Membranoproliferative glomerulonephritis complicating Propionibacterium acnes infection

Delayed Manifestation of Shunt Nephritis: A Case Report and Review of the Literature

We present an unusual case of shunt nephritis in a 39-year-old male who presented 21 years after placement of a ventriculoperitoneal (VP) shunt. He complained of fevers, headaches, dizziness, and urticarial plaques on arms, trunks, and legs and was found to have anemia, low complement levels, elevated serum creatinine, proteinuria, and new onset microhematuria. Blood and urine cultures were negative. Renal biopsy showed features of acute tubulointerstitial nephritis attributed to vancomycin use. Glomeruli showed increased mesangial hypercellularity and segmental endocapillary proliferation. Immunofluorescence showed focal IgM and C3 staining. Electron microscopy revealed small subendothelial electron-dense deposits. Symptoms and renal insufficiency appeared to improve with antibiotic therapy. He was discharged and readmitted 2 months later with similar presentation. CSF grew Propionibacterium acnes and shunt hardware grew coagulase-negative Staphylococcus. He completed an intravenous antibiotic course and was discharged. On 1-month follow-up, skin lesions persisted but he was otherwise asymptomatic. Follow-up labs showed significant improvement. We did a brief systematic review of the literature on shunt nephritis and report our findings on 79 individual cases. In this review, we comment on the presentation, lab findings, pathological features, and management of this rare, potentially fatal, but curable disease entity.

Gemella sanguinis endocarditis with c-ANCA/anti-PR-3-associated immune complex necrotizing glomerulonephritis with a 'full-house' pattern on immunofluorescence microscopy

A 67-year-old man was evaluated for haematuria, with a rising creatinine level from 88 to 906 µmol/L and positive c-anti-neutrophil cytoplasm antibody (ANCA)/anti-proteinase 3 (anti-PR3). A kidney biopsy revealed necrotizing glomerulonephritis with a ‘full-house’ pattern on immunofluorescence microscopy. Echocardiography and blood cultures growing Gemella sanguinis diagnosed endocarditis. Dialysis was required for a month. Three months later, following valve replacement, glucocorticoids and 2 months of antibiotic therapy, the creatinine level decreased to 62 µmol/L and c-ANCA/anti-PR3 disappeared. This first case of c-ANCA/anti-PR3 positive glomerulonephritis with a ‘full-house’ immunofluorescence pattern due to bacterial endocarditis underlines the importance of ruling out infection with ANCA positivity or kidney biopsy suggestive of lupus nephritis.