Nephropathy in remnant kidneys: pathological proteinuria after unilateral nephrectomy

It is a matter of dispute as to whether and to what extent hyperfiltrative nephropathy occurs in a contralateral remnant kidney after unilateral nephrectomy. This question was investigated in a retrospective progress observation using urinary electrophoresis among other methods. Of 106 patients who underwent nephrectomy between 1963 and 1984 because of unilateral kidney diseases, only 39 fulfilled all of the requisite criteria for a followup examination 2 to 23 years later. Whereas there was arterial hypertension or decreased kidney function in 4 cases (10.3%), pathological proteinuria was found in 32 of the remnant kidneys (82.1%): tubular in 13 (40.6%) and glomerular in 19 (59.4%). In contrast to that of arterial hypertension or decreased kidney function, this incidence is far greater than the expected risk in the normal population, which in our opinion indicates that hyperfiltrative nephropathy occurs in the contralateral remnant kidney after unilateral nephrectomy without causing relevant restriction of kidney function or increasing the arterial pressure.