Piagnerelli Michael, Boudjeltia Karim Zouaoui, Brohee Danny, Piro Pietrina, Carlier Eric, Vincent Jean-Louis, Lejeune Philippe, Vanhaeverbeek Michel
Department of Critical Care Medicine, Erasme Hospital, Free University of Brussels, Belgium.
Crit Care Med. 2003 Aug;31(8):2156-62. doi: 10.1097/01.CCM.0000079608.00875.14.
To investigate the relationship between red blood cell (RBC) shape and modifications of RBC membrane protein content in critically ill patients with or without sepsis compared with healthy control volunteers.
Prospective, observational in vitro study.
University-affiliated cell biology laboratory.
Human erythrocytes from healthy volunteers and nonseptic and septic intensive care unit patients.
Sialic acid membrane content was measured on isolated RBC membrane proteins by high-performance liquid chromatography. RBC shape, estimated by the spherical index (M2/M1) or by the moment and effect of osmolality on RBC shape, was studied by flow cytometry at 25 degrees C. Glycophorin A content was measured with antiglycophorin antibodies in flow cytometry.
Sialic acid content was lower in the septic than in the nonseptic patients (1.98 +/- 0.79, 2.20 +/- 0.39 microg/100 microg membrane protein, respectively; p =.01) and than in the volunteers (2.71 +/- 1.00 microg/100 microg membrane protein; p <.001). No significant difference was found in glycophorin A content between septic and nonseptic patients. RBCs from septic patients had a more spherical shape in isotonic solution than those of healthy volunteers, as assessed by a computed spherical index (M2/M1 ratio: 1.68 +/- 0.34 vs. 1.95 +/- 0.32; p =.001). Only the RBCs of septic patients failed to change their shape in hypo-osmolar solution (M2/M1 ratio: 1.68 +/- 0.34 in iso-osmolar, 1.56 +/- 0.28 in hypo-osmolar solution; p =.17). There was a significant correlation between the RBC shape evaluated by the spherical index or by the moment of the cytometric histogram and the sialic acid membrane content in all critically ill patients (septic and nonseptic patients) (r2 =.16, p =.01 for the moment, and r2 =.17, p =.01 for the spherical index, respectively).
RBCs of septic patients are characterized by a more spherical shape, a decreased capacity of sphericity in hypo-osmolar solution, and a reduction in the sialic acid content of the RBC membrane. These modifications in RBC shape and membrane may contribute to the RBC rheologic abnormalities frequently described in sepsis.
研究重症患者（无论是否患有脓毒症）与健康对照志愿者相比，红细胞（RBC）形状与RBC膜蛋白含量改变之间的关系。
前瞻性体外观察研究。
大学附属细胞生物学实验室。
来自健康志愿者以及非脓毒症和脓毒症重症监护病房患者的人红细胞。
通过高效液相色谱法测定分离的RBC膜蛋白上的唾液酸膜含量。在25℃下通过流式细胞术研究RBC形状，通过球形指数（M2/M1）或渗透压对RBC形状的影响和作用来估计。在流式细胞术中用抗血型糖蛋白A抗体测量血型糖蛋白A含量。
脓毒症患者的唾液酸含量低于非脓毒症患者（分别为1.98±0.79、2.20±0.39μg/100μg膜蛋白；p = 0.01），且低于志愿者（2.71±1.00μg/100μg膜蛋白；p <0.001）。脓毒症患者与非脓毒症患者之间血型糖蛋白A含量无显著差异。通过计算球形指数评估，脓毒症患者的RBC在等渗溶液中比健康志愿者的RBC更呈球形（M2/M1比值：1.68±0.34对1.95±0.32；p = 0.001）。只有脓毒症患者的RBC在低渗溶液中未能改变其形状（M2/M1比值：等渗时为1.68±0.34，低渗时为1.56±0.28；p = 0.17）。在所有重症患者（脓毒症和非脓毒症患者）中，通过球形指数或细胞直方图矩评估的RBC形状与唾液酸膜含量之间存在显著相关性（细胞直方图矩的r2 = 0.16，p = 0.01；球形指数的r2 = 0.17，p = 0.01）。
脓毒症患者的RBC特征为形状更呈球形、在低渗溶液中球形化能力降低以及RBC膜唾液酸含量减少。RBC形状和膜的这些改变可能导致脓毒症中经常描述的RBC流变学异常。
