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Lactulose: mannitol diagnostic test by HPLC and LC-MSMS platforms: considerations for field studies of intestinal barrier function and environmental enteropathy.

Lee GO, Kosek P, Lima AA, Singh R, Yori PP, Olortegui MP, Lamsam JL, Oliveira DB, Guerrant RL, Kosek M - J. Pediatr. Gastroenterol. Nutr. (2014)

Bottom Line: In addition, the HPLC-PAD platform overestimated the lowest disaccharide concentrations to the greatest degree.Given the large analyte concentration range, the improved accuracy of LC-MSMS has important consequences for the assessment of lactulose and mannitol following oral administration in populations at risk for EE.We recommend that researchers wishing to implement a dual-sugar test as part of a study of EE use an LC-MSMS platform to optimize the accuracy of results and increase comparability between studies.

View Article: PubMed Central - PubMed

Affiliation: *Department of International Health, Johns Hopkins School of Public Health, Baltimore, MD †Pain Consultants of Oregon, Eugene ‡Department of Physiology and Pharmacology, Federal University of Ceara, Fortaleza, Brazil §Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN //Asociación Benéfica Proyectos de Informática, Salud, Medicina, y Agricultura (A.B. PRISMA), Iquitos, Peru ¶Center for Global Health and Division of Infectious Disease, University of Virginia, Charlottesville.

ABSTRACT

Objectives: The lactulose:mannitol (L:M) diagnostic test is frequently used in field studies of environmental enteropathy (EE); however, heterogeneity in test administration and disaccharide measurement has limited the comparison of results between studies and populations. We aim to assess the agreement between L:M measurement between high-performance liquid chromatography with pulsed amperometric detection (HPLC-PAD) and liquid chromatography-tandem mass spectrometry (LC-MSMS) platforms.

Methods: The L:M test was administered in a cohort of Peruvian infants considered at risk for EE. A total of 100 samples were tested for lactulose and mannitol at 3 independent laboratories: 1 running an HPLC-PAD platform and 2 running LC-MSMS platforms. Agreement between the platforms was estimated.

Results: The Spearman correlation between the 2 LC-MSMS platforms was high (ρ ≥ 0.89) for mannitol, lactulose, and the L:M ratio. The correlation between the HPLC-PAD platform and LC-MSMS platform was ρ = 0.95 for mannitol, ρ = 0.70 for lactulose, and ρ = 0.43 for the L:M ratio. In addition, the HPLC-PAD platform overestimated the lowest disaccharide concentrations to the greatest degree.

Conclusions: Given the large analyte concentration range, the improved accuracy of LC-MSMS has important consequences for the assessment of lactulose and mannitol following oral administration in populations at risk for EE. We recommend that researchers wishing to implement a dual-sugar test as part of a study of EE use an LC-MSMS platform to optimize the accuracy of results and increase comparability between studies.

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Related in: MedlinePlus

Flow diagram of selection of samples for study inclusion.
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Figure 1: Flow diagram of selection of samples for study inclusion.

Mentions: Between May 2011 and November 2012, a substudy was completed to determine the validity of L:M results between HPLC and LC-MSMS platforms. From among all of the L:M tests administered by May 2011, 100 samples, whose urinary lactulose and mannitol concentrations had previously been determined by the HPLC-PAD system described below, were selected for additional testing for lactulose and mannitol on 2 LC-MSMS systems. Testing in all 3 laboratories was blinded. Because it was hypothesized that accuracy may be associated with concentration, the sample selection included a subset of samples stratified by the concentration of analytes based on data from the HPLC laboratory. Because it was further hypothesized that interfering substances may be present that affect assay performance, and that the composition of urine may be age dependent, samples were also stratified by age. This included 5 relatively low and 5 relatively high-concentration urines from 3-, 6-, and 9-month-olds; and 9 relatively low- and high-concentration samples from 15-month-olds (39 total samples). In addition, 18 three-month urines, 19 six-month urines, 19 nine-month urines, and 5 fifteen-month urines were selected at random from a list of available specimens without regard for analyte concentration (61 randomly selected samples from a pool of ∼143–15 samples available per age point) (Fig. 1).


Lactulose: mannitol diagnostic test by HPLC and LC-MSMS platforms: considerations for field studies of intestinal barrier function and environmental enteropathy.

Lee GO, Kosek P, Lima AA, Singh R, Yori PP, Olortegui MP, Lamsam JL, Oliveira DB, Guerrant RL, Kosek M - J. Pediatr. Gastroenterol. Nutr. (2014)

Flow diagram of selection of samples for study inclusion.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4222705&req=5

Figure 1: Flow diagram of selection of samples for study inclusion.
Mentions: Between May 2011 and November 2012, a substudy was completed to determine the validity of L:M results between HPLC and LC-MSMS platforms. From among all of the L:M tests administered by May 2011, 100 samples, whose urinary lactulose and mannitol concentrations had previously been determined by the HPLC-PAD system described below, were selected for additional testing for lactulose and mannitol on 2 LC-MSMS systems. Testing in all 3 laboratories was blinded. Because it was hypothesized that accuracy may be associated with concentration, the sample selection included a subset of samples stratified by the concentration of analytes based on data from the HPLC laboratory. Because it was further hypothesized that interfering substances may be present that affect assay performance, and that the composition of urine may be age dependent, samples were also stratified by age. This included 5 relatively low and 5 relatively high-concentration urines from 3-, 6-, and 9-month-olds; and 9 relatively low- and high-concentration samples from 15-month-olds (39 total samples). In addition, 18 three-month urines, 19 six-month urines, 19 nine-month urines, and 5 fifteen-month urines were selected at random from a list of available specimens without regard for analyte concentration (61 randomly selected samples from a pool of ∼143–15 samples available per age point) (Fig. 1).

Bottom Line: In addition, the HPLC-PAD platform overestimated the lowest disaccharide concentrations to the greatest degree.Given the large analyte concentration range, the improved accuracy of LC-MSMS has important consequences for the assessment of lactulose and mannitol following oral administration in populations at risk for EE.We recommend that researchers wishing to implement a dual-sugar test as part of a study of EE use an LC-MSMS platform to optimize the accuracy of results and increase comparability between studies.

View Article: PubMed Central - PubMed

Affiliation: *Department of International Health, Johns Hopkins School of Public Health, Baltimore, MD †Pain Consultants of Oregon, Eugene ‡Department of Physiology and Pharmacology, Federal University of Ceara, Fortaleza, Brazil §Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN //Asociación Benéfica Proyectos de Informática, Salud, Medicina, y Agricultura (A.B. PRISMA), Iquitos, Peru ¶Center for Global Health and Division of Infectious Disease, University of Virginia, Charlottesville.

ABSTRACT

Objectives: The lactulose:mannitol (L:M) diagnostic test is frequently used in field studies of environmental enteropathy (EE); however, heterogeneity in test administration and disaccharide measurement has limited the comparison of results between studies and populations. We aim to assess the agreement between L:M measurement between high-performance liquid chromatography with pulsed amperometric detection (HPLC-PAD) and liquid chromatography-tandem mass spectrometry (LC-MSMS) platforms.

Methods: The L:M test was administered in a cohort of Peruvian infants considered at risk for EE. A total of 100 samples were tested for lactulose and mannitol at 3 independent laboratories: 1 running an HPLC-PAD platform and 2 running LC-MSMS platforms. Agreement between the platforms was estimated.

Results: The Spearman correlation between the 2 LC-MSMS platforms was high (ρ ≥ 0.89) for mannitol, lactulose, and the L:M ratio. The correlation between the HPLC-PAD platform and LC-MSMS platform was ρ = 0.95 for mannitol, ρ = 0.70 for lactulose, and ρ = 0.43 for the L:M ratio. In addition, the HPLC-PAD platform overestimated the lowest disaccharide concentrations to the greatest degree.

Conclusions: Given the large analyte concentration range, the improved accuracy of LC-MSMS has important consequences for the assessment of lactulose and mannitol following oral administration in populations at risk for EE. We recommend that researchers wishing to implement a dual-sugar test as part of a study of EE use an LC-MSMS platform to optimize the accuracy of results and increase comparability between studies.

Show MeSH
Related in: MedlinePlus