Extended diagnosis of purine and pyrimidine disorders from urine: LC MS/MS assay development and clinical validation

Peter Monostori*, Glynis Klinke, Jana Hauke, Sylvia Richter, Jorgen Bierau, Sven F. Garbade, Georg F. Hoffmann, Claus-Dieter Langhans, Dorothea Haas, Juergen G. Okun

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

8 Citations (Web of Science)

Abstract

Background and aims

Inborn errors of purine and pyrimidine metabolism are a diverse group of disorders with possible serious or life-threatening symptoms. They may be associated with neurological symptoms, renal stone disease or immunodeficiency. However, the clinical presentation can be nonspecific and mild so that a number of cases may be missed. Previously published assays lacked detection of certain diagnostically important biomarkers, including SAICAr, AICAr, beta-ureidoisobutyric acid, 2,8-dihydroxyadenine and orotidine, necessitating the use of separate assays for their detection. Moreover, the limited sensitivity for some analytes in earlier assays may have hampered the reliable detection of mild cases. Therefore, we aimed to develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay that allows the simultaneous and sensitive detection of an extended range of purine and pyrimidine biomarkers in urine.

Methods

The assay was developed and validated using LC-MS/MS and clinically tested by analyzing ERNDIM Diagnostic Proficiency Testing (DPT) samples and further specimens from patients with various purine and pyrimidine disorders.

Results

Reliable determination of 27 analytes including SAICAr, AICAr, beta-ureidoisobutyric acid, 2,8-dihydroxyadenine and orotidine was achieved in urine following a simple sample preparation. The method clearly distinguished pathological and normal samples and differentiated between purine and pyrimidine defects in all clinical specimens.

Conclusions

A LC-MS/MS assay allowing the simultaneous, sensitive and reliable diagnosis of an extended range of purine and pyrimidine disorders has been developed. The validated method has successfully been tested using ERNDIM Diagnostic Proficiency Testing (DPT) samples and further clinical specimens from patients with various purine and pyrimidine disorders. Sample preparation is simple and assay duration is short, facilitating an easier inclusion of the assay into the diagnostic procedures.

Original languageEnglish
Article number0212458
Number of pages17
JournalPLOS ONE
Volume14
Issue number2
DOIs
Publication statusPublished - 28 Feb 2019

Keywords

  • TANDEM MASS-SPECTROMETRY
  • ADENYLOSUCCINATE LYASE DEFICIENCY
  • LABELED INTERNAL STANDARDS
  • INBORN-ERRORS
  • ELECTROSPRAY-IONIZATION
  • OROTIC ACIDURIA
  • METABOLISM
  • CHILDREN
  • UPDATE
  • HPLC

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