title: A sensitive and specific LC-MS/MS method for rapid diagnosis of Niemann-Pick C1 disease from human plasma.
abstract: Niemann-Pick type C1 (NPC1) disease is a rare, progressively fatal neurodegenerative disease for which there are no FDA-approved therapies. A major barrier to developing new therapies for this disorder has been the lack of a sensitive and noninvasive diagnostic test. Recently, we demonstrated that two cholesterol oxidation products, specifically cholestane-3β,5α,6β-triol (3β,5α,6β-triol) and 7-ketocholesterol (7-KC), were markedly increased in the plasma of human NPC1 subjects, suggesting a role for these oxysterols in diagnosis of NPC1 disease and evaluation of therapeutics in clinical trials. In the present study, we describe the development of a sensitive and specific LC-MS/MS method for quantifying 3β,5α,6β-triol and 7-KC human plasma after derivatization with N,N-dimethylglycine. We show that dimethylglycine derivatization successfully enhanced the ionization and fragmentation of 3β,5α,6β-triol and 7-KC for mass spectrometric detection of the oxysterol species in human plasma. The oxysterol dimethylglycinates were resolved with high sensitivity and selectivity, and enabled accurate quantification of 3β,5α,6β-triol and 7-KC concentrations in human plasma. The LC-MS/MS assay was able to discriminate with high sensitivity and specificity between control and NPC1 subjects, and offers for the first time a noninvasive, rapid, and highly sensitive method for diagnosis of NPC1 disease.
authors.affiliation: Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Xuntian
authors.initials: X
authors.lastname: Jiang
authors.forename: Rohini
authors.initials: R
authors.lastname: Sidhu
authors.forename: Forbes D
authors.initials: FD
authors.lastname: Porter
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Yanjanin
authors.forename: Anneliese O
authors.initials: AO
authors.lastname: Speak
authors.forename: Danielle Taylor
authors.initials: DT
authors.lastname: te Vruchte
authors.forename: Frances M
authors.initials: FM
authors.lastname: Platt
authors.forename: Hideji
authors.initials: H
authors.lastname: Fujiwara
authors.forename: David E
authors.initials: DE
authors.lastname: Scherrer
authors.forename: Jessie
authors.initials: J
authors.lastname: Zhang
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Dietzen
authors.forename: Jean E
authors.initials: JE
authors.lastname: Schaffer
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Ory
mesh_terms: D000293:Adolescent; D000328:Adult; D002138:Calibration; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002777:Cholestanols / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007653:Ketocholesterols / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification; D008297:Male; D008875:Middle Aged; D052556:Niemann-Pick Disease, Type C / Q000097:blood* / Q000175:diagnosis*; D012521:Sarcosine / Q000031:analogs & derivatives / Q000737:chemistry; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013997:Time Factors; D055815:Young Adult
chemical_list: D002777:Cholestanols; D007653:Ketocholesterols; C000474:cholestane-3,5,6-triol; C025138:dimethylglycine; C003001:7-ketocholesterol; D012521:Sarcosine