Tiffany Tate

Non-genotoxic conditioning for hematopoietic stem cell transplantation using a hematopoietic-cell-specific internalizing immunotoxin

Hematopoietic stem cell transplantation (HSCT) offers curative therapy for patients with hemoglobinopathies, congenital immunodeficiencies, and other conditions, possibly including AIDS. Autologous HSCT using genetically corrected cells would avoid the risk of graft-versus-host disease (GVHD), but the genotoxicity of conditioning remains a substantial barrier to the development of this approach. Here we report an internalizing immunotoxin targeting the hematopoietic-cell-restricted CD45 receptor that effectively conditions immunocompetent mice. A single dose of the immunotoxin, CD45–saporin (SAP), enabled efficient (>90%) engraftment of donor cells and full correction of a sickle-cell anemia model. In contrast to irradiation, CD45–SAP completely avoided neutropenia and anemia, spared bone marrow and thymic niches, enabling rapid recovery of T and B cells, preserved anti-fungal immunity, and had minimal overall toxicity. This non-genotoxic conditioning method may provide an attractive alternative to current conditioning regimens for HSCT in the treatment of non-malignant blood diseases.

Role of lipegfilgrastim in the management of chemotherapy-induced neutropenia

Chemotherapy, irradiation, and other agents are widely used to target the process of cell division in neoplastic cells. However, while these therapies are effective against most cancers, the high proliferative rate of the cells of the hematopoietic system that produce billions of blood cells needed daily throughout life is extremely sensitive to these agents, resulting in loss of blood cell populations, which can be life threatening. Neutropenia is the most serious hematologic toxicity of chemotherapy, which can result in patient morbidity and mortality due to opportunistic infection and often is the limiting factor in dose escalation or duration of chemotherapeutic administration. Neutropenic patients often require hospitalization and incur substantial medical costs associated with anti-infective therapy. Treatment of iatrogenic and congenic neutropenia was changed in the early 1990s with the introduction of filgrastim (Neupogen®) and pegfilgrastim (Neulasta®). With the expiration of patent lives of both of these drugs, biosimilars have begun to emerge. In this review, we will summarize the chemical characteristics, pharmacokinetics, safety and efficacy of lipegfilgrastim (Lonquex®), the first long-acting biosimilar filgrastim to receive regulatory approval and enter the marketplace.

Bleeding the laboratory mouse: Not all methods are equal.

The laboratory mouse is the model most frequently used in hematologic studies and assessment of blood parameters across a broad range of disciplines. Often, analysis of blood occurs in a nonterminal manner. However, the small body size of the mouse limits collection based on volume, frequency, and accessible sites. Commonly used sites in the mouse include the retro-orbital sinus, facial vein, tail vein, saphenous vein, and heart. The method of blood acquisition varies considerably across laboratories and is often not reported in detail. In this study, we report significant alterations in blood parameters, particularly of total white blood cells, specific populations of dendritic cells and myeloid-derived suppressor cells, and hematopoietic progenitor cells, as a result of site and manner of sampling. Intriguingly, warming of mice prior to tail bleeding was found to significantly alter blood values. Our findings suggest that the same method should be used across an entire study, that mice should be warmed prior to tail bleeds to make levels uniform, and that accurate description of bleeding methods in publications should be provided to allow for interpretation of comparative reports and inter- and intralaboratory experimental variability.

Role of lipegfilgrastim in the management of chemotherapy-induced neutropenia [Corrigendum]

License. The full terms of the License are available at http://creativecommons.org/licenses/by-nc/3.0/. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. Permissions beyond the scope of the License are administered by Dove Medical Press Limited. Information on how to request permission may be found at: http://www.dovepress.com/permissions.php International Journal of Nanomedicine 2015:10 5421 International Journal of Nanomedicine Dovepress