Table 1.

Clinical features, complement assessment, genetic screening, and histologic features in patients classified according to the C3G/IC-MPGN classification

VariableC3GNDDDIC-MPGNOverall P Value
N682580
Sex, % men6056530.64
Data at onset
 Age, yr18.2 (±16.1)15.3 (±11.2)20.8 (±15.8)0.26
 Microhematuria, %8592820.50
 Gross hematuria, %3744290.34
 Proteinuria, %9388900.77
 Nephrotic syndrome, %2924430.12
 Renal impairment, %194230.10
 Trigger event, %3432250.49
 Familiarity for nephropathy, %1812130.70
Serum C3, mg/dl50.9 (±41.8)33.8 (±36.1)49.8 (±39)0.16
Serum C4, mg/dl21.8 (±8.9)24.4 (±9.6)21.1 (±10.6)0.35
Plasma SC5b-9, ng/ml1163 (±1289)545 (±524)1120 (±1248)0.08
Low serum C3 and normal serum C4, %7484700.38
LPV carriers, %2516160.53
C3NeF positive, %3878a,b400.002
LPV carriers and/or C3NeF, %5683a,b490.02
Data during follow-up, %
 Nephrotic syndrome46b5270<0.01
 High BP3424b490.04
 CKD3128440.17
 ESRD10490.76
 Thrombotic microangiopathy6040.67
Histologic features
 Time onset to biopsy, yr, median (IQR)0.4 (0.0–2.9)1.1 (0.3–4.0)0.4 (0.1–2.3)0.29
Light microscopy
 Sclerotic glomeruli, %8 (±17)2 (±7)8 (±14)0.17
 Crescents, %3 (±11)6 (±20)7 (±18)0.40
 Degree of mesangial proliferationc1.7 (±1)1.8 (±0.7)1.9 (±0.9)0.19
 Degree of endocapillary proliferationc1 (±1.1)0.9 (±1.1)1.2 (±1)0.29
 Degree of interstitial inflammationc0.5 (±0.8)0.6 (±0.8)0.9 (±0.8)a0.03
 Degree of interstitial fibrosisc0.4 (±0.7)0.2 (±0.4)0.6 (±0.8)0.07
 Degree of arteriolar sclerosisc0.3 (±0.8)0 (±0.1)0.3 (±0.7)0.16
IFc
 C32.7 (±0.5)2.8 (±0.3)2.6 (±0.7)0.12
 IgA0 (±0.1)0.1 (±0.3)0.5 (±0.8)a,d<0.001
 IgG0.2 (±0.4)0.2 (±0.4)1.6 (±1.1)a,d<0.001
 IgM0.3 (±0.4)b0.7 (±0.7)a,b1.4 (±0.9)<0.001
 C1q0.1 (±0.3)0.1 (±0.3)1.2 (±1)a,d<0.001
 Fibrinogen0.3 (±0.7)0.3 (±0.8)0.3 (±0.7)0.98
Electron microscopy, %
 Mesangial deposits7248580.08
 Subepithelial deposits57b8a,b37<0.001
 Subepithelial hump-like deposits278140.63
 Subendothelial deposits7112a,b80<0.001
 Intramembranous granular deposits540a,b47<0.001
 Intramembranous highly electron-dense ribbon-like deposits0100a,b4<0.001
  • Quantitative variables are expressed as mean (±SD) unless otherwise specified. Serum C3: reference 90–180 mg/dl; serum C4: reference 10–40 mg/dl; plasma SC5b-9: reference ≤400 ng/ml. IQR, interquartile range.

  • a Significantly different versus C3GN.

  • b Significantly different versus IC-MPGN.

  • c Degrees of mesangial proliferation, endocapillary proliferation, interstitial inflammation, interstitial fibrosis, and arteriolar sclerosis as well as IF findings were graded using a scale of 0–3, including 0, trace (0.5+), 1+, 2+, and 3+.

  • d Significantly different versus DDD.