A 13-year-old boy presents with periorbital edema, hematuria, and declining renal function. Vital signs show BP 145/92 mmHg, HR 88 bpm, RR 16, temperature 37.2°C, SpO2 98%. Serum creatinine is 1.8 mg/dL (elevated), C3 is low at 35 mg/dL, but C4 is normal at 18 mg/dL. Urinalysis shows 3+ protein. Renal biopsy demonstrates dense ribbon-like intramembranous electron-dense deposits on electron microscopy. No respiratory involvement is noted. Which mechanism most likely explains this disease?
- A)Antibody to phospholipase A2 receptor
- B)Autoantibodies against double-stranded DNA
- C)Defect in alpha-3 chain of type IV collagen
- D)Autoantibody stabilizing C3 convertaseGABARITO
- E)IgA deposition after mucosal infection
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 →