This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
Gross hematuria, 3 days following an attack of UI in a young female is likely due to? 
Select and explain. 
A. Post streptococcal glomerulonephritis, B. IgA nephropathy, C. Minimal change disease, D. Membranous glomerulonephritis
B: IgA nephropathy
Answer: B: IgA nephropathy 
Explanation: The two most common presentations of IgA nephropathy are recurrent episodes of macroscopic hematuria during or immediately following an upper respiratory infection often accompanied by proteinuria or persistent asymptomatic microscopic hematuria. So the most likely diagnosis in this patient is IgA nephropathy. IgA nephropathy is an immune complex-mediated glomerulonephritis defined by the presence of diffuse mesangial IgA deposits often associated with mesangial hypercellularity. A renal biopsy is necessary to confirm the diagnosis. There is no optimal treatment. Angiotensin-conveing enzyme (ACE) inhibitors are given in patients with proteinuria or declining renal function. Poststreptococcal glomerulonephritis due to impetigo develops 2-6 weeks after skin infection and 1-3 weeks after streptococcal pharyngitis. This rules out Poststreptococcal glomerulonephritis from the diagnosis in this case. Minimal change disease and Membranous Glomerulonephritis does not produce gross hematuria but instead microscopic hematuria. Ref: Harrison's Internal Medicine, 18th Edition, Pages 2342-2343, 2340, 2345, 2347