Characteristics and mechanisms to control a COVID-19 outbreak on a leukemia and stem cell transplantation unit.

Immunosuppressed patients like patients with leukemia or lymphoma, but also patients after autologous or allogeneic stem cell transplantation are at particular risk for an infection with COVID-19. We describe a COVID-19 outbreak on our leukemia and stem cell transplantation unit (LSCT-Unit) originating from a patient with newly diagnosed acute myeloid leukemia. The patient was treated with intensive induction chemotherapy and we characterize the subsequent outbreak of COVID-19 on a LSCT-Unit. We describe the characteristics of the 36 contacts among the medical team, the results of their PCR and antibody tests and clinical aspects and features of infected employees. Of these 36 close contacts, 9 employees of the LSCT-Unit were infected and were tested positive by PCR and/or antibody-testing. 8/9 of them were symptomatic, 3/9 with severe, 5/9 with mild symptoms, and one person without symptoms. Due to stringent hygiene measures, the outbreak did not lead to infections of other patients despite ongoing clinical work. Moreover, we demonstrate that incubation period and clinical course of a COVID-19 infection in an immunosuppressed patient could be unusual compared to that of immunocompetent patients. Consistent PCR and antibody testing are helpful to understand, control, and prevent outbreaks. For the safety of health-care workers and patients alike, all employees wore FFP2 masks and were trained to adhere to several further safety guidelines. The implementation of rigorous hygiene measures is the key to controlling an outbreak and preventing infections of other patients.

A multicenter prospective, randomized, placebo-controlled phase II/III trial for preemptive acute graft-versus-host disease therapy.

Acute graft-versus-host disease (aGvHD) contributes to about 50% of transplant-related mortality (non-relapse mortality) after allogeneic hematopoietic stem cell transplantation (HSCT). Here the predictive value of a urinary proteomic profile (aGvHD_MS17) was tested together with preemptive prednisolone therapy. Two-hundred and fifty-nine of 267 patients were eligible for analysis. Ninety-two patients were randomized upon aGvHD_MS17 classification factor above 0.1 to receive either prednisolone (2-2.5 mg/kg, N = 44) or placebo (N = 47; N = 1 randomization failure) for 5 days followed by tapering. The remaining 167 patients formed the observation group. The primary endpoint of the randomized trial was incidence of aGvHD grade II between randomization and day +100 post HSCT. Analysis of the short-term preemptive prednisolone therapy in the randomized patients showed no significant difference in incidence or severity of acute GvHD (HR: 1.69, 95% CI: 0.66-4.32, P = 0.27). Prednisolone as preemptive treatment did not lead to an increase in relapse (20.2% in the placebo and 14.0% in the prednisolone group (P = 0.46)). The frequency of adverse events was slightly higher in the placebo group (64.4% versus 50%, respectively). Taken together, the results of the Pre-GvHD trial demonstrated the feasibility and safety of preemptive prednisolone treatment in the randomized patients.

Fibroblasts retrovirally transfected with the human IL-3 gene initiate and sustain multilineage human hematopoiesis in SCID mice: comparison of CD34-enriched vs CD34-enriched and in vitro expanded grafts.

Peripheral blood progenitor cells (PBPCs) obtained from cytapheresis products (CPs) of tumor patients undergoing mobilizing chemotherapy for PBPC support and dose-intensified anticancer chemotherapy initiate multilineage human hematopoiesis after intraperitoneal (i.p.) transplantation into young severe combined immunodeficient (SCID) mice. The engraftment process was significantly accelerated by subcutaneous cotransplants of a rat fibroblast cell line stably transfected with a retroviral vector carrying the human interleukin-3 (hIL-3) gene and producing sustained in vivo levels of circulating human IL-3 over a prolonged period of time. These cotransplants were found to provide a suitable microenvironment for i.p. transplanted CD34-positive cells separated from PBPC preparations using immunomagnetic beads. Flow cytometry analysis and immunocytology revealed that selected PB CD34- cells, more than 90% pure, were capable of initiating and sustaining a productive multilineage hematopoiesis preferentially within the hIL-3-secreting cotransplants followed by release of mature human cells into the circulation, spleen and thymus. The percentages of human cells found in hIL-3 cotransplants 8 weeks post-transplantation (p.t.) were generally higher than those measured after transplantation of complete CP mononuclear cells containing comparable doses of CD34-positive cells. When selected PB CD34+ cells that were expanded ex vivo with combinations of human hematopoietic growth factors including the c-kit ligand (KL), interleukin (IL)-1 beta, IL-3, IL-6, erythropoietin (EPO) and granulocyte-macrophage colony-stimulating factor (GM-CSF) for 14 days were grafted to cotransplant-carrying SCID mice, a considerable loss of their proliferative potential was observed regardless of the HGF combination used. When experiments with grafts of selected PBPC were compared to those performed with selected/expanded PBPC on a per CD34+ cell basis the results revealed that over a dose range of 0.3 to 1.0 x 10(6) cells/graft the in vivo proliferative capacity of expanded cells was reduced by a factor of 2 to 3.

Personality influences quality-of-life assessments in adult patients after allogeneic hematopoietic SCT: results from a joint evaluation of the prospective German Multicenter Validation Trial and the Fred Hutchinson Cancer Research Center.

The influence of personality on health related quality of life (QoL) and physical functioning in the setting of allogeneic hematopoietic SCT (alloHSCT) is unknown. We conducted a joint evaluation within two independent cohorts of alloHSCT recipients to investigate the impact of personality on reported QoL and physical functioning. Two-hundred-eight patients (median age 44 years, range 18-72) of cohort 1 and 93 patients (median age 55 years, range 19-79) of cohort 2 after alloHSCT were evaluated. Personality was assessed using the 24-adjective measure (AM), which measures the Big-Five personality domains and the Life Orientation Test-Revised (LOT-R), measuring optimism and pessimism. QoL was measured using the Functional Assessment of Cancer Therapy with bone marrow transplantation subscale (FACT-BMT), Short Form 36 (SF-36), the human activity profile (HAP), as well as the NIH criteria-based cGVHD activity assessment form and the Lee cGVHD symptom scale. Neuroticism was significantly associated with worse function measured by the HAP and FACT-BMT. Optimism significantly improved QoL captured by the FACT-BMT. Pessimism significantly impaired physical function captured by the HAP and SF-36. Extraversion was significantly associated with reduced depression and lower severity of cGVHD symptoms reported by the patient and the physician. The results suggest that personality traits and pre-treatment QoL assessments should be measured in clinical trials to facilitate the interpretation of QoL data.

Dose-escalated radioimmunotherapy as part of reduced intensity conditioning for allogeneic transplantation in patients with advanced high-grade non-Hodgkin lymphoma.

A total of 20 patients enrolled in a multicenter phase II dose escalation study of radioimmunotherapy (RIT) using yttrium-90-ibritumomab tiuxetan at two dose levels (22 and 30 MBq/kg) in 10 patients, combined with reduced intensity conditioning (RIC) using fludarabine, melphalan and alemtuzumab followed by allogeneic hematopoietic cell transplantation (HCT) from either matched-related (n=5) or matched-unrelated donors (n=15). Postgrafting immunosuppression with cyclosporine was administered. Diagnoses were diffuse large B-cell lymphoma (n=13), transformed CLL (n=4), blastic mantle cell lymphoma (n=2) and follicular lymphoma grade 3 (n=1). Median age was 51 (range, 29-69) years. All patients were high risk with relapsed/refractory disease or relapse after preceding autologous HCT. Median follow-up of patients alive was 1115 (range, 1006-1252) days. No directly RIT-related toxicities were observed. The cumulative incidence of non-relapse mortality was 30%. Incidences of grade II-IV acute and chronic GvHD was 45% and 70%, respectively. Kaplan-Meier estimated 3-year OS and EFS were 20% for both dose levels. In conclusion, dose escalation of RIT and combined use with RIC is feasible with no additional toxicity due to dose escalation. This study is registered on http://clinicaltrials.gov as NCT00302757.

Nilotinib hampers the proliferation and function of CD8+ T lymphocytes through inhibition of T cell receptor signalling.

The novel selective BCR-ABL Breakpoint cluster region--Abelson murine leukemia viral oncogene homolog 1 (BCR-AML) inhibitor nilotinib (AMN107) is a tyrosine kinase inhibitor that is more potent against leukaemia cells in vitro than imatinib. As nilotinib might be used in the context of allogeneic stem cell transplantation where CD8+ T lymphocytes play a pivotal role in the graft-versus-leukaemia (GVL) effect, we investigated effects of nilotinib on this lymphocyte subpopulation. Nilotinib inhibits phytohemagglutinin (PHA)-induced proliferation of CD8+T lymphocytes in vitro at therapeutically relevant concentrations (0.5-4 microM). The inhibition of CD8+ T lymphocytes specific for leukaemia or viral antigens through nilotinib was associated with a reduced expansion of antigen peptide specific CD8+ T lymphocytes and with a decreased release of interferon-gamma and granzyme B by these cells as analysed by flow cytometry and enzyme-linked immunospot (ELISPOT) assays. The inhibitory effect caused by nilotinib was two times stronger than by imatinib. These effects were mediated through the inhibition of the phosphorylation of ZAP-70, Lck and ERK 1/2 and the NF-kappaB signalling transduction pathway. Taken together, we observed a strong suppressive impact of nilotinib on the CD8+ T lymphocyte function which should be considered carefully in the framework of allogeneic stem cell transplantation or other T cell based immunotherapies.

The severe combined immunodeficient-human peripheral blood stem cell (SCID-huPBSC) mouse: a xenotransplant model for huPBSC-initiated hematopoiesis.

Mononuclear cells (MNCs) containing peripheral blood stem cells (PBSCs) were obtained from solid-tumor patients undergoing mobilizing chemotherapy followed by granulocyte colony-stimulating factor for PBSC transplantation-supported dose-intensified anticancer chemotherapy and were transplanted into unconditioned "nonleaky" young severe combined immunodeficient mice. Multilineage engraftment was shown by flow cytometry and immunocytochemistry using monoclonal antibodies to various human cell surface antigens as well as identification of human immunoglobulin in murine sera. Within a dose range of MNCs suitable for transplantation (10 to 36 x 10(6) cells/graft) the number of CD34+ cells injected (optimal at > 0.7 x 10(6)/graft) determined the yield of human cells produced in recipient animals. Engraftment of hu PBSC preparations resulted in prolonged generation of physiologic levels of human cytokines including interleukin-3 (IL-3), IL-6, and granulocyte-macrophage colony-stimulating factor, which were detectable in the murine blood over a period of at least 4 months. In vivo survival of immature human progenitor cells was preserved even 9 months after transplantation. Because human IL-3 is known to stimulate early hematopoiesis, a rat fibroblast cell line was stably transfected with a retroviral vector carrying the human IL-3 gene and cotransplanted subcutaneously as additional source of growth factor. Cotransplants of this cell line producing sustained in vivo levels of circulating human IL-3 for at least 12 weeks significantly accelerated the process of engraftment of huPBSC and spurred the spread of mature human cells to the murine spleen, liver, thymus, and peripheral blood. Cotransplants of allogeneic human bone marrow stromal cells derived from long-term cultures resulted in a comparable--though less prominent--support of engraftment.