[Isolated hematurias: histologic and immunologic study].

An immunologic study and a renal biopsy were performed in 64 patients with isolated hematuria. Fifty of them had macroscopic hematuria and 14 microscopic hematuria. The kidney was normal in 66% by light microscopy; in the remaining 34% glomerular lesions were moderate: thickening of the mesangial matrix, diffuse or segmentary mesangial proliferation. Four patterns were observed by immunofluorescence: C3 located either in the mesangium, or at the level of the vascular pole, mesangial IgA, mesangial IgM and lack of deposits. According to our experience IgA nephropathy presenting as isolated hematuria has a better prognosis than the other symptomatic forms of this glomerulonephritis. No patient with the other renal pathological changes so far developed hypertension or renal failure. We prefer to perform biopsies on patients with isolated hematuria, considering the frequency of IgA nephropathy and the possibility of finding mesangial deposits of IgM and C3 whose significance is so far poorly known.