TY - JOUR AB - In neurosurgery, δ-aminolevulinic acid-induced fluorescence-guided resection (ALA-FGR) of high grade gliomas (HGGs) improves tumor resection. ALA is a precursor of protoporphyrin IX (PPIX) and accumulates in tumor tissue assisting surgery by its fluorescence. In an effort to investigate whether ALA-induced PPIX can also be a serum biomarker for HGGs, a method for its detection in blood was developed. It involved analyte purification by liquid-liquid-extraction and its detection using target-MRM with an ion trap mass spectrometer coupled to capillary liquid chromatography. Analysis was possible from both serum and anticoagulated whole blood, but only ¼ of the starting sample volume was needed in case of the latter (4 ml serum vs. 1 ml whole blood). However, handling was also more challenging for whole blood so that, ultimately, an optimized method for the analysis of serum is aimed for. It will also resolve the problem that PPIX is measured as the sum of PPIX and endogenous Zn-bound PPIX in whole blood, while the detection of the latter can be avoided in serum. Preliminary results indicate higher PPIX levels in whole blood of patients suffering from HGG, who received ALA prior to venipuncture, in comparison to healthy controls. A time-series of PPIX levels in whole blood of a HGG patient undergoing surgery agreed with the observed fluorescence changes in tissue. These promising results encourage further method optimization and investigations both in whole blood and serum, which provides the purer analyte, but much less of it. AU - Walke, Anna AU - Suero Molina, Eric Jose AU - Müther, Michael AU - Stummer, Walter AU - König, Simone DA - 2019-05 KW - Massenspektrometrie KW - Protoporphyrin IX KW - Hirntumor KW - ALA-FRG KW - Mass spectrometry KW - protoporphyrin IX KW - brain tumor KW - ALA-FGR LA - eng IS - Mercator Journal of Biomolecular Analysis M2 - 1 PY - 2019-05 SP - 1-13 T2 - Mercator Journal of Biomolecular Analysis TI - Determination of δ-aminolevulinic acid-induced protoporphyrin IX in blood UR - https://nbn-resolving.org/urn:nbn:de:hbz:6-84199486146 Y2 - 2024-12-27T06:27:46 ER -