Search

Hematopoietic stem cell transplantation (HSCT) from haploidentical donors is a viable option for patients lacking HLA-matched donors. Here we report the results of a prospective multicenter phase I/II trial of transplantation of TCRαβ and CD19-depleted peripheral blood stem cells from haploidentical family donors after a reduced-intensity conditioning with fludarabine, thiotepa, and melphalan. Thirty pediatric and 30 adult patients with acute leukemia (n = 43), myelodysplastic or myeloproliferative syndrome (n = 6), multiple myeloma (n = 1), solid tumors (n = 6), and non-malignant disorders (n = 4) were enrolled. TCR αβ/CD19-depleted grafts prepared decentrally at six manufacturing sites contained a median of 12.1 × 10 6 CD34 + cells/kg and 14.2 × 10 3 TCRαβ + T-cells/kg. None of the patients developed grade lll/IV acute graft-versus-host disease (GVHD) and only six patients (10%) had grade II acute GVHD. With a median follow-up of 733 days 36/60 patients are alive. The cumulative incidence of non-relapse mortality at day 100, 1 and 2 years after HSCT was 5%, 15%, and 17% for all patients, respectively. Estimated probabilities of overall and disease-free survival at 2 years were 63% and 50%, respectively. Based on these promising results in a high-risk patient cohort, haploidentical HSCT using TCRαβ/CD19-depleted grafts represents a viable treatment option., (© 2021. The Author(s).)

Background: Dendritic cells (DCs) generated from leukemic blasts constitute a promising tool in immunotherapy for acute myeloid leukemia patients (AML-DCs), because AML-DCs express human leukocyte antigens and costimulatory molecules such as CD40, CD80, and CD86 at a higher level than leukemic blasts. Potentiation of AML-DC vaccine might become feasible by the addition of adjuvants such as lipopolysaccharides (LPS) or CPG-rich oligodeoxyribonucleotides binding to Toll-like receptors (TLR) and inducing a stronger Type 1 T-cell response., Study Design and Methods: mRNA and protein expression of TLR-2, -4, and -9 were analyzed with quantitative real-time polymerase chain reaction, Western blot, and flow cytometry for mature monocyte-derived DCs generated from 14 AML patients versus 14 healthy volunteers (HV-DCs), and the response of the AML- and HV-DCs to different microbial TLR ligands was determined by enzyme-linked immunosorbent assay for the proinflammatory cytokines tumor necrosis factor (TNF)-alpha, inducible protein (Ip)-10, and interleukin (IL)-6., Results: AML-DCs and HV-DCs strongly expressed TLR-2 and TLR-4, while TLR-9 was expressed at a lower level in both groups. There was no significant difference in TLR expression between the two groups of AML-DCs and HV-DCs. In accordance with the TLR expression levels, DCs generated from both AML patients and HVs responded to the known microbial ligands peptidoglycan (PGN) and lipoteichoic acid for TLR-2 and LPS as ligand for TLR-4, by producing TNF-alpha and IL-6. A response to the ODNs 2006 and 2216 binding to TLR-9 was only detected in AML-DCs., Conclusion: Microbial ligands like ODNs and LPS constitute promising adjuvants for enhancing (AML-) DC vaccines.

Background: Mononuclear cells (MNCs) of severely impaired acute myeloid leukemia (AML) patients may be collected by leukapheresis for large-scale generation of dendritic cells (AML-DCs) under good manufacturing practice (GMP) conditions for adoptive immunotherapy., Study Design and Methods: In five end-stage AML patients, a leukapheresis procedure was performed with a cell separator (either COBE Spectra [Gambro BCT] or Amicus [Baxter]). For large-scale AML-DC generation, the MNCs of a single leukapheresis concentrate were isolated by density gradient and plated into a cell factory under GMP conditions. The AML-DCs were harvested on Day 8 of culture, and their viability, the mature morphology, and the phenotype were evaluated. The AML-DCs were injected subcutaneously into five AML patients up to four times at a biweekly interval., Results: All AML patients entered the leukapheresis procedure with a highly pathologic blood count. In a mean separation time of 198 +/- 33 minutes, a mean of 1.3 +/- 0.2-fold the total blood volume was processed with a white blood cell (WBC) yield of 9 x 10(9) to 70 x 10(9) per collection dependent on the precollection WBC count. After density gradient a mean of 2.2 x 10(9) +/- 0.3 x 10(9) MNCs were plated into a cell factory. This resulted in a mean viable and mature DC yield of 0.01 x 10(9) of MNCs., Conclusion: The leukapheresis procedure is a feasible and safe procedure even in patients with hematologic malignancies and highly pathologic blood counts. Sufficient amounts of MNCs can be collected in leukopenic patients and the large-scale generation of AML-DCs in cell factories under GMP conditions yields in an adequate quantity of viable and mature AML-DCs.

Autologous platelets of 5 alloimmunized patients with acute leukemia in remission were cryopreserved with 5% dimethylsulfoxide in liquid nitrogen and retransfused in the following therapy-induced thrombocytopenic phase. The mean platelet recovery after freezing, thawing and washing was 85 +/- 6%. The mean corrected 1-hour increment in platelet counts was 11 (4-27) x 10(9)/l, i.e. 61% in comparison with fresh platelet transfusions in other patients. In vivo function of frozen platelets was documented by improvement of the posttransfusion bleeding time. Cryopreserved autologous platelets function hemostatically and can be used even for completely refractory patients and thus permit curative antileukemic therapy.

A 23-year-old male patient undergoing first induction chemotherapy for acute myeloid leukaemia received granulocyte transfusions on 10 consecutive days. An average of 2.1 X 10(10) granulocytes was given per square metre body surface area per day. Transfusion reactions and absence of post-transfusion granulocyte increment after the fifth granulocyte transfusion suggested the presence of leukocyte antibodies. However, no antibodies were detectable at this time by the lymphocytotoxicity test, the indirect granulocyte immunofluorescence test, or the platelet suspension immunofluorescence test. In contrast to the clinical observation, the serological detection of leukocyte antibodies was only possible 1 day after the last granulocyte transfusion.

40 patients with acute leukaemia and severe granulocytopenia were treated with granulocyte transfusions for bacteriologically documented or clinically suspected septicaemia. The patients received an average of 5 transfusions each with 2.1 X 10(10) granulocytes per m2 body surface area per day. 26 patients showed clinical benefit from transfusion therapy as documented by the course of blood cultures, local lesions and fever. Only patients with regeneration of granulopoiesis had definite benefit from granulocyte transfusions. All other patients died ultimately from septicaemia.