Traitement de la glomérulonéphrite membranoproliférative avec C3 glomérulopathie chez les adultes (18+)
Scénario clinique
Adultes ≥ 18 ans
Ce protocole s'adresse aux adultes âgés de 18 ans ou plus diagnostiqués avec une C3 glomérulopathie (C3G) — un schéma spécifique de glomérulonéphrite membranoproliférative — affectant soit un rein natif soit un rein post-transplantation.
Objectifs thérapeutiques
Les objectifs principaux sont une réduction substantielle et durable de la protéinurie (évaluée à 26 semaines puis à 12 mois), la stabilisation du DFGe à 6 mois et la réduction de la coloration glomérulaire C3 à la biopsie rénale à la semaine 26.
Approche thérapeutique
Les données probantes actuelles soutiennent l'ajout d'un inhibiteur proximal du complément en plus des soins de soutien continus chez les adultes présentant une protéinurie significative au départ. Le protocole complet précise les agents éligibles, leurs voies d'administration et tous les critères pertinents.
References
DOI: 10.1016/j.ekir.2025.10.020
In 2025, iptacopan was also approved by the US Food and Drug Administration for the treatment of adults with C3G to reduce proteinuria, and by the European Medicines Agency for the treatment of adults with C3G in combination with a renin-angiotensin-aldosterone system inhibitor or as monotherapy in patients who are renin-angiotensin-aldosterone system inhibitor-intolerant.
The phase 3 trial data suggest that we should be using these agents in patients with significant proteinuria at the outset.
Patients who achieve a UPCR < 0.88 g/g (< 100 mg/mmol) at 12 months after diagnosis benefit from a 90% lower risk of kidney failure than those who did not achieve this threshold.
For both C3G and primary IC-MPGN, a ≥ 50% proteinuria reduction after 12 months has consistently been associated with significantly lower risk of kidney failure, as demonstrated by both the UK RaDaR and Spanish GLOSEN registries.
In this context, even stabilization of eGFR may be considered a success after 6 months of complement inhibitor therapy, although it must be acknowledged that changes in eGFR are dependent on factors such as disease chronicity.
Pegcetacoplan treatment resulted in 74.3% (26/35) of patients achieving a meaningful reduction in staining (≥ 2 point improvement on the 0–3 scale) by week 26 and 71.4% (25/35) had zero C3 staining in the biopsy after treatment.
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