After allogeneic stem cell transplantation (alloSCT), patient-derived stem cells that survived the pretransplantation conditioning compete with engrafting donor stem cells for bone marrow (BM)... Show moreAfter allogeneic stem cell transplantation (alloSCT), patient-derived stem cells that survived the pretransplantation conditioning compete with engrafting donor stem cells for bone marrow (BM) repopulation. In addition, donor-derived alloreactive T cells present in the stem cell product may favor establishment of complete donor-derived hematopoiesis by eliminating patient-derived lymphohematopoietic cells. T cell-depleted alloSCT with sequential transfer of potentially alloreactive T cells by donor lymphocyte infusion (DLI) provides a unique opportunity to selectively study how competitive repopulation and allo-immunologic pressure influence lymphohematopoietic recovery. This study aimed to determine the relative contribution of competitive repopulation and donor-derived anti-recipient alloimmunologic pressure on the establishment of lymphohematopoietic chimerism after alloSCT. In this retrospective cohort study of 281 acute leukemia patients treated according to a protocol combining alemtuzumab-based T cell-depleted alloSCT with prophy-lactic DLI, we investigated engraftment and quantitative donor chimerism in the BM and immune cell subsets. DLI-induced increase of chimerism and development of graft-versus-host disease (GVHD) were analyzed as complementary indicators for donor-derived anti-recipient alloimmunologic pressure. Profound suppression of patient immune cells by conditioning sufficed for sustained engraftment without necessity for myeloablative conditioning or development of clinically significant GVHD. Although 61% of the patients without any DLI or GVHD showed full donor chimerism (FDC) in the BM at 6 months after alloSCT, only 24% showed FDC in the CD4+ T cell compartment. In contrast, 75% of the patients who had received DLI and 83% of the patients with clinically significant GVHD had FDC in this compartment. In addition, 72% of the patients with mixed hematopoiesis receiving DLI converted to complete donor-derived hematopoiesis, of whom only 34% developed clinically significant GVHD. Our data show that competitive repopulation can be sufficient to reach complete donor-derived hematopoiesis, but that some alloimmunologic pressure is needed for the establishment of a completely donor-derived T cell compartment, either by the development of GVHD or by administration of DLI. We illustrate that it is possible to separate the graft-versus-leukemia effect from GVHD, as conversion to durable complete donor-derived hematopoiesis following DLI did not require induction of clinically significant GVHD. (c) 2023 The American Society for Transplantation and Cellular Therapy. Show less
Zouwen, B. van der; Koster, E.A.S.; Borne, P.A. von dem; Oosten, L.E.M.; Roza-Scholten, M.W.I.; Snijders, T.J.F.; ... ; Halkes, C.J.M. 2023
Prophylactic donor lymphocyte infusion (DLI) starting at 6 months after T cell-depleted allogeneic stem cell transplantation (TCD-alloSCT) can introduce a graft-versus-leukemia (GvL) effects with... Show moreProphylactic donor lymphocyte infusion (DLI) starting at 6 months after T cell-depleted allogeneic stem cell transplantation (TCD-alloSCT) can introduce a graft-versus-leukemia (GvL) effects with low risk of severe graft-versus-host-disease (GvHD). We established a policy to apply low-dose early DLI at 3 months after alloSCT to prevent early relapse. This study analyzes this strategy retrospectively. Of 220 consecutive acute leukemia patients undergoing TCD-alloSCT, 83 were prospectively classified to have a high relapse risk and 43 were scheduled for early DLI. 95% of these patients received freshly harvested DLI within 2 weeks of the planned date. In patients transplanted with reduced intensity conditioning and an unrelated donor, we found an increased cumulative incidence of GvHD between 3 and 6 months after TCD-alloSCT for patients receiving DLI at 3 months compared to patients who did not receive this DLI (0.42 (95%Confidence Interval (95% CI): 0.14-0.70) vs 0). Treatment success was defined as being alive without relapse or need for systemic immunosuppressive GvHD treatment. The five-year treatment success in patients with acute lymphatic leukemia was comparable between high- and non-high-risk disease (0.55 (95% CI: 0.42-0.74) and 0.59 (95% CI: 0.42-0.84)). It remained lower in high-risk acute myeloid leukemia (AML) (0.29 (95% CI: 0.18-0.46)) than in non-high-risk AML (0.47 (95% CI: 0.42-0.84)) due to an increased relapse rate despite early DLI. Show less
Jeyaratnam, J.; Faraci, M.; Gennery, A.R.; Drabko, K.; Algeri, M.; Morimoto, A.; ... ; EBMT Inborn Errors Working Party 2022
Objectives Mevalonate kinase deficiency (MKD) is a rare autoinflammatory syndrome. Several reports have described allogeneic hematopoietic stem cell transplantation in severely affected patients,... Show moreObjectives Mevalonate kinase deficiency (MKD) is a rare autoinflammatory syndrome. Several reports have described allogeneic hematopoietic stem cell transplantation in severely affected patients, sometimes with promising results. In view of the scarcity of data, this study aims to analyse the efficacy and safety of allogeneic hematopoietic stem cell transplantation (HSCT) to give a more complete overview of this treatment. Methods This multicentre retrospective study on behalf of the European Society for Blood and Marrow Transplantation aimed to include all MKD patients who had undergone allogeneic HSCT. All centres related to EMBT and centres that have reported cases of allogeneic HSCT in the literature were contacted via the EBMT data office. Results We analyzed 9 patients (5 male). Treosulfan based conditioning was the most frequently used conditioning regimen. Engraftment occurred in all but one patient. Source of stem cells was cord blood (n = 2), peripheral blood stem cells (n = 4) and bone marrow (n = 5). Two patients needed a second transplantation due to an incomplete response or primary graft failure. Seven patients went into complete remission after stem cell transplantation. At final follow-up these patients reported no symptoms of MKD. Four patients suffered from grade II-IV acute graft-versus-host disease (GvHD). During follow-up two patients died due to transplantation related complications. Conclusion In conclusion, allogeneic stem cell transplantation represents an effective treatment for the most severely affected MKD patients. However, treatment-related morbidity and mortality are significant. Transplantation may be justified in patients with a severe disease course on conservative therapy. Show less
Allogeneic stem cell transplantation (alloSCT) is a curative treatment for a variety of hematologic diseases. The mechanism of curation by an alloSCT is the induction of an immune response of donor... Show moreAllogeneic stem cell transplantation (alloSCT) is a curative treatment for a variety of hematologic diseases. The mechanism of curation by an alloSCT is the induction of an immune response of donor T cells attacking patients hematopoiesis, including the malignant hematopoietic cells. This is called the graft-versus-leukemia (GVL) reactivity. However, donor T cells can also be directed against healthy tissue cells of the recipient, causing graft-versus-host disease (GVHD). In this thesis we focused on targeting HLA class II by donor CD4 T cells to induce GVL without GVHD, because under non-inflammatory conditions, HLA class II is mainly expressed on hematopoietic cells and not on other tissue cells. We showed that CD4 T cells from HLA-identical sibling donors can induce conversion from mixed to full donor chimerism with GVL reactivity, but without GVHD, by targeting HLA class II restricted minor histocompatibility antigens. We also analyzed the immunopeptidome of different HLA-DP alleles. HLA-DP peptide binding motifs showed a clear association with the HLA-DP allele specific sequences of the binding groove. Functional hierarchies among HLA-DP alleles were unravelled, providing new molecular insights into HLA-DP classification. Permissiveness of mismatches between donor and recipient is not a black and white phenomenon, but rather gradual based on similarities and differences in the peptidomes. Show less
Alemtuzumab (ALM) is a cytotoxic monoclonal antibody that is used as a therapeutic agent in a variety of clinical settings. The target antigen for ALM is CD52, which is highly expressed on the... Show moreAlemtuzumab (ALM) is a cytotoxic monoclonal antibody that is used as a therapeutic agent in a variety of clinical settings. The target antigen for ALM is CD52, which is highly expressed on the membrane of mature lymphocytes, but not or only marginally on hematopoietic stem cells, red blood cells, and non-hematopoietic tissues. As such, ALM can be administered for the purpose of lymphocyte depletion with no or only minimal toxicity to other tissues. In this thesis, the mechanism of action of ALM was investigated in the context of two clinical settings, i.e. T-cell depletion before allogeneic stem cell transplantation (alloSCT) and depletion of malignant cells in B lymphoblastic leukemia (B-ALL). Show less
Administration of alemtuzumab (targeting the CD52 antigen) to the patient (in-vivo) or to the graft (in-vitro) before allogeneic stem cell transplantation (alloSCT) decreases the incidence of graft... Show moreAdministration of alemtuzumab (targeting the CD52 antigen) to the patient (in-vivo) or to the graft (in-vitro) before allogeneic stem cell transplantation (alloSCT) decreases the incidence of graft-versus-host disease (GvHD). Effectiveness of this treatment relies on depletion of donor T cells. Currently, no data are available on alemtuzumab pharmacokinetics and pharmacodynamics in patients who received combined in-vivo and in-vitro alemtuzumab-based T-cell depletion. In this prospective study, we analyzed alemtuzumab pharmacokinetics and its effect on the circulating T cells in 36 patients who received an allogeneic T-cell-depleted graft by addition of 20 mg alemtuzumab "to the bag" with or without prior alemtuzumab (30 mg cumulative dose intravenously) as part of the conditioning regimen. Effective T-cell depletion was shown for all patients, even though alemtuzumab plasma levels varied considerably. Peak alemtuzumab levels were observed directly after graft infusion and were not associated with the number of circulating T cells pre-infusion, but with plasma volumes of the patients. All patients engrafted, confirming feasibility of this transplantation protocol. Only three patients with low alemtuzumab levels developed acute GvHD (grade II in 2 patients and grade III in 1 patient). Persistence of circulating alemtuzumab at 3 weeks after transplantation had prevented reconstitution of CD52-positive T cells when alemtuzumab plasma levels were above 0.7 mu g/mL. However, overall T-cell reconstitution did not correlate with the levels of alemtuzumab exposure, due to early reconstitution of CD52-negative alemtuzumab-resistant T cells. The protective effect of these cells likely explains the low incidence of Epstein-Barr-virus- and cytomegalovirus-related disease despite circulating alemtuzumab. Show less
Following allogeneic stem cell transplantation (alloSCT), most patients experience a period of profound and prolonged T cell deficiency due to the immune suppression and/or T cell depletion (TCD... Show moreFollowing allogeneic stem cell transplantation (alloSCT), most patients experience a period of profound and prolonged T cell deficiency due to the immune suppression and/or T cell depletion (TCD). In this period the patients are at risk for developing infectious complications by reactivation of endogenous herpes like viruses cytomegalovirus (CMV), Epstein-Barr virus (EBV) and varicella zoster virus (VZV). Reactivation of endogenous CMV is the most frequently occurring herpes virus reactivation following alloSCT. Approximately 60% of alloSCT recipients are seropositive for CMV and are therefore at risk for endogenous reactivation of latent CMV. CMV reactivation can lead to potentially fatal CMV disease, comprising CMV pneumonitis, CMV colitis or CMV encephalitis. The aim of this thesis was to evaluate factors that influence the incidence of CMV disease after TCD alloSCT. These factors include the conditioning regimen, serostatus of the donor, pharmacological intervention following alloSCT and adoptive T cell transfer for treatment of refractory CMV reactivation or CMV disease. Show less
The effect of donor lymphocyte infusions (DLI) after allogeneic stem cell transplantation is difficult to determine and currently unknown. The thesis describes different statistical methods the... Show moreThe effect of donor lymphocyte infusions (DLI) after allogeneic stem cell transplantation is difficult to determine and currently unknown. The thesis describes different statistical methods the determine the effect of DLI after T-cell depleted allogeneic stem cell transplantation for ALL, AML, MDS, relapse AML and multiple myeloma. The effect on bone marrow disease appears strong as compared to extramudullary disease. Show less
Garderet, L.; Ziagkos, D.; Biezen, A. van; Lacobelli, S.; Finke, J.; Maertens, J.; ... ; Kroeger, N. 2018
Allogeneic stem cell transplantation (alloSCT) can be a curative treatment for hematological malignancies. However, the desired anti-tumor or Graft-versus-Leukemia (GvL) effect is often... Show moreAllogeneic stem cell transplantation (alloSCT) can be a curative treatment for hematological malignancies. However, the desired anti-tumor or Graft-versus-Leukemia (GvL) effect is often accompanied by undesired side effects, a complication known as Graft-versus-Host Disease (GvHD). GvL and GvHD are both caused by donor-derived T-cells recognizing alloantigens on patient cells. The main challenge for treatment of hematological malignancies with alloSCT is to evoke effective GvL reactivity, while limiting the risk of severe GvHD. In HLA-matched alloSCT, alloantigens recognized by donor T-cells are polymorphic peptides presented by HLA surface molecules on patient cells, the so-called minor histocompatibility antigens (MiHA). MiHA with hematopoiesis-restricted expression are relevant targets for immunotherapy, since donor T-cells for these MiHA will attack the malignant cells of the patient, while sparing healthy hematopoietic cells of donor origin. This thesis focused on efficient characterization of MiHA with potential therapeutic relevance, including MiHA that are encoded or produced by alternative transcripts, by analysis of in vivo immune responses after alloSCT. This analysis is relevant to provide insight into the immunobiology of GvL and GvHD after alloSCT and to identify MiHA with restricted expression on hematopoietic cells as potential targets for T-cell therapy to stimulate GvL reactivity after alloSCT without GvHD. Show less
Minor histocompatibility antigens (MiHA) are structures that can be recognized by T cells. In the setting of allogeneic stem cell transplantation MiHA presented by patient cells can be recognized... Show moreMinor histocompatibility antigens (MiHA) are structures that can be recognized by T cells. In the setting of allogeneic stem cell transplantation MiHA presented by patient cells can be recognized by donor T cells. If MiHA that are targeted by donor T cells are selectively expressed by leukemic cells, beneficial graft-versus-leukemia reactivity can be observed. However, if MiHA are presented by normal tissue cells, graft-versus-host disease can be a serious complication. The thesis describes methods that were applied to characterize the molecular structure of MiHA. T cells that recognized MiHA recognized on malignant hematopoietic and solid tumor cells were identified. MiHA recognition on both normal and malignant cells was measured. We finally investigated the differences of the donor T cell response of patients with a clinical graft-versus-leukemia reactivity who did or did not develop graft-versus-host disease. Show less
Pharmacotherapy plays an essential role in an allogeneic hematopoietic stem cell transplantation (allo-HSCT) procedure. Busulfan and treosulfan are two alkylating agents often applied in the... Show morePharmacotherapy plays an essential role in an allogeneic hematopoietic stem cell transplantation (allo-HSCT) procedure. Busulfan and treosulfan are two alkylating agents often applied in the conditioning regimen administered prior to the allo-HSCT. Finding the right balance between efficacious conditioning and toxicity remains the challenge for both agents. A majore One of the major complications after allo-HSCT is Acute graft-versus-host disease (aGvHD). When patients are diagnosed with grade 2 or higher aGvHD, systemic treatment with high-dose glucocorticoids is started as first line treatment. However, only half of the patients respond adequately to this therapy and also in other diseases non-responsiveness to glucocorticoids has been observed. Optimization of current drug therapies in allo-HSCT holds the potential to improve the outcome and safety. The goal of this thesis is to optimize busulfan- and treosulfan-based conditioning regimens and acute GvHD treatment with glucocorticoids by applying pharmacokinetic and pharmacogenetic profiling. Studies are performed in adults and pediatric patients. Show less
Zouwen, B. van der; Kruisselbrink, A.B.; Falkenburg, J.H.F.; Jedema, I. 2014
