C3 and diabetic kidney disease: As compared to patients with both C3 and immunoglobulin deposits, those with isolated C3 deposits had long standing diabetes with more advanced DKD (63.8% vs. 43.8%, p = .081) and a lower median (IQR) eGFR [8.9 (6.3–19.9) vs. 18.3 (7.6–33.4) mL/min/1.73 m2, p = .008] at presentation (Table S1).