Related Experiment Videos
Involvement of the macrophage in experimental chronic immune complex glomerulonephritis
Abstract:
Serial renal biopsies for glomerular culture, histochemical staining for beta-glucuronidase, electron microscopy (EM) and light microscopy, were used to study macrophage involvement in experimental chronic immune complex (IC) glomerulonephritis (GN) induced in rabbits by daily intravenous injections of bovine serum albumin (BSA). In the 26 animals studied, proliferative GN of variable severity was induced, with mild disease in 5 animals, moderate proliferation in 15 and crescentic GN in 6. Macrophages first appeared in glomerular culture outgrowths during the 2nd and 3rd weeks, coincident with the onset of proteinuria and rising serum creatinine concentration. Large numbers of macrophages (in excess of 20 per glomerulus) were seen by the 5th weeks and persisted to the 9th week. The number of macrophages in outgrowths was not significantly greater in animals with crescentic disease. EM demonstrated macrophages in capillary loops, and in glomeruli with crescents, macrophages could be seen in the urinary space. Histochemical staining for beta-glucuronidase also demonstrated macrophages in the glomerular tuft and in crescents when present. These results indicate that macrophages constitute a considerable proportion of the glomerular hypercellularity seen in chronic IC glomerulonephritis.
Insights
Macrophages play a significant role in chronic immune complex glomerulonephritis (IC GN). These immune cells are a major component of glomerular hypercellularity in this kidney disease.
Area of Science:
- Nephrology
- Immunology
- Pathology
Background:
- Chronic immune complex glomerulonephritis (IC GN) is a kidney disease characterized by inflammation and damage to the glomeruli.
- The cellular mechanisms driving the progression of IC GN require further elucidation.
Purpose of the Study:
- To investigate the role of macrophages in the pathogenesis of experimental chronic IC GN.
- To quantify macrophage infiltration and distribution within the glomeruli during disease progression.
Main Methods:
- Induction of chronic IC GN in rabbits using bovine serum albumin (BSA) injections.
- Serial renal biopsies analyzed via glomerular culture, histochemical staining for beta-glucuronidase, light microscopy, and electron microscopy (EM).
Main Results:
- Macrophage infiltration was observed in glomerular outgrowths starting in the 2nd-3rd week, coinciding with proteinuria and elevated serum creatinine.
- Large numbers of macrophages (>20 per glomerulus) were present from week 5 to week 9.
- EM confirmed macrophages within capillary loops and urinary spaces (in crescentic GN); beta-glucuronidase staining identified macrophages in glomerular tufts and crescents.
Conclusions:
- Macrophages are a substantial component of glomerular hypercellularity in chronic IC GN.
- Macrophage presence is a key feature throughout the course of experimental IC GN, irrespective of disease severity (mild to crescentic).