IGA NEPHROPATHY WITH GLOMERULAR EXTRACAPILLARY PROLIFERATION IN ADULTS

Abstract

Glomerular extracapillary proliferation in IgA nephropathy is one of the unfavorable prognostic signs that in some cases, contributes to a rapid progression of the renal failure. The aim of the study was to assess the effect of extracapillary proliferation and its degree on clinical and morphological parameters and the prognosis of IgA nephropathy. Two hundred and six cases of IgA nephropathy diagnosed on kidney biopsy with light and luminescence microscopy using the Oxford classification were analyzed. Quantitative evaluation of the crescents was done by calculating their percentage and crescent score. Extracapillary proliferation was detected in 64 cases (31.1 %) and was associated with more frequent deposits of IgA and C3 in the glomerular basal membranes. In most cases (59.4 %), extracapillary proliferation affects less than a quarter of the glomeruli, while more than half of the glomerulus lesions develops only in single cases (6.3 %). Clinical manifestations of cases of IgA nephropathy with crescents were overwhelmingly characterized by nephritic syndrome (71.9 %) in single cases (3.1 %) there was a rapidly progressive lesion, not associated with the presence of more than half of crescentic glomeruli in the biopsy. Glomerular extracapillary proliferation in every fourth patient was accompanied by isolated urinary abnormalities. The crescent score of 0.75 and more, associated with impaired renal function, revealed more frequently hypertension and more pronounced sclerotic glomerular and interstitial changes. The progression of IgA nephropathy with extracapillary proliferation in the form of reduction in glomerular filtration rate by 50 % or the onset of dialysis (12.5 %) was combined with a high level of proteinuria and marked interstitial fibrosis in the biopsy. The kidney function survival analysis revealed a one-year survival in 87 %, 3 years – in 84 and 5 years – in 67 % of cases.