This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidney, Subject name: Medicine
[{'content': 'A boy is suffering from acute pyelonephritis. Most specific urinary finding will be - \nSelect and explain. \nA. W.B.C. casts, B. Leucocyte esterase test, C. Nitrite test, D. Bacteria in gram stain', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Wbc casts are seen in- Interstitial nephritis Acute pyelonephritis Allograft rejection Malignant infiltration of the kidney. Rbc casts - GN vasculitis Malignant hypeension Thrombotic microangiopathy Granular casts- ATN GN vasculitis Tubulointerstitial nephritis. Ref:Harrison 20 th edition pg no. 2106', 'role': 'assistant'}]