Nephrotic syndromes Quiz: Ace Your Exams

An 8-year-old boy presents to the primary care physician with facial puffiness. The patient’s parent states, “He seems like he's gained some weight recently, and he's always complaining about his feet hurting now.” She reports the patient had a “sore throat” 2-4 weeks ago. The patient’s temperature is 37.0°C (98.6°F), pulse is 80/min, respirations are 22/min, blood pressure is 100/64 mmHg, and O2 saturation is 96% on room air. On physical exam, a comfortable appearing boy is noted to have 2+ pitting edema in the lower extremities. The posterior pharynx is without erythema or exudate. Cardiopulmonary exam demonstrates normal heart sounds and clear lung fields bilaterally. The patient is asked to provide a urine sample, and it is noted to appear frothy. Which of the following pathophysiologic processes is most likely contributing to this patient’s clinical presentation?