Hähnel Viola, Dormann Frauke, Nitsopoulos Athanasios, Friedle Albrecht, Ahrens Norbert
Institute for Clinical Chemistry and Laboratory Medicine, Transfusion Medicine, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany.
Labor Friedle GmbH, von-Heyden-Str. 11, 93105 Tegernheim, Germany.
Photochem Photobiol Sci. 2017 Feb 15;16(2):193-200. doi: 10.1039/c6pp00327c.
Extracorporeal photopheresis (ECP) is an efficient method to treat various autoimmune diseases, cutaneous T-cell lymphoma, and graft-versus-host disease. It is based on the ex vivo inactivation of lymphocytes by 8-methoxypsoralen (8-MOP)/UV light treatment. Despite the adhesive, lipophilic nature of 8-MOP, no quality control is established for the ECP procedure.
We developed a sensitive high-performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS) assay to monitor residual 8-MOP concentration after UVA irradiation in the whole blood supernatant after acetonitrile precipitation.
The preanalytical stability of 8-MOP exceeded 7 days, allowing batch mode analysis. Linearity was determined with R above 0.99. The 8-MOP concentrations decreased exponentially after UV exposure, with decay constants of 0.0259 in plasma and 0.0528 in saline. The recovery of 8-MOP in photopheresates was about 68%, indicating binding to DNA as well as to plastic structures. UVA induced no 8-MOP fragmentation, but caused self-adducts under extreme conditions (10-fold UV dosage).
Detection of 8-MOP proved to be feasible and demonstrated that the doses were in the pharmaceutically active range.
体外光化学疗法（ECP）是治疗各种自身免疫性疾病、皮肤T细胞淋巴瘤和移植物抗宿主病的有效方法。它基于通过8-甲氧基补骨脂素（8-MOP）/紫外线照射对淋巴细胞进行体外灭活。尽管8-MOP具有粘性和亲脂性，但ECP程序尚未建立质量控制。
我们开发了一种灵敏的高效液相色谱/串联质谱（HPLC-MS/MS）测定法，用于监测乙腈沉淀后全血上清液中紫外线照射后残留的8-MOP浓度。
8-MOP的分析前稳定性超过7天，允许进行批量模式分析。线性测定的R值高于0.99。紫外线照射后8-MOP浓度呈指数下降，血浆中的衰减常数为0.0259，盐水中的衰减常数为0.0528。光采集中8-MOP的回收率约为68%，表明其与DNA以及塑料结构结合。紫外线A不会诱导8-MOP断裂，但在极端条件下（紫外线剂量增加10倍）会导致自身加合物的形成。
8-MOP的检测被证明是可行的，并表明剂量处于药物活性范围内。
