An 8-year-old boy and his father visit the pediatrician's office with reports of a sudden onset of abdominal pain and reddish-brown urine. A urinalysis shows 4+ protein. On taking the boy's health history, the nurse learns that he had strep throat a little over a week ago. Assessment findings: Temp 100.6F, RR-22. HR-105, BP= 130/89 Which condition should the nurse suspect?