Go back to clinical information and images

Diagnosis: Proliferative Endocapillary GN with Predominant deposits of C3: C3GN (Versus Postinfectious)

There seems to be an almost general agreement in the nephropathology community, that in cases of GN with exclusive or very predominant deposits of C3, with negative or weak deposits of any immunoglobulin or C1q, the correct diagnosis we C3GN. This case, based only on that criterion (IF only), fit into that diagnosis. That's fine from my perspective, because what this diagnosis means is that you should make long-term monitoring with serum complement, or ideally, studying all factors involved in the alternative pathway of complement (most of these tests are not available outside referral centers or well-equipped research centers).

In the case presented here, however, are striking the presence of "humps" on the ultrastructure and features of the IF: thick deposits with large granules, the pattern described as "bumps and humps" or "lumpy-dumpy"; both features are traditionally associated with postinfectious GN. Strictly speaking, to confirm this diagnosis is essential to demonstrate the association with a previous infection, which could not be done in our case. However, in clinical follow-up, she had complete remission of the disease and serum C3 levels normalized. So it seems to behave like a post-infectious GN. Still, it is known that infections can challenge the complement system and unmask an underlying alteration in the alternative pathway. So, regardless of whether or not this case is a true post-infectious GN, it is recommended long-term monitoring with at least measurements of serum complement levels.

Visit the chapter: Proliferative Endocapillary Glomerulonephritisof our Tutorial.

Go back to clinical information and images

References

• Al-Ghaithi B, Chanchlani R, Riedl M, Thorner P, Licht C. C3 Glomerulopathy and post-infectious glomerulonephritis define a disease spectrum. Pediatr Nephrol. 2016 Mar 23. [Epub ahead of print] [PubMed link]
• Barbour TD, Ruseva MM, Pickering MC. Update on C3 glomerulopathy. Nephrol Dial Transplant. 2014 Oct 17. [Epub ahead of print] [PubMed link]
• Viswanathan GK, Nada R, Kumar A, Ramachandran R, Rayat CS, Jha V, Sakhuja V, Joshi K. Clinico-pathologic spectrum of C3 glomerulopathy-an Indian experience. Diagn Pathol. 2015;10:6. [PubMed link]
• Taborda_Murillo A, Arroyave-Suárez MJ, Arias LF. Glomerulonefritis C3: una nueva categoría de glomerulonefritis con implicaciones etiopatogénicas. Iatreia. 2015; 28(1): 24-34. [Link]
• Fervenza FC, Sethi S. Circulating complement levels and C3 glomerulopathy. Clin J Am Soc Nephrol. 2014;9(11):1829-31. [PubMed link]

[Top]

Go back to clinical information and images