PMC6276453_01
Light microscopy and ultrastructural features. (a) Glomerulus showing a cellular crescent and fibrin within Bowman's space (Jones Silver stain, 400x). (b) Glomerulus with fibrinoid necrosis and segmental mild mesangial hypercellularity (PAS stain, 600x). (c) Electron microscopy showing mesangial electron dense deposits (white arrow).
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fig1
Renal biopsy was done on the 4th hospital day and showed an acute necrotizing and crescentic glomerulonephritis, with ten of fourteen glomeruli showing cellular crescents, often in association with areas of fibrinoid necrosis (Figures 1(a) and 1(b)). The glomeruli had mild mesangial and no endocapillary hypercellularity (Figure 1(b)). The electron microscopy performed on glomeruli extracted from the paraffin block showed predominantly mesangial and rare subendothelial immune-type electron dense deposits (Figure 1(c)).
Immunofluorescence microscopy. Granular predominantly mesangial staining for the immunoglobulins (a) IgG (1+), (b) IgM (1+), and (c) IgA (1+) and complement components (d) C3 (2+) and (e) C1q (1+). (f) Segmental fibrinogen staining in an area of fibrinoid necrosis.
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fig2
Immunofluorescence showed mostly mesangial and rare capillary wall weak granular positivity for IgG (1+), IgM (1+), IgA (1+), C1q (1+), and C3 (2+), with equal kappa (1+) and lambda (1+) (Figure 2).