Lumpy-bumpy appearance of glomeruli on immunofluorescence is indicative of?

The lumpy-bumpy appearance of glomeruli on immunofluorescence is characteristic of poststreptococcal glomerulonephritis. This appearance is caused by the presence of immune complex deposition along the glomerular basement membrane and mesangial areas, which results from a previous infection, typically a group A beta-hemolytic streptococcal infection. The immunofluorescence microscopy shows granular staining due to these immune complexes.

In poststreptococcal glomerulonephritis, the lumpy-bumpy pattern reflects the localized deposits of antibodies and complement, primarily C3, along the glomerular capillaries. This phenomenon can also lead to the characteristic symptoms of hematuria, proteinuria, and often a decrease in complement levels, particularly C3.

Other types of glomerular diseases present differently under immunofluorescence. For instance, focal segmental glomerulosclerosis typically shows diffuse staining patterns without the lumpy-bumpy appearance. Diabetic nephropathy generally presents with changes in the mesangium and thickening of the basement membrane, which do not produce the lumpy-bumpy pattern. Membranous nephropathy is characterized by a more diffuse