Fig. 1

Light and immunofluorescence microscopy images: a. H&E section showing a representative glomerulus with capillary loops obstructed by pseudothrombi, X 600; b-c. PAS (b) and Masson trichrome (c) stained sections showing segmental to global occlusion of glomerular capillaries by pseudothrombi, X 600. The glomerulus in b also shows segmental double contours, and has a membranoproliferative appearance; d-f Immunofluorescence staining for IgA (d), kappa (e), and lambda (f) showing staining of the pseudothrombi for IgA, kappa, and lambda, with similar intensity. Within some pseudothrombi are intensely stained foci that are more numerous for IgA and kappa than lambda (arrow in image e)