[Prolonged engraftment syndrome following autologous stem cell transplantation in Hodgkin lymphoma with prior immune checkpoint inhibitor therapy].

A 51-year-old woman with classical Hodgkin lymphoma refractory to multiple chemotherapy regimens, including an immune check inhibitor (ICI), was admitted to our hospital for autologous stem cell transplantation (auto-SCT). On day 7, she presented with a fever, skin rash, and elevated monocyte counts. We diagnosed engraftment syndrome (ES) and initiated corticosteroid therapy. Her symptoms resolved quickly, and we continued hydrocortisone until day 10. On day 11, she developed a fever, skin rash, and hypoxia, which we recognized as a relapse of ES. We started prednisolone at 0.5 mg/kg/day, leading to rapid symptom resolution of her symptoms, then we tapered the prednisolone on day 18. On day 19, she presented with hypotension and hypoxia, prompting us to increase the prednisolone dose to 1 mg/kg/day. Her symptoms resolved, and we gradually tapered the prednisolone dosage; she did not experience any further relapses of ES. Prior usage of ICIs has been reported to increase the risk of immune-related toxicity during allogeneic stem cell transplantation. Based on our experience, patients who have received ICIs before auto-SCT should also be closely monitored for immune-related toxicities in the early post-transplant period.