A Novel Use of Anifrolumab for a Novel Disease

To explore the potential role of type-I interferon (IFN-I) signaling in autoimmune cytopenias outside the context of systemic lupus erythematosus (SLE), and to evaluate the clinical response to off-label anifrolumab in two patients with fatigue and immune-mediated cytopenias who did not meet established criteria for SLE.

We describe two older White male patients with fatigue and autoimmune cytopenias who did not meet established SLE criteria and were refractory to standard immunosuppressants. Both received off-label anifrolumab.

Both patients experienced rapid and sustained improvement in fatigue and resolution of cytopenias following treatment, with continued benefit and no significant adverse effects.

These cases suggest IFN-I signaling may underlie autoimmune cytopenias outside classic SLE. The positive response to anifrolumab raises the possibility of an atypical or distinct IFN-mediated autoimmune condition and supports broader investigation of IFN blockade in hematologic autoimmunity.