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: Pathology
[{'content': 'Serum C3 is persistently low in the following except? \nSelect and explain. \nA. Post streptococcal glomerulonephritis, B. Membranoproliferative glomerulonephritis, C. Lupus nephritis, D. Glomerulonephritis related to bacterial endocarditis', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Post streptococcal glomerulonephritisAlthough 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 weeksPersistently depressed levels after this period should suggest another cause such as presence of C3 nephritic factor (Membranoproliferative glomenulonephritis) - Harrison", 'role': 'assistant'}]