. 2017 Oct 13;29(1):283–294. doi: 10.1681/ASN.2017030258

Table 6.

Clinical features, complement assessment, genetic screening, and histologic features in patients classified according to the clusters obtained through the three-step algorithm for cluster definition

Variable	Cluster 1	Cluster 2	Cluster 3	Cluster 4	Overall P Value
N	56	40	28	49
Sex, % men	57	48	57	61	0.62
Data at onset
Age, yr	15.3 (±12.4)	18 (±12.7)	15 (±10.8)	26.3 (±19.8)^a^,^b^,^c	<0.001
Microhematuria, %	89	87	93	73	0.08
Gross hematuria, %	36	30	43	31	0.65
Proteinuria, %	93	98	86	86	0.17
Nephrotic syndrome, %	32	68^a^,^c^,^d	21	18	<0.001
Renal impairment, %	13	23^c	4	31^a^,^c	0.01
Trigger event, %	32	26	32	29	0.92
Familiarity for nephropathy, %	16	13	11	17	0.89
Serum C3, mg/dl	31.6 (±21.2)	21 (±18.8)^a^,^c	35.6 (±35.6)	96.2 (±28.8)^a^,^b^,^c	<0.001
Serum C4, mg/dl	21.6 (±9.7)	20.6 (±12.6)	24.2 (±9.2)	21.8 (±7.5)	0.53
Plasma SC5b-9, ng/ml	1297 (±1281)^c^,^d	2003 (±1389)^a^,^c^,^d	523 (±508)^d	308 (±154)	<0.001
Low serum C3 and normal C4, %	95	78	86	42^a^,^b^,^c	<0.001
LPV carriers, %	34	25	14	2^a^,^b	<0.001
C3NeF positive, %	52	60	79	7^a^,^b^,^c	<0.001
LPV carriers and/or C3NeF, %	75	75	83	9^a^,^b^,^c	<0.001
Data during follow-up, %
Nephrotic syndrome	48	90^a^,^c^,^d	50	47	<0.001
High BP	27	45	25	57^a^,^c	0.004
CKD	27	45	25	47	0.06
ESRD	5	8	4	16	0.20
Thrombotic microangiopathy	2	0	0	12^a^,^b	0.01
Histologic features
Time onset to biopsy, yr, median (IQR)	0.4 (0.1–2.1)	0.3 (0.0–1.9)	0.4 (0.4–3.8)	0.4 (0.0–3.0)	0.23
Light microscopy
Sclerotic glomeruli, %	4 (±8)	6 (±12)	2 (±6)	16 (±21)^a^,^b^,^c	<0.001
Crescents, %	6 (±17)	3 (±8)	6 (±19)	6 (±17)	0.73
Degree of mesangial proliferation^e	2 (±0.9)	1.7 (±1.1)	1.9 (±0.8)	1.6 (±1)	0.22
Degree of endocapillary proliferation^e	1.3 (±1.2)^d	1.6 (±1)^c^,^d	1 (±1.1)	0.6 (±0.8)	<0.001
Degree of interstitial inflammation^e	0.4 (±0.6)^b^,^d	0.8 (±0.7)	0.7 (±0.9)	1 (±0.9)	0.001
Degree of interstitial fibrosis^e	0.3 (±0.6)	0.5 (±0.8)	0.2 (±0.4)	0.8 (±0.9)^a^,^c	0.003
Degree of arteriolar sclerosis^e	0.1 (±0.5)	0.2 (±0.5)	0.1 (±0.2)	0.6 (±1)^a^,^b^,^c	<0.001
IF^e
C3	2.7 (±0.5)	2.7 (±0.5)	2.8 (±0.3)	2.5 (±0.7)^a^,^c	0.04
IgA	0.1 (±0.4)^b^,^d	0.4 (±0.7)^c	0.1 (±0.3)	0.4 (±0.8)	<0.01
IgG	0.3 (±0.8)	1.5 (±1)^a^,^c	0.4 (±0.7)	1.2 (±1.2)^a^,^c	<0.001
IgM	0.6 (±0.8)	1.3 (±0.9)^a^,^c^,^d	0.7 (±0.6)	0.8 (±1)	0.001
C1q	0 (±0.1)^c^,^d	1.7 (±0.7)^a^,^c^,^d	0.2 (±0.5)^d	0.7 (±0.9)	<0.001
Fibrinogen	0.4 (±0.8)	0.5 (±0.9)	0.3 (±0.7)	0.1 (±0.3)^a^,^b	0.05
Electron microscopy, %
Mesangial deposits	72	72	50	50^a^,^b	0.04
Subepithelial deposits	48	49	11^a^,^b^,^d	43	<0.01
Subepithelial hump-like deposits	22	14	11	20	0.55
Subendothelial deposits	77	87	11^a^,^b^,^d	70	<0.001
Intramembranous granular deposits	60	54	0^a^,^b^,^d	40	<0.001
Intramembranous highly electron-dense ribbon-like deposits	0	0	100^a^,^b^,^d	0	<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.

Significantly different versus cluster 1.

Significantly different versus cluster 2.

Significantly different versus cluster 3.

Significantly different versus cluster 4.

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+.