Based on the electron microscopic image, what would be your initial underlying clinical concern for the findings seen?

 

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Answer: The electron microscopic image demonstrates occasional large hump-like subepithelial deposits which are concerning for an underlying infection. By light microscopy, the biopsy demonstrated a diffuse proliferative and exudative glomerulonephritis characterized by diffuse endocapillary hypercellularity with numerous intracapillary neutrophils. By immunofluorescence, the biopsy demonstrated C3-dominant deposits predominately along capillary loops in a somewhat “starry-sky” pattern. Thus, the biopsy features taken with the patient’s history of an active abscess are compatible with an infection-associated glomerulonephritis.