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
Serum C3 is persistently low in the following except: 
Select and explain. 
A. Post streptococcal glomerulonephritis, B. Membranoproliferative glomerulonephritis, C. Lupus nephritis, D. Glomerulonephritis related to bacterial endocarditis
A: Post streptococcal glomerulonephritis
Answer: A: Post streptococcal glomerulonephritis 
Explanation: Answer is A (Post streptococcal glomerulonephritis): Although all conditions mentioned in the question are associated with low compliment levels 'persistently depressed levels' are not seen in post streptococcal glomerulonephritis. In post streptococcal glomerulonephritis: serum C3 levels are depressed within 2 weeks, however these usually return to normal levels within 6 to 8 weeks Persistently depressed levels after this period should suggest another cause such as presence of C3 nephritic factor (Membranoproliferative glomenulonephritis) - Harrison Low complement levels (Immune complex glonerulonephritis) Idiopathic proliferative glomerulonephritis Crescentric glomenelonephritis Membranoproliferative glomerulonephritis Lupus nephritis Cryoglobulinemia Bacterial endocarditis Shunt nephritis Post infectious glomerulonephritis.(post streptococcal) Normal complement levels Anti GBM disease: Good posture's syndrome Pauci immune glomenulonephritis - Wegeners granulomatoses - Microscopic polyaeritis nodosa Immune complex mediated - IgA Nephropathy - Henoch schonlein purpura - Fibrillar)/ Glomerulonephritis