Hidrólisis de acilcarnitinas durante el análisis en sangre y plasma por espectrometría de masas en tandem / Hydrolysis of acylcarnitines during measurement in blood and plasma by tandem mass spectrometry

La determinación de acilcarnitinas en sangre es una herramienta importante para el diagnóstico de algunas enfermedades hereditarias, así como deficiencias metabólicas secundarias. Bajo las condiciones acídicas y la alta temperatura utilizadas durante el proceso de derivatización, es posible que pueda ocurrir algún grado de hidrólisis de acilcarnitinas, lo cual puede potencialmente interferir con las determinaciones de la carnitina libre. El objetivo del presente estudio fue investigar la hidrólisis de las acilcarnitinas (de cadena corta, media y larga) durante el proceso de derivatización y analizar su efecto sobre la determinación de carnitina libre. El porcentaje de hidrólisis fue de 27% para acilcarnitinas de cadena corta, 17% para acilcarnitinas de cadena media y 5% para acilcarnitinas de cadena larga. Estos resultados pueden ocasionar un incremento en los niveles de carnitina libre de las muestras analizadas.

The measurement of acylcarnitines in blood is an important tool for diagnosis of some inherited metabolic diseases and secondary metabolic deficiencies. Under the acidic conditions and the high temperature used for the derivatisation process, it is feasible that some degree of hydrolysis of acylcarnitines to free carnitine may occur and therefore potentially interfere with free carnitine measurements. The objective of the present study was to investigate the hydrolysis of acylcarnitines (short-chain-, medium-chain, and long chain acylcarnitines) during derivatisation process and to analyse its effect on free carnitine measurement. The average percentage of hydrolysis was 27% for short-chain acylcarnitines, 17% for medium-chain acylcarnitines, and 5% for long-chain acylcarnitines. These results can increase the free carnitine levels in the analysed samples.

Assessment of plasma carnitine and acylcarnitine levels in preeclampsia

Objective: carnitine plays a crucial role in fatty acids oxidation. The aim of the study is to assess plasma carnitine and acylcarnitines levels in preeclamptic womedas a measure of abnormal fatty acid oxidation

Methods: the study included 40 women with preeclampsia and 30 normotensive control women in the third trimester of pregnancy. Women with multiple pregnancy, chronic hypertension, diabetes mellitus and renal diseases were excluded. Plasma levels of free carnitine and acylcarnitines were measured with high performance liquid chromatography [HPLC]

results: total and free carnitines and acylcamitines were significantly increased in preeclamptic cases in comparison to the control group. A positive correlation was found between acylcarnitines and diastolic blood pressure [r=0.382, p= 0.018]

Conclusion: the significantly high plasma carnitine concentrations found in this study supports the hypothesis of abnormal fatty acid metabolism in the pathophysiology of preeclampsia. This may contribute to the endothelial cell dysfunction of preeclarnpsia