True vs. false immune-mediated thrombotic thrombocytopenic purpura exacerbations: a clinical case in the caplacizumab era.

Acquired thrombotic thrombocytopenic purpura (aTTP) is a medical emergency requiring urgent plasma exchange and immunosuppressive agents. Recently, the therapeutic options have been expanded by the approval of a novel anti-von Willebrand factor (vWF) nanobody, caplacizumab, inhibiting vWF-platelet aggregation. Here, we present a rare case of a patient affected by immune-mediated TTP (iTTP) reporting ischemic stroke caused by a real iTTP exacerbation during caplacizumab administration and subsequent pancytopenia caused by cytomegalovirus (CMV) infection that mimicked another iTTP exacerbation. The case is a real-life example of a not-frequent iTTP exacerbation in the caplacizumab era and of the new management issues arising with the introduction of the new drugs in clinical practice, highlighting the need of new comprehensive response criteria and treatment guidelines.