Preanalytical aspects and sample quality assessment in metabolomics studies of human blood.

Metabolomics is a powerful tool that is increasingly used in clinical research. Although excellent sample quality is essential, it can easily be compromised by undetected preanalytical errors. We set out to identify critical preanalytical steps and biomarkers that reflect preanalytical inaccuracies. We systematically investigated the effects of preanalytical variables (blood collection tubes, hemolysis, temperature and time before further processing, and number of freeze-thaw cycles) on metabolomics studies of clinical blood and plasma samples using a nontargeted LC-MS approach. Serum and heparinate blood collection tubes led to chemical noise in the mass spectra. Distinct, significant changes of 64 features in the EDTA-plasma metabolome were detected when blood was exposed to room temperature for 2, 4, 8, and 24 h. The resulting pattern was characterized by increases in hypoxanthine and sphingosine 1-phosphate (800% and 380%, respectively, at 2 h). In contrast, the plasma metabolome was stable for up to 4 h when EDTA blood samples were immediately placed in iced water. Hemolysis also caused numerous changes in the metabolic profile. Unexpectedly, up to 4 freeze-thaw cycles only slightly changed the EDTA-plasma metabolome, but increased the individual variability. Nontargeted metabolomics investigations led to the following recommendations for the preanalytical phase: test the blood collection tubes, avoid hemolysis, place whole blood immediately in ice water, use EDTA plasma, and preferably use nonrefrozen biobank samples. To exclude outliers due to preanalytical errors, inspect the biomarker signal intensities reflecting systematic as well as accidental and preanalytical inaccuracies before processing the bioinformatics data.

Yin P ，Peter A ，Franken H ，Zhao X ，Neukamm SS ，Rosenbaum L ，Lucio M ，Zell A ，Häring HU ，Xu G ，Lehmann R ... -  《-》

Quality markers addressing preanalytical variations of blood and plasma processing identified by broad and targeted metabolite profiling.

Kamlage B ，Maldonado SG ，Bethan B ，Peter E ，Schmitz O ，Liebenberg V ，Schatz P ... -  《-》

Assessment of the effects of repeated freeze thawing and extended bench top processing of plasma samples using untargeted metabolomics.

Goodman K ，Mitchell M ，Evans AM ，Miller LAD ，Ford L ，Wittmann B ，Kennedy AD ，Toal D ... -  《-》

The key points in the pre-analytical procedures of blood and urine samples in metabolomics studies.

Bi H ，Guo Z ，Jia X ，Liu H ，Ma L ，Xue L ... -  《-》

Preanalytical variables for liquid chromatography-mass spectrometry (LC-MS) analysis of human blood specimens.

The use of liquid chromatography-mass spectrometry (LC-MS) for both diagnostics and research purposes is rapidly growing in clinical laboratories. As for more conventional areas of in vitro diagnostic testing, many preanalytical variables have an impact on these techniques and may hence jeopardize the quality of tests results. The leading preanalytical variables include patient preparation, the nature of the blood collection tubes and additives, interference from spurious hemolysis, sample handling and management, composition of blood tubes, contamination, as well as storage conditions. Therefore, the aim of this article is provide a narrative overview about the leading preanalytical issues which may ultimately influence LC-MS testing of human blood samples, and provide tentative indications, as for current evidence, about optimal preanalytical management of blood samples for proteomics and metabolomics studies. These general recommendations entail pre-storage centrifugation, use of appropriate tubes and additives, addition of bacteriostatic preservatives, enrichment and purification of samples, elimination of unsuitable specimens, rapid analysis or immediate storage at -70°C, and avoidance of analyzing frozen-thawed specimens.

Salvagno GL ，Danese E ，Lippi G 《-》