system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 15-year-old boy is brought to the physician because his urine has been pink since that morning. During the past 2 days, he has had a sore throat and difficulty swallowing. He also reports having a low-grade fever. He has no pain with urination or changes in urinary frequency. He has had 2 similar episodes involving a sore throat and pink urine over the past 2 years. His older sister has systemic lupus erythematosus. His temperature is 38.3°C (101°F), pulse is 76/min, and blood pressure is 120/80 mm Hg. Oral examination shows an erythematous pharynx and enlarged tonsils. The remainder of the examination shows no abnormalities. Laboratory studies show:
Leukocyte count 20,000/mm3
Serum
Urea nitrogen 8 mg/dL
Creatinine 1.4 mg/dL
Urine
Blood 3+
Protein 1+
RBC 15–17/hpf with dysmorphic features
RBC casts numerous
Ultrasound of both kidneys shows no abnormalities. A renal biopsy is most likely to show which of the following findings?"
assistant
IgA mesangial deposition