Publications by authors named "J K Tjon"

Background: Cytotoxic T-lymphocyte antigen 4 (CTLA-4) insufficiency causes a primary immune regulatory disorder characterized by lymphoproliferation, dysgammaglobulinemia, and multiorgan autoimmunity including cytopenias and colitis.

Objective: We examined the outcome of hematopoietic stem cell transplantation (HSCT) for CTLA-4 insufficiency and study the impact of pre-HSCT CTLA-4 fusion protein (CTLA-4-Ig) therapy and pre-HSCT immune dysregulation on survival and immunologic outcome.

Methods: This was a retrospective study of HSCT for CTLA-4 insufficiency and 2q33.

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Cytokine release syndrome (CRS) occurs frequently after haplo-identical allogeneic stem cell transplantation (alloSCT) with post-transplant cyclophosphamide (PTCy), increasing nonrelapse mortality (NRM) and decreasing survival. Data on CRS in HLA-matched alloSCT are limited and effects of specific HLA-mismatches on CRS development unknown. We hypothesized that in HLA-matched alloSCT increasing degrees of HLA-mismatching influence CRS incidence, NRM and survival.

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Acquired aplastic anemia (AA) is a rare form of immune-mediated bone marrow failure, which can result in life-threatening infections or bleeding if left untreated. Treatment consists of either immune suppressive therapy (IST) or allogeneic stem cell transplantation (alloHSCT). While considerable research has been published regarding survival, response rate and toxicity of both treatments, knowledge on the impact on quality of life (QoL) is scarce.

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Article Synopsis
  • Unmodified donor lymphocyte infusions (DLI) after allogeneic stem cell transplantation (alloSCT) can enhance the beneficial Graft-versus-Leukemia (GvL) effects but also pose a risk for severe Graft-versus-Host Disease (GvHD).
  • Key factors influencing GvHD risk after DLI include patient-derived antigen-presenting cells, lymphocyte count, and recent viral infections, particularly in patients with acute leukemia or myelodysplastic syndrome.
  • Results indicate that certain conditions, like the timing of DLI and mixed bone marrow chimerism, significantly impact the likelihood of developing GvHD, with those receiving DLI three months post-transplant facing higher risks associated with
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Idiopathic acquired aplastic anemia (AA) is considered an immune-mediated syndrome of bone marrow failure since approximately 70% of patients respond to immunosuppressive therapy (IST) consisting of a course of anti-thymocyte globulin (ATG) followed by long-term use of ciclosporin. However, the immune response that underlies the pathogenesis of AA remains poorly understood. In this study, we applied high-dimensional mass cytometry on bone marrow aspirates of AA patients pre-ATG, AA patients post-ATG and healthy donors to decipher which immune cells may be implicated in the pathogenesis of AA.

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