Nieuwhof C, Doorenbos C, Grave W, deHeer F, deLeeuw P,
Zeppenfeldt E, van Breda Vriesman PJC
A prospective study of the natural history of idiopathic non-
(Jan) 49:222-224 1996
Hematuria is a common problem for which renal consultation is frequently
sought. There are few studies that have examined the issues of etiology and
long term prognosis of patients with hematuria in a prospective manner.
As part of
their multicenter prospective study of glomerulonephritis, Nieuwhof et al
investigated 49 patients with gross (18 patients) or microscopic (31
hematuria which was persistent for 6 months. These patients had a negative
urologic workup, did not have any systemic diseases, liver disease,
or familial diseases associated with hematuria. Patients were allowed to
more than 500 mg/day of proteinuria and all had normal renal function. All
underwent renal biopsy and were followed prospectively for a median of 11
years. Of the 49 patients, idiopathic IgA nephropathy and thin glomerular
basement membrane ( GBM ) disease accounted for 12 and 13 patients,
respectively. Three patients had interstitial nephritis, one had focal
sclerosis and twenty had normal histology.
In patients with IgA nephropathy, thin GBM disease and normal histology, GFR
well maintained over the follow-up period. Microscopic hematuria persisted
majority of patients
with glomerular diseases but resolved in 65% of patients with normal
some of whom had symptoms of urolithiasis. Patients with interstitial
and focal global sclerosis were found to have diminished renal function. The
disturbing finding is that of the 29 patients with renal pathology 15
hypertension compared to one of 20 with normal renal histology.
Comments: The strengths of the study are: patients were studied
renal histology was examined in all patients and the follow-up period was a
median of 11 years. The good news is renal function is well maintained in
hematuric patients with glomerular diseases who have normal or only mildly
increased protein losses in the urine. The bad news is that patients with
interstitial nephritis may progressively lose renal function and that
hypertension appears in more than 50% of patients with renal pathology. One
would have liked to have seen a more thorough investigation of
in patients with normal histology.
B.S. Kasinath, M.D.