Description of analytical method and clinical utility of measuring serum 7-alpha-hydroxy-4-cholesten-3-one (7aC4) by mass spectrometry

Leslie J. Donato, Alan Lueke, Stacy M. Kenyon, Jeffrey W. Meeusen, Michael Camilleri

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Background: Imbalance of bile acids (BA) homeostasis in the gastrointestinal tract can lead to chronic diarrhea or constipation when BA in the colon are in excess or low, respectively. Since both disturbances of bowel function can result from other etiologies, identifying BA imbalance is important to tailor treatment strategies. Serum concentrations of 7-alpha-hydroxy-4-cholesten-3-one (7aC4), a precursor in bile acid synthesis, reflect BA homeostasis. Here we describe a method to accurately measure serum 7aC4 and evaluate the clinical utility in patients with diarrhea or constipation phenotypes. Methods: Serum 7aC4 is measured after acetonitrile protein precipitation using C18 liquid chromatography, tandem mass spectrometry, and deuterium-labeled 7aC4 internal standard. Assay performance including linearity, precision, and accuracy was assessed using waste serum samples. The reference interval was established in healthy individuals without BA-altering conditions or medications. Clinical performance was assessed in patients with irritable bowel syndrome. Results: The method precisely and accurately measured 7aC4 in human serum from 1.4-338. ng/mL with no ion suppression or interference from related 7-keto-cholesterol. Central 95th percentile reference interval was 2.5-63.2. ng/mL. Lower serum 7aC4 was found in patients with constipation with sensitivity/specificity of 79%/55% compared to healthy controls. Higher 7aC4 was found in patients with bile acid diarrhea (BAD) compared to those without BAD with sensitivity/specificity of 82%/53%. Conclusions: We have developed a sensitive and precise assay for measuring the concentration of 7aC4 in serum. The assay can be used to screen for diarrhea caused by bile acid malabsorption.

Original languageEnglish (US)
JournalClinical Biochemistry
DOIs
StateAccepted/In press - 2017

Fingerprint

Bile Acids and Salts
Mass spectrometry
Mass Spectrometry
Serum
Diarrhea
Constipation
Assays
Homeostasis
7 alpha-hydroxy-4-cholesten-3-one
Sensitivity and Specificity
Irritable Bowel Syndrome
Deuterium
Liquid chromatography
Tandem Mass Spectrometry
Liquid Chromatography
Gastrointestinal Tract
Colon
Cholesterol
Ions
Phenotype

ASJC Scopus subject areas

  • Clinical Biochemistry

Cite this

Description of analytical method and clinical utility of measuring serum 7-alpha-hydroxy-4-cholesten-3-one (7aC4) by mass spectrometry. / Donato, Leslie J.; Lueke, Alan; Kenyon, Stacy M.; Meeusen, Jeffrey W.; Camilleri, Michael.

In: Clinical Biochemistry, 2017.

Research output: Contribution to journalArticle

@article{b52c522d1d914f00bf0fb6e38b7f6bbc,
title = "Description of analytical method and clinical utility of measuring serum 7-alpha-hydroxy-4-cholesten-3-one (7aC4) by mass spectrometry",
abstract = "Background: Imbalance of bile acids (BA) homeostasis in the gastrointestinal tract can lead to chronic diarrhea or constipation when BA in the colon are in excess or low, respectively. Since both disturbances of bowel function can result from other etiologies, identifying BA imbalance is important to tailor treatment strategies. Serum concentrations of 7-alpha-hydroxy-4-cholesten-3-one (7aC4), a precursor in bile acid synthesis, reflect BA homeostasis. Here we describe a method to accurately measure serum 7aC4 and evaluate the clinical utility in patients with diarrhea or constipation phenotypes. Methods: Serum 7aC4 is measured after acetonitrile protein precipitation using C18 liquid chromatography, tandem mass spectrometry, and deuterium-labeled 7aC4 internal standard. Assay performance including linearity, precision, and accuracy was assessed using waste serum samples. The reference interval was established in healthy individuals without BA-altering conditions or medications. Clinical performance was assessed in patients with irritable bowel syndrome. Results: The method precisely and accurately measured 7aC4 in human serum from 1.4-338. ng/mL with no ion suppression or interference from related 7-keto-cholesterol. Central 95th percentile reference interval was 2.5-63.2. ng/mL. Lower serum 7aC4 was found in patients with constipation with sensitivity/specificity of 79{\%}/55{\%} compared to healthy controls. Higher 7aC4 was found in patients with bile acid diarrhea (BAD) compared to those without BAD with sensitivity/specificity of 82{\%}/53{\%}. Conclusions: We have developed a sensitive and precise assay for measuring the concentration of 7aC4 in serum. The assay can be used to screen for diarrhea caused by bile acid malabsorption.",
author = "Donato, {Leslie J.} and Alan Lueke and Kenyon, {Stacy M.} and Meeusen, {Jeffrey W.} and Michael Camilleri",
year = "2017",
doi = "10.1016/j.clinbiochem.2017.10.008",
language = "English (US)",
journal = "Clinical Biochemistry",
issn = "0009-9120",
publisher = "Elsevier Inc.",

}

TY - JOUR

T1 - Description of analytical method and clinical utility of measuring serum 7-alpha-hydroxy-4-cholesten-3-one (7aC4) by mass spectrometry

AU - Donato, Leslie J.

AU - Lueke, Alan

AU - Kenyon, Stacy M.

AU - Meeusen, Jeffrey W.

AU - Camilleri, Michael

PY - 2017

Y1 - 2017

N2 - Background: Imbalance of bile acids (BA) homeostasis in the gastrointestinal tract can lead to chronic diarrhea or constipation when BA in the colon are in excess or low, respectively. Since both disturbances of bowel function can result from other etiologies, identifying BA imbalance is important to tailor treatment strategies. Serum concentrations of 7-alpha-hydroxy-4-cholesten-3-one (7aC4), a precursor in bile acid synthesis, reflect BA homeostasis. Here we describe a method to accurately measure serum 7aC4 and evaluate the clinical utility in patients with diarrhea or constipation phenotypes. Methods: Serum 7aC4 is measured after acetonitrile protein precipitation using C18 liquid chromatography, tandem mass spectrometry, and deuterium-labeled 7aC4 internal standard. Assay performance including linearity, precision, and accuracy was assessed using waste serum samples. The reference interval was established in healthy individuals without BA-altering conditions or medications. Clinical performance was assessed in patients with irritable bowel syndrome. Results: The method precisely and accurately measured 7aC4 in human serum from 1.4-338. ng/mL with no ion suppression or interference from related 7-keto-cholesterol. Central 95th percentile reference interval was 2.5-63.2. ng/mL. Lower serum 7aC4 was found in patients with constipation with sensitivity/specificity of 79%/55% compared to healthy controls. Higher 7aC4 was found in patients with bile acid diarrhea (BAD) compared to those without BAD with sensitivity/specificity of 82%/53%. Conclusions: We have developed a sensitive and precise assay for measuring the concentration of 7aC4 in serum. The assay can be used to screen for diarrhea caused by bile acid malabsorption.

AB - Background: Imbalance of bile acids (BA) homeostasis in the gastrointestinal tract can lead to chronic diarrhea or constipation when BA in the colon are in excess or low, respectively. Since both disturbances of bowel function can result from other etiologies, identifying BA imbalance is important to tailor treatment strategies. Serum concentrations of 7-alpha-hydroxy-4-cholesten-3-one (7aC4), a precursor in bile acid synthesis, reflect BA homeostasis. Here we describe a method to accurately measure serum 7aC4 and evaluate the clinical utility in patients with diarrhea or constipation phenotypes. Methods: Serum 7aC4 is measured after acetonitrile protein precipitation using C18 liquid chromatography, tandem mass spectrometry, and deuterium-labeled 7aC4 internal standard. Assay performance including linearity, precision, and accuracy was assessed using waste serum samples. The reference interval was established in healthy individuals without BA-altering conditions or medications. Clinical performance was assessed in patients with irritable bowel syndrome. Results: The method precisely and accurately measured 7aC4 in human serum from 1.4-338. ng/mL with no ion suppression or interference from related 7-keto-cholesterol. Central 95th percentile reference interval was 2.5-63.2. ng/mL. Lower serum 7aC4 was found in patients with constipation with sensitivity/specificity of 79%/55% compared to healthy controls. Higher 7aC4 was found in patients with bile acid diarrhea (BAD) compared to those without BAD with sensitivity/specificity of 82%/53%. Conclusions: We have developed a sensitive and precise assay for measuring the concentration of 7aC4 in serum. The assay can be used to screen for diarrhea caused by bile acid malabsorption.

UR - http://www.scopus.com/inward/record.url?scp=85032184314&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85032184314&partnerID=8YFLogxK

U2 - 10.1016/j.clinbiochem.2017.10.008

DO - 10.1016/j.clinbiochem.2017.10.008

M3 - Article

C2 - 29051033

AN - SCOPUS:85032184314

JO - Clinical Biochemistry

JF - Clinical Biochemistry

SN - 0009-9120

ER -