C3 and infection: Compared to patients who did not progress to ESRD (n = 37), these patients (n = 10) were older (73 vs. 58 years, p = 0.04), had higher creatinine level (5.9 vs 1.6 mg/dL, p = 0.000), proteinuria > 1 g/24 h (70% vs. 30%, p = 0.120) and lower serum C3 levels (60% vs 14%, p = 0.006), had more often double positivity [anti-GBM with ANCA] (20% vs. 0%, p = 0.014) at diagnosis and sclerotic histological pattern (30% vs 0%, p = 0.03), more frequently required hemodialysis at diagnosis (70% vs 8%, p = 0.000) and developed serious infection at follow-up (50% vs 32%, p = 0.045).