Experimental studies on factors causing acute serum sickness glomerulonephritis of immune complex origin. II. Pathomorphological analysis

Experimental glomerular lesions induced by chronic immune complex formation. I. Formation and elimination of the immune complex (relationship between the immune status and the glomerular changes)

Chronic immune complex formation was induced in rabbits by daily administration of 12.5 g bovine serum. In good antibody producer animals immediate immune complex production and elimination from the circulation were demonstrable. This was followed within a few minutes by the appearance of free 125I in fairly large amounts in blood, as a sign of immediate phagocytosis and disintegration of the 125I-labelled immune complexes. Phagocytic activity decreased in the host animal during chronic heteroprotein administration in every case. The earliest glomerular changes were those of exudative glomerulonephritis, the extent of which depended on the antibody productivity of the animal. Persistent immunocomplexaemia induced by administration of the antigen over 60 and 100 days, respectively, resulted in mesangioproliferative glomerulonephritis in 7, in membranoproliferative glomerulonephritis in 3, and in membraneous glomerulonephritis in 1 out of 11 laboratory animals.

Experimental glomerular lesions induced by chronic immune complex formation. II. Pathomorphological analysis

Eleven rabbits were given bovine serum albumin i.v., in daily doses of 25 mg. Renal biopsy was performed on the 30th, 60th and 100th day of treatment and the specimens were subjected to light-, electron-microscopic and immunofluorescent studies, so as to follow up the dynamics of the glomerular process. Proteinuria and the serum creatinine and BUN levels were also measured. By the 100th day of treatment mesangioproliferative glomerulopathy had developed in 7, membranoproliferative glomerulopathy in 3 cases and membraneous glomerulopathy in 1 case. On the 30th day of treatment exudative glomerulopathy was demonstrable in the majority of the cases (in 9 animals). It is suggested that the earliest stage of the various glomerulopathies, regardless of their type, is marked by exudative lesions. The heaviest proteinuria was found in membraneous and membranoproliferative glomerulopathies. Changes in the serum creatinine and BUN levels indicative of a deteriorating renal function were noted in the membranoproliferative cases. The results are correlated with clinical observations of human glomerulopathies.

Granulomatous glomerulonephritis, without systemic disorder

The case of a 12-year-old girl dying of renal insufficiency is described. At autopsy granulomatous glomerulonephritis was found without any systemic disease. The glomerular light-, immunofluorescent- and electron microscopic changes were studied. Four hundred glomeruli were analyzed by light microscopic investigation and graded (I-IV). By immunofluorescent investigation, intraglomerular and in the more severely affected glomeruli, periglomerular immunoglobulin deposition was detected. Electron microscopic investigation revealed mononuclear cells and fibroblasts in the glomerular and periglomerular cellular infiltrate, resulting in fragmentation and rupture of Bowman's capsule and loss of the glomerular structure.