Pb2418: clinical features and prognosis of adenovirus infection after haploidentical donor hematopoietic stem cell transplantation

Topic: 22. Stem cell transplantation - Clinical Background: Infection is a common complication after hematopoietic stem cell transplantation (HSCT) and is also the main cause of non-relapse mortality. Adenovirus may cause systemic disease or lethal organ damage. Few data are available on the clinical features of adenovirus infection after haploidentical (haplo) HSCT. Aims: This is the first study in which we aimed to investigate the clinical characteristics and prognosis in patients who experienced adenovirus infection after haplo-HSCT. Methods: Medical records of patients with hematological diseases who received haplo-HSCT at the Institute of Hematology, Peking University from January 2013 to December 2022 were retrieved in the transplantation program database retrospectively. Adenovirus infection was used as a retrieval condition to identify adenovirus infection cases. When patients have unexplained fever, pancytopenia, and organ injury, adenovirus DNA was screened. Adenovirus viremia was defined as positive adenovirus PCR, virus isolation, or antigen detection in peripheral blood. Probable adenovirus disease was defined as adenovirus infection plus corresponding symptoms and signs without histological confirmation. The endpoint of the last follow-up was January 1, 2023. Results: Thirty-five patients (22 males and 13 females) had adenovirus infection. The median age was 24 (4-53) years old. The underlying disease included 20 patients of ALL/NHL, 11 patients of AML, 3 patients of MDS, and 1 patient of aplastic anemia. The median time of neutrophil and platelet engraftment was 14(10-24) and 15(10-98) days, respectively. A total of 14 patients developed grade II-IV acute GVHD. CMV and EBV viremia was observed in 32 patients and 20 patients, respectively. The median follow-up time was 9.0 (1.4-70.7) months. Eight patients (22.9%) showed adenovirus viremia, and 27 patients (77.1%) showed probable adenovirus disease. The median time from allo-HSCT to adenovirus infection was 102 (8-608) days. Among the 27 patients with probable adenovirus disease, 20 cases (57.1%) had single organ infection (6 cases of pneumonia, 7 cases of enteritis, 4 cases of hepatitis, 2 cases of encephalitis, and 1 case of cystitis), 2 patients (11.4%) had two organs infection, and 3 patients (8.6%) had three organs infection. Twenty-two patients (62.9%) became adenovirus negative after antivirus treatment. The median time for becoming negative was 14 (3-46) days. For 8 patients with adenovirus viremia, 3 cases were treated with cidofovir, while 5 patients were treated with acyclovir, ganciclovir, foscarnet sodium, or ribavirin. All of the patients (100%) showed adenovirus. For 27 patients with probable adenovirus disease, 14 patients used cidofovir, with 6 (42.9%) patients becoming negative, while 13 patients were treated with other antivirus agents, with 8 (61.5%) patients becoming negative. The negative rate was not significantly different between cidofovir and other antivirus agents (P=0.33). Twenty patients died during the follow-up period. The median survival time was 9.2 months (95% CI 2.7-15.7 months). The 2-year overall survival rate was 35.7%. Of the 31 patients with acute leukemia, 7 patients relapsed, and the 2-year relapse-free survival rate was 63.3%. Summary/Conclusion: The survival with currently available agents for adenovirus was suboptimal. Adenovirus disease after haplo-HSCT remains a challenge. Better antiviral modalities are necessary. Keywords: Adenovirus, Infection, Allogeneic hematopoietic stem cell transplant