A 13-year-old boy presents with periorbital and lower extremity edema. Vital signs reveal BP 142/88 mmHg, HR 88/min, RR 18/min, and Temp 37.2°C. Urinalysis shows hematuria and proteinuria (3.2 g/day). Serum creatinine is 1.8 mg/dL (baseline 0.8), with low C3 (45 mg/dL) and normal C4 levels. Renal biopsy demonstrates electron-dense ribbon-like intramembranous deposits on electron microscopy. He denies recent streptococcal infection. Which mechanism most likely explains his glomerulonephritis?
- A)Defect in alpha-3 chain of type IV collagen
- B)Autoantibody stabilizing C3 convertaseGABARITO
- C)Antibody to phospholipase A2 receptor
- D)IgA deposition after mucosal infection
- E)Autoantibodies against double-stranded DNA
Explicação
Dense deposit disease, a form of C3 glomerulopathy, is driven by dysregulation of the alternative complement pathway, often due to C3 nephritic factor that stabilizes C3 convertase. This causes persistent complement activation, low C3, and dense intramembranou... Ver explicação completa e trilha adaptativa →