Table 2

Correlations between IFN scores and serum KYN/TRP pathway metabolite levels in subjects with SLE according to ISG expression subgroup

ISG expression subgroupIFN score method (z-scores)KYN/TRP (rs)P valueQA/KA (rs)P value
IFN high (n=36)ISG-A0.4900.002*0.1290.453
19 type I ISG0.4870.003*0.2160.205
IFN low (n=23)ISG-A−0.1740.427−0.2860.187
19 type I ISG0.2690.215−0.2100.335
IFN similar to HC(n=13)ISG-A0.1700.578−0.1260.681
19 type I ISG0.2420.4260.0001.000
  • Subjects with SLE were assigned to one of three subgroups: ‘IFN high’ (Z-IFN score ≥SD above HC mean), ‘IFN low’ (Z-IFN score ≥1 to <2) or ‘IFN similar to HC’ (Z-IFN score <1). In each subgroup, correlations between IFN scores (derived from ISG-A and the 19 type I ISG) and metabolite ratios are displayed.

  • *Remained significant after Benjamini-Hochberg correction for multiple comparisons.

  • HC, healthy control; IFN, interferon; ISG, interferon-stimulated gene; KA, kynurenic acid; KYN, kynurenine; QA, quinolinic acid; rs, Spearman correlation; TRP, tryptophan.