Elevated ferritin as a companion biomarker of myeloid-driven inflammation in RNP/Sm co-positive, treatment-resistant SLE endotype

Anti-RNP/Sm co-positivity defines a high-risk, flare-prone, myeloid-dominant SLE endotypeRNP⁺Sm⁺ patients, especially Black patients, show profound refractoriness to first-line and B-cell depletion therapiesExpanded intermediate monocytes with TLR4 upregulation and IFNA10-biased interferon signallingHyperferritinaemia correlates with disease activity exclusively in RNP⁺Sm⁺ patients.