Can plasma ammonia be measured in patients with acute liver disease?

Ann Clin Biochem 2008;45:426-428
© 2008 Association for Clinical Biochemistry

This Article
Right arrow
Figures Only
Right arrow
Full Text
Right arrow

Full Text (PDF)

Right arrow
Alert me when this article is cited
Right arrow
Alert me if a correction is posted
Right arrow
Email this article to a friend
Right arrow

Similar articles in this journal

Right arrow
Similar articles in PubMed
Right arrow
Alert me to new issues of the journal
Right arrow
Download to citation manager
Right arrow
Google Scholar
Right arrow
Articles by Herrera, D. J.
Right arrow
Articles by Griffiths, P.
Right arrow
PubMed Citation
Social Bookmarking

What’s this?

Short Reports

Daniel Juan Herrera,
Steven Moore,
Sarah Heap,
Mary Anne Preece and
Paul Griffiths

Department of Clinical Chemistry, Birmingham Children’s Hospital, Steelhouse Lane, Birmingham B4 6NH, UK

Corresponding author: Mr Daniel Herrera. Email: Daniel.Herrera{at}

Background: Plasma ammonia (PA) measurement is of key importance in thediagnosis and monitoring of some inherited metabolic disordersand to monitor subsequent treatment of hyperammonaemia.

Methods: Over a six-month period, patients’ ammonia concentrations weremeasured in parallel, using an enzymatic–UV kit (InfinityAmmonia Liquid Stable Reagent, Thermo Electron Corporation,Australia) on an Olympus AU640 analyser (Olympus UK Ltd, Hertfordshire)and on our current dry chemistry system (Vitros 250, Ortho ClinicalDiagnostic). Alanine amino transferase (ALT) was added to ahuman plasma sample to investigate its effect on the assessmentof ammonia concentration.

Results: Both methods correlated well (InfinityTM kit = 1.12 x Vitros 250 + 39, R2 = 0.95, n = 105). However, clinically important discrepancies ranging from 100 to 380 µmol/L were found in patients with acute liver failure. Ammonia concentration measured with the enzymatic InfinityTM kit increased by 137 µmol/L when ALT was added up to 17,000 IU/L.

Conclusions: ALT produces a positive interference in the enzymatic InfinityTMkit which may affect interpretation and influence further clinicalaction. However, this positive interference due to ALT doesnot fully explain the discrepant results observed between thetwo methods in patients with acute liver failure.

CiteULike    Complore    Connotea    Digg    Reddit    Technorati    What’s this?