title: Hydrophilic-interaction liquid chromatography-tandem mass spectrometric determination of erythrocyte 5-phosphoribosyl 1-pyrophosphate in patients with hypoxanthine-guanine phosphoribosyltransferase deficiency.
abstract: Mutations in the gene encoding hypoxanthine-guanine phosphoribosyltransferase (HPRT) cause Lesch-Nyhan disease (LND) and its variants (LNV). Due to the technical problems for measuring the HPRT activity in vitro, discordances between the residual HPRT activity and the clinical severity were found. 5-Phosphoribosyl 1-pyrophosphate (PRPP) is a substrate for HPRT. Since increased PRPP concentrations were observed in erythrocytes from patients with LND and LNV, we have turned our attention to erythrocyte PRPP as a biomarker for the phenotype classification. In the present work, a method for determination of PRPP concentration in erythrocyte was developed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with multiple reaction monitoring (MRM). Packed erythrocyte samples were deproteinized by heating and the supernatants were injected into the LC-MS/MS system. All measurement results showed good precision with RSD <6%. PRPP concentrations of nine normal male subjects, four male patents with LND and six male patients with LNV were compared. The PRPP concentrations in erythrocyte from patients with LND were markedly increased compared with those from normal subjects, and those from patients with LNV were also increased but the degree was smaller than those with LND. The increase pattern of PRPP concentration in erythrocyte from patients with HPRT deficiency was consistent with the respective phenotypes and was correlated with the disease severity. PRPP concentration was suggested to give us supportive information for the diagnosis and the phenotype classification of LND and LNV.
authors.affiliation: Department of Pathophysiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan. Electronic address: hasegawa@toyaku.ac.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hasegawa
authors.affiliation: Department of Pathophysiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Shinohara
authors.affiliation: Department of Pathophysiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan.
authors.forename: Sayako
authors.initials: S
authors.lastname: Nozaki
authors.affiliation: Department of Pathophysiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan.
authors.forename: Makiko
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Department of Orthopedics, Showa University Yokohama Northern Hospital, Yokohama, Japan.
authors.forename: Koei
authors.initials: K
authors.lastname: Oh
authors.affiliation: Department of Orthopedics, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Namiki
authors.affiliation: Division of Pediatrics, Toyohashi Medical Center, Aichi, Japan.
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Division of Pediatrics, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Nakahara
authors.affiliation: Division of Pediatrics, Kochi Health Sciences Center, Kochi, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Miyazawa
authors.affiliation: Department of Pediatrics, Iwate Medical University, Iwate, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Ishikawa
authors.affiliation: Department of Neurology, Brain Attack Center Ota Memorial Hospital, Hiroshima, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Himeno
authors.affiliation: Department of Pediatrics, Nara Prefectural General Medical Center, Nara, Japan.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Yoshida
authors.affiliation: First Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Ueda
authors.affiliation: Department of Genetics, Institute for Developmental Research, Aichi Human Service Center, Aichi, Japan.
authors.forename: Yasukazu
authors.initials: Y
authors.lastname: Yamada
authors.affiliation: Department of Pathophysiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan.
authors.forename: Kimiyoshi
authors.initials: K
authors.lastname: Ichida
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D007926:Lesch-Nyhan Syndrome / Q000378:metabolism*; D008297:Male; D010754:Phosphoribosyl Pyrophosphate / Q000032:analysis*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D010754:Phosphoribosyl Pyrophosphate
keywords: HPRT; LC–MS/MS; Lesch–Nyhan disease; PRPP