# Eculizumab in C3 Glomerulopathy: A Systematic Review of Therapeutic Efficacy and Clinical Outcomes

## TL;DR

Eculizumab helps some patients with C3 glomerulopathy by improving kidney function and reducing proteinuria, but its effects are limited and more research is needed.

## Contribution

This systematic review evaluates eculizumab's efficacy in C3 glomerulopathy, highlighting its clinical benefits and limitations in a rare kidney disease.

## Key findings

- Eculizumab stabilized renal function and reduced proteinuria in most patients with C3G or DDD.
- Histopathological improvements were variable, and some patients experienced recurrence after discontinuation.
- Responses were limited in cases with alternative mechanisms of C5 activation.

## Abstract

Background: C3 glomerulopathies (C3G), including dense deposit disease (DDD) and C3 glomerulonephritis (C3GN), are rare kidney disorders driven by dysregulation of the alternative complement pathway. Eculizumab, a terminal complement inhibitor targeting C5, has emerged as a potential therapeutic option in these conditions. This systematic review evaluated the efficacy and safety of eculizumab in patients with C3G or DDD. Methods: Literature searches in PubMed and Cochrane databases identified case reports and case series reporting eculizumab use. Results: Only eight studies involving ten patients met the inclusion criteria. Eculizumab stabilized renal function and reduced proteinuria in most cases, especially when C5b-9 deposition was present. Histopathological improvements were variable, and recurrence after discontinuation occurred in some patients. Responses were limited in cases with alternative mechanisms of C5 activation. Conclusions: Eculizumab offers clinical benefit in select C3G and DDD patients but does not address the underlying cause of complement dysregulation. The need for long-term therapy, incomplete histologic resolution, and risk of relapse underscore the necessity of larger trials and the development of personalized treatment strategies.