Centre for Human Drug Research, 2333 CL, Leiden, The Netherlands.
Division of Nephrology, Department of Internal Medicine, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands.
Int J Mol Sci. 2019 Sep 23;20(19):4710. doi: 10.3390/ijms20194710.
Therapeutic drug monitoring is routinely performed to maintain optimal tacrolimus concentrations in kidney transplant recipients. Nonetheless, toxicity and rejection still occur within an acceptable concentration-range. To have a better understanding of the relationship between tacrolimus dose, tacrolimus concentration, and its effect on the target cell, we developed functional immune tests for the quantification of the tacrolimus effect. Twelve healthy volunteers received a single dose of tacrolimus, after which intracellular and whole blood tacrolimus concentrations were measured and were related to T cell functionality. A significant correlation was found between tacrolimus concentrations in T cells and whole blood concentrations (r = 0.71, = 0.009), while no correlation was found between tacrolimus concentrations in peripheral blood mononuclear cells (PBMCs) and whole blood (r = 0.35, = 0.27). Phytohemagglutinin (PHA) induced the production of IL-2 and IFNγ, as well as the inhibition of CD71 and CD154 expression on T cells at 1.5 h post-dose, when maximum tacrolimus levels were observed. Moreover, the in vitro tacrolimus effect of the mentioned markers corresponded with the ex vivo effect after dosing. In conclusion, our results showed that intracellular tacrolimus concentrations mimic whole blood concentrations, and that PHA-induced cytokine production (IL-2 and IFNγ) and activation marker expression (CD71 and CD154) are suitable readout measures to measure the immunosuppressive effect of tacrolimus on the T cell.
治疗药物监测通常用于维持肾移植受者中环孢素的最佳浓度。然而，在可接受的浓度范围内仍会发生毒性和排斥反应。为了更好地理解环孢素剂量、浓度及其对靶细胞的影响之间的关系，我们开发了用于定量环孢素作用的功能性免疫测试。12 名健康志愿者接受了单剂量的环孢素，之后测量了细胞内和全血中环孢素的浓度，并将其与 T 细胞功能相关联。我们发现 T 细胞中环孢素浓度与全血浓度之间存在显著相关性（r = 0.71， = 0.009），而外周血单核细胞（PBMCs）中环孢素浓度与全血浓度之间无相关性（r = 0.35， = 0.27）。在观察到最大环孢素水平的 1.5 小时后，植物血凝素（PHA）诱导了 T 细胞产生白细胞介素-2（IL-2）和干扰素-γ（IFNγ），以及抑制 CD71 和 CD154 的表达。此外，所述标记物的体外环孢素作用与给药后的体外作用相对应。总之，我们的结果表明，细胞内环孢素浓度模拟全血浓度，PHA 诱导的细胞因子产生（IL-2 和 IFNγ）和激活标记物表达（CD71 和 CD154）是衡量环孢素对 T 细胞免疫抑制作用的合适读出措施。
