Quantification of Tryptophan, Indole, and Indoxyl Sulfate in Urine Using Liquid Chromatography-Tandem Mass Spectrometry

Serena Baird; C Clinton Frazee 3rd; Uttam Garg

doi:10.1007/978-1-0716-2565-1_44

Quantification of Tryptophan, Indole, and Indoxyl Sulfate in Urine Using Liquid Chromatography-Tandem Mass Spectrometry

Methods Mol Biol. 2022:2546:493-500. doi: 10.1007/978-1-0716-2565-1_44.

Authors

Serena Baird¹, C Clinton Frazee 3rd¹, Uttam Garg²

Affiliations

¹ Department of Pathology and Laboratory Medicine, Children's Mercy Hospital, Kansas City, MO, USA.
² Department of Pathology and Laboratory Medicine, Children's Mercy Hospital, Kansas City, MO, USA. ugarg@cmh.edu.

PMID: 36127616
DOI: 10.1007/978-1-0716-2565-1_44

Abstract

Having a diverse gut microbiota has been correlated with the short- and long-term success of allogeneic stem cell transplantation. Intestinal bacteria metabolize the amino acid tryptophan to indole. Indole is further oxidized and sulfonated in the liver to 3-indoxyl sulfate (3-IS), which is then excreted in urine. Urinary 3-IS is a potential biomarker for intestinal health and an early predictor of successful stem cell transplantation. We describe a rapid method for quantifying tryptophan, indole, and 3-indoxyl sulfate in urine specimens, in which urine samples are diluted with a formic acid solution and deuterated internal standards, and then injected on LC-MS/MS for analysis.

Keywords: Allogeneic stem cell transplantation; Graft-versus-host disease; Gut microbiota; Indoxyl sulfate; LC-MS/MS; Tryptophan.

MeSH terms

Chromatography, Liquid
Indican*
Indoles
Tandem Mass Spectrometry / methods
Tryptophan* / metabolism

Substances

Indoles
Tryptophan
Indican