PD-1 Blockade Immunotherapy As a Successful Rescue Treatment for Disseminated Adenovirus Infection After Allogeneic Hematopoietic Stem Cell Transplantation

Disseminated adenovirus infection is a complication with a relatively high mortality rate among patients undergoing hematopoietic stem cell transplantation. The low efficacy and poor availability of current treatment options are of major concern. Programmed cell death 1 (PD-1) blockade has been used to treat several chronic viral infections. Herein, we report a case of disseminated adenovirus infection in the early posttransplant period. The patient was diagnosed with diffuse large B-cell lymphoma at first and underwent 8 cycles of chemotherapy, including rituximab. She was subsequently diagnosed with acute myeloid leukemia and received haploidentical transplantation. She was diagnosed with Epstein‒Barr virus (EBV)-positive posttransplant lymphoproliferative disorder (PTLD) 2 months after the transplant, and 3 doses of rituximab were administered. The patient was diagnosed with disseminated adenovirus infection with upper respiratory tract, gastrointestinal tract and blood involved at 3 months after transplantation. She was first treated with a reduction in immunosuppression, cidofovir and ribavirin. Then, the patient received salvage treatment with the PD-1 inhibitor sintilimab (200 mg) after achieving no response to conventional therapy. The adenovirus was cleared 3 weeks later, and concomitant EBV was also cleared. Although the patient developed graft-versus-host disease of the liver after the administration of the PD-1 inhibitor, she was cured with steroid-free therapy. Therefore, PD-1 blockade immunotherapy can be considered a promising treatment option for patients with disseminated adenovirus infection after transplantation, with fully weighing the hazards of infection and the side effects of this therapy.