Sub-epithelial humps are characteristic of -

Post streptococcal (Acute proliferative) glomerulonephritis Post-streptococcal glomerulonephritis (PSGN) is an acute proliferative glomerulonephritis which is characterized by diffuse proliferation of glomerular cells, associated with an influx of leukocytes. PSGN is characterized by - (i) Enlarged, hypercellular glomeruli that are caused by Infiltration of leukocytes, both neutrophils and monocytes. Proliferation of endothelial cells and mesangial cells. Proliferation and leukocyte infiltration is diffuse, i.e. involving all lobules of all glomeruli. In severe form → Crescent formation. By immunofluorescence microscopy, there are granular deposits of IgG, IgM and C3 in the mesangium and along the basement membrane. The characteristic electron microscopic findings are discrete, amorphous, electron-dense deposits on the epithelial side of the membrane, often having the appearance of humps → Subepithelial humps. Subendothelial, intramembranous (within GBM) and mesangial deposits may be present. Also, know In its severe form acute diffuse proliferative GN may show rapid deterioration of renal function with the formation of the crescent in the glomeruli → it is referred as rapidly progressive glomerulonephritis.