Table 1.

Characteristics of subjects with SLE and HCs and KYN:TRP pathway metabolite ratios

Subject characteristics	SLE (N=72)	HC (N=73)	P value
Age (years), mean±SD (range)	37.9±9.6 (22–57)	36.2±9.5 (18–55)	0.28
Ethnicity (Hispanic/Latino), n (%)	13 (18.1)	13 (17.8)	0.97
Race, n (%)			0.91
Black	43 (59.7)	41 (56.2)
White	16 (22.2)	18 (24.7)
Other	13 (18.1)	14 (19.2)
KYN:TRP ratio, median±IQR (range)	0.04±0.03 (0.01–0.23)	0.03±0.01 (0.01–0.13)	<0.01
QA:KA ratio, median±IQR (range)	18.4±14.7 (4.0–121.2)	8.9±5.8 (2.9–45.9)	<0.01
Disease duration, mean±SD (range)	12.3±8.5 (1–38)	n/a	n/a
SELENA SLEDAI score, mean±SD (range)	5.4±5.1 (0–29)	n/a	n/a
Prednisone dose (mg/day), median±SD (range)	2.5±10.0 (0–75)	n/a	n/a
Current hydroxychloroquine use, n (%)	54 (75.0)	n/a	n/a
Current immunosuppressant use, n (%)	34 (47.2)	n/a	n/a
Anti-dsDNA positive (>29 IU/mL), n (%)	50 (69.4)	n/a	n/a
C3 low (<81 mg/dL), n (%)	28 (38.9)	n/a	n/a
C4 low (<13 mg/dL)	24 (33.3)	n/a	n/a

All data are reported either as a mean (or median where indicated)±SD (or IQR), or as a frequency (%). All data refer to those which were collected at the time of evaluation.

HC, healthy control; KYN, kynurenine; n/a, not applicable; TRP, tryptophan.