FcRn Blockade as a Targeted Therapeutic Strategy in Antibody-Mediated Autoimmune Diseases: A Focus on Warm Autoimmune Hemolytic Anemia.

Antibody-mediated autoimmune diseases are common, can involve any organ system, and pose a large burden for patients and healthcare systems. Most antibody-mediated diseases are mediated by IgG antibodies. Selective targeting of pathogenic antibodies is an attractive treatment option which has already proven to be effective in antibody-positive generalized myasthenia gravis, maternal-fetal alloimmune cytopenias, and immune thrombocytopenic purpura. Warm autoimmune hemolytic anemia (wAIHA) is an autoimmune disorder mediated by pathogenic antibodies mainly of the IgG class with no approved therapy. Current treatment includes non-specific immunosuppression with corticosteroids, rituximab, and other immunosuppressive agents. With most therapies, time to response can be delayed and transfusions may be needed. Neonatal Fc receptor (FcRN) therapies provide rapid and sustained reduction of pathogenic IgG levels providing potential for fast, effective therapy in antibody-mediated autoimmune diseases including warm autoimmune hemolytic anemia. This review focuses on the emerging role of FcRn inhibition in autoimmune hematologic diseases, and their therapeutic potential in wAIHA.