Galectin-9 reflects the interferon signature and correlates with disease activity in systemic autoimmune diseases.

With much interest, we read the comments1 of our colleagues Yavuz and Ronnblom regarding our manuscript on galectin-9 as an easy to measure biomarker to detect the interferon (IFN) signature in patients with systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS).2 We thank them for their interest in our manuscript and their shared interest in the importance of the IFN signature in SLE and the subsequent need for more easily applicable markers to detect IFN activity. In the paper, we reported independently replicated correlations of galectin-9 with the IFN signature in patients with SLE and APS. The aim of our manuscript was to identify more easy to measure markers to detect the IFN signature. Besides serving as a marker for the IFN signature, we found that galectin-9 was elevated in patients with SLE and APS and correlated with signs …