A PROSPECTIVE-STUDY OF THE NATURAL-HISTORY OF IDIOPATHIC NON-PROTEINURIC HEMATURIA

In a prospective study of idiopathic glomerulonephritis we determined the natural history of 49 adult patients (12 primary IgA nephropathy, 13 thin GBM nephropathy, 20 normal renal tissue and 4 miscellaneous ne phropathies) who presented with idiopathic non-protein-uric non-azotem ic hematuria of at least six months duration, in the absence of hypert ension and with a negative urological work-up. The median follow-up wa s 11 years with a range of 8 to 14 years. At the end of the follow-up, renal function had remained stable in all subsets except for those wi th miscellaneous disease. Hematuria was still present in all patients with thin GBM nephropathy, in all but two patients with IgA nephropath y who went into immunopathological remission, in three out of four mis cellaneous nephropathies, and in seven out of 20 patients with normal renal tissue. Of the latter patients five had a history suggestive of urolithiasis at follow-up, which was in the absence of hypercalciuria and hyperuricosuria. Seven thin GBM patients, five IgA nephropathy pat ients and three miscellaneous nephropathies developed hypertension; th e incidence of hypertension in each subset was significantly higher th an in patients with normal renal tissue. This study shows that in youn g adults with idiopathic chronic non-proteinuric hematuria of four yea rs duration, renal biopsy will give a definite diagnosis in 86% of the patients, and that those patients with so-called minor glomerular dis eases are at high risk for hypertension. Those patients with normal re nal tissue have a high incidence of urolithiasis and should have an ur ological follow-up.