"Cresentic glomerular deposits" are seen in?

Ans. A. Wegener granulomatosis. (Ref, Robbin's Pathology8th/pg, Table 14-2)Rapidly Progressive (Crescentic) Glomerulonephritis# RPGN is a clinical syndrome and not a specific etiologic form of GN.# Clinically, it is characterized by rapid and progressive loss of renal function with features of the nephritic syndrome, often with severe oliguria and (if untreated) death from renal failure within weeks to months.# Regardless of the cause, the histologic picture is characterized by the presence of crescents (crescentic GN).# These are produced in part by proliferation of the parietal epithelial cells of Bowman's capsule in response to injury and in part by infiltration of monocytes and macrophages.# Pathogenesis:# Crescentic glomerulonephritis (CrGN) may be caused by a number of different diseases, some restricted to the kidney and others systemic.# Types of Crescentic Glomerulonephritis:A. Type I (Anti-GBM Antibody)1. Idiopathic2. Goodpasture syndromeB. Type II (Immune Complex)1. Idiopathic2. Postinfectious/infection related3. Systemic lupus erythematosus4. Henoch-Schonlein purpura/IgA nephropathyC. Type III (Pauci-Immune) ANCA Associated1. Idiopathic2. Wegener granulomatosis03. Microscopic angiitisAnti-Glomerular Basement Membrane Antibody (Type I) Crescentic Glomerulonephritis* Anti-GBM antibody crescentic glomerulonephritis, or type I CrGN, is characterized by linear deposits of IgG and, in many cases, C3 on the GBM, as described above. In some of these individuals the anti-GBM antibodies also bind to pulmonary alveolar capillary basement membranes to produce the clinical picture of pulmonary hemorrhages associated with renal failure. These persons are said to have Goodpasture syndrome, to distinguish their condition from socalled idiopathic cases in which renal involvement occurs in the absence of pulmonary disease. Anti-GBM antibodies are present in the serum and are helpful in diagnosis. It is important to recognize type I CrGN because these individuals benefit from plasmapheresis, which removes pathogenic antibodies from the circulation.* Immune Complex-Mediated (Type II) Crescentic Glomerulonephritis* Type II CrGNs are immune complex-mediated disorders. This can be a complication of any of the immune complex nephritides, including poststreptococcal GN, SLE, IgA nephropathy, and Henoch-Schonlein purpura. In some cases, immune complexes can be demonstrated but the underlying cause is undetermined. In all of these cases, immunofluorescence studies reveal the characteristic granular ("lumpy bumpy") pattern of staining of the GBM and/or mesangium for immunoglobulin and/or complement. These individuals cannot usually be helped by plasmapheresis.Pauci-Immune (Type III) Crescentic GlomerulonephritisType III CrGN, also called pauci-immune type CrGN, is defined by the lack of anti-GBM antibodies or significant immune complex deposition detectable by immunofluorescence and electron microscopy. Most of these individuals have antineutrophil cytoplasmic antibodies in the serum, which, as we have seen, have a role in some vasculitides. Therefore, in some cases type III CrGN is a component of a systemic vasculitis such as microscopic polyangiitis or Wegener granulomatosis. In many cases, however, pauci-immune CrGN is limited to the kidney and is thus called idiopathic