Two-Parametric Immunological Score Development for Assessing Renal Involvement and Disease Activity in Systemic Lupus Erythematosus

Table 1

Detailed characteristics of the 261 SLE patients in relation to disease activity.

Patient characteristics	Mean (range) or %			value
	All ()	Active ()	Inactive ()
Background variables
Females (n)	86.6 (226)	75.7 (28)	83.0 (198)	<0.0001
Age (years)	49.2 (18–88)	43.2 (18–80)	50.3 (18–88)	0.02
Disease duration (years)	15.0 (0–45)	9.4 (0–32)	16.0 (0–45)	<0.0001
Caucasian ethnicity (n)	90.8 (237)	83.8 (31)	92.0 (206)	<0.0001
Ongoing tobacco smoking (n)	9.9 (26)	5.4 (2)	10.7 (24)	n.s.
SLICC/ACR damage index (score)	1.3 (0–9)	1.0 (0–7)	1.4 (0–9)	n.s.
SLEDAI (score)	2.9 (0–24)	11.0 (5–24)	1.6 (0–4)	<0.0001
mSLEDAI (score)	2.0 (0–20)	9.3 (5–20)	0.8 (0–4)	<0.0001
Estimated glomerular filtration rate (mL/min/1.73 m^2)	84.0 (5–225)	91.4 (14–225)	82.8 (5–201)	n.s.
Ongoing medication
Prednisolone dose (mg)	6 (0–60)	17.4 (0–60)	4.1 (0–50)	<0.0001
Antimalarials (%, n)	60.5 (158)	62.2 (23)	60.2 (135)	n.s.
Azathioprine (%, n)	5.7 (15)	5.4 (2)	5.8 (13)	n.s.
Cyclophosphamide (%, n)	0.8 (2)	5.4 (2)	0 (0)	∞
Cyclosporin (%, n)	1.5 (4)	0 (0)	1.8 (4)	∞
Methotrexate (%, n)	9.6 (25)	8.1 (3)	9.8 (22)	n.s.
Mycophenolate mofetil (%, n)	12.3 (32)	27.0 (10)	9.8 (22)	0.003
Rituximab (%, n)	3.1 (8)	8.1 (3)	2.2 (5)	n.s.
Sirolimus (%, n)	3.1 (8)	0 (0)	3.8 (8)	∞
Tacrolimus (%, n)	0.8 (2)	2.7 (1)	0.4 (1)	n.s.
Warfarin (%, n)	17.2 (45)	13.5 (5)	17.9 (40)	n.s.
Acetylsalicylic acid (%, n)	26.1 (68)	18.9 (7)	27.2 (61)	n.s.
Statins (%, n)	19.9 (52)	21.6 (8)	19.6 (44)	n.s.
Clinical phenotypes (ACR-97 definitions)
Malar rash (%, n)	43.3 (113)	48.6 (18)	42.4 (95)	n.s.
Discoid rash (%, n)	15.7 (41)	13.5 (5)	16.1 (36)	n.s.
Photosensitivity (%, n)	49.0 (128)	51.4 (19)	48.7 (109)	n.s.
Oral ulcers (%, n)	11.9 (31)	27.2 (10)	9.4 (21)	0.002
Arthritis (%, n)	77.4 (202)	78.4 (29)	77.2 (173)	n.s.
Serositis (%, n)	39.1 (102)	27.0 (10)	41.1 (92)	n.s.
Renal disorder (%, n)	26.4 (69)	51.4 (19)	22.3 (50)	0.0002
Neurologic disorder (%, n)	5.4 (14)	8.1 (3)	4.9 (11)	n.s.
Hematologic disorder (%, n)	59.0 (154)	70.3 (26)	57.1 (128)	n.s.
Immunologic disorder (%, n)	49.4 (129)	62.2 (23)	47.3 (106)	n.s.
IF-ANA (%, n)	98.5 (257)	94.6 (35)	99.1 (222)	n.s.
Other characteristics
Hypertension (%, n)	26.1 (68)	48.6 (18)	22.3 (50)	0.0007
APS-associated nephropathy (%, n)	1.9 (5)	2.7 (1)	1.8 (4)	n.s.
Diabetes mellitus (%, n)	5.4 (14)	0 (0)	6.3 (14)	∞
End-stage renal disease (%, n)	3.1 (8)	5.4 (2)	2.7 (6)	n.s.

ACR = American College of Rheumatology; APS = antiphospholipid syndrome; IF-ANA = immunofluorescence microscopy antinuclear antibodies; n.s. = not significant; SLEDAI = systemic lupus erythematosus disease activity index 2000; mSLEDAI = modified SLE disease activity index; SLICC = Systemic Lupus International Collaborating Clinics. Presence of APS-associated nephropathy was defined by histology characterized by acute thrombotic lesions in glomeruli and/or arterioles (thrombotic microangiopathy) or more chronic vascular lesions [18, 19]. Performed with Mann–Whitney U test or Fisher’s test or chi-square test (where appropriate).