Tubular and interstitial lesions and mononuclear cell infiltration in primary forms of glomerulonephritis.

In the present study of 246 patients with primary forms of glomerulonephritis (GN) we investigated their tubular and interstitial changes, especially mononuclear cell infiltration and optical microscopy, and compared this finding with the outcome of the disease (5-year survival rate). Only first biopsies were analyzed in order to detect early tubulointerstitial changes which occur together with the glomerular changes. Different degrees of the lesions of tubules and interstitium were present in different forms of GN. Mononuclear cell infiltration was present in 100% of the patients with crescentic, in 90.9% in focal sclerosing, in 89% in membranoproliferative, and in 76.4% of patients with chronic diffuse GN. Less than 50% of the other patients showed infiltration. Using monoclonal antibodies it was demonstrated that mononuclear cell infiltrates mainly consisted of T and T4 cells. Interstitial edema was expressed in the same forms of GN and in similar proportions. Interstitial fibrosis was found only in patients with: focal sclerosing GN (13.7%), IgA GN (4.1%), membranoproliferative GN (31.4%), chronic diffuse GN (23%), and crescentic GN (27.7%). Tubular atrophic changes were again dominantly present in: crescentic GN (94.2%), focal sclerosing GN (77.8%), chronic diffuse GN (76.4%), and membranoproliferative GN (68.4%). Patients with severe tubulointerstitial changes together with the glomerular changes had a low 5-year survival rate of renal function.