A hydrophilic-interaction chromatography tandem mass spectrometry method for quantitation of serum s-adenosylmethionine in patients infected with human immunodeficiency virus

作者：Wang Ping^*; Huang Laurence; Davis J Lucian; Swartzman Alexandra; Roth Brenna; Stone Judy; Wu Alan H B

来源：Clinica Chimica Acta, 2008, 396(1-2): 86-88.

DOI：10.1016/j.cca.2008.06.014

• Hydrophilic-interaction chromatography
• Mass spectrometry
• s-Adenosylimethionine
• Human immunodeficiency virus

Background: s-Adenosylmethionine (SAM)(1) has been suggested as a diagnostic test and surrogate marker for Prieurnocystisfirovecii pneumonia (PCP) in HIV-positive patients. In this study, we report a robust hydrophilic-interaction liquid chromatography tandem mass spectrometry (LC-MS/MS) assay that can be used to quantitate serum SAM in clinical laboratories.
Methods: Proteins in serum samples were precipitated using trichloroacetic acid. The supernatant was separated after centrifugation. D(3)d(3)-SAM was added as the internal standard. SAM and d(3)-SAM were extracted using a mixed-mode cation exchange column. Extracts were dried under nitrogen and reconstituted in H(2)O and acetonitrile (1:9, vol:vol). HPLC-tandem mass spectrometry analysis was performed with a silica column and multiple reaction monitoring for SAM and d3-SAM.
Results: The limit ofquantitation (LOQ) for SAM was 10ng/mL The assay was linear between 10 and 500ng/mL. Intra-assay coefficient of variation (CV) was 8% and inter-assay CV was 17% at the LOQ. Turnaround time for each specimen was approximately 1 h. Using this method, we found that serum SAM concentration was correlated with fasting status, especially methionine intake. We also measured acute and convalescent serum SAM levels of 8 HIV-positive patients with PCP and non-PCP pneumonia. SAM concentrations in convalescent samples were significantly increased compared to acute levels only in patients with PCP.
Conclusions: The LC-MS/MS method had sufficient analytical sensitivity for detecting low levels of SAM found in HIV-infected patients and can be used for quantitative measurements in a clinical laboratory.

• 出版日期2008-10