C3 glomerulopathy is highly prevalent in French Polynesia

Abstract

Objective: To compare the natural history of C3 glomerulopathy (C3G) to acute post-infectious glomerulonephritis (APIGN) in a cohort of patients with a relative homogeneity of environment conditions and genetic background. Methods: We retrospectively reviewed the characteristics of all patients with biopsy proven C3G or APIGN referred in 2013–2019 to the only renal unit in French Polynesia. Results: Point prevalence of C3G is ∼23 cases per 100,000 inhabitants. A recurrent variation of CFI (p.Arg406His) was identified at the heterozygous state in 4/8 (50 %) patients with C3G but its pathogenicity remain elusive. Characteristics at presentation and kidney outcomes were roughly similar between C3G (n = 16) and APIGN (n = 20), excepted for the presence of humps on kidney biopsy. Conclusions: C3G is highly prevalent in French Polynesia suggesting specific genetic or environmental susceptibility factors. Systematic diagnosis workflow should be proposed to all patients with C3 predominant glomerulonephritis.

Keywords

• C3 glomerulonephritis
• Acute post-infectious glomerulopathy
• Complement alternative pathway
• Complement factor I