Hematopoietic stem cell mobilization following PD-1 blockade: Cytokine release syndrome after transplantation managed with ascorbic acid.

Checkpoint inhibitor therapy is effective in the treatment of relapsed classical Hodgkin's Lymphoma. Here, we report a patient with relapsed Hodgkin's Lymphoma who received nivolumab prior to autologous stem cell mobilization. She went on to develop cytokine storm shortly following transplantation, with marked T-cell proliferation coincident with myeloid engraftment. Non-cardiogenic pulmonary edema and alveolar hemorrhage developed despite corticosteroid therapy. There was rapid and complete resolution of these complications with parenteral ascorbic acid infusion. Our case illustrates the risk of cytokine release syndrome following infusion of stem cells mobilized after checkpoint inhibitor therapy and the role of ascorbic acid in its management.