A state-of-the-science review and guide for measuring environmental exposure biomarkers in dried blood spots

Development and validation of the UHPLC-MS/MS method for the quantitative determination of 25 PFAS in dried blood spots

Per- and polyfluoroalkyl substances (PFAS) are anthropogenic fluorine-containing compounds largely used in industrial and consumer applications. They tend to bioaccumulate in the human body after intake from various sources in daily life. Following repeated exposure to PFAS, a broad range of adverse health outcomes has been reported. Consequently, monitoring PFAS levels in human blood is of paramount importance for public health policies. In contrast with traditional venipuncture, dried blood spots (DBS) constitute a reliable, cheap, and less invasive technique to allow microsampling by capillary blood collected on a specific device. This work aimed to develop and validate an innovative analytical method, combining quantitative DBS with UHPLC-MS/MS instrumentation to identify and quantify 25 PFAS. The extraction procedure was developed and optimized within the range 2-100 ng/mL. Specifically, fortified blood was applied on Capitainer®B devices providing 10 μL of blood volume through a microfluidic channel. After 3 h of drying, the extraction was performed by methanol under sonication, followed by centrifugation. Then, the extraction solvent was evaporated; the residue was reconstituted with the mobile phase solution. The validated method evidenced good sensitivity, with limits of detection ranging from 0.4 ng/mL (PFODA, PFOS) to 1.0 ng/mL (PFOA, 3,6-OPFHpA). The ± 20% acceptability criteria established for intra- and inter-day precision and accuracy were fulfilled for all analytes. High recovery-above 80%-was recorded, whereas significant matrix effect resulted in ion enhancement (> 50%) for 13 analytes. In conclusion, the proposed workflow proved to be reliable, fit for purpose, and easily adaptable in the laboratory routine.

"Using dried blood spots beyond newborn screening - is Hong Kong ready?": navigating the intersection of innovation readiness, privacy concerns, and Chinese parenting culture

BACKGROUND

Newborn screening programmes offer an opportunity to obtain dried blood spots (DBS) cards that contain a wealth of biological information that can be stored for long periods and have potential benefits for research and quality assurance. However, the storage and secondary uses of DBS cards pose numerous ethical, clinical, and social challenges. Empirical research exploring public attitudes is central to public policy planning as it can indicate whether or not there is broad public support, define public concerns, and ascertain the circumstances required to alleviate concerns and ensure support. This study aims to describe the clinical experience and attitudes towards newborn screening and investigate the perceptions and expectations of Hong Kong parents and healthcare providers regarding the retention of DBS cards and their usage for research.

METHODS

We conducted semi-structured in-person interviews with 20 parents and healthcare providers in Hong Kong. Thematic analysis was conducted.

RESULTS

Awareness of the significant research value of secondary uses of dried blood spot cards is low. Parents and healthcare providers support the storage and secondary uses of DBS cards with some concerns, including privacy and confidentiality breaches, the risk of discrimination or stigmatisation based on genetic information, and their inability to oversee the use of their child's biospecimen. Parents, however, prioritise their child's health over privacy concerns and support identifiable storage using pseudonymity to gain more information about their children's health.

CONCLUSION

Child information takes precedence over potential concerns over privacy, underscoring the significance of engaging patients and the public in shaping public policy related to biobanking and healthcare research, in line with cultural and social values.

Evaluating the detection of barbiturates in dried blood spots: A comparative analysis using gas chromatography-mass spectrometry, gas chromatography-tandem mass spectrometry, and liquid chromatography-tandem mass spectrometry with different extraction methods

Rapid and accurate characterization and quantitation of blood barbiturates and their combination drugs are very important for the clinical treatment of acute barbiturate poisoning. A comparison of dried blood spot (DBS) and traditional liquid-liquid extraction (LLE) in the pre-treatment stage, as well as a comparison of gas chromatography-mass spectrometry (GC-MS), gas chromatography-tandem mass spectrometry (GC-MS/MS), and liquid chromatography-tandem mass spectrometry (LC-MS/MS) as instrumental analysis methods, revealed differences in the analysis results of barbiturates and their combination drugs under different conditions. Based on these findings, we introduce a DBS-GC-MS/MS method. The developed and validated method showed good selectivity, sensitivity (LOD: 0.1 μg mL-1, LOQ: 0.2 μg mL-1), linearity (R2>0.9992), trueness (<15 %, except for carbamazepine, at 29.4 %), and precision (<15 %). Recovery was also good for most target compounds, but significant matrix effects were evident. Compared with the LLE method, the DBS method has the benefits of easy sample collection, storage, and transport, as well as simple pre-treatment and reduced reagent and energy consumption. Compared to LC-MS/MS, GC-MS/MS requires no switching between positive and negative ion modes and uses the MRM detection mode, meaning that more information about the sample compounds can be obtained in less analysis time. Using actual sample analysis, we have demonstrated the advantages of the DBS-GC-MS/MS method for the qualitative and quantitative analysis of barbiturates and poisoning events due to combinations of these drugs. Comparison of the three instruments and the two treatment methods revealed their analysis characteristics. From the perspective of practical application, the broad practical value and advantages of DBS should be embraced in more applications, and future analytical laboratory development should continue to recognize GC-MS/MS as a useful supplement to LC-MS/MS.

Cord Blood Adductomics Reveals Oxidative Stress Exposure Pathways of Bronchopulmonary Dysplasia

Fetal and neonatal exposures to perinatal oxidative stress (OS) are key mediators of bronchopulmonary dysplasia (BPD). To characterize these exposures, adductomics is an exposure science approach that captures electrophilic addition products (adducts) in blood protein. Adducts are bound to the nucleophilic cysteine loci of human serum albumin (HSA), which has a prolonged half-life. We conducted targeted and untargeted adductomics to test the hypothesis that adducts of OS vary with BPD. We studied 205 preterm infants (≤28 weeks) and 51 full-term infants from an ongoing birth cohort. Infant plasma was collected at birth (cord blood), 1-week, 1-month, and 36-weeks postmenstrual age. HSA was isolated from plasma, trypsin digested, and analyzed using high-performance liquid chromatography-mass spectrometry to quantify previously annotated (known) and unknown adducts. We identified 105 adducts in cord and postnatal blood. A total of 51 known adducts (small thiols, direct oxidation products, and reactive aldehydes) were increased with BPD. Postnatally, serial concentrations of several known OS adducts correlated directly with supplemental oxygen exposure. The application of large-scale adductomics elucidated OS-mediated pathways of BPD. This is the first study to investigate the "neonatal-perinatal exposome" and to identify oxidative stress-related exposure biomarkers that may inform antioxidant strategies to protect the health of future generations of infants.

Advancing Global Health Surveillance of Mycotoxin Exposures using Minimally Invasive Sampling Techniques: A State-of-the-Science Review

Mycotoxins are a heterogeneous group of toxins produced by fungi that can grow in staple crops (e.g., maize, cereals), resulting in health risks due to widespread exposure from human consumption and inhalation. Dried blood spot (DBS), dried serum spot (DSS), and volumetric tip microsampling (VTS) assays were developed and validated for several important mycotoxins. This review summarizes studies that have developed these assays to monitor mycotoxin exposures in human biological samples and highlights future directions to facilitate minimally invasive sampling techniques as global public health tools. A systematic search of PubMed (MEDLINE), Embase (Elsevier), and CINAHL (EBSCO) was conducted. Key assay performance metrics were extracted to provide a critical review of the available methods. This search identified 11 published reports related to measuring mycotoxins (ochratoxins, aflatoxins, and fumonisins) using DBS/DSS and VTS assays. Multimycotoxin assays adapted for DBS/DSS and VTS have undergone sufficient laboratory validation for applications in large-scale population health and human biomonitoring studies. Future work should expand the number of mycotoxins that can be measured in multimycotoxin assays, continue to improve multimycotoxin assay sensitivities of several biomarkers with low detection rates, and validate multimycotoxin assays across diverse populations with varying exposure levels. Validated low-cost and ultrasensitive minimally invasive sampling methods should be deployed in human biomonitoring and public health surveillance studies to guide policy interventions to reduce inequities in global mycotoxin exposures.

Trace elements in hair or fingernail and gastroesophageal cancers: results from a population-based case-control study

BACKGROUND

Growing evidence suggests that environmental factors probably play important roles in the development of gastroesophageal cancers (GOC), however, the effects of trace elements on GOC remain unclear.

OBJECTIVE

To assess the effect of trace elements on GOC and the effect modification by other factors.

METHODS

Hair and fingernail samples were collected from GOC cases and controls in a population-based case-control study in Taixing, China, and were used to detect the concentrations of 12 trace elements using inductively coupled plasma mass spectrometry. Unconditional logistic regression models were used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for concentrations of 12 trace elements in association with GOC after adjusting the other factors.

RESULTS

A total of 830 hair samples (581 controls and 249 cases) and 895 fingernail samples (559 controls and 336 cases) were included. Compared to the lowest-tertile concentration, the higher tertiles of Ca, Zn, Fe, Al, Cr, Pb, Se, and V were positively associated with GOC, while the higher tertiles of Mg, Mn, Sr, and As were inversely associated with GOC. Significant interactions between the hair level of Cr and two other risk factors, including smoking (P for interaction = 0.044) and alcohol drinking (P for interaction = 0.028), were observed in association with GOC.

SIGNIFICANCE

The current study reveals that these 12 trace elements in hair and fingernails are associated with GOC to varying degrees. Further studies and animal experiments are needed to clarify the associations and explore potential mechanisms.

IMPACT STATEMENT

The role of trace elements in the development or inhibition of gastroesophageal cancers (GOC) remains unclear. In this study, we further explored the associations between 12 trace elements and GOC based on a population-based case-control study conducted in Taixing, China. Higher levels of Ca, Zn, Fe, Al, Cr, Pb, Se, and V were positively associated with increased GOC, while inverse associations between higher levels of Mg, Mn, Sr, As, and GOC were observed. Observed associations were consistent in hair and fingernail samples. Moreover, interaction effects between hair level of Cr and smoking or alcohol drinking were identified.

Per- and polyfluoroalkyl substances (PFAS) and thyroid hormone measurements in dried blood spots and neonatal characteristics: a pilot study

BACKGROUND

Pediatric thyroid diseases have been increasing in recent years. Environmental risk factors such as exposures to chemical contaminants may play a role but are largely unexplored. Archived neonatal dried blood spots (DBS) offer an innovative approach to investigate environmental exposures and effects.

OBJECTIVE

In this pilot study, we applied a new method for quantifying per- and polyfluoroalkyl substances (PFAS) to 18 archived DBS from babies born in California from 1985-2018 and acquired thyroid hormone measurements from newborn screening tests. Leveraging these novel data, we evaluated (1) changes in the concentrations of eight PFAS over time and (2) the relationship between PFAS concentrations, thyroid hormone concentrations, and neonatal characteristics to inform future research.

METHODS

PFAS concentrations in DBS were measured using ultra-high-performance liquid chromatography-mass spectrometry. Summary statistics and non-parametric Wilcoxon rank-sum and Kruskal-Wallis tests were used to evaluate temporal changes in PFAS concentrations and relationships between PFAS concentrations, thyroid hormone concentrations, and neonatal characteristics.

RESULTS

The concentration and detection frequencies of several PFAS (PFOA, PFOS, and PFOSA) declined over the assessment period. We observed that the timing of specimen collection in hours after birth was related to thyroid hormone but not PFAS concentrations, and that thyroid hormones were related to some PFAS concentrations (PFOA and PFOS).

IMPACT STATEMENT

This pilot study examines the relationship between concentrations of eight per- and polyfluoroalkyl substances (PFAS), thyroid hormone levels, and neonatal characteristics in newborn dried blood spots (DBS) collected over a period of 33 years. To our knowledge, 6 of the 22 PFAS we attempted to measure have not been quantified previously in neonatal DBS, and this is the first study to examine both PFAS and thyroid hormone concentrations using DBS. This research demonstrates the feasibility of using newborn DBS for quantifying PFAS exposures in population-based studies, highlights methodological considerations in the use of thyroid hormone data for future studies using newborn DBS, and indicates potential relationships between PFAS concentrations and thyroid hormones for follow-up in future research.

Emerging Microfluidic Devices for Sample Preparation of Undiluted Whole Blood to Enable the Detection of Biomarkers

Blood testing allows for diagnosis and monitoring of numerous conditions and illnesses; it forms an essential pillar of the health industry that continues to grow in market value. Due to the complex physical and biological nature of blood, samples must be carefully collected and prepared to obtain accurate and reliable analysis results with minimal background signal. Examples of common sample preparation steps include dilutions, plasma separation, cell lysis, and nucleic acid extraction and isolation, which are time-consuming and can introduce risks of sample cross-contamination or pathogen exposure to laboratory staff. Moreover, the reagents and equipment needed can be costly and difficult to obtain in point-of-care or resource-limited settings. Microfluidic devices can perform sample preparation steps in a simpler, faster, and more affordable manner. Devices can be carried to areas that are difficult to access or that do not have the resources necessary. Although many microfluidic devices have been developed in the last 5 years, few were designed for the use of undiluted whole blood as a starting point, which eliminates the need for blood dilution and minimizes blood sample preparation. This review will first provide a short summary on blood properties and blood samples typically used for analysis, before delving into innovative advances in microfluidic devices over the last 5 years that address the hurdles of blood sample preparation. The devices will be categorized by application and the type of blood sample used. The final section focuses on devices for the detection of intracellular nucleic acids, because these require more extensive sample preparation steps, and the challenges involved in adapting this technology and potential improvements are discussed.

Reliability and feasibility of home-based dried blood spot in therapeutic drug monitoring: a systematic review and meta-analysis

PURPOSE

Dried blood spot (DBS) is one of promising home sampling methods for therapeutic drug monitoring (TDM). However, the associated reliability and feasibility (including yield, adherence, and preference), which are criteria for the promotion of home-based DBS, remain unknown. This systematic review and meta-analysis aimed to evaluate the reliability and feasibility of TDM using DBS sampling.

METHODS

In this study, a combination of MeSH and free terms for (dried blood spot*[title/abstract])AND ("Drug Monitoring"[Mesh])AND(home OR venous)was surveyed using EMBASE, PubMed, Cochrane Library, and Web of Science upon gathering published. we registered this study protocol with the International Prospective Registry of Systematic Reviews (CRD42021247559).

RESULTS

Approximately half (35/75) of the evaluations reported good agreement between DBS and plasma, and the results for drugs with poor agreement may be improved using a haematocrit-based physiological equation. The yield and adherence to home-based DBS exceeded 87%, and questionnaire-based preference for DBS was 77%.

CONCLUSIONS

DBS may be a reliable and feasible home sampling method; however, it requires intricate design and evaluation before implementation.

Mass Spectrometry of Transferrin and Apolipoprotein CIII from Dried Blood Spots for Congenital Disorders of Glycosylation

Dried blood spot (DBS) is the standard specimen for the newborn screening of inborn errors of metabolism (IEM) by tandem mass spectrometry. Availability of DBS for the mass spectrometric analysis of the diagnostic marker proteins, transferrin (Tf) and apolipoprotein CIII (apoCIII), of congenital disorders of glycosylation (CDG) was examined. Recovery of Tf from DBS was only slightly reduced compared with fresh serum. Although oxidation of the core polypeptides was observed, glycans of Tf and apoCIII were unaffected by storage of DBS in the ambient environment for at least 1 month. The combination of DBS and the triple quadrupole mass spectrometer used for IEM screening was sufficient to characterize the aberrant glycoprofiles of Tf and apoCIII in CDG. DBS or dried serum spot on filter paper can reduce the cost of sample transportation and potentially promote mass spectrometric screening of CDG.