Quantitating fatty acids in dried blood spots on a common collection card versus a novel wicking sampling device

Targeted and untargeted metabolomics and lipidomics in dried blood microsampling: Recent applications and perspectives

Blood microsampling (BµS) offers an alternative to conventional methods that use plasma or serum for profiling human health, being minimally invasive and cost effective, especially beneficial for vulnerable populations. We present a non-systematic review that offers a synopsis of the analytical methods, applications and perspectives related to dry blood microsampling in targeted and untargeted metabolomics and lipidomics research in the years 2022 and 2023. BµS shows potential in neonatal and paediatric studies, therapeutic drug monitoring, metabolite screening, biomarker research, sports supervision, clinical disorders studies and forensic toxicology. Notably, dried blood spots and volumetric absorptive microsampling options have been more extensively studied than other volumetric technologies. Therefore, we suggest that a further investigation and application of the volumetric technologies will contribute to the use of BµS as an alternative to conventional methods. Conversely, we support the idea that harmonisation of the analytical methods when using BµS would have a positive impact on its implementation.

Ceramides biomarkers determination in quantitative dried blood spots by UHPLC-MS/MS

A method was developed for the analysis of four ceramide species; namely C16:0, C18:0, C24:0 and C24:1 in quantitative Dried Blood Samples (qDBS) by LC-MS/MS and validated with the aim to give prominence to an interesting application of at-home blood microsampling for health monitoring. Ceramides, being key-role metabolites implicated in regulation of diverse cellular processes have been considered as emerging biomarkers for different disease states, such as cardiovascular diseases, type 2 diabetes and others. Here, Capitainer device was utilized to provide accurate and consistent volumes of samples, ideal for accurate determinations. The method requires a 10 μL sample offering duplicate analysis by device, is quick and enables the sample collection by distance as it was proved that ceramides under study were stable at various conditions, including RT. Intra and inter-day accuracy of the determination were estimated between 87.6% - 113% and 90.6% -113%, respectively, while intra- and inter-day precision were calculated from 0.2% to 9.9% %RSD and 0.1% - 8.0% %RSD, respectively. The data acquired by ten healthy individuals indicated that circulating ceramides are at higher levels in whole blood taken from the fingertip in comparison to the reported values in plasma or serum.

Dried blood spots in clinical lipidomics: optimization and recent findings

Dried blood spots (DBS) are being considered as an alternative sampling method of blood collection that can be used in combination with lipidomic and other omic analysis. DBS are successfully used in the clinical context to collect samples for newborn screening for the measurement of specific fatty acid derivatives, such as acylcarnitines, and lipids from whole blood for diagnostic purposes. However, DBS are scarcely used for lipidomic analysis and investigations. Lipidomic studies using DBS are starting to emerge as a powerful method for sampling and storage in clinical lipidomic analysis, but the major research work is being done in the pre- and analytical steps and procedures, and few in clinical applications. This review presents a description of the impact factors and variables that can affect DBS lipidomic analysis, such as the type of DBS card, haematocrit, homogeneity of the blood drop, matrix/chromatographic effects, and the chemical and physical properties of the analyte. Additionally, a brief overview of lipidomic studies using DBS to unveil their application in clinical scenarios is also presented, considering the studies of method development and validation and, to a less extent, for clinical diagnosis using clinical lipidomics. DBS combined with lipidomic approaches proved to be as effective as whole blood samples, achieving high levels of sensitivity and specificity during MS and MS/MS analysis, which could be a useful tool for biomarker identification. Lipidomic profiling using MS/MS platforms enables significant insights into physiological changes, which could be useful in precision medicine.

Dried blood spot as an alternative sample for screening of fatty acids, amino acids, and keto acids metabolism in humans

The dried blood spot is a simple and non-invasive sample collection technique allowing self-collection at home. It can be used as an alternative sample for the screening of metabolism in humans since changes in the levels of some fatty acids, amino acids, and keto acids can be associated with metabolic disorders (for example diabetes mellitus). In this study we optimized three different methods that are sensitive enough for the determination of above-mentioned analytes from a small volume of a biological material in dried blood spot. In total 20 amino acids, 5 keto acids, and 24 fatty acids were determined. This sample technique was applied to prepare samples from 60 individuals by a finger prick. Samples were analysed with chromatographic methods and acquired data were statistically evaluated. Even though most analytes were higher in men, only 5 amino acids, 3 keto acids and 8 fatty acids showed significant gender-dependency (α = 0.05). Asparagine, serine, α- and γ-linolenic acids showed significant age-dependency (α = 0.05). The most of statistically significant correlations were positive and were found within one category. This work shows that because of many benefits, the dried blood spot sample could be a good alternative to whole blood sample collection for the screening of metabolism in humans in general or in individualised medicine. The chromatographic methods can be used in the next research, for example to set reference range or plasma-correction factors (various aspects as age or gender should be considered).

Evaluation of Different Extraction Methods for the Analysis of Per- and Polyfluoroalkyl Substances in Dried Blood Spots from the Florida Manatee (Trichechus manatus)

Per- and polyfluoroalkyl substances (PFAS) are environmental contaminants linked to adverse health effects in humans and wildlife. Marine mammals, particularly manatees, have shown potential as sentinels for evaluating the presence and effects of anthropogenic chemicals. However, traditional blood collection techniques with marine mammals can be challenging, highlighting the need for improved strategies. In the present study, four different methods for the extraction of PFAS from dried blood spots were evaluated. Environ Toxicol Chem 2021;40:2726-2732. © 2021 SETAC.

Assessment of polyunsaturated fatty acids: A self-report and biomarker assessment with a racially and ethnically diverse sample of women

Polyunsaturated fatty acids (PUFAs) play an important role in human health, influencing chronic disease and mortality. Food Frequency Questionnaires (FFQs) are widely used to assess self-reported diet, but they can be subject to a variety of errors. Accordingly, an accurate assessment of diet is crucial in nutrition research. This study examined the association between a widely-used self-report measure of PUFAs (Diet History Questionnaire-II: DHQ-II) with the proportion of PUFA in red blood cell (RBC) membranes, and examined whether this relationship was moderated by race/ethnicity. In a racially and ethnically diverse sample of 132 female participants (M_age = 21.97±3.98, range 18 to 42 years), bivariate correlations and linear regression analyses demonstrated associations between DHQ-II and proportion of nutrients in RBCs for omega-3 fatty acids EPA (r = 0.39, ß = 0.38, p < .01), DHA (r = 0.48, ß = 0.47, p < .01), and EPA+DHA (r = 0.51, β = 0.49, p < .01). No associations were found for omega-3 fatty acid ALA or omega-6 fatty acids LA or ARA. DHQ-II and RBC associations for EPA, DHA, and EPA+DHA were moderated by race/ethnicity, controlling for age. Self-report of EPA was most consistent with RBC proportions for Caucasian individuals, and less consistent for Black/African American individuals. Self-reports of DHA and EPA+DHA were most consistent with RBC proportions for Caucasian individuals, and less consistent for Black/African American individuals and Hispanic/Latina individuals, although still statistically significant. No associations were detected for Hispanic/Latina individuals (for EPA only), Asian/Pacific Islanders or individuals of mixed/other descent. The present study found that when compared to PUFA biomarkers, the DHQ-II did not assess PUFAs consistently across all racial/ethnic groups in this sample of women. Further research is needed to determine what factors contribute to weak or lacking correlations between reported fat intake and corresponding values in RBCs, including but not limited to recall errors, underestimations of fatty acids in food composition databases, insufficient DHQ-II assessment of fatty acids in general and from particular cultures, and genetic differences in fat metabolism.

Global Surveillance of trans-Fatty Acids

Trans-fatty acid (TFA) intake can increase the risk of coronary heart disease (CHD) morbidity and mortality and all-cause mortality. Industrially produced TFAs and ruminant TFAs are the major sources in foods. TFA intake and TFA-attributed CHD mortality vary widely worldwide. Excessive TFA intake is a health threat in high-income countries; however, it is also a threat in low- and middle-income countries (LMICs). Data on TFA intake are scarce in many LMICs and an urgent need exists to monitor TFAs globally. We reviewed global TFA intake and TFA-attributed CHD mortality and current progress toward policy or regulation on elimination of industrially produced TFAs in foods worldwide. Human biological tissues can be used as biomarkers of TFAs because they reflect actual intake from various foods. Measuring blood TFA levels is a direct and reliable method to quantify TFA intake.