Background and objectives: Interferon-a (IFN-a), a cytokine with both antiviral and immune-regulatory functions, was suggested as a useful tool which can evaluate current systemic lupus erythematosus (SLE) disease activity and identify patients whoare at risk of future disease flares. In the current study, serum IFN-a levels and associated demographic, and serological features in Egyptian SLE patients and their first degree relatives (FDRs) in comparison to unrelated healthy controls (UHCs) were examined, in order to identify individuals at the greatest risk for clinical illness.Methods: In a cross-sectional study, blood samples were drawn from 54 SLE patients, 93 of their FDRs who consented to enroll into the study and 76 UHCs. Measurement of serum IFN-a by a modified ELISA was carried out. Data were analyzed for associations of serum IFN-a levels with autoantibodies titer.Results: Meanserum IFN-a inFDRswas statistically higher than theUHCsand lower than inSLE patients (P < 0.0001) and it was correlated with ANA titer (r = 0.6, P < 0.0001) and anti ds DNA titer (r = 0.62, P < 0.0001).Conclusion: IFN-a is a crucial player in the complicated autoimmune changes that occur in SLE and serum IFN-a can be a useful marker identifying persons who are at risk of future disease development.Keywords: Interferon-a; Systemic lupus erythematosus; First degree relatives; Autoantibodie
