BACKGROUND: Systemic lupus erythematosus (SLE) is a complex multi-system 
disease, characterized by both autoimmune and autoinflammatory clinical and 
laboratory features. The role of type I interferon (IFN) in SLE has been 
demonstrated from the 2000s, by gene expression analyses showing significant 
over-expression of genes related to type I IFN signalling pathway (IFN 
signature). However, several studies questioned the role of measuring the 
intensity of IFN signature (IFN score) to chase SLE activity. We would assess if 
the IFN signature can help the clinical and therapeutic stratification of 
patients with pediatric SLE.
METHODS: We measured the IFN score in peripheral whole blood from a series of 
subjects with childhood-onset SLE and correlated the results with clinical and 
laboratory parameters.
RESULTS: Thirty-one subjects were included in the study, among which the 87% 
displayed a positive IFN score. The only significant relation was found for high 
IFN score in subjects with normocomplementemia. No correlation was observed 
between IFN score and SLEDAI-2K, BILAG-2004 and SLICC. Patients with high IFN 
score and normal complement levels also presented lower anti-dsDNA antibodies.
CONCLUSIONS: The integration between IFN signature analysis and complement 
levels may easily distinguish two groups of subjects, in which the autoimmune or 
autoinflammatory component of the disease seems to be prevalent.