Clinicopathological characteristics and long-term outcomes of adult patients with proliferative lupus nephritis

Table 1 Baseline demographic and clinical characteristics of patients with proliferative lupus nephritis, n (%)

	n = 207
Age at systemic lupus erythematosus diagnosis (years), mean ± SD	24.12 ± 8.89
Age at renal biopsy (years), mean ± SD	26.63 ± 8.61
Sex
Male	23 (11.1)
Female	184 (88.9)
Weight (kg), mean ± SD	51.47 ± 11.97
Duration between onset of symptoms and biopsy (months), mean ± SD	12.21 ± 14.58
Hypertension	126 (60.9)
Oliguria at presentation	25 (12.1)
Macroscopic hematuria	3 (1.4)
Edema	44 (64.7)
Constitutional symptoms	204 (98.6)
Sinus/ENT	3 (1.4)
Skin rash/purpura	162 (78.3)
Lung involvement	50 (24.2)
Arthritis/polyarthalgia	202 (97.6)
Neurological	38 (18.4)
Renal biopsy International Society of Nephrology/Renal Pathology Society classification
III	43 (20.8)
IV	103 (49.8)
III/IV	6 (2.9)
III/V	5 (2.4)
IV/V	50 (24.2)
Antiphospholipid syndrome positive	20 (9.7)
Extractable nuclear antigen positive	20 (9.7)
Proteinuria (dipstick)
1+	9 (4.3)
2+	50 (24.2)
3+	119 (57.5)
4+	25 (12.1)
Microscopic hematuria
Trace	38 (18.4)
1+	31 (15)
2+	44 (21.3)
3+	66 (31.9)
4+	14 (6.8)
Serum creatinine (mg/dL), mean ± SD	1.67 ± 1.79
Estimated glomerular filtration rate (mL/minute/1.73 m²), mean ± SD	75.21 ± 42.59
Serum albumin (g/dL), mean ± SD	2.30 ± 0.62
Spot protein creatinine ratio (g/dL) or 24 hours urinary protein (g/day), mean ± SD	3.54 ± 3.13
Serum C3 levels
Low (< 0.8)	171 (82.6)
Normal (> 0.8)	36 (17.4)
Serum C4 levels
Low (< 0.16)	138 (66.7)
Normal (> 0.16)	69 (33.3)
Kidney replacement therapy on admission	19 (9.2)
Immunosuppression before biopsy	133 (64.3)
Maintenance treatment
Azathioprine	144 (69.56)
Mycophenolate mofetil	63 (30.43)
Hydroxychloroquine	131 (63.28)

ENT: Ear, nose, and throat; SD: Standard deviation.

Table 2 Histopathological characteristics in patients with proliferative lupus nephritis, n (%)

	n = 207
Total glomeruli ± SD	19.43 ± 7.39
Globally sclerosed ± SD	1.31 ± 2.60
Presence of crescents	74 (35.7)
Mesangial/endocapillary proliferation
Focal	49 (23.67)
Diffuse	158 (76.32)
Interstitial fibrosis/tubular atrophy
None	43 (20.7)
Mild	111 (53.62)
Moderate	38 (18.35)
Severe	3 (1.44)
IgA	133 (64.3)
IgG	164 (79.2)
IgM	160 (77.3)
C3	180 (87)
C1q	160 (77.3)

C1q: Complement component 1q; C3: Complement component 3; Ig: Immunoglobulin; SD: Standard deviation.

Table 3 5-year renal outcomes in patients with and without requirement of kidney replacement therapy on presentation, n (%)

	Overall (n = 207)	Required KRT on presentation (n = 19)	Not required KRT on presentation (n = 188)	P value
Renal outcomes after induction with pulse cyclophosphamide at 6 months
CR	64 (30.9)	2 (10.52)	62 (32.97)	0.04
PR	122 (58.9)	9 (47.36)	113 (60.1)	0.28
ESKD	7 (3.4)	3 (15.7)	4 (2.12)	0.002
Mortality	14 (6.8)	5 (26.3)	9 (4.78)	0.000
Final outcomes at 5 years
CR	94 (45.4)	3 (15.7)	91 (48.40)	0.005
PR	47 (22.7)	2 (10.52)	45 (23.9)	0.170
ESKD	38 (18.35)	8 (42.10)	30 (15.95)	0.010
Mortality	28 (13.52)	6 (31.57)	22 (11.7)	0.016
Renal relapses during 5-year follow-up	34 (16.4)	0	34 (18.0)	0.043
Azathioprine	30 (88.2)	0	30 (88.2)
Mycophenolate mofetil	4 (11.76)		4 (11.76)
Re-biopsy	23 (11.1)	1 (5.2)	22 (11.70)	0.67

CR: Complete remission; ESKD: End-stage kidney disease; KRT: Kidney replacement therapy; PR: Partial remission.

Table 4 Comparison between renal outcomes and baseline mean values of clinicopathological characteristics by using analysis of variance test, n (%)

Variable	Complete remission (n = 94)	Partial remission (n = 47)	End-stage kidney disease (n = 38)	Mortality (n = 28)	P value
Age (years), mean ± SD	26.21 ± 45 7.54	27.89 ± 11.05	25.87 ± 7.98	26.14 ± 8.37	0.699
Duration between onset of symptoms and biopsy (months), mean ± SD	10.98 ± 13.94	11.79 ± 10.85	16.63 ± 21.44	11.07 ± 9.40	0.225
Hypertension	40 (42.5)	31 (65.95)	13 (34.21)	24 (85.71)	< 0.0001
Serum creatinine (mg/dL), mean ± SD	1.14 ± 0.82	1.49 ± 1.01	2.54 ± 2.50	2.59 ± 2.99	< 0.0001
Serum albumin on admission (g/dL), mean ± SD	2.42 ± 0.70	2.32 ± 0.55	2.05 ± 0.44	2.16 ± 0.50	0.014
Protein creatinine ratio (g/dL), mean ± SD	3.27 ± 2.82	4.17 ± 3.94	3.05 ± 2.26	4.16 ± 3.71	0.45
Estimated glomerular filtration rate (mL/minute/1.73 m²) mean ± SD	90.27 ± 30.08	71.62 ± 40.29	56.31 ± 44.96	60.25 ± 41.68	< 0.0001
Required kidney replacement therapy on admission	3 (3.19)	2 (4.25)	8 (21.05)	6 (21.42)	0.001
Mesangial/endocapillary proliferation
Focal	33 (35.10)	11 (23.40)	4 (10.52)	1 (3.571)	0.001
Diffuse	61 (64.89)	36 (76.59)	34 (89.47)	27 (96.42)
Number of globally sclerosed glomeruli, mean ± SD	0.55 ± 1.2	1.44 ± 2.22	2.62 ± 4.05	1.80 ± 3.21	< 0.0001
Presence of crescents	30 (31.9)	18 (38.29)	15 (39.47)	11 (39.28)	0.010
Interstitial fibrosis/tubular atrophy					< 0.0001
None	36 (38.29)	4 (8.51)	2 (5.26)	2 (7.14)
Mild	49 (52.12)	30 (63.8)	22 (57.89)	10 (35.7)
Moderate	9 (9.57)	13 (27.65)	14 (36.8)	12 (42.85)
Severe	0	0	0	4 (14.2)

SD: Standard deviation.