Clinically feasible method for assessing leukocyte rheology in whole blood

Abstract

This study reports a novel method for assessment of leukocyte rheological activation with a new designed microchannel array chip to mimic the human microvascular network for microchannel array flow analysis (MCFAN). Study subjects were 79 healthy volunteers and 42 patients with type 2 diabetes mellitus (DM) and 36 patients with acute coronary syndrome (ACS). Using the anticoagulants heparin and ethylene-diamine-tetraacetic acid (EDTA)-2Na which inhibits platelets and leukocytes by chelating Ca 2+ , we were able to quantify leukocyte rheological activation by the subtraction of passage time of blood treated with both heparin and EDTA-2Na from that of blood treated with heparin only. We confirmed that passage times of whole blood with heparin + EDTA-2Na were always shorter than those of whole blood with only heparin in healthy subjects and patients with DM or ACS under suction pressures of − 30 cmH 2 O. There was a significant correlation between delta whole blood passage time {(heparin tube) − (EDTA-2Na + heparin)} and serum levels of myeloperoxidase and adhesive leukocyte number, respectively, even in blood from patients with DM or ACS, who suffered from inflammation. In conclusion we have developed a clinically feasible method for assessing leukocyte rheological activation in whole blood in ex vivo.

Microcirculatory and Metabolic Responses during Voluntary Cycle Ergometer Exercise with a Whole-Body Neuromuscular Electrical Stimulation Device

“…Whole blood passage time was measured with a microchannel flow analyzer system (BWA-MCFAN; Kikuchi Microtechnology Co., Ltd., Ibaraki, Japan) using a microchannel array chip (BK 7-7-4.5 microchannels; Kikuchi Microtechnology Co., Ltd. Ibaraki, Japan) for ex vivo microcirculatory evaluation. The BWA-MCFAN has been used in previous studies to assess ex vivo whole blood rheology and leukocyte activity, with detailed procedures and equipment described elsewhere [13][14][15]. Briefly, 0.1 mL of blood was drawn through the BK 7-7-4.5 microchannels as an ex vivo capillary model (7854-parallel, 7 × 4.5 µm equivalent cross-section, 30 µm long) under a constant vacuum of 20 cm H 2 O (1.96 kPa).…”