Endogenous type-I interferon activity is not associated with depression or fatigue in systemic lupus erythematosus

Patients with systemic lupus erythematosus (SLE) often suffer from depression and fatigue in addition to the physical manifestations of the autoimmune disease. Elevated production of type-I interferons (IFN-I) has been found in lupus patients and IFN-I can precipitate a variety of neuropsychiatric side effects. This study was conducted to evaluate the relationship between dysregulated IFN-I production and the presence of depression or fatigue in lupus patients. Through cross-sectional and longitudinal analysis we found no significant correlation between abnormal IFN-I levels (as measured by peripheral blood expression of IFN-I-stimulated genes) and neuropsychiatric manifestations. Elevation of endogenous serum IFN-I levels is unlikely to account for the depression and fatigue associated with SLE.