Serum C3 is persistently low in the following, EXCEPT:
Post streptococcal glomerulonephritis is associated with normal C4 levels and decreased CH50 and C3 levels in more than 90% of the cases, and these return to normal in 1 -3 months. A normal serum complement in the acute phase as well as hypocomplementemia lasting longer than 1-3 months should raise the suspicion of a diagnosis different than APSGN. Serum IgG and IgM are usually elevated and IgA is normal. Electron microscopy shows immunecomplex deposition in the form of subepithelial humps. Immunoflouresence shows immune complex deposition in the glomerular basement membrane and mesangium. Ref: Harrisons Principles of Internal Medicine, 18th Edition, Chapter 283 ; Manual of Pediatric Therapeutics By John W. Graef, Page 318 ; Rheumatology Secrets By Sterling G. West, 2nd Edition, Page 99 ; Pediatric Nephrology By Ellis D. Avner, Page 783 ; Clinical Use of Pediatric Diagnostic Tests Edited By Enid Gilbe - Barnes, 2nd Edition, Page 620
Post streptococcal glomerulonephritis
Membranoproliferative glomerulonephritis
Lupus nephritis
Glomerulonephritis related to bacterial endocarditis