Evidence map›Paper›PMID 29679555›Full record

ArticleClinical biochemistry2018

Mass spectrometric measurement of urinary kynurenine-to-tryptophan ratio in children with and without urinary tract infection.

Melanie L Yarbrough, Kelleigh E Briden, John V Mitsios, Annette L Weindel, Cindy M Terrill, David A Hunstad, Dennis J Dietzen

Open access · greenAbstract readComparative Study
PubMed Full text at PMC Publisher
In one paragraph

Article in Clinical biochemistry, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers.

0numbers the graph read from it
0cells of the map it votes in
6citing papers in PubMed
1.1field-weighted citation impact, top 27% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

6 citing papers in PubMed, 21 citations in OpenAlex.

  1. Trial
  2. Article
  3. The Role of Metabolomics and Microbiology in Urinary Tract Infection.International journal of molecular sciences · 2024
    Review
  4. Review
  5. Article
  6. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors at 2 institutions in 1 country.

Melanie L YarbroughDepartments of Pathology and Immunology, School of Medicine, Washington University, St. Louis, Missouri, USA.
Kelleigh E BridenDepartments of Pediatrics, School of Medicine, Washington University, St. Louis, Missouri, USA.
John V MitsiosDepartments of Pathology and Immunology, School of Medicine, Washington University, St. Louis, Missouri, USA.
Annette L WeindelSt. Louis Children's Hospital, St. Louis, Missouri, USA.
Cindy M TerrillDepartments of Pediatrics, School of Medicine, Washington University, St. Louis, Missouri, USA.
David A HunstadDepartments of Pediatrics, School of Medicine, Washington University, St. Louis, Missouri, USA; Departments of Molecular Microbiology, School of Medicine, Washington University, St. Louis, Missouri, USA.
Dennis J DietzenDepartments of Pathology and Immunology, School of Medicine, Washington University, St. Louis, Missouri, USA; Departments of Pediatrics, School of Medicine, Washington University, St. Louis, Missouri, USA. Electronic address: dietzen_d@wustl.edu.
Washington University in St. Louis · USSt. Louis Children's Hospital · US

Funding

pan-Genome of E.coli in the bladder and gut of women with recurrent UTIP50DK064540 · NIDDK · WASHINGTON UNIVERSITY · PI HULTGREN, SCOTT J. · 2002 to 2017
$17.9M
NIDDK NIH HHS P50 DK064540
6 · The paper itself

Abstract

backgroundIndoleamine-2,3-dioxygenase (IDO) catalyzes the first step of tryptophan (Trp) catabolism, yielding kynurenine (Kyn) metabolites. The kynurenine-to-tryptophan (K/T) ratio is used as a surrogate for biological IDO enzyme activity. IDO expression is increased during Escherichia coli urinary tract infection (UTI). Thus, our objective was to develop a method for measurement of Kyn/Trp ratio in human blood and urine and evaluate its use as a biomarker of UTI.

methodsA mass spectrometric method was developed to measure Trp and Kyn in serum and urine specimens. The method was applied to clinical urine specimens from symptomatic pediatric patients with laboratory-confirmed UTI or other acute conditions and from healthy controls.

resultsThe liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was linear to 500 μmol/L for both Trp and Kyn. Imprecision ranged from 5 to 15% for Trp and 6-20% for Kyn. Analytical recoveries of Trp and Kyn ranged from 96 to 119% in serum and 90-97% in urine. No correlation was found between the K/T ratio and circulating IDO mass (r = 0.110) in serum. Urinary Kyn and Trp in the pediatric test cohort demonstrated elevations in the K/T ratio in symptomatic patients with UTI (median 13.08) and without UTI (median 14.38) compared to healthy controls (median 4.93; p < 0.001 for both comparisons). No significant difference in K/T ratio was noted between symptomatic patients with and without UTI (p = 0.84).

conclusionsMeasurement of Trp and Kyn by LC-MS/MS is accurate and precise in serum and urine specimens. While urinary K/T ratio is not a specific biomarker for UTI, it may represent a general indicator of a systemic inflammatory process.

Indexed as

AlgorithmsBiomarkersChromatography, High Pressure LiquidCohort StudiesFemaleHumansIndoleamine-Pyrrole 2,3,-DioxygenaseInfantKynurenineMaleReproducibility of ResultsSensitivity and SpecificitySpectrometry, Mass, Electrospray IonizationTandem Mass SpectrometryTryptophanUrinary Tract InfectionsBiomarkersIndoleamine-Pyrrole 2,3,-DioxygenaseKynurenineTryptophanIndoleamine 2,3-dioxygenaseK/T ratioMass spectrometryUrine

Identifiers

PMID29679555
PMCPMC6007864
OpenAlexW2802769072

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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.