Caplacizumab in Lupus-Associated Thrombotic Thrombocytopenic Purpura (TTP): Navigating Autoimmunity and Microangiopathy.

Thrombotic thrombocytopenic purpura (TTP) is a rare but potentially life-threatening complication associated with systemic lupus erythematosus (SLE). This condition is characterized by microangiopathic hemolytic anemia and thrombocytopenia, which can result from either an acquired deficiency of the ADAM metallopeptidase with thrombospondin type 1 motif 13 (ADAMTS13) or through complement-mediated mechanisms. We present the case of a 55-year-old female with a history of Sjögren's disease and a recent diagnosis of SLE. She exhibited severe anemia, thrombocytopenia, and symptoms suggestive of immune-mediated TTP with markedly reduced ADAMTS13 activity. Her diagnosis was confirmed through clinical evaluations, laboratory tests, and immunologic findings. After initially responding to urgent therapy with plasmapheresis, high-dose corticosteroids, and rituximab, the addition of caplacizumab led to a rapid and sustained improvement in her thrombocytopenia. This report highlights the successful use of caplacizumab in lupus-associated immune TTP and reviews diagnostic and therapeutic challenges.