Clinical features and natural history of IgA nephropathy

IgA nephropathy (IgAN) is the most common form of glomerulonephritis worldw ide. It is characterized by recurrent gross hematuria, microhematuria and/o r proteinuria and diffuse mesangial IgA deposits in glomeruli, It is predom inantly a disease of young mates. Apart from primary IgAN (Berger's disease ), IgA deposits in the glomeruli are also seen in Henoch-Schonlein purpura and in association with various of other diseases, particularly liver cirrh osis. Originally it was thought that IgAN was a benign disease, but it is n ow known that approximately 20-40% of patients develop progressive renal di sease 5 to 25 years after diagnosis and progress to end-stage renal disease . Clinical predictors of progressive disease are elevated serum creatinine concentration at presentation, increased systemic blood pressure, persisten t protein excretion > 1.0 g/day and histological predictors are glomerulosc lerosis, tubular atrophy/interstitial fibrosis, extension of immune deposit s to the perivascular space and crescent formation, Progression correlates more closely with the severity of tubulointerstitial lesions than with the degree of glomerular lesions. These features of IgAN reported in literature were mostly, but not completely, confirmed by analysis of all consecutive patients with biopsy proven IgAN and follow-up > 12 months in the renal uni ts of Heidelberg and Prague using univariate analysis, multiple range test and multiple regression analysis.