Anti GBM antibodies are seen in?

Ans: b (Goodpasture's syndrome) Ref: Robbins, 7th ed, p. 968Goodpasture syndrome is due to anti GBM antibodies that react with GBM as well as other basement membranes especially those in the lung alveoli, resulting in simultaneous lung and kidney lesions. The GBM antigen is a component of the noncollagenous domain (NC1) of the a3 chain of collagen Type 4.Comparison of GlomerulonephritisPost streptococcal GNGood pasture SyndromeRapidly Progressive GN (Cresentic GN)C/F: Sore throat/ skin inf -GlomerulonephritisInitially pul.Haemorrage with hemoptysis - RPGNAcute Renal Failure within weeksLow C3 returns to normal within weeksNormal C3 levelsLow C3 levelsM/E light: RBC castsHypercellularity crescentsHypercellularity cresentsIF: Granular IgG, C3,IgM, Starry sky patternLinear IgG, C3Granular & linear IgG, C3 (both)Electro: Subepithelial humpsGBM disruption, no depositsGBM disruption,Electron dense deposits