Effect of Hyperbaric Oxygen on Hematopoietic Stem Cell Transplantation

In this chapter the accumulated evidence that supports the role of hyperbaric oxygen therapy (HBOT) in improving the process of hematopoietic stem/progenitor cell (HSPC) homing, engraftment, and immune-reconstitution will be reviewed. The underlying mechanism by which HBO modulates erythropoietin (EPO)/EPOR signaling to improve HSPC homing and engraftment will be described. Also the pre-clinical evidence and pilot clinical trial evidence that supports HBO role in improving HSPC homing and engraftment will be examined. Current and future clinical trial studies that stem from this concept will be detailed. Finally, areas that need future investigations to optimally utilize HBO in the field of HSPC transplantation will be described

Inflammatory response following neutrophil recovery postchemotherapy in acute myeloid leukemia cases without evidence of infection: role of homing of neutrophils

A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author’s publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.Neutropenic sepsis is a common clinical entity occurring in postchemotherapy patients. Infection may not be the cause of fever in such patients after neutrophil-count recovery. Herein, we present two patients who developed fever during the neutropenic phase of induction chemotherapy and were treated with broad-spectrum antibiotics until they were no longer febrile and had recovered their neutrophil count. Being off antibiotics, they redeveloped fever within 48–72 hours. These fevers seemed to be secondary to postinfectious inflammatory response and not infection, supported by the fact that adequate antibiotic treatment was given and the collected fluid contained neutrophils but the cultures were negative. We hypothesize an explanation for this phenomenon based on the “homing of neutrophils” to bone marrow, which involves chemoattraction of CXC chemokine receptor (CXCR)-4 expressed on neutrophils towards the chemokine stromal cell-derived factor (SDF)-1 (CXCL12) expressed constitutively by bone marrow. Literature has shown that elevation of SDF-1 levels at injured/inflamed sites might create a similar gradient. This gradient results in the migration of neutrophils to the sites of previous injury/inflammation, leading to the formation of sterile abscesses. Based on our cases, we also conclude that antibiotics do not prevent the formation or treat such sterile “abscesses”; however, the drainage of these “abscesses” and treatment with anti-inflammatory agents are useful in such cases

Tolerability and outcome of once weekly liposomal amphotericin B for the prevention of invasive fungal infections in hematopoietic stem cell transplant patients with graft-versus-host disease

BACKGROUND: Invasive fungal infections remain problematic in immunosuppressed allogeneic stem cell transplant recipients and the use of corticosteroids for the treatment of graft-versus-host-disease can increase the risk three-fold. Although antifungal prophylaxis has been shown to decrease the incidence of infection, the optimal antifungal prophylactic regimen in this patient population has yet to be identified. Since early diagnosis of fungal infections might not be possible and the treatment of established fungal infections might be difficult and associated with high infection related mortality, prevention has become an important strategy in reducing overall morbidity and mortality. While triazoles are the preferred agents, some patients are unable to tolerate them and an alternative drug is warranted. OBJECTIVES: To assess the tolerability of once weekly liposomal amphotericin B as a prophylactic strategy in patients undergoing stem cell transplantation by evaluating any adverse events leading to its discontinuation. In terms of efficacy, to also compare the outcome and incidence of invasive fungal infections in patients who received amphotericin B, triazoles, and echinocandins.RESULTS: A total of 101 allogeneic transplant recipients receiving corticosteroids for the treatment of graft-versus-host-disease and antifungal prophylaxis were evaluated from August 2009 to September 2012. Liposomal amphotericin B 3 mg/kg intravenous once weekly was found to be well-tolerated. The incidence of invasive fungal infections was 19%, 17%, and 7% in the liposomal amphotericin B, echinocandin, and triazole groups, respectively. Two deaths occurred in the liposomal amphotericin B group and one death occurred in the echinocandin group. None of the deaths were fungal infection-related. CONCLUSION: Antifungal prophylaxis with liposomal amphotericin B was well-tolerated but the incidence of invasive fungal infections in patients receiving liposomal amphotericin B was higher than other antifungal agents in this study. The optimal dose and schedule of liposomal amphotericin B for antifungal prophylaxis in this patient population is still not known and considering its broad spectrum activity, prospective trials in comparison to triazoles are warranted

Hyperbaric oxygen improves engraftment of ex-vivo expanded and gene transduced human CD34+ cells in a murine model of umbilical cord blood transplantation

Delayed engraftment and graft failure represent major obstacles to successful umbilical cord blood (UCB) transplantation. Herein, we evaluated the use of hyperbaric oxygen (HBO) therapy as an intervention to improve human UCB stem/progenitor cell engraftment in an immune deficient mouse model. Six-to eight-week old NSG mice were sublethally irradiated 24 hours prior to CD34+ UCB cell transplant. Irradiated mice were separated into a non-HBO group (where mice remained under normoxic conditions) and the HBO group (where mice received two hours of HBO therapy; 100% oxygen at 2.5 atmospheres absolute). Four hours after completing HBO therapy, both groups intravenously received CD34+ UCB cells that were transduced with a lentivirus carrying luciferase gene and expanded for in vivo imaging. Mice were imaged and then sacrificed at one of 10 times up to 4.5 months post-transplant. HBO treated mice demonstrated significantly improved bone marrow, peripheral blood , and spleen (p=0.0293) retention and subsequent engraftment. In addition, HBO significantly improved peripheral, spleen and bone marrow engraftment of human myeloid and B-cell subsets. In vivo imaging demonstrated that HBO mice had significantly higher ventral and dorsal bioluminescence values. These studies suggest that HBO treatment of NSG mice prior to UCB CD34+ cell infusion significantly improves engraftment

The Potential Role of 3D In Vitro Acute Myeloid Leukemia Culture Models in Understanding Drug Resistance in Leukemia Stem Cells

The complexity of the bone marrow (BM) microenvironment makes studying hematological malignancies in vitro a challenging task. Three-dimensional cell cultures are being actively studied, particularly due to their ability to serve as a bridge of the gap between 2D cultures and animal models. The role of 3D in vitro models in studying the mechanisms of chemotherapeutic resistance and leukemia stem cells (LSCs) in acute myeloid leukemia (AML) is not well-reviewed. We present an overview of 3D cell models used for studying AML, emphasizing the recent advancements in microenvironment modeling, chemotherapy testing, and resistance

RSV-Related Thrombocytopenia Associated with Transient Cytogenetic Abnormalities in a Recipient of Umbilical Cord Blood Transplantation

Respiratory syncytial virus (RSV) infections are associated with thrombocytopenia. The underlying mechanism of thrombocytopenia in this setting is unknown. Herein, we report a case of RSV-related thrombocytopenia associated with transient cytogenetic abnormalities that occurred following umbilical cord blood transplantation

Autologous Stem Cell Rescue recipient with neutrophil tissue delivery detected prior to blood engraftment: a case report

Neutrophil recovery after autologous hematopoietic cell transplantation (auto-HCT) is affirmed with achievement of an Absolute Neutrophil Count (ANC) of ≥ 500/uL. There is growing evidence that neutrophils may be observed despite undetectable peripheral ANC counts following autologous hematopoietic cell transplant and are preferentially delivered to sites of inflammation. We report an interesting case that confirms neutrophil tissue delivery to the skin two days prior to evidence of blood engraftment after an auto-HCT

Bendamustine Associated with Irreversible Ascending Paralysis

Bendamustine is an alkylating agent currently used in the treatment of lymphoproliferative disorders. Many adverse effects, including a rare case of reversible neurotoxicity, have been reported in association with bendamustine. Herein, we report the first case of irreversible ascending paralysis related to bendamustine