Scanning electron microscopy analysis of erythrocytes in thromboembolic ischemic stroke.

INTRODUCTION: Erythrocytes play an important role in hemostasis and disease conditions. During ischemic stroke, erythrocytes undergo oxidative and proteolytic changes resulting in a changed cellular rheology.
METHODS: Blood samples were obtained from controls and thromboembolic ischemic stroke patients (within 48 h of stroke). The ultrastructure of erythrocytes was compared, using a scanning electron microscope (SEM). Abnormal morphology included codocytes, knizocytes, stomatocytes, and echinocytes. Percentage of abnormal cells was calculated, and the analyses were performed using the statistical program NCSS with the level of significance set at 0.05. A t-test was carried out to compare the data from the erythrocyte counts of stroke patients with that of the control subjects.
RESULTS: Ultrastructural SEM results showed that there are a large percentage of erythrocytes in healthy individuals that do not have a typical discoid shape, when studying the cells using a high magnification electron microscope. Furthermore, analysis showed that variation in shape is so subtle that it is not clearly visible using a typical light microscopy blood smear analysis. Thromboembolic ischemic stroke patients presented with a significant amount of erythrocytes with abnormal morphology.
CONCLUSION: We suggest that in healthy individuals, a typical smear would contain several nondiscoid-shaped erythrocytes, only clearly visible at high magnification. However, thromboembolic ischemic stroke does significantly impact erythorcyte shape, and this change in morphology may result in an impaired microcirculation, as well as impaired oxygen carrying capacity. This changed morphology may further complicate the restoring of homeostasis caused by acute thromboembolic stroke.