A feasibility study of metabolic phenotyping of dried blood spot specimens in rural Chinese women exposed to household air pollution

Abstract

Background Exposure-response studies and policy evaluations of household air pollution (HAP) are limited by current methods of exposure assessment which are expensive and burdensome to participants. Methods We collected 152 dried blood spot (DBS) specimens during the heating and non-heating seasons from 53 women who regularly used biomass-burning stoves for cooking and heating. Participants were enrolled in a longitudinal study in China. Untargeted metabolic phenotyping of DBS were generated using ultra-high performance liquid chromatography coupled with mass spectrometry to exemplify measurement precision and assessment for feasibility to detect exposure to HAP, evaluated by season (high pollution vs. low pollution) and measured personal exposure to fine particulate matter <2.5 μm diameters (PM 2.5) and black carbon (BC) in the 48-h prior to collecting the DBS specimen. Results Metabolites e.g., amino acids, acyl-carnitines, lyso-phosphorylcholines, sphinganine, and choline were detected in the DBS specimens. Our approach is capable of detecting the differences in personal exposure to HAP whilst showing high analytical reproducibility, coefficient of variance (CV) <15%, meeting the U.S. Food and Drug Administration criteria. Conclusions Our results provide a proof of principle that high-resolution metabolic phenotypic data can be generated using a simple DBS extraction method thus suitable for exposure studies in remote, low-resource settings where the collection of serum and plasma is logistically challenging or infeasible. The analytical run time (19 min/specimen) is similar to most global phenotyping methods and therefore suitable for large-scale application. Keywords Dried blood spot • Exposome • Metabonomics/metabolomics/metabolic phenotyping • Molecular epidemiological study • Biomass-related air pollution • PM 2.5

Advanced Microsamples: Current Applications and Considerations for Mass Spectrometry-Based Metabolic Phenotyping Pipelines

“…DBS samples have been evaluated in MS-based metabolic phenotyping and have been used in applications of cancer diagnostics [42], cancer treatments [43], air pollution [44], drug discovery [45], acidemia [46], and pyruvate kinase deficiency [47]. Despite this wide range of applications of DBS samples, there still remain concerns around their volumetric accuracy, This review of microsamples, to our knowledge, is the first of its kind to summarise applications to the metabolic phenotyping literature, wherein we highlight where applications have been successful/advantageous.…”

“…To date, studies have successfully performed DBS haematocrit normalisation through potassium content [54], using near-infrared (NIR) spectroscopy [55], haemoglobin measurement using non-contact diffuse reflectance spectroscopy [56], and using wax barriers on DBSs [57]. Despite the development of these normalisation techniques for DBSs, they are yet to be widely adopted in metabolic phenotyping workflows, with many literature examples not implementing a normalisation step in their protocol descriptions [43,44,46,47,55,[58][59][60]. Only two studies have openly reported hct normalisation of their DBS samples as part of their metabolic phenotyping workflow.…”

Advanced Microsamples: Current Applications and Considerations for Mass Spectrometry-Based Metabolic Phenotyping Pipelines

“…DBS samples have been evaluated in MS-based metabolic phenotyping and have been used in applications of cancer [42,43], air-pollution [44], drug discovery [45], acidemia [46], and pyruvate kinase deficiency [47]. Despite this wide range of applications of DBS samples, there still remains concerns around their volumetric accuracy, particulary in metabolic phenotyping where standardisation of sample volume is required.…”

“…To date, studies have successfully performed DBS haematocrit normalisation through potassium content [54], using near infrared (NIR) spectroscopy [55], haemoglobin measurement using non-contact diffuse reflectance spectroscopy [56], and using wax barriers on DBSs [57]. Despite the development of these normalisation techniques for DBSs, they are yet to be widely adopted in metabolic phenotyping workflows, with many literature examples not implementing a normalisation step in their protocol descriptions [43,44,46,47,55,[58][59][60]. Only two studies have openly reported hct normalisation of their DBS samples as part of their metabolic phenotyping workflow.…”

Rapid quantification of 50 fatty acids in small amounts of biological samples for population molecular phenotyping

“…In biological samples, these FAs are present in the forms of free fatty-acids (FFAs) and esterified FAs such as phospholipids, sphingolipids (SPs), glycerides, cholesterol-esters (CEs), FA-esters of hydroxyl-FAs (FAHFAs) and acylcarnitines (ACars) (Fahy et al 2005 ; Han 2016 ; Zhang et al 2023 ). In human blood plasma and serum, for example, FAs are present as FFAs and lipoproteins implicated in numerous pathophysiological processes (Chen et al 2020 , 2023 ; Li et al 2015b , 2023a ; Loo et al 2021 ; Nicholson 2021 ; Wu et al 2021b ; Xia et al 2021 , 2022 ). The biological functions of FAs and their metabolites are diverse including cellular membrane homeostasis (Romero et al 2019 ), energy generation (Lopaschuk et al 2010 ), regulation of transcription-factor activity (Zhang et al 2021 ) and signaling (Dalile et al 2019 ).…”