Table 1: Studies in patients with SLE showing statistical significant associations () between peripheral type I IFN activity and clinical and serological features.

Author No. of patients Type I IFN levels Type I IFN-inducible genes Clinical associations Serological associations Hooks et al. [2] 28 High NM Disease activity Anti-dsDNA Low C3 Kanayama et al. [8] 25 High NM Fever NM Bengtsson et al. [9] 30 High NM Disease activity Fever Skin Anti-dsDNA Low C1q Low C3 Leucopenia Baechler et al. [10] 48 NM High Renal and/or NPSLE Hematologic NM Dall’era et al. [11] 65 High NM Disease activity Skin Anti-dsDNA Low C3 Kirou et al. [12] 77 NM High Renal Anti-dsDNA Anti-Ro Anti-U1 RNP Anti-Sm Low C3 Low C4 Feng et al. [13] 48 NM High Renal NPSLE (weak association) Anti-dsDNA Anti-Sm Anti-Ro/La Low C3 Weckerle et al. [14] 1089 High NM NS Anti-dsDNA Anti-Ro

NM: not measured, NS: not statistically significant. All abbreviations are explained in the text.