In Goodpasture syndrome, autoantibodies against collagen IV in the basement membrane of alveoli produce necrotizing hemorrhagic interstitial pneumonitis. Similarly, the basement membrane of glomeruli is affected. Photo A shows active hemorrhagic lung involvement. In photo B the end result with interstitial fibrosis and hemosiderin-laden alveolar macrophages is illustrated.
From the slide collection of the late Dr. Charles Kuhn