title: Detection of cresyl phosphate-modified butyrylcholinesterase in human plasma for chemical exposure associated with aerotoxic syndrome.
abstract: Flight crews complain of illness following a fume event in aircraft. A chemical in jet engine oil, the neurotoxicant tri-o-cresyl phosphate, after metabolic activation to cresyl saligenin phosphate makes a covalent adduct on butyrylcholinesterase (BChE). We developed a mass spectrometry method for detection of the cresyl phosphate adduct on human BChE as an indicator of exposure. Monoclonal mAb2, whose amino acid sequence is provided, was crosslinked to cyanogen bromide-activated Sepharose 4B and used to immunopurify plasma BChE treated with cresyl saligenin phosphate. BChE was released with acetic acid, digested with pepsin, and analyzed by liquid chromatography-tandem mass spectrometry (LC-MSMS) on the Triple TOF 5600 mass spectrometer. Peptide FGES198AGAAS with an added mass of 170 Da from cresyl phosphate on serine 198 (Ser198) was detected as parent ion 966.4 Da. When characteristic daughter ions were monitored in the MSMS spectrum, the limit of detection was 0.1% cresyl saligenin phosphate inhibited plasma BChE. This corresponds to 2×10(-9) g in 0.5 ml or 23×10(-15) moles of inhibited BChE in 0.5 ml of plasma. In conclusion, a sensitive assay for exposure to tri-o-cresyl phosphate was developed. Laboratories that plan to use this method are cautioned that a positive result gives no proof that tri-o-cresyl phosphate is toxic at low levels.
authors.affiliation: Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198, USA. Electronic address: lmschopf@unmc.edu.
authors.forename: Lawrence M
authors.initials: LM
authors.lastname: Schopfer
authors.affiliation: Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Masson
authors.affiliation: CEA Saclay, iBiTec-S/SPI, Laboratoire d'Etudes et de Recherche en Immunoanalyse, 91191 Gif sur Yvette Cedex, France.
authors.forename: Patricia
authors.initials: P
authors.lastname: Lamourette
authors.affiliation: CEA Saclay, iBiTec-S/SPI, Laboratoire d'Etudes et de Recherche en Immunoanalyse, 91191 Gif sur Yvette Cedex, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Simon
authors.affiliation: Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198, USA.
authors.forename: Oksana
authors.initials: O
authors.lastname: Lockridge
mesh_terms: D000393:Air Pollutants / Q000737:chemistry* / Q000633:toxicity; D000401:Aircraft; D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology; D000918:Antibody Specificity; D002091:Butyrylcholinesterase / Q000097:blood* / Q000737:chemistry* / Q000276:immunology; D004781:Environmental Exposure / Q000032:analysis*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D014317:Tritolyl Phosphates / Q000737:chemistry* / Q000633:toxicity
chemical_list: D000393:Air Pollutants; D000911:Antibodies, Monoclonal; D014317:Tritolyl Phosphates; D002091:Butyrylcholinesterase; C025541:tri-o-cresyl phosphate
keywords: Aerotoxic syndrome; Butyrylcholinesterase; Mass spectrometry; Monoclonal antibody mAb2