Table 2.

Clinical characteristics of SLE patients stratified by their number of anti-KIR autoantibodies.

Number of anti-KIRs	0	1	2-3	>3	p†
Number of individuals	147	18	16	10
Age at disease-onset, Years	30 (20–40)	30 (19–42)	27 (19–40)	21 (16–40)	0.74
Age at serum sampling, Years	45 (30–58)	43 (30–50)	47 (34–61)	32 (22–52)	0.42
Disease duration*, Years	16 (11–29)	20 (11–39)	18 (9–28)	11 (3–25)	0.54
Number of ACR criteria	6 (5–7)	6 (4–6)	7 (5–7)	7 (7–8) ‡	0.02
SLEDAI-2K	2 (0–4)	2 (1–7)	2 (1–7)	13 (7–15)§	<0.0001
SDI	1 (0–3)	0 (0–2)	1.5 (0–3)	1.5 (0–4)	0.31
Serum IFN-α, U/ml	0 (0–0)	0 (0–1.1)	0 (0–3.7)	11.6 (5.2–35.0)§	<0.0001
Treatment
Glucocorticoids, %	57.9	55.6	73.3	90.0	0.15
Hydroxychloroquine/ Chloroquine, %	51.0	50.0	46.7	40.0	0.93
Azathioprine, %	23.4	27.8	26.7	0	0.31
Mycophenolate mofetil, %	7.6	5.6	26.7‡	20.0	0.05
Methotrexate, %	6.2	0	0	10.0	0.51

Data are presented as median (interquartile range) or as frequencies (%). SLEDAI-2K = SLE Disease Activity Index 2000, SDI = Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index.

^*At medical record review.

^†The Kruskal-Wallis test (numerical values) or the Fischer's exact test (categorical values) was used to compare all 4 groups. For p <0.05 each of the three anti-KIR positive groups were compared to the anti-KIR-negative group using the Dunn's multiple comparisons test or the Fischer's exact test and p < 0.05 are indicated.

^‡p = 0.04;

^§p < 0.0001.

Data for serum IFN-α are from 123 (0 anti-KIR), 15 (1 anti-KIR), 12 (2-3 anti-KIR), and 8 patients (>3 anti-KIR). Data for SLEDAI-2K are from 138 (0 anti-KIR), 17 (1 anti-KIR), 13 (2-3 anti-KIR), and 10 patients (>3 anti-KIR).