@article{3003333,
    title = "Extramedullary leukemia relapse after allogeneic stem cell transplantation: A novel mechanism of immune escape?",
    author = "Gkirkas, K. and Stamouli, M. and Karagiannidou, A. and Chondropoulos, S. and Tsirigotis, P.",
    journal = "Journal of Immunotherapy",
    year = "2020",
    volume = "12",
    number = "9",
    pages = "635-640",
    publisher = "Future Medicine Ltd",
    issn = "1524-9557",
    doi = "10.2217/imt-2019-0215",
    keywords = "azacitidine;  cyclosporine;  cytarabine;  fludarabine;  granulocyte colony stimulating factor;  HLA antigen;  idarubicin;  nivolumab;  sorafenib, acute graft versus host disease;  acute lymphoblastic leukemia;  acute myeloid leukemia;  adult;  allogeneic stem cell transplantation;  antigen expression;  Article;  cancer regression;  donor;  donor lymphocyte infusion;  down regulation;  female;  haploidentical transplantation;  haplotype;  HLA matching;  human;  leukemia cell;  leukemia relapse;  major clinical study;  male;  middle aged;  mortality;  myelodysplastic syndrome;  priority journal;  treatment outcome;  tumor escape;  tumor microenvironment;  allograft;  graft versus host reaction;  immunology;  leukemia;  procedures;  recurrent disease;  stem cell transplantation, Adult;  Allografts;  Female;  Graft vs Host Disease;  Humans;  Leukemia;  Male;  Middle Aged;  Recurrence;  Stem Cell Transplantation;  Treatment Outcome",
    abstract = "Background: Relapse is a significant cause of treatment failure after allogeneic stem cell transplantation. In many cases relapse occurs when leukemic cells escape from immune surveillance. Methods &results: In the setting of haploidentical transplantation, immune escape is usually the result of the loss of the mismatched haplotype from leukemic cells, while downregulation of HLA-expression has been postulated as a significant cause of immune escape after transplantation with the use of HLA-matched donors. We observed that patients with acute leukemia who relapse at the time of active graft-versus-host-disease, usually develop extramedullary leukemia while they remain free of leukemia in peripheral blood and bone marrow. Conclusion: Our observation points toward a novel mechanism of immune escape which is microenvironment-specific. © 2020 Future Medicine Ltd."
}