Safety and efficacy of cryopreserved platelets in bleeding patients with thrombocytopenia.

BACKGROUND: The short dating period of room temperature-stored platelets (PLTs; 5-7 days) limits their availability at far-forward combat facilities and at remote civilian sites in the United States. PLT cryopreservation in 6% DMSO and storage for up to 2 years may improve timely availability for bleeding patients. STUDY DESIGN AND METHODS: A dose escalation trial of DMSO-cryopreserved PLTs (CPPs) compared to standard liquid-stored PLTs (LSPs) was performed in bleeding patients with thrombocytopenia. Within each of four cohorts, six patients received escalating doses of CPP (0.5 unit, 1 unit, and sequential transfusions of 2 and 3 units) and one received a LSP transfusion. Patients were monitored for adverse events (AEs), coagulation markers, PLT responses, and hemostatic efficacy. RESULTS: Patients with a World Health Organization bleeding score of 2 or more received from 0.5 to 3 units of CPP (n = 24) or 1 unit of LSP (n = 4). There were no related thrombotic or other serious AEs experienced. Mild transfusion-related AEs of chills and fever (n = 1), transient increased respiratory rate (n = 1), DMSO-related skin odor (n = 2), and headache (n = 1) were observed after CPP transfusion. Among CPP recipients 14 of 24 (58%) had improved bleeding scores, including three of seven (43%) patients who had intracerebral bleeding. CPP posttransfusion PLT increments were significantly less than those of LSPs; however, days to next transfusion were the same. After transfusion, the CPP recipients had improvements in some variables of thrombin generation tests and thromboelastography. CONCLUSION: Cryopreserved PLT transfusions appear to be safe and effective when given to bleeding patients with thrombocytopenia.

Compartmental hollow fiber capillary membrane-based bioreactor technology for in vitro studies on red blood cell lineage direction of hematopoietic stem cells.

Continuous production of red blood cells (RBCs) in an automated closed culture system using hematopoietic stem cell (HSC) progenitor cell populations is of interest for clinical application because of the high demand for blood transfusions. Previously, we introduced a four-compartment bioreactor that consisted of two bundles of hollow fiber microfiltration membranes for transport of culture medium (forming two medium compartments), interwoven with one bundle of hollow fiber membranes for transport of oxygen (O(2)), carbon dioxide (CO(2)), and other gases (forming one gas compartment). Small-scale prototypes were developed of the three-dimensional (3D) perfusion cell culture systems, which enable convection-based mass transfer and integral oxygenation in the cell compartment. CD34(+) HSC were isolated from human cord blood units using a magnetic separation procedure. Cells were inoculated into 2- or 8-mL scaled-down versions of the previously designed 800-mL cell compartment devices and perfused with erythrocyte proliferation and differentiation medium. First, using the small-scale 2-mL analytical scale bioreactor, with an initial seeding density of 800,000 cells/mL, we demonstrated approximately 100-fold cell expansion and differentiation after 7 days of culture. An 8-mL laboratory-scale bioreactor was then used to show pseudocontinuous production by intermediately harvesting cells. Subsequently, we were able to use a model to demonstrate semicontinuous production with up to 14,288-fold expansion using seeding densities of 800,000 cells/mL. The down-scaled culture technology allows for expansion of CD34(+) cells and stimulating these progenitors towards RBC lineage, expressing approximately 40% CD235(+) and enucleation. The 3D perfusion technology provides an innovative tool for studies on RBC production, which is scalable.