<prompt> Serum C3 is persistently low in the following except?Post streptococcal glomerulonephritisMembranoproliferative glomerulonephritisLupus nephritisGlomerulonephritis related to bacterial endocarditis  <response>: 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 