Jamar F, Leners N, Beckers C, Manicourt D H
Centre of Nuclear Medicine, University of Louvain Medical School, Brussels, Belgium.
Scand J Clin Lab Invest. 1997 Nov;57(7):621-8. doi: 10.3109/00365519709055286.
The distribution of 99mTc-labelled human polyclonal non-specific immunoglobulin G (HIG) in the synovial fluid was studied in 14 patients with rheumatoid and non-rheumatoid arthritides. Analysis included the determination of the total activity per ml synovial fluid 6 h post-injection (p.i.) of the tracer as well as of the protein- and cell-bound fractions. At 6 h p.i., > 60% of the injected dose remained in plasma as protein-bound radioactivity. Values in the synovial fluid ranged between 0.001 and 0.009% of the injected dose per ml. Importantly, the synovial fluid to plasma ratio was consistently < 1 (range: 0.09-0.43), which is in the range of ratios observed for endogenous proteins in vivo. Similar values were obtained in samples of synovial tissue obtained at surgery in two patients. These data are consistent with the hypothesis that labelled HIG accumulates in the extracellular fluid (both within the synovial tissue and fluid) by non-specific mechanisms (such as increased blood pool and capillary permeability) and does not equilibrate with circulating plasma proteins in accordance with basic knowledge of synovial physiology. In addition, it was found that most of the activity remained bound to the proteins in the fluid and that cell-binding occurred to a very low degree that cannot be considered an important mechanism of uptake of this radiolabelled agent in vivo. These results provide the first evidence in an in vivo human setting that radiolabelled HIG accumulates mainly by non-specific mechanisms in inflamed joints.
在14例类风湿性和非类风湿性关节炎患者中研究了99mTc标记的人多克隆非特异性免疫球蛋白G（HIG）在滑液中的分布。分析包括在注射示踪剂后6小时（p.i.）测定每毫升滑液中的总活性以及蛋白质结合和细胞结合部分。在注射后6小时，超过60%的注射剂量以蛋白质结合放射性的形式保留在血浆中。滑液中的值在每毫升注射剂量的0.001%至0.009%之间。重要的是，滑液与血浆的比值始终<1（范围：0.09 - 0.43），这处于体内内源性蛋白质观察到的比值范围内。在两名患者手术时获取的滑膜组织样本中也得到了类似的值。这些数据与以下假设一致，即标记的HIG通过非特异性机制（如血池增加和毛细血管通透性增加）在细胞外液（滑膜组织和滑液内）中蓄积，并且根据滑膜生理学的基本知识，不会与循环血浆蛋白达到平衡。此外，发现大部分活性仍与滑液中的蛋白质结合，细胞结合程度非常低，不能被认为是这种放射性标记剂在体内摄取的重要机制。这些结果在人体体内环境中首次提供了证据，表明放射性标记的HIG主要通过非特异性机制在炎症关节中蓄积。
