Serum antineutrophil cytoplasmic antibody positivity at the time of renal biopsy is associated with disease activity of lupus nephritis

Figures & data

Figure 1. Flow chart manifesting LN patients enrollment.

Table 1. Clinical characteristics and laboratory parameters of LN patients with and without ANCA.

	ANCA-positive group (n = 35)	ANCA-negative group (n = 80)	p-value
Female, n (%)	28 (80)	73 (91.25)	0.086
Age, years	35 (26, 48)	31.5 (24.5, 40)	0.319
Disease duration, months	12 (0.5, 60)	5 (1, 57)	0.954
Clinical manifestations
Malar rash, n (%)	20 (57.14)	33 (41.25)	0.116
Photosensitivity, n (%)	9 (25.71)	15 (18.75)	0.398
Alopecia, n (%)	9 (25.71)	17 (21.25)	0.598
Oral ulcers, n (%)	10 (28.57)	7 (8.75)	0.006
Arthritis, n (%)	18 (51.43)	32 (40)	0.255
Serositis, n (%)	4 (11.43)	3 (3.75)	0.125
Neurological disorder, n (%)	0 (0)	4 (5)	0.229
Anemia, n (%)	22 (62.86)	48 (60)	0.773
Leukopenia, n (%)	4 (11.43)	8 (10)	0.526
Thrombocytopenia, n (%)	9 (25.71)	7 (8.75)	0.019
Fever (noninfectious), n (%)	3 (8.57)	13 (16.25)	0.215
Edema, n (%)	29 (82.86)	64 (80)	0.720
Laboratory indexes
Lymphocyte count, ×10^9/L	0.82 (0.67, 1.11)	1.13 (0.69, 1.66)	0.039
Albumin, g/L	23.1 (19.1, 29.2)	26.7 (21.4, 32.28)	0.027
Uric acid, μmol/L	498.67 ± 167.68	408.14 ± 132.62	0.002
Serum creatinine, μmol/L	100.1 (63.1, 163.7)	74.6 (53.88, 109.55)	0.040
eGFR, ml/min/1.73m^2	50.16 (37.8, 75.36)	65.84 (46.92, 95.64)	0.045
24-h urinary protein, g/24h	3.35 (1.31, 5.93)	2.08 (0.71, 3.92)	0.023
Microscopic hematuria, n (%)	27 (77.14)	53 (66.25)	0.243
Leucocyturia (noninfectious), n (%)	26 (74.29)	40 (50)	0.012
C3, g/L	0.35 (0.23, 0.45)	0.43 (0.30, 0.65)	0.009
C4, g/L	0.06 (0.04, 0.1)	0.07 (0.04, 0.11)	0.276
ANA, n (%)	34 (97.14)	74 (92.5)	0.313
Anti-dsDNA antibody, n (%)	34 (97.14)	56 (70)	0.001
Anti-Sm antibody, n (%)	14 (40)	30 (37.5)	0.800
Anti-SSA antibody, n (%)	17 (48.57)	51 (63.75)	0.128
Anti-SSB antibody, n (%)	5 (14.29)	14 (17.5)	0.669
Anti-nucleosome antibody, n (%)	21 (60)	33 (41.25)	0.064
Anti-ribosomal P antibody, n (%)	12 (34.29)	30 (37.5)	0.742
Anti-Ro-52 antibody, n (%)	17 (48.57)	44 (55)	0.525
Anti-histone antibody, n (%)	17 (48.57)	21 (26.25)	0.019
SLEDAI, score	17.37 ± 4.58	13.91 ± 6.33	0.001

Values for continuous variables are given as means ± standard deviation or median (interquartile range); values for categorical variables are given as count (percentage). eGFR, estimated glomerular filtration rate; C3, complement 3; C4, complement 4; SLEDAI, systemic lupus erythematosus disease activity index.

Figure 2. Pathological classifications of LN patients with and without ANCA. *p = 0.027.

Table 2. Pathological features of LN patients with and without ANCA.

	ANCA-positive group (n = 35)	ANCA-negative group (n = 80)	p-value
Endocapillary hypercellularity, n (%)	33 (94.29)	77 (96.25)	0.483
Glomerular leukocyte infiltration, n (%)	20 (57.14)	44 (55)	0.831
Microthrombosis/wire loop lesions, n (%)	21 (60)	35 (43.75)	0.109
Fibrinoid necrosis/karyorrhexis, n (%)	21 (60)	23 (28.75)	0.002
Cellular crescents, n (%)	17 (48.57)	37 (46.25)	0.818
Interstitial inflammation, n (%)	35 (100)	75 (93.75)	0.157
Glomerular sclerosis, n (%)	14 (40)	36 (45)	0.619
Fibrous crescents, n (%)	4 (11.43)	16 (20)	0.264
Tubular atrophy, n (%)	31 (88.57)	72 (90)	0.526
Interstitial fibrosis, n (%)	29 (82.86)	60 (75)	0.354
Arteriolar lesions, n (%)	8 (22.86)	10 (12.5)	0.160
AI, score	11 (5, 14)	8 (4, 12)	0.028
CI, score	2 (2, 3)	2.5 (2, 4)	0.529
TIL, score	3 (3, 4)	3 (3, 5)	0.839

Values for nonparametric continuous variables are given as median (interquartile range); values for categorical variables are given as count (percentage). AI, activity index; CI, chronicity index; TIL, tubular interstitial lesion.

Figure 3. Induction therapy, treatment response and renal outcomes of LN patients with and without ANCA. (a) Induction therapy of LN patients between ANCA-positive and ANCA-negative groups. (b) Induction therapy of ANCA-positive LN patients. (c) Treatment response of LN patients between ANCA-positive and ANCA-negative groups. (d) Renal outcomes of LN patients between ANCA-positive and ANCA-negative groups. *p = 0.028. CYC, cyclophosphamide; MMF, mycophenolate mofetil; ESRD, end-stage renal disease; Scr, serum creatinine.

Figure 4. Cumulative renal survival rate of LN patients with and without ANCA.

Data availability statement

The data will be available from the corresponding author upon reasonable request.