Asymptomatic urinary abnormalities: histopathological analysis

The aim of the study was to assess the characteristics of histopathological changes in 120 young males, both recruits and soldiers, who had undergone successful renal biopsy due to asymptomatic urinary abnormalities. The patients were subdivided into a group with isolated microhematuria (IMH-62 patients) and a group with asymptomatic microhematuria and proteinuria (MHP-58 patients). Light, immunofluorescence, and electron microscopy revealed that MHP was associated with more severe morphological changes, than IMH. The latter group included 6 subjects with normal biopsies and 13 subjects with minor abnormalities found only in two patients with MHP. The frequencies of particular nephropathies in the groups with IMH and MHP were as follows: 35% and 55% for IgA nephritis, 24% and 31% for non-IgA mesangioproliferative glomerulonephritis (GN), 2% and 3% for focal proliferative GN, 3% and 3% for diffuse proliferative GN, 5% and 1% for thin basement membrane nephropathy, respectively. Rebiopsy, performed in eight patients due to worsening of proteinuria during the follow-up period, showed evidence of progression of morphological changes. Patients with IMH had significantly less prominent histopathological changes than patients with MHP. Therefore, renal biopsy cannot be recommended for patients with IMH unless specific indications are present.