Multidimensional mass spectrometry of serum and cellular lipids directly from biologic extracts

Abstract

A method for determination of at least one of the lipid species in a biological sample comprising subjecting the sample to lipid extraction to obtain a lipid extract and subjecting the resulting lipid extract to multidimensional electrospray ionization mass spectrometry using either precursor ion or neutral loss scanning (or both) of all naturally occurring aliphatic chains, lipid fragments and precursor ions leading to observed fragments to generate a multidimensional matrix whose contour densities provides structural and quantitative information directly without chromatography. A method for determination of lipid content and/or lipid molecular species composition and quantity directly from lipid extracts of a biological sample comprising subjecting said lipid extract to electrospray ionization multidimensional mass spectrometry by comparisons to standards and algorithms described herein.

1 . A method for assessing a risk to an individual based on molecular species as an independent factor in the development of at least one condition in that individual for a medical condition selected from coronary artery disease, diabetes, stroke, atherosclerosis and obesity, wherein the method comprises:
 subjecting a first biological sample taken of an individual to a mass spectrometer for molecular species determination by comparing peaks heights of a plot of molecular ions of a lipid extract of the molecular species versus at least one of neutral loss scans and precursor ion scans of at least one of fatty acids and lipid classes that include constituents present in the lipid extract;   administering a therapeutic amount of a drug to the individual;   subjecting a corresponding biological sample of the individual; and   comparing the molecular species determination after drug administration with the molecular species determination prior to the drug administration.   
   
   
       2 . A method in accordance with  claim 1  wherein the comparison of the molecular species determination of the biological samples is indicative of development of the condition for that individual. 
   
   
       3 . A method in accordance with  claim 1  wherein said mass spectrometer is a two dimensional electrospray ionization tandem mass spectrometry (ESI/MS/MS). 
   
   
       4 . A method in accordance with  claim 1  wherein said lipid comprises at least one of phospholipids (e.g., choline glycerophospholipides (e.g., plasmenycholine, phosphatidylcholine, plasmanylcholine), sphingomeyelin, ethanolamine glycerophospholipids, mono and dimethyl ethanolamine, glycerophospholipds, serine glycerophospholipids, inositol glycerophospholipids, cardiolipin, phosphatidic acid, phosphatidylglycerol, phasphatidylethanol and oxidized derivatives thereof), fatty acids, fatty amides, eicosanoids, sphingolipids, glycolipids, steroids, ceramides, acylCoA, acylcarnitine, acylprotiens, acylpeptides, diglycerides, monoglycerides, anadamide and 2-arachidonyl glycerol. 
   
   
       5 . A method for identifying an agent which selectively targets specific to at least one of a lipid and triacylglyceride molecular species, wherein the method comprises:
 subjecting a first biological sample of at least one treated individual to a mass spectrometer for molecular species or lipid molecular species determination by comparing peaks heights of a plot of molecular ions of a lipid extract of the molecular species versus at least one of neutral loss scans and precursor ion scans of the lipid extract;   administering a drug to the individual;   subjecting a second biological sample from the individual to the mass spectrometer; and   comparing the molecular species determination after said administration with the molecular species determination prior to drug administration.   
   
   
       6 . A method in accordance with  claim 5  wherein said comparison of the molecular species determination of the biological samples is indicative of development of the condition for that individual. 
   
   
       7 . A method in accordance with  claim 5  wherein said mass spectrometer is a two dimensional electrospray ionization tandem mass spectrometry (ESI/MS/MS). 
   
   
       8 . A method of identifying a candidate lipid modulating drug having lipid modulating drug efficacy, wherein the method comprises:
 subjecting a first biological sample of at least one individual subject to a mass spectrometer for molecular species determination by comparing peaks heights of a plot of molecular ions of a lipid extract of the molecular species versus at least one of neutral loss scans and precursor ion scans of the lipid extract;   administering a therapeutic amount of a candidate lipid modulating drug to the individual subject;   subjecting a second biological sample of the individual to the mass spectrometer; and   comparing the molecular species determination after said administration with the molecular species determination prior to the drug administration.   
   
   
       9 . A method in accordance with  claim 8  wherein said mass spectrometer is a two dimensional electrospray ionization tandem mass spectrometry (ESI/MS/MS). 
   
   
       10 . A method in accordance with  claim 8  wherein said comparison is indicative of a lipid modulating capacity of an administered drug. 
   
   
       11 . A method in accordance with  claim 10  wherein said modulating comprises lowering. 
   
   
       12 . A method for diagnosing and determining the response of a patient to tailored drug therapy, wherein the method comprises:
 subjecting a first biological sample of a patient to be treated to a mass spectrometer for molecular species or lipid molecular species determination by comparing peaks heights of a plot of molecular ions of a lipid extract of the molecular species versus at least one of neutral loss scans and precursor ion scans of the lipid extract;   administering an amount of a drug to the patient;   subjecting a second biological sample taken from the treated patient; and   comparing the molecular species determination after the administration with the molecular species determination prior to the drug administration.   
   
   
       13 . A method in accordance with  claim 12  wherein said comparison of analysis is indicative of a successful tailored drug therapy. 
   
   
       14 . A method in accordance with  claim 12  wherein said mass spectrometer is a two dimensional electrospray ionization tandem mass spectrometry (ESI/MS/MS). 
   
   
       15 . A method of determining a subject's response to administration of a drug, wherein the method comprises:
 subjecting a first biological sample of at least one treated subject to a multidimensional ESI/MS for molecular species or lipid molecular species determination by comparing peaks heights of a plot of molecular ions of a lipid extract of the molecular species versus at least one of neutral loss scans and precursor ion scans of the lipid extract;   administering a drug to the subject; and   subjecting a second biological sample taken of a subject to multidimensional ESI/MS for lipid molecular analysis by following said administration, molecular species and quantitation, wherein the biological sample is analyzed by comparing peaks heights of a plot of molecular ions of a lipid extract of the molecular species versus at least one of neutral loss scans and precursor ion scans of at least one of fatty acids and lipid classes that include constituents present in the lipid extract.   
   
   
       16 . A method in accordance with  claim 15  wherein the subject is human.