteinuria(0.52±0.35, 1.85±1.55, 2.79±2.51 g/day, p<0.06) were significant correlation. 2) Chronic renal failure was significantly higher in patients with nonselective proteinuria in comparison with patients with selective proteinuria(p<0.05). 3) Markers of renal failure by the Cox proportional hazards model were Cr(Exp(B)=4.2, p<0.001), Ccr (Exp(B)=2.1, p<0.05), SPI(Exp(B)=1.7, p<0.05), hypertension(Exp(B)=1.6, p<0.05). 4) In 28 patients of IgA nephropathy with nephrotic syndrome, 9 patients were moderately selective, 19 patients were nonselective. The response to therapy, evaluated retrospectively, was 67% and 16% in moderate and nonselective proteinuria(p=0.01). Conclusion : There is ´ a significant relationship between selectivity -of proteinuria and clinical parameters. Moreover, the selectivity of proteinuria has a predictive value on functional outcome.