Table 1.

SLE patient characteristics.

	All cohort, N = 109	IL-26 “low”, N = 88 (81%)	IL-26 “high”, N = 21 (19%)	p-value
Baseline characteristics
Age	38 [33-45]	38 [33-46]	39 [33-44]	0.6
Female sex	94 (86%)	78 (89%)	16 (76%)	0.2
Years since SLE diagnosis	8 [5-14]	7 [5-13]	11 [10-14]	0.036
SLEDAI	1 [0-2]	0 [0-2]	4 [4-6]	< 0.001
SLEDAI > 4	10 (9.2%)	0 (0%)	10 (48%)	< 0.001
Biological presentation
Antiphospholipid syndrome	55 (50%)	42 (48%)	13 (62%)	0.4
Antinuclear antibodies titer	640 [160-1280]	640 [160-1280]	640 [320-1280]	0.16
Antinuclear antibodies titer (ranges)				0.09
0 - 1/200	29 (27%)	27 (31%)	2 (9.5%)
1/200 - 1/500	20 (18%)	14 (16%)	6 (29%)
> 1/500	60 (55%)	47 (53%)	13 (62%)
Anti-DNA
Farr assay (UI/mL)	6 [5-16]	5 [5-10]	17 [9-53]	< 0.001
Positivity in Farr assay (> 9 UI/mL)	38 (35%)	23 (26%)	15 (71%)	< 0.001
ELISA (UI/mL)	18 [7-52]	15 [6-52]	27 [20-55]	0.035
Positivity in ELISA (> 28 UI/mL)	42 (39%)	32 (36%)	10 (48%)	0.5
Urine Protein to Creatinine ratio
uPCR (g/g)	0.0 [0.0-0.1]	0.0 [0.0-0.1]	0.1 [0.0-0.3]	0.003
Significant uPCR (> 0.5 g/g)	5 (4.6%)	1 (1.1%)	4 (19%)	0.7
eGFR (mL/min/1.73 m²)	108 [86-131]	103 [84-130]	119 [96-133]	0.3
Creatininemia (µmol/L)	65 [58-73]	65 [58-72]	66 [61-80]	0.5
Complement components
C3 (g/L)	1.02 [0.88-1.15]	1.03 [0.91-1.16]	0.88 [0.68-1.05]	0.013
Low C3 levels (< 0.7 g/L)	8 (7.3%)	2 (2.3%)	6 (29%)	< 0.001
C4 (g/L)	0.19 [0.15-0.24]	0.19 [0.16-0.24]	0.16 [0.11-0.24]	0.2
Low C4 levels (< 0.15 g/L)	26 (24%)	17 (19%)	9 (43%)	0.047
IL-26 level (ng/ml)	0 [0-0]	0 [0-0]	12 [6-28]	< 0.001
Ongoing therapy				0.12
None	39 (36%)	34 (39%)	5 (24%)
Steroids or immunosuppressive therapy	54 (50%)	44 (50%)	10 (48%)
Both	16 (15%)	10 (11%)	6 (29%)

Data are shown as median [interquartile range] for continuous variables and as number (%) for categorical variables.

eGFR, estimated glomerular filtration rate; SLE, systemic lupus erythematosus; SLEDAI, SLE disease activity; uPCR, urine protein to creatinine ratio.

Significant p-values are in bold.