Paques M, Boval B, Richard S, Tadayoni R, Massin P, Mundler O, Gaudric A, Vicaut E
Departments of Ophthalmology, Nuclear Medicine and Immunohematology, Assistance Publique-Hôpitaux de Paris and Université Paris 7, H opital Lariboisière, and Laboratoire d'Etude de la Microcirculation, Paris, France.
Curr Eye Res. 2000 Jul;21(1):560-5.
Increased leukocyte-endothelium interaction have been suggested as a phenomenon contributing to capillary occlusion and/or rupture of the blood-retina barrier during human retinal vascular diseases. This study was performed to evaluate if fluorescein-labeled autologous leukocytes (FLALs) can be used for examination of leukocyte transit in the human retina.
The preparation consisted of human dextran-separated leukocytes mixed with fluorescein. After reinjection in normal subjects and in one diabetic patient, a confocal scanning laser ophthalmoscope was used to visualize them in the retinal circulation. The changes between FLALs and control leukocytes in the expression of leukocytes adhesion molecules CD11b and CD62L were evaluated by flow cytometry.
The circulating FLALs were clearly visible in retinal vessels. The mean (+/- SD) capillaries velocity was 1.43 (+/- 1.3) mm/s in the macula and 1.82 (+/- 1.4) mm/s in the peripapillary area. No leukostasis was detected in the normal subjects, while it was detected in te diabetic patient. Flow cytometry revealed an increase in CD11b and a decrease in CD62L expression of leukocytes after labeling, suggesting that compared to normal leukocytes FLALs are more susceptible to interact with vascular endothelium.
The use of FLAL is presently the only technique applicable in humans for study of leukocyte transit in the retina. Their preparation is technically simple and unexpensive. Precise measurement of the velocity of leukocytes in small vessels can be obtained. Despite evidence of a certain degree of leukocyte activation after the labeling procedure, no leukostasis was detected in vivo in normal subjects. Potential applications for this technique may include the detection of leukostasis in the human retina during severe forms of diabetes and retinal phlebitis.
白细胞与内皮细胞间相互作用增强被认为是导致人类视网膜血管疾病期间毛细血管阻塞和/或血视网膜屏障破裂的一种现象。本研究旨在评估荧光素标记的自体白细胞（FLALs）是否可用于检测人类视网膜中的白细胞转运。
制备物由与荧光素混合的人右旋糖酐分离白细胞组成。在正常受试者和一名糖尿病患者中重新注射后，使用共聚焦扫描激光眼科显微镜在视网膜循环中观察它们。通过流式细胞术评估FLALs与对照白细胞在白细胞粘附分子CD11b和CD62L表达上的变化。
循环中的FLALs在视网膜血管中清晰可见。黄斑区平均（±标准差）毛细血管速度为1.43（±1.3）mm/s，视乳头周围区域为1.82（±1.4）mm/s。正常受试者未检测到白细胞停滞，而在糖尿病患者中检测到。流式细胞术显示标记后白细胞CD11b表达增加，CD62L表达减少，表明与正常白细胞相比，FLALs更容易与血管内皮相互作用。
目前，使用FLAL是唯一适用于人类研究视网膜中白细胞转运的技术。其制备在技术上简单且成本低廉。可以精确测量小血管中白细胞的速度。尽管标记过程后有一定程度的白细胞活化证据，但正常受试者体内未检测到白细胞停滞。该技术的潜在应用可能包括在严重糖尿病和视网膜静脉炎期间检测人类视网膜中的白细胞停滞。
