Ruef P, Linderkamp O
Department of Pediatrics, University of Heidelberg, Medical School, Germany.
Pediatr Res. 1999 Jan;45(1):114-9. doi: 10.1203/00006450-199901000-00019.
More stomatocytes, spherocytes, and erythrocytes with spicules and protrusions are found in blood from newborn infants than in blood from adults. The objective of this study was to measure volume, surface area, membrane rigidity, and viscosity of red blood cells (RBC) with irregular shapes in preterm and full-term neonates. RBC from 13 full-term and 12 preterm (25-36 wk of gestation) infants were studied by means of a micropipette system. In full-term neonates and in preterm infants, 19 and 26% of RBC, respectively, showed shapes different from those of discocytes. Keratocytes, spherocytes, akanthocytes (in full-term infants), and elliptocytes (in preterm infants) had smaller volumes than did discocytes (p < 0.05). Spherocytes showed decreased and elliptocytes had increased excess surface area and swelling capacity compared with discocytes, indicating both volume and membrane loss for spherocytes and only volume loss for elliptocytes. Immature RBC and knizocytes had similar large volumes and surface areas, suggesting that knizocytes in neonates are relatively young RBC. Increased membrane rigidity was found only in stomatocytes. Membrane viscosity was decreased in immature RBC and knizocytes and increased in stomatocytes, keratocytes, akanthocytes, and elliptocytes when compared with discocytes. There were inverse relationships between RBC volume and membrane rigidity (r=-0.42) and between RBC volume and membrane viscosity (r=-0.72). This suggests that volume loss of neonatal RBC is associated with impaired membrane deformability. Moreover, we conclude that the geometry and membrane deformability of some of the irregularly shaped neonatal RBC resemble properties of RBC in hemolytic anemias (e.g. spherocytosis).
与成人血液相比,新生儿血液中发现有更多的口形红细胞、球形红细胞以及带有刺突和突起的红细胞。本研究的目的是测量早产和足月新生儿中形状不规则的红细胞(RBC)的体积、表面积、膜刚性和粘度。通过微量移液器系统研究了13名足月和12名早产(妊娠25 - 36周)婴儿的红细胞。在足月新生儿和早产儿中,分别有19%和26%的红细胞呈现出与双凹圆盘形红细胞不同的形状。角化细胞、球形红细胞、棘形红细胞(在足月婴儿中)和椭圆形红细胞(在早产儿中)的体积比双凹圆盘形红细胞小(p < 0.05)。与双凹圆盘形红细胞相比,球形红细胞的表面积减少,椭圆形红细胞的过剩表面积和肿胀能力增加,这表明球形红细胞既有体积损失又有膜损失,而椭圆形红细胞只有体积损失。未成熟红细胞和锯齿形红细胞具有相似的大体积和表面积,这表明新生儿中的锯齿形红细胞是相对年轻的红细胞。仅在口形红细胞中发现膜刚性增加。与双凹圆盘形红细胞相比,未成熟红细胞和锯齿形红细胞的膜粘度降低,而口形红细胞、角化细胞、棘形红细胞和椭圆形红细胞的膜粘度增加。红细胞体积与膜刚性之间(r = -0.42)以及红细胞体积与膜粘度之间(r = -0.72)存在负相关关系。这表明新生儿红细胞的体积损失与膜变形性受损有关。此外,我们得出结论,一些形状不规则的新生儿红细胞的几何形状和膜变形性类似于溶血性贫血(如球形红细胞增多症)中红细胞的特性。