Of note, X6 was also more effective than HCQ in reducing ISG expression in vitro (P < 0.05 for IFI27 and MX1, and P < 0.01 for IFI44L and PKR) in human peripheral blood mononuclear cells from patients with SLE.
Finally, a recent study revealed that DNA methylation levels at IFI44L can accurately distinguish SLE patients from healthy controls, and from patients with other autoimmune diseases, promising to be the first epigenetic diagnostic marker for SLE.
Significant up-regulation of IFI6, IFI27, and IFI44L with SLE was observed in all the studied sample types, though the FC was most striking in monocyte, compared with PBMC and whole blood (8.82-251.66 vs. 3.73-74.05 vs. 1.19-1.87).
In addition, the methylation levels of Site1 and Site2 within IFI44L promoter were significantly lower in patients with SLE with renal damage than those without renal damage.