GLOMERULONEPHRITIS-C3 GN

SUMMARY

1. Characterised by the presence of dominant C3 deposits in the glomeruli with minimal or no Ig deposits on IF or IHC.

2. Further characterized as C3GN or Dense Deposit Disease (DDD) on the basis of EM findings.

3. Pattern of glomerular injury is variable and can be mesangial proliferative, diffuse endocapillary proliferative, membranoproliferative, necrotizing and crescentic or sclerosing GN.

4. Associated with abnormalities in regulation of the alternate pathway of complement. Can be primary (due to mutations in the complement regulatory proteins) or secondary (acquired due to autoantibodies to complement regulatory proteins).

5. Pathology: due to dysregulation and persistent activation of the alternative complement pathway. The C3 convertase activity is increased.

6. Presentation: proteinuria, NS, haematuria, variable HTN and renal impairment, C3 levels low, C4 levels normal, some patients present post non-strep URTI with GN.

Reference(s)

Wilkinson, I., Furmedge, D. and Sinharay, R. (2017). Oxford handbook of clinical medicine. Oxford: Oxford University Press. Get it on Amazon.
Feather, A., Randall, D. and Waterhouse, M. (2020). Kumar And Clark’s Clinical Medicine. 10th ed. S.L.: Elsevier Health Sciences. Get it on Amazon.
Hannaman, R. A., Bullock, L., Hatchell, C. A., & Yoffe, M. (2016). Internal medicine review core curriculum, 2017-2018. CO Springs, CO: MedStudy.
Therapeutic Guidelines. Melbourne: Therapeutic Guidelines Limited. https://www.tg.org.au [Accessed 2021].