Activity of the liver enzyme ornithine carbamoyltransferase (OTC) in blood: LC-MS/MS assay for non-invasive diagnosis of ornithine carbamoyltransferase deficiency

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11110%2F17%3A10364224" target="_blank" >RIV/00216208:11110/17:10364224 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00064165:_____/17:10364224

Výsledek na webu

<a href="http://dx.doi.org/10.1515/cclm-2016-0715" target="_blank" >http://dx.doi.org/10.1515/cclm-2016-0715</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1515/cclm-2016-0715" target="_blank" >10.1515/cclm-2016-0715</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Activity of the liver enzyme ornithine carbamoyltransferase (OTC) in blood: LC-MS/MS assay for non-invasive diagnosis of ornithine carbamoyltransferase deficiency

Popis výsledku v původním jazyce

Background: Liver enzymes are released from hepatocytes into circulation and their activity can be measured in the blood. We examined whether the plasma activity of the liver enzyme ornithine carbamoyltransferase, determined by a novel liquid chromatography-mass spectrometry (LC-MS/MS) assay, could be utilized for the detection of OTC deficiency (OTCD), an X-linked inborn error of the urea cycle. Methods: The plasma ornithine carbamoyltransferase (OTC) activity was assayed in the reverse reaction using isotopically labeled citrulline-d4 as a substrate and by determination of the product, ornithine-d4, by LC-MS/MS analysis. Results: The plasma OTC activity in the controls was in the range of 111-658 pkat/L (n = 49, median 272 pkat/L), and the activity increased linearly with serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in patients with hepatopathy. The OTC activity was subsequently determined in 32 individuals carrying mutations in the OTC gene, and OTC/ALT and OTC/AST ratios were calculated to account for the degree of hepatopathy, which is a common finding in OTCD. The OTC/ALT ratio enabled clear differentiation of OTCD hemizygotes (n = 11, range 0-69 x 10(-6)) from controls (504-3440 x 10(-6)). This ratio also enabled the detection of 11 of 12 symptomatic heterozygotes (range 38-794 x 10(-6)), while this marker did not allow for reliable differentiation of asymptomatic heterozygotes (n = 9) from controls. Conclusions: LC-MS/MS assay of plasma OTC activity enabled the detection of all hemizygous and the majority of symptomatic heterozygous OTCD patients in the tested cohort. This study demonstrates that non-invasive assay of enzymes expressed predominantly in the liver could be used as an alternative approach for diagnosing inborn errors of metabolism.

Název v anglickém jazyce

Activity of the liver enzyme ornithine carbamoyltransferase (OTC) in blood: LC-MS/MS assay for non-invasive diagnosis of ornithine carbamoyltransferase deficiency

Popis výsledku anglicky

Background: Liver enzymes are released from hepatocytes into circulation and their activity can be measured in the blood. We examined whether the plasma activity of the liver enzyme ornithine carbamoyltransferase, determined by a novel liquid chromatography-mass spectrometry (LC-MS/MS) assay, could be utilized for the detection of OTC deficiency (OTCD), an X-linked inborn error of the urea cycle. Methods: The plasma ornithine carbamoyltransferase (OTC) activity was assayed in the reverse reaction using isotopically labeled citrulline-d4 as a substrate and by determination of the product, ornithine-d4, by LC-MS/MS analysis. Results: The plasma OTC activity in the controls was in the range of 111-658 pkat/L (n = 49, median 272 pkat/L), and the activity increased linearly with serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in patients with hepatopathy. The OTC activity was subsequently determined in 32 individuals carrying mutations in the OTC gene, and OTC/ALT and OTC/AST ratios were calculated to account for the degree of hepatopathy, which is a common finding in OTCD. The OTC/ALT ratio enabled clear differentiation of OTCD hemizygotes (n = 11, range 0-69 x 10(-6)) from controls (504-3440 x 10(-6)). This ratio also enabled the detection of 11 of 12 symptomatic heterozygotes (range 38-794 x 10(-6)), while this marker did not allow for reliable differentiation of asymptomatic heterozygotes (n = 9) from controls. Conclusions: LC-MS/MS assay of plasma OTC activity enabled the detection of all hemizygous and the majority of symptomatic heterozygous OTCD patients in the tested cohort. This study demonstrates that non-invasive assay of enzymes expressed predominantly in the liver could be used as an alternative approach for diagnosing inborn errors of metabolism.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

30209 - Paediatrics

Projekt

<a href="/cs/project/NT14159" target="_blank" >NT14159: Plazmatické aktivity intracelulárních enzymů u vybraných dědičných poruch metabolismu – možnosti využití pro diagnostiku a predikci účinnosti léčby.</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Clinical Chemistry and Laboratory Medicine

ISSN

1434-6621

e-ISSN

—

Svazek periodika

55

Číslo periodika v rámci svazku

8

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

10

Strana od-do

1168-1177

Kód UT WoS článku

000405506000022

EID výsledku v databázi Scopus

2-s2.0-85025107396