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 12-year-old boy presents with a 3-day history of frothy brown urine. He does not complain of any other symptoms. He notes that 3 weeks ago he had a fever with a sore throat, but he did not receive any treatment at the time. His blood pressure is 152/94 mm Hg, heart rate is 72/min, respiratory rate is 15/min, and temperature is 37.0°C (98.6°F). Review of his medical record shows that his blood pressure was 118/74 mm Hg just 4 weeks ago. Laboratory analysis reveals elevated serum creatinine, hematuria with RBC casts, and elevated urine protein without frank proteinuria. What laboratory test can confirm the most likely diagnosis in this patient?
assistant
Antistreptolysin O (ASO) titer