Hemolytic Rebound and Recurrent Thromboembolic Event Following Ravulizumab Discontinuation in a Patient with PNH and MDS: A Case Report

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare clonal hematopoietic stem cell disorder characterized by complement-mediated hemolysis and thrombotic complications. The introduction of complement inhibitors has markedly improved survival outcomes by reducing intravascular hemolysis and thrombotic risk. We report the case of a 73-year-old man with PNH and myelodysplastic neoplasm (MDS) who developed severe thromboembolic and hemolytic events following the discontinuation of ravulizumab. His disease had previously evolved from aplastic anemia to MDS. Despite prior resolution of PNH-related thrombosis and maintained clinical stability, the cessation of treatment precipitated rebound hemolysis and multiple thrombotic events 8 months after discontinuation. These events included ischemic enterocolitis, necrotic gingivitis, ischemic epididymo-orchitis, and portal vein thrombosis. Resumption of complement inhibition with ravulizumab successfully halted the progression of PNH-related complications. This case emphasizes the life-threatening risks associated with the withdrawal of complement blockade in patients with a prior thromboembolic history and highlights the critical importance of continuous therapy, even in the context of bone marrow failure.