Crescents and pauci-immune pattern in biopsy with SAGN. Patient 1 from Table 5, a twenty-two-year-old white man, intravenous drug user with tricuspid valve endocarditis, methicillin-resistant Staphylococcus aureus bacteremia, and cytoplasmic ANCA positivity showing “pauci-immune pattern” on the biopsy with concomitantly trace IgA, IgG, and C3. (A) Focal crescents (Periodic acid Schiff-trichrome stain; original magnification, ×400). (B) Trace IgA staining (original magnification, ×400). (C) Trace C3 staining (original magnification, ×400). (D) Few small paramesangial electron dense immune-type deposits. No subepithelial humps seen (uranyl acetate and lead citrate fixation; original magnification, ×25,000).