Whole‐blood leukodepletion filters as a source of CD34+ progenitors potentially usable in cell therapy

Abstract

MNCs and CD 34+ cells recovered from the LDFs exhibit unimpaired functional capacities. Recent development of ex vivo technologies for expansion, retro-differentiation, and differentiation reinforces the value in cell therapy of these LDG-recovered peripheral blood progenitor cells that are routinely discarded.

Obtaining of CD34+ cells from healthy blood donors: development of a rapid and efficient procedure using leukoreduction filters

“…The growth and mortality rates of CD34+ cells after 3 and 6 days of liquid culture with IL‐3 (Table 3, Columns 2 and 3) as well as the frequency of progenitors (Column 4) were very similar to those previously found for steady‐state blood CD34+ cells selected with other methods 1‐3 . Their cell cycling was also similar to the one of CD34+ cells from other sources 10 .…”

“…After comparing the effects of elution with various buffers at 4 and 20°C on WBC recovery, PLT reduction, and lymphocyte yield, all further experiments were performed at 20°C in PBS supplemented with ACD‐A and HuS. Our previously described 500‐mL continuous elution method 2 was compared with sequential back‐flushing with 50 or 20 mL of elution buffer using a 50‐mL syringe. RBC, PLT, and WBC counts and differentials in the collected fractions were performed with an automatic multivariable hematology analyzer (CELL‐DYN 3500, Abbott Laboratories, Inc., Abbott Park, IL).…”

“…Despite the very low percentage of CD34+ cells in the steady‐state blood of healthy donors—approximately 0.15% of mononuclear cells (MNCs) 1 —adult blood is an attractive alternative to umbilical cord blood and marrow for research and, in the future, for regenerative medicine 2 . Indeed, a blood gift bag (400 to 450 mL with 1.6 × 10 9 to 4 × 10 9 white blood cells [WBCs]), represents a potential source of large numbers of CD34+ cells (0.4 × 10 6 to 1.6 × 10 6 /400 mL of blood), since leukoreduction filters (LRFs) are discarded after the preparation of therapeutic red blood cells (RBCs) devoid of WBCs and platelets (PLTs).…”

“…Indeed, a blood gift bag (400 to 450 mL with 1.6 × 10 9 to 4 × 10 9 white blood cells [WBCs]), represents a potential source of large numbers of CD34+ cells (0.4 × 10 6 to 1.6 × 10 6 /400 mL of blood), since leukoreduction filters (LRFs) are discarded after the preparation of therapeutic red blood cells (RBCs) devoid of WBCs and platelets (PLTs). CD34+ cell isolation from LRFs has already been an objective for us and others 2,3 . Differences in deformability, 4 electronic charges, 5 and surface antigens 6,7 between blood cell types explain that LRFs trap approximately 99% of PLT and WBCs within the filter matrix fibers 8,9 .…”

Component therapy to cellular therapy and beyond— a Darwinian approach to transfusion medicine

“…There are a variety of articles showing various sources of cells that can be used in regenerative medicine programs, including MNCs that can be eluted from leukoreduction filters or from the devices used in some apheresis machines for process leukoreduction 15,16 . In his landmark article in 2001, Dr. Toshiharu Shinoka, 17 now from Yale University, published “Transplantation of a Tissue‐Engineered Pulmonary Artery,” in which he took a small amount of vein from an individual, expanded it ex vivo in culture for several weeks, and then seeded it on a polymer scaffold, followed by implantation.…”