[Clinicopathological study on the relationship between appearance of type I or III collagen in IgA nephropathy]

This study was designed to determine whether or not the appearance of type I or type III collagen in glomeruli and serum procollagen III peptide (PIIIP) concentration are affecting the prognosis of patients with IgA nephropathy. In cases with reduced creatinine clearance (Ccr < 80 ml/min) at the time of renal biopsy, the appearance of type III collagen increased, and subsequently type I collagen appeared as Ccr decreased. In addition, we measured serum PIIIP concentration in these cases. The increase of serum PIIIP correlated with the decrease of Ccr. These results suggest that the appearance of type I and III collagen in glomeruli and the increase in serum PIIIP concentration might be a useful marker to predict the outcome of IgA nephropathy.