Modification of the leukapheresis procedure for use in rhesus monkeys (Macaca mulata)

Abstract

One of the most serious problems in applying leukapheresis to human infants is the large extracorporeal blood volume (ECV), resulting in substantial loss of platelets and red blood cells (RBCs). In this study, we developed a safe and effective modified procedure to collect peripheral blood stem cells (PBSCs) from rhesus monkeys (Macaca mulata) using a Baxter CS3000+ Blood Cell Separator (Baxter, Deerfield, IL) with several devices that reduced chamber size and shortened the standard apheresis kit to decrease ECV from 130 to 70 ml. Pump speed was controlled by monitoring hematocrit values and platelet counts during leukapheresis. This system makes it possible to perform safe and effective leukapheresis in rhesus monkeys whose body weight is similar to that of human infants. A total of 12 leukapheresis procedures were performed in nine monkeys and resulted in the collection of sufficient numbers of white blood cells (mean, 1.38 x 10(9) cells/kg), CD34(+) cells (mean, 17.80 x 10(6) cells/kg), mononuclear cells (mean, 3.67 x 10(8) cells/kg), and colony forming units (mean, 75.02 x 10(6) cells/kg) in all cases. In addition, no complications, such as anemia or thrombocytopenia, occurred after leukapheresis. This modified leukapheresis procedure will be useful to test new approaches in gene therapy, perform organ transplantation using nonhuman primates, and collect PBSCs from human infants in a noninvasive manner. Our nonhuman primate model provides an important framework for such future clinical studies.

Safe And Efficient Collection of Cytokine-Mobilized Peripheral Blood Cells From Cynomolgus Monkeys (Macaca fascicularis) with Human Newborn-Equivalent Body Weights

“…There was no significant difference in the increase in the peripheral WBC counts after cytokine treatment between the unmodified and modified procedure groups. In the modified protocol, a small separation chamber (S25A) was installed instead of the regular one in the blood separator, and the extracorporeal blood lines in the standard apheresis kit were shortened [3,9,22]. As a result, the extracorporeal blood volume was reduced from 130 to 70 ml (Fig.…”

“…A CS3000 blood separator (Baxter, Deerfield, IL, USA) was used as described previously [3]. Briefly, a standard apheresis kit was installed in the CS3000 blood separator.…”

“…We and others have previously reported leukapheresis procedures for non-human primates with body weights of less than 10 kg using rhesus monkeys (Macaca mulata, average 7 kg) [3,9]. In such small animals, acute cardiac failure due to the relatively large extracorporeal blood flow is a critical adverse event which can occur during leukapheresis.…”

“…In such small animals, acute cardiac failure due to the relatively large extracorporeal blood flow is a critical adverse event which can occur during leukapheresis. To avoid this, we modified the procedure by reducing the extracorporeal blood volume as much as possible and adjusting the withdrawal speed frequently in response to the results of real-time monitoring of hemoglobin (Hb) and hematocrit (Ht) values [3]. In this study, we examined the efficacy and safety of our procedure using even smaller non-human primates, cynomolgus monkeys (Macaca fascicularis, average 3.3 kg), which have body weights equivalent to human newborns.…”

A novel CD4‐conjugated ultraviolet light‐activated photocatalyst inactivates HIV‐1 and SIV efficiently

“…3B). Sequential plasma separation from whole blood using the CS3000 was performed by centrifugation, and circuit and circulation protocols were modified and applied to rhesus monkeys [Donahue et al, 1996;Ageyama et al, 2003]. The plasma separation system was synchronized to the CD4-TiO 2 circulatory system, with a blood flow rate of 8-12 ml/min and a plasma flow rate of 100 ml/min in the circulatory system of CD4-TiO 2 .…”