Type I interferon in patients with systemic autoimmune rheumatic disease is associated with haematological abnormalities and specific autoantibody profiles.

In SARD patients, IFNα-positivity was associated with specific autoantibodies and haematological parameters but not with other clinical features. The variable NAR expression suggests that different pathways may drive IFNα production in individual patients. The identification of an IFNα-positive subgroup within a mixed SARD cohort supports a pathology-based approach to treatment.