Urinary Neutrophil Gelatinase-Associated Lipocalin Is a Potential Biomarker for Renal Damage in Patients with Systemic Lupus Erythematosus

Table 1

Demographic, laboratory, and clinical characteristics of the different patient groups.^a,  b

Clinical parameter	SLE			DC
	SLE-active nephritis	SLE-renal	SLE-non-renal
Patients (number)	24	34	8	14
Age (years)	33 (16) (24)	33 (12) (34)	36 (7) (8)	36 (26) (14)
Female: male ratio	18 : 6 (24)	27 : 7 (34)	8 : 0 (8)	14 : 0 (14)
Laboratory data
Leukocyte (10^9/I)	7.26 (4.92) (24)	6.47 (5.47) (34)	6.73 (5.80) (8)	9.33 (9.28) (13)
Neutrophil (10^9/I)	5.27 (4.62) (16)	4.27 (5.52) (23)	4.48 (5.82) (5)	7.45 (6.62) (6)
Lymphocyte (10^9/I)^†, §§	0.76 (0.71) (16)	0.64 (0.65) (23)	1.45 (1.30) (5)	2.12 (1.65) (6)
Hemoglobin (g/I)^††, §§	95 (24) (24)	99 (24) (34)	115 (33) (8)	117 (18) (13)
Platelet count (10^9/I)	210 (180) (24)	199 (145) (34)	252 (334) (8)	198 (159) (13)
Serum creatinine (μmoI/I)^††, §§	124 (283) (24)	106 (160) (34)	71 (9) (8)	62 (88) (14)
Serum albumin(g/I)^**, ††, &, §§	28 (8) (23)	30 (8) (31)	43 (3) (7)	41 (7) (12)
24-hour Ccr (mL/sec)	0.72 (1.32) (20)	0.89 (1.29) (24)	1.09 (—) (3)	4.91 (0.27) (7)
24-hour urine protein (g/day)^**, ††, &, §§	2.82 (7.59) (23)	2.26 (4.64) (33)	0.06 (0.05) (8)	0.04 (0.11) (13)
ESR 1 hour (mm)	44 (32) (16)	49 (30) (22)	31 (46) (5)	30 (46) (10)
C3 (g/I)^*, ††, #, §§	0.56 (0.47) (23)	0.60 (0.54) (31)	0.80 (0.37) (8)	1.24 (0.41) (12)
C4 (g/I)	0.13 (0.16) (18)	0.14 (0.15) (26)	0.13 (0.13) (8)	0.19 (0.10) (13)
Positive anti-dsDNA^†, §	12/24 (50)	15/32 (46.9)	3/8 (37.5)	0/7 (0)
Disease activity
Total SLEDAI^**, &	15 (10) (23)	14 (10) (29)	8 (5) (8)	—
Extrarenal SLEDAI	4 (4) (23)	4 (7) (29)	8 (5) (8)	—
Renal SLEDAI^**, &	12 (4) (23)	8 (8) (32)	0 (0) (8)	—
Proteinuria >0.5 g/day^**, &	19/23 (82.6)	29/33 (87.9)	0/8 (0)	—
Hematuria^**, &	20/24 (83.3)	20/33 (60.6)	0/8 (0)	—
Pyuria*	10/24 (41.7)	10/33 (30.3)	0/8 (0)	—
Urinary casts	9/24 (37.5)	9/33 (27.3)	0/8 (0)	—
Clinical features
Active nephritis	24/24 (100)	24/34 (70.6)	0/8 (0)	0/14 (0)
Leukopenia	1/24 (4.2)	5/34 (14.7)	1/8 (12.5)	0/13 (0)
Lymphopenia^†, §§	13/16 (81.3)	19/23 (82.6)	3/5 (60)	1/6 (16.7)
Thrombocytopenia	2/24 (8.3)	3/34 (8.8)	0/8 (0)	0/13 (0)
Low complement^†, §	20/24 (83.3)	27/33 (81.8)	5/8 (62.5)	6/14 (42.9)
Arthritis	1/24 (4.2)	2/34 (5.9)	0/8 (0)	—
Rash	5/24 (20.8)	8/34 (23.5)	2/8 (25)	—
Serositis	2/24 (8.3)	2/34 (5.9)	0/8 (0)	—
CNS involvement	3/24 (12.5)	5/34 (14.7)	2/8 (25)	—
Vasculitis	1/24 (4.2)	3/34 (8.8)	2/8 (25)	—
Disease duration (years)	3.5 (7.5) (24)	5.0 (9.5) (34)	3.1 (3.8) (8)	—
Drug treatment
Steroids^††, §§	24/24 (100)	34/34 (100)	8/8 (100)	9/14 (64.3)
Daily prednisolone or equivalent dosage (mg/day)^c †, §	18.4 (17) (24)	18 (14) (34)	13 (20) (8)	7 (20) (13)
Hydroxychloroquine	22/24 (91.7)	30/34 (88.2)	8/8 (100)	12/14 (85.7)
Azathioprine	6/24 (25)	11/34 (32.4)	0/8 (0)	3/14 (21.4)
Mycophenolate mofetil	1/24 (4.2)	2/34 (5.9)	0/8 (0)	0/14 (0)
Cyclophosphamide	4/24 (16.7)	4/34 (11.8)	2/8 (25)	1/14 (7.1)
Aspirin or NSAIDs	9/24 (37.5)	14/34 (41.2)	6/8 (75)	7/14 (50)
ACEIs or ARBs^*, ††, §	10/24 (41.7)	12/34 (35.3)	0/8 (0)	0/14 (0)
Pulse therapy^d	11/24 (45.8)	12/34 (35.3)	3/8 (37.5)	3/14 (21.4)

^aIn continuous variables, data are shown as median (IQR) (number). In categorical variables, data are shown as number (percent).
^b* 𝑃<0.05 and **𝑃<0.01 for SLE-active nephritis group versus SLE non-renal group; ^† 𝑃<0.05 and ^†† 𝑃<0.01 for SLE-active nephritis group versus DC group; ^# 𝑃<0.01 for SLE-non-renal group versus DC group; ^**& < 0.01 for SLE-renal group versus SLE-non-renal group; ^§ 𝑃<0.05 and ^§§ 𝑃<0.01 for SLE-renal group versus DC group.
^cThe mean daily dosage of prednisolone or its equivalent during the preceding 30 days.
^dNumbers of patients who were treated by methylprednisolone or cyclophosphamide pulse therapy during the preceding 30 days.
SLE: systemic lupus erythematosus; DC: disease control; Ccr: creatinine clearance; ESR: erythrocyte sedimentation rate; C3: complement 3; C4: complement 4; anti-dsDNA: anti-double stranded DNA; SLEDAI: SLE Disease Activity Index; CNS: central nervous system; NSAIDs: nonsteroidal anti-inflammatory drugs; ACEIs: angiotensin-converting enzyme inhibitors; ARBs: angiotensin II receptor antagonists; IQR: interquartile range.