Hung Joseph C, Iverson Barton C, Toulouse Kyra A, Mahoney Douglas W
Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.
J Nucl Med. 2002 Jul;43(7):928-32.
This study was conducted to evaluate the effects of methylene blue/phosphate buffer stabilizer on the labeling efficiency, cell membrane integrity, chemotaxis, and in vitro stability of leukocytes labeled with 99mTc-exametazime.
Whole blood (480 mL) was obtained from each of 3 healthy donors and divided equally into eight 60-mL aliquots. Two aliquots from each of the 3 subjects were used as a control (i.e., leukocytes were not labeled with either nonstabilized or stabilized 99mTc-exametazime) in this study. The remaining 6 aliquots from each of the 3 subjects were divided equally into the following formulation groups: (a) leukocytes labeled with nonstabilized 99mTc-exametazime, (b) leukocytes labeled with stabilized 99mTc-exametazime containing 250 microg methylene blue, and (c) leukocytes labeled with stabilized 99mTc-exametazime containing 500 microg methylene blue. Duplicate samples were evaluated to confirm the repeatability of the study. Six samples were studied under each experimental condition (i.e., control, a, b, and c groups). The cell membrane integrity and chemotatic capacity of leukocytes were measured at 1 and 3 h after preparation, whereas a complete blood count was obtained at 3 h after preparation. The labeling efficiency was calculated immediately on conclusion of cell labeling, whereas the in vitro stability of the radiolabeled leukocytes was evaluated at 3 h after radiolabeling.
None of the samples showed trypan blue-stained cells. For the chemotactic index, no statistically significant differences were noted between the 3 labeling formulations at 1 h (P = 0.43) or 3 h (P = 0.10) after preparation. None of the labeling formulations differed significantly from the control values of the chemotactic index (all P > 0.25). For the complete blood count, no significant differences were observed between any of the groups, with the exception of platelet number in the control group (P = 0.004). The labeling efficiency (P = 0.10) and in vitro stability (P = 0.33) were also similar in our comparison of the 3 labeling formulations.
With no major statistically significant difference noted either between the 3 labeling formulations or between the control and the 3 labeling formulations, we concluded that the methylene blue/phosphate buffer stabilizer (250 or 500 microg methylene blue) did not affect the cell membrane integrity, chemotactic capacity, labeling efficiency, in vitro stability, or complete blood count of leukocytes labeled with stabilized 99mTc-exametazime.
本研究旨在评估亚甲蓝/磷酸盐缓冲稳定剂对用99mTc-依美他嗪标记的白细胞的标记效率、细胞膜完整性、趋化性和体外稳定性的影响。
从3名健康供体中每人采集480 mL全血，并将其平均分成8个60 mL的等分试样。在本研究中，从3名受试者中的每一个采集的2个等分试样用作对照（即白细胞未用未稳定化或稳定化的99mTc-依美他嗪标记）。从3名受试者中的每一个采集的其余6个等分试样平均分为以下制剂组：(a) 用未稳定化的99mTc-依美他嗪标记的白细胞，(b) 用含有250 μg亚甲蓝的稳定化99mTc-依美他嗪标记的白细胞，以及(c) 用含有500 μg亚甲蓝的稳定化99mTc-依美他嗪标记的白细胞。对重复样本进行评估以确认研究的可重复性。在每个实验条件（即对照、a、b和c组）下研究6个样本。在制备后1小时和3小时测量白细胞的细胞膜完整性和趋化能力，而在制备后3小时获得全血细胞计数。在细胞标记结束时立即计算标记效率，而在放射性标记后3小时评估放射性标记白细胞的体外稳定性。
所有样本均未显示台盼蓝染色的细胞。对于趋化指数，在制备后1小时（P = 0.43）或3小时（P = 0.10），3种标记制剂之间未观察到统计学上的显著差异。没有一种标记制剂与趋化指数的对照值有显著差异（所有P > 0.25）。对于全血细胞计数，除对照组的血小板数量外（P = 0.004），任何组之间均未观察到显著差异。在我们对3种标记制剂的比较中，标记效率（P = 0.10）和体外稳定性（P = 0.33）也相似。
由于在三种标记制剂之间或对照与三种标记制剂之间均未观察到主要的统计学显著差异，我们得出结论，亚甲蓝/磷酸盐缓冲稳定剂（250或500 μg亚甲蓝）不会影响用稳定化的99mTc-依美他嗪标记的白细胞的细胞膜完整性、趋化能力、标记效率、体外稳定性或全血细胞计数。
