A 19-year-old man presents to the emergency department with symptoms of malaise, nausea, and decreased urine output. He was previously well, and his physical examination is normal except for an elevated jugular venous pressure (JVP) and a pericardial rub. His electrolytes reveal acute kidney injury (AKI). Which of the following findings on the urinalysis is most likely in keeping with acute glomerulonephritis (GN)?

Both granular and erythrocyte casts are present, but the latter indicate bleeding from the glomerulus and are most characteristically seen. Red cells reach the urine probably via capillary wall "gaps" and form casts as they become embedded in concentrated tubular fluid with high protein content. Proteinuria is invariably present but is not as specific. White blood cell casts are indicative of interstitial nephritis or infection, and hyaline casts are nonspecific findings.