A 3-year-old boy presents with periorbital and pedal edema. Vital signs show BP 95/60 mmHg, HR 102/min, RR 22/min, temperature 37.2°C, and SpO2 98% on room air. Urinalysis demonstrates heavy proteinuria (4+ protein, 24-hour urine protein 3.5 g/day) consisting predominantly of albumin with no hematuria. Serum albumin is 1.8 g/dL. Kidney biopsy shows normal light microscopy findings. Which mechanism best explains the selective protein loss in this disorder?
- A)Linear antibody deposition along type IV collagen
- B)Loss of the negative charge barrier in the glomerular basement membraneGABARITO
- C)Mesangial trapping of IgA-containing immune complexes
- D)Subendothelial immune complex deposition with complement activation
- E)Amyloid infiltration of the interstitium
Explicação
In minimal change disease, cytokine-mediated podocyte injury causes loss of the negative charge barrier, leading to selective albuminuria. The normal light microscopy and childhood nephrotic syndrome strongly support this diagnosis. Ver explicação completa e trilha adaptativa →