What a drop can do: dried blood spots as a minimally invasive method for integrating biomarkers into population-based research

Telomere length analysis from minimally-invasively collected samples: Methods development and meta-analysis of the validity of different sampling techniques: American Journal of Human Biology

OBJECTIVES

Telomeres are the protective caps of chromosomes. They shorten with cell replication, age, and possibly environmental stimuli (eg, infection and stress). Short telomere length (TL) predicts subsequent worse health. Although venous whole blood (VWB) is most commonly used for TL measurement, other, more minimally invasive, sampling techniques are becoming increasingly common due to their field-friendliness, allowing for feasible measurement in low-resource contexts. We conducted statistical validation work for measuring TL in dried blood spots (DBS) and incorporated our results into a meta-analysis evaluating minimally invasive sampling techniques to measure TL.

METHODS

We isolated DNA extracts from DBS using a modified extraction protocol and tested how they endured different shipping conditions and long-term cryostorage. We then included our in-house DBS TL validation statistics (correlation values with VWB TL and age) in a series of meta-analyses of results from 24 other studies that published similar associations for values between TL measured in DBS, saliva, and buccal cells.

RESULTS

Our modified DBS extraction technique produced DNA yields that were roughly twice as large as previously recorded. Partially extracted DBS DNA was stable for 7 days at room temperature, and still provided reliable TL measurements, as determined by external validation statistics. In our meta-analysis, DBS TL had the highest external validity, followed by saliva, and then buccal cells-possibly reflecting similarities/differences in cellular composition vs VWB.

CONCLUSIONS

DBS DNA is the best proxy for VWB from the three minimally-invasively specimen types evaluated and can be used to expand TL research to diverse settings and populations.

Loop mediated isothermal amplification (LAMP) of Toxoplasma DNA from dried blood spots

INTRODUCTION

The cosmopolitan protozoan Toxoplasma gondii is a major parasite of warm-blooded animals including man. Early and accurate diagnosis is a must for proper treatment that prevents life threatening sequels. Loop-mediated isothermal amplification (LAMP) is a novel technique that can amplify DNA with high sensitivity and specificity under isothermal conditions.

AIM OF THE STUDY

To validate a LAMP-specific protocol for detection of Toxoplasma DNA using dried blood spots (DBS) from mice experimentally infected with the cystogenic Toxoplasma ME-49 strain.

METHODS

In this study, the target DNA fragment was the Toxoplasma 529-bp repeat element that exists in 200-300 copies per T. gondii genome. The sensitivity of both LAMP and conventional PCR techniques was estimated in DBS samples from experimental mice at 1-week and 8-weeks post-infection.

RESULTS

Out of 20 blood samples gathered on Whatman filter paper from mice at 1-week post-infection, 18 and 16 were positive by LAMP and conventional PCR, respectively. Neither techniques detected parasite DNA in blood at 8th week of infection.

CONCLUSION

Dried blood spots are easy source of material for molecular studies. LAMP assay proved higher sensitivity than the conventional PCR in detecting parasitemia in early infection with the cystogenic Toxoplasma strain.

Hematocrit, blood volume, and surface area of dried blood spots - a quantitative model

The use of the dried blood spot (DBS) sampling technique has extended the scope of clinical research, particularly in children. The effects of different hematocrit levels (25-55%) and different blood volumes (7.5-30 μL) on the surface area of the blood spots were investigated using ImageJ® software. Variation in hematocrit levels between patients and inaccuracies in blood volumes applied to Guthrie cards can have a marked effect on analyte concentrations measured in DBS samples. The current study presents a validated model that links blood volume and hematocrit to the surface area of the blood spot. The final model showed that both factors affect the blood spot surface area, however, the positive effect of blood volume is higher than the negative effect of hematocrit. The measurement of surface area could be added as an additional quality control step in clinical studies that have adopted fixed volume DBS sampling for the quantification of the analytes. This approach can be used in estimating the hematocrit if this is not known for a patient or estimating the volume in spots that are visually different in size from the norm, i.e. technical error.

Mercury Speciation in Whole Blood and Dried Blood Spots from Capillary and Venous Sources

There is interest in measuring total mercury (THg) and methylmercury (MeHg) in dried blood spots (DBS) though more research is required to evaluate mercury (Hg) speciation in DBS and to validate the agreement between blood sources (venous vs capillary) and matrices (whole blood vs DBS). Therefore, the present study aimed to develop, evaluate, and validate a DBS-based method to assess MeHg and inorganic mercury (InHg) exposure in human population studies. First, we used volume-controlled (40 μL) paired DBS-whole blood samples to develop an analytical method that involved the extraction and quantification of MeHg and InHg with gas chromatography-cold vapor atomic fluorescence spectrometry (GC-CVAFS). Next, we carried out a validation study using paired DBS-whole blood samples from venous and capillary sources from 49 volunteers with Hg exposures similar to background populations (i.e., MeHg in venous whole blood ranged from 0.2 to 3 μg/L with a median value of 0.8). The limits of detection were higher for InHg (1.9 and 1.1 μg/L in DBS and whole blood, respectively) than MeHg (0.3 and 0.2 μg/L in DBS and whole blood, respectively). The MeHg concentrations among blood sources and matrices were highly correlated (r ranged from 0.85 to 0.95), with no constant bias (intercept ranged from -0.05 to 0.13 μg/L) and small proportional bias (slopes ranged from 0.92 to 1.08). Bland-Altman plots indicated little bias between MeHg measurements with 82-98% of the cases meeting the analytical acceptance criterion of 35% maximum allowed difference. Our results indicate that measures of MeHg in capillary DBS reflect concentrations in the gold standard (i.e., venous whole blood) and that DBS is a suitable tool for assessing MeHg exposure in human population studies, but that more work is required to assess InHg exposures.

Minimally-invasive methods for examining biological changes in response to chronic stress: A scoping review

BACKGROUND

Nurse researchers are increasingly interested in incorporating biological indicators related to chronic stress, or repeated or constant exposure to psychological stressors. Minimally invasive collection methods may improve access to vulnerable populations.

OBJECTIVE

To map biological indicators measured through minimally invasive methods investigating biological changes in response to chronic stress.

DESIGN, DATA SOURCES, AND METHODS

The paper seeks to answer two questions: What are the characteristics of the minimally-invasive methods used to measure the biological correlates of chronic stress? What are the limitations regarding the use of the minimally-invasive methods and/or biological indicators identified above? Authors completed a scoping review following guidelines from the Joanna Briggs Institute Manual and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for Scoping Reviews. A literature search was completed in PubMed, PsycINFO, and Scopus. 2518 articles were screened and 145 studies were included. Data were extracted using a standardized extraction tool, compiled, and coded.

RESULTS

Studies included minimally-invasive methods to measure the hypothalamic-adrenal-pituitary axis (N = 173), immune and inflammatory markers (N = 118), and adult neurogenesis (N = 6). Cortisol was most frequently measured (N = 136), usually in saliva (N = 86). Studies included a variety of limitations for the methods and indicators, including concerns about timing and accuracy of collection, frequency of sampling, and controlling for acute stressors.

CONCLUSIONS

Nurse researchers have access to many minimally-invasive methods to measure altered biological processes related to chronic stress. A gap identified by this review is the paucity of minimally-invasive methods for investigating neurogenesis; the measurement of brain derived neurotrophic factor in plasma is a distal proxy and further research is needed to test the response of peripheral levels to psychosocial stress interventions. Additionally, while this scoping review allows nurse researchers to consider possible biological indicators to include in their research, future research is still needed on some of the basic premises of stress research, including agreement on the conceptualization of chronic stress.

The potential of neurofilaments analysis using dry-blood and plasma spots

The lack of biomarkers for an early diagnosis of neurodegenerative disorders (NDs) has hampered the development of therapeutics whose effect would be enhanced by a timely intervention. Neurofilaments light chain (Nf-L), an integral part of the axonal structure, has emerged as a robust fluid biomarker for fatal neurodegenerative disorders like amyotrophic lateral sclerosis (ALS). To facilitate large-scale studies into early-stage neurodegeneration, reduce costs of samples collection/processing and cold-chain storage, we describe the measurement of Nf-L in blood fractions obtained from dry blood spots (DBS) and dry plasma spots (DPS), two filter paper-based remote blood collection tools. To test the feasibility of using this approach, Nf-L analysis in DBS/DPS is compared to that in plasma obtained from the same blood sample, looking at Nf-L discriminatory power in the clinical stratification of ALS compared to healthy controls. With the best pre-analytical treatment for total protein recovery and using highly sensitive immunoassays, we report the detection of different Nf-L levels in DBS elute compared to reference plasma and DPS from the same blood samples. However, Nf-L measurement in DBS elutes provides a very good discrimination of ALS from healthy controls which is comparable to that obtained using plasma Nf-L assays. With the available immunodetection methods, we show that Nf-L measurement based on DPS microsampling is similar to that in plasma. The filter-paper biophysical characteristics and the interference of high haemoglobin concentration released by erythrocyte lysis is likely to perturb Nf-L detection in DBS elute. Further studies into DBS-based Nf-L detection and its analytical optimization are needed to make this method suitable for routine Nf-L blood analyses in neurodegeneration.

Effects of school-based physical activity and multi-micronutrient supplementation intervention on growth, health and well-being of schoolchildren in three African countries: the KaziAfya cluster randomised controlled trial protocol with a 2 × 2 factorial design

BACKGROUND

In low- and middle-income countries, infectious diseases remain a key public health issue. Additionally, non-communicable diseases are a rapidly growing public health problem that impose a considerable burden on population health. One way to address this dual disease burden, is to incorporate (lifestyle) health promotion measures within the education sector. In the planned study, we will (i) assess and compare physical activity, physical fitness, micronutrient status, body composition, infections with soil-transmitted helminths, Schistosoma mansoni, malaria, inflammatory and cardiovascular health risk markers, cognitive function, health-related quality of life, and sleep in schoolchildren in Côte d'Ivoire, South Africa and Tanzania. We will (ii) determine the bi- and multivariate associations between these variables and (iii) examine the effects of a school-based health intervention that consists of physical activity, multi-micronutrient supplementation, or both.

METHODS

Assuming that no interaction occurs between the two interventions (physical activity and multi-micronutrient supplementation), the study is designed as a cluster-randomised, placebo-controlled trial with a 2 × 2 factorial design. Data will be obtained at three time points: at baseline and at 9 months and 21 months after the baseline assessment. In each country, 1320 primary schoolchildren from grades 1-4 will be recruited. In each school, classes will be randomly assigned to one of four interventions: (i) physical activity; (ii) multi-micronutrient supplementation; (iii) physical activity plus multi-micronutrient supplementation; and (iv) no intervention, which will serve as the control. A placebo product will be given to all children who do not receive multi-micronutrient supplementation. After obtaining written informed consent from the parents/guardians, the children will be subjected to anthropometric, clinical, parasitological and physiological assessments. Additionally, fitness tests will be performed, and children will be invited to wear an accelerometer device for 7 days to objectively assess their physical activity. Children infected with S. mansoni and soil-transmitted helminths will receive deworming drugs according to national policies. Health and nutrition education will be provided to the whole study population independently of the study arm allocation.

DISCUSSION

The study builds on the experience and lessons of a previous study conducted in South Africa. It involves three African countries with different social-ecological contexts to investigate whether results are generalisable across the continent.

TRIAL REGISTRATION

The study was registered on August 9, 2018, with ISRCTN. https://doi.org/10.1186/ISRCTN29534081.

Effects of school-based physical activity and multi-micronutrient supplementation intervention on growth, health and well-being of schoolchildren in three African countries: the KaziAfya cluster randomised controlled trial protocol with a 2 × 2 factorial design

BACKGROUND

In low- and middle-income countries, infectious diseases remain a key public health issue. Additionally, non-communicable diseases are a rapidly growing public health problem that impose a considerable burden on population health. One way to address this dual disease burden, is to incorporate (lifestyle) health promotion measures within the education sector. In the planned study, we will (i) assess and compare physical activity, physical fitness, micronutrient status, body composition, infections with soil-transmitted helminths, Schistosoma mansoni, malaria, inflammatory and cardiovascular health risk markers, cognitive function, health-related quality of life, and sleep in schoolchildren in Côte d'Ivoire, South Africa and Tanzania. We will (ii) determine the bi- and multivariate associations between these variables and (iii) examine the effects of a school-based health intervention that consists of physical activity, multi-micronutrient supplementation, or both.

METHODS

Assuming that no interaction occurs between the two interventions (physical activity and multi-micronutrient supplementation), the study is designed as a cluster-randomised, placebo-controlled trial with a 2 × 2 factorial design. Data will be obtained at three time points: at baseline and at 9 months and 21 months after the baseline assessment. In each country, 1320 primary schoolchildren from grades 1-4 will be recruited. In each school, classes will be randomly assigned to one of four interventions: (i) physical activity; (ii) multi-micronutrient supplementation; (iii) physical activity plus multi-micronutrient supplementation; and (iv) no intervention, which will serve as the control. A placebo product will be given to all children who do not receive multi-micronutrient supplementation. After obtaining written informed consent from the parents/guardians, the children will be subjected to anthropometric, clinical, parasitological and physiological assessments. Additionally, fitness tests will be performed, and children will be invited to wear an accelerometer device for 7 days to objectively assess their physical activity. Children infected with S. mansoni and soil-transmitted helminths will receive deworming drugs according to national policies. Health and nutrition education will be provided to the whole study population independently of the study arm allocation.

DISCUSSION

The study builds on the experience and lessons of a previous study conducted in South Africa. It involves three African countries with different social-ecological contexts to investigate whether results are generalisable across the continent.

TRIAL REGISTRATION

The study was registered on August 9, 2018, with ISRCTN. https://doi.org/10.1186/ISRCTN29534081.

Cohort Profile: The Precipitating Events Project (PEP Study)

The Precipitating Events Project (PEP Study) is an ongoing longitudinal study of 754 nondisabled community-living persons age 70 years or older who were members of a large health plan in greater New Haven, Connecticut, USA. The study was established to rigorously evaluate the epidemiology of disability in older persons and to elucidate the role of intervening illnesses and injuries on the disabling process. Of the eligible members, 75.2% agreed to participate and were enrolled between March 1998 and October 1999. Participants have completed comprehensive home-based assessments at 18-month intervals and have been interviewed monthly over the phone with a completion rate of 99%. Detailed participant-level data on health care utilization are obtained annually through linkages with Medicare claims. Through June 2019, 702 (93.1%) participants have died after a median of 109 months, while 43 (5.7%) have dropped out of the study after a median of 27 months. Death certificates are available for all decedents. To date, 117 original reports have been published using data from the PEP Study, including many focusing on other high priority areas such as end of life, frailty, depressive symptoms, aging stereotypes, pain, sleep, and methodologic research. The PEP Study welcomes proposals to access data for meritorious analyses from qualified investigators.

C-reactive protein from dried blood spots: Application to household air pollution field studies

Household air pollution (HAP) is estimated to be an important risk factor for cardiovascular disease, but little clinical evidence exists and collecting biomarkers of disease risk is difficult in low-resource settings. Among 54 Nicaraguan women with woodburning cookstoves, we evaluated cross-sectional associations between 48-hour measures of HAP (eg, fine particulate matter, PM_2.5 ) and C-reactive protein (CRP) via dried blood spots; secondary analyses included seven additional biomarkers of systemic injury and inflammation. We conducted sub-studies to calculate the intraclass correlation coefficient (ICC) in biomarkers collected over four consecutive days in Nicaragua and to assess the validity of measuring biomarkers in dried blood by calculating the correlation with paired venous-drawn samples in Colorado. Measures of HAP were associated with CRP (eg, a 25% increase in indoor PM_2.5 was associated with a 7.4% increase in CRP [95% confidence interval: 0.7, 14.5]). Most of the variability in CRP concentrations over the 4-day period was between-person (ICC: 0.88), and CRP concentrations were highly correlated between paired dried blood and venous-drawn serum (Spearman ρ = .96). Results for secondary biomarkers were primarily consistent with null associations, and the sub-study ICCs and correlations were lower. Assessing CRP via dried blood spots provides a feasible approach to elucidate the association between HAP and cardiovascular disease risk.

Building on the biocultural syntheses: 20 years and still expanding

Building a New Biocultural Synthesis: Political Economic Perspectives in Human Biology called for an integration of political economy with ecological and adaptability perspectives in biocultural anthropology. A major goal of this volume was to explore the utility of including political-economic and sociocultural processes in analyses of human biological variation, nutrition, and health. A second goal was to enhance collaboration among subfields and work against the "chasm" that separated complementary perspectives in cultural and biological anthropology. Twenty years hence, new ways to link social inequalities and human biology have emerged in part through contributions of developmental origins of health and disease, epigenetics, microbiomes, and other new methods for tracing pathways of embodiment. Equally important, notions of "local/situated biologies" and "reactive genomes," provide frameworks for understanding biology and health at the nexus of ecologies, societies, and histories. We review and highlight these contributions toward expanding critical approaches to human biology. Developments over the past two decades have reinforced the central role of social environments and structural inequalities in shaping human biology and health. Yet, within biocultural approaches, a significant engagement with historical, political-economic, and sociocultural conditions remains relatively rare. We review potential barriers to such analyses, focusing on theoretical and methodological challenges as well as the subfield structure of anthropology. Achieving politically and socially contextualized and relevant critical biocultural approaches remains a challenge, but there is reason for optimism amid new theoretical and methodological developments and innovations brought by new generations of scholars.

Constraint and trade-offs regulate energy expenditure during childhood

Children's metabolic energy expenditure is central to evolutionary and epidemiological frameworks for understanding variation in human phenotype and health. Nonetheless, the impact of a physically active lifestyle and heavy burden of infectious disease on child metabolism remains unclear. Using energetic, activity, and biomarker measures, we show that Shuar forager-horticulturalist children of Amazonian Ecuador are ~25% more physically active and, in association with immune activity, have ~20% greater resting energy expenditure than children from industrial populations. Despite these differences, Shuar children's total daily energy expenditure, measured using doubly labeled water, is indistinguishable from industrialized counterparts. Trade-offs in energy allocation between competing physiological tasks, within a constrained energy budget, appear to shape childhood phenotypic variation (e.g., patterns of growth). These trade-offs may contribute to the lifetime obesity and metabolic health disparities that emerge during rapid economic development.

Analysis of copper, selenium, and zinc in newborn dried bloodspots using total reflection X-ray fluorescence (TXRF) spectroscopy

Background

There exists great interest in using dried bloodspots across the clinical, public health, and nutritional sciences to characterize circulating levels of essential elements yet current methods face several challenges related to instrumentation, quality control, and matrix effects. Elemental analysis via total X-ray fluorescence (TXRF) may help overcome these challenges. The objective of this study was to develop and apply a novel TXRF-based analytical method to quantify essential elements (copper, selenium, zinc) in dried bloodspots.

Methods

Analytical methods were developed with human whole blood standard reference materials from the Institut National de Santé Publique du Québec (INSPQ). The method was developed in careful consideration of several quality control parameters (e.g., analytical accuracy, precision, linearity, and assay range) which were iteratively investigated to help refine and realize a robust method. The developed method was then applied to a quantitative descriptive survey of punches (n = 675) taken from residual dried bloodspots from a newborn screening biobank program (Michigan BioTrust for Health).

Results

The analytical method developed to quantify the three target elements in dried bloodspots fared well against a priori quality control criteria (i.e., analytical accuracy, precision, linearity and range). In applying this new method, the average (±SD) blood copper, selenium, and zinc levels in the newborn samples were 1,117.0 ± 627.1 µg/L, 193.1 ± 49.1 µg/L, and 4,485 ± 2,275 µg/L respectively. All the elements were normally distributed in the sample population, and the measured concentrations fall within an expected range.

Conclusions

This study developed and applied a novel and robust method to simultaneously quantify three essential elements. The method helps overcome challenges in the field concerning elemental analysis in dried bloodspots and the findings help increase understanding of nutritional status in newborns.

Positive mental well-being and immune transcriptional profiles in highly involved videogame players

Previous research has identified a link between experiencing life as meaningful and purposeful-what is referred to as "eudaimonia"-and reduced expression of a stress-induced gene profile known as the "conserved transcriptional response to adversity" (CTRA). In the current study, we examine whether similar links between eudaimonic well-being and CTRA reduction occur in a sample of 56 individuals with a particularly strong engagement with virtual worlds: avid online videogame players. Results consistently linked higher eudaimonic well-being, and more specifically the social well-being subdomain of eudaimonia, to lower levels of CTRA gene expression. That favorable psychobiological relationship between eudaimonia and CTRA appeared most strongly among individuals reporting high levels of positive psychosocial involvement with gaming. Findings are consistent with the hypothesis that committed social/recreational activity may help damp CTRA expression especially among persons who are already experiencing some kind of threshold of positive eudaimonic experience.

Presoaking dried blood spot with water improves efficiency for small-molecule analysis

The current method of extracting small molecules from dried blood spots (DBSs) and liquid blood is similar. However, owing to their different physical characteristics, a modification of the extraction process for DBS is required. We propose a modified method involving presoaking in water that results in better extraction efficiency for small-molecule analysis than the conventional protein precipitation method. Using blood and DBSs from eight subjects, the similarities, recovery rates and extraction efficiencies of both methods were compared. Quantitative analysis showed that seven and six out of ten conditions for the modified method group exhibited almost 100% recovery and extraction efficiency rates, respectively, compared with the conventional method group. Taken together, the results suggest that a presoaking step is needed for efficient DBS analysis.

Accurate dried blood spots collection in the community using non-medically trained personnel could support scaling up routine viral load testing in resource limited settings

Regular plasma HIV-RNA testing for persons living with HIV on antiretroviral therapy (ART) is now the global standard, but as many as 60% of persons in Africa today on ART do not have access to standard laboratory HIV-RNA assays. As a result, patients in Zambia often receive treatment without any means of determining true virologic failure, which poses a risk of premature switch of ART regimens and widespread HIV drug resistance. Dry blood spots (DBS) on the other hand require unskilled personnel and less complex storage supply chain so are ideal to capture viral-load results from HIV patients outside clinic settings. We assess collection of DBS in the community using non-medically trained personnel (NMP) and documented challenges. We trained 23 NMP to collect DBS from lost to follow-up (LTFU) patients in 4 rural and urban Zambian districts. We developed a phlebotomy box to transport DBS without contamination at ambient temperature and concomitant training and standard operating procedures. We evaluated this through field observations, bi-weekly meetings, reports, and staff meetings. The laboratory assessed DBS quality for testing validity. We attempted to collect DBS from 357 participants in the community. Though individual reasons for refusal from the remaining 37% were not collected, NMPs reported privacy concerns, awkward box-size which drew attention in the community and fears of undisclosed uses of samples related to witchcraft and circulating narratives about past research. Successful DBS collection was not associated with patient gender, age, time on ART, enrolment CD4, facility. DBS viral-load collection by NMP is feasible in Zambia. Our training approach and assessments of NMP not part of the health system can be extended to patients by giving them more responsibility to manage their own differentiated care groups. Concerted efforts that compare collection of DBS by NMP to those collected by skilled-medical personnel are needed.

Determination of Antidepressants and Antipsychotics in Dried Blood Spots (DBSs) Collected from Post-Mortem Samples and Evaluation of the Stability over a Three-Month Period

An LC-MS/MS method for the identification and quantification of antidepressants and antipsychotics was developed on dried blood spots (DBSs). Moreover, analyte stability on DBSs within a 3-month period was monitored. Aliquots of 85 µL of blood from autopsy cases were pipetted onto DBS cards, which were dried and stored at room temperature. DBSs were analyzed in triplicate immediately, within the following 3 weeks, and after 3 months. For each analysis, a whole blood stain was extracted in phosphate buffer and purified using Solid Phase Extraction (SPE) cartridges in order to avoid matrix effects and injected in the LC-MS/MS system. Thirty-nine molecules were screened. Limits of detection (LODs) ranged between 0.1 and 3.2 ng/mL (g) and 0.1 and 5.2 ng/mL (g) for antidepressants and antipsychotics, respectively. Limits of quantification (LOQs) varied from 5 to 10.0 ng/mL for both. Sixteen cases among the 60 analyzed resulted positive for 17 different analytes; for 14 of these the method was fully validated. A general good agreement between the concentrations on DBSs and those measured in conventional blood samples (collected concurrently and stored at -20 °C) was observed. The degradation/enhancement percentage for most of the substances was lower than 20% within the 3-month period. Our results, obtained from real post-mortem cases, suggest that DBSs can be used for routine sample storage.

Inflammation in multimorbidity and disability: An integrative review

OBJECTIVE

Multimorbidity is a robust predictor of disability in aging adults, but the mechanisms by which multimorbidity is disabling are not clear. Most existing research focuses on disease-specific phenomena, such as diminished lung capacity in chronic obstructive pulmonary disease, which can result in functional limitations. This review takes a different approach by highlighting the potential role of a biological process-inflammation-that is common to many chronic medical conditions and thus, from a medical perspective, relatively disease nonspecific.

METHOD

Beginning with a description of inflammation and its measurement, this paper will provide an overview of research on inflammation as a predictor of disease risk in healthy adults and of adverse outcomes (e.g., disability) in those with multimorbidity.

RESULTS

The discussion of inflammation is then situated in the context of biopsychosocial influences on health, as inflammation has been shown to be sensitive to a wide range of social and psychological processes that are thought to contribute to healthy aging, including successful adaptation to multimorbidity and reduced risk of disability.

CONCLUSIONS

Finally, implications of this broader perspective for interventions to improve outcomes in aging adults with multimorbidity are briefly considered. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Testing plausible biopsychosocial models in diverse community samples: Common pitfalls and strategies

It is imperative that research interrogating the biological pathways linking stress processes to health continue to translate the results of basic, preclinical experimental research to diverse and under-represented populations, particularly those at elevated risk for morbidity and mortality. Conducting research within these populations and in community settings involves a number of challenges that ultimately contribute to their rarity and uneven quality in the scientific literature. In this review, we summarize the experiences and insights of members of an expert panel on this topic held at the 2018 meeting of the International Society of Psychoneuroendocrinology in Newport Beach, CA. The goals of the session were to identify challenges and share strategies for testing plausible biopsychosocial models within diverse community samples in order to encourage others and improve future research. The present paper is organized into three themes: 1) Recruitment and retention, 2) Collecting biological samples outside of the laboratory, 3) Data analysis, interpretation, and dissemination. Our goal in composing this overview of the conference session was to share within the field of psychoneuroendocrinology the challenges inherent in translating basic research to community populations.

Feasibility of a mail-in, self-administered dried blood spot collection method in national, population-based alcohol surveys in the United States

BACKGROUND AND AIMS

Including a low-intensity blood collection method in population-based alcohol studies would advance our ability to study biological mechanisms related to alcohol. However, the likelihood of participation in such a blood collection method remains understudied. This study's primary aims were to (1) estimate the return rate of mail-in, self-administered dried blood spot (saDBS) samples in national surveys and (2) test correlates of returning a sample.

DESIGN

Re-contact of all eligible participants from two telephone, population-based alcohol surveys followed by χ² tests and multivariate logistic regression analysis.

SETTING

Non-institutionalized US population in all 50 states and Washington, DC.

PARTICIPANTS

Adults aged 18+ who reported drinking at least one alcoholic beverage in the past 12 months (assessed 2017-18). Contact was made with 680 eligible participants, and 257 consented.

MEASUREMENTS

The return rate of saDBS samples was defined as the proportion of returned samples among those who were eligible and contacted. Key correlates examined were gender, age, race/ethnicity and education.

FINDINGS

Among the 680 eligible people contacted, 179 (26.3%) returned a saDBS sample. Blacks [odds ratio (OR) = 0.58, 95% confidence interval (CI) = 0.35-0.95], Latinos (OR = 0.40, 95% CI = 0.23-0.69) and those with a high school education or less (OR = 0.50, 95% CI = 0.31-0.81).

CONCLUSIONS

The likelihood of participating in mail-in, self-administered dried blood spot (saDBS) sampling among drinkers in the US general population appears low, and blacks, Latinos and people with lower levels of education appear less likely to provide a saDBS sample compared with whites and people with higher levels of education.

Dried blood spot N-glycome analysis by MALDI mass spectrometry

Body fluid N-glycome analysis as well as glyco-proteoform profiling of existing protein biomarkers potentially provides a stratification layer additional to quantitative, diagnostic protein levels. For clinical omics applications, the collection of a dried blood spot (DBS) is increasingly pursued as an alternative to sampling milliliters of peripheral blood. Here we evaluate DBS cards as a blood collection strategy for protein N-glycosylation analysis aiming for high-throughput clinical applications. A protocol for facile N-glycosylation profiling from DBS is developed that includes sialic acid linkage differentiation. This protocol is based on a previously established total plasma N-glycome mass spectrometry (MS) method, with adjustments for the analysis of DBS specimens. After DBS-punching and protein solubilization N-glycans are released, followed by chemical derivatization of sialic acids and MS-measurement of N-glycan profiles. With this method, more than 80 different glycan structures are identified from a DBS, with RSDs below 10% for the ten most abundant glycans. N-glycan profiles of finger-tip blood and venous blood are compared and short-term stability of DBS is demonstrated. This method for fast N-glycosylation profiling of DBS provides a minimally invasive alternative to conventional serum and plasma protein N-glycosylation workflows. With simplified blood sampling this DBS approach has vast potential for clinical glycomics applications.

Profiles of gene expression in maternal blood predict offspring birth weight in normal pregnancy

The association between lower birth weight and increased disease risk in adulthood has drawn attention to the physiological processes that shape the gestational environment. We implement genome-wide transcriptional profiling of maternal blood samples to identify subsets of genes and associated transcription control pathways that predict offspring birth weight. Female participants (N = 178, mean = 27.0 years) in a prospective observational birth cohort study were contacted between 2009 and 2014 to identify new pregnancies. An in-home interview was scheduled for early in the third trimester (mean = 30.3 weeks) to collect pregnancy-related information and a blood sample, and birth weight was measured shortly after delivery. Transcriptional activity in white blood cells was determined with a whole-genome gene expression direct hybridization assay. Fifty transcripts were differentially expressed in association with offspring birth weight, with 18 up-regulated in relation to lower birth weight, and 32 down-regulated. Examination of transcription control pathways identified increased activity of NF-κB, AP-1, EGR1, EGR4, and Gfi families, and reduced the activity of CEBP, in association with lower birth weight. Transcript origin analyses identified non-classical CD16+ monocytes, CD1c+ myeloid dendritic cells, and neutrophils as the primary cellular mediators of differential gene expression. These results point toward a systematic regulatory shift in maternal white blood cell activity in association with lower offspring birth weight, and they suggest that analyses of gene expression during gestation may provide insight into regulatory and cellular mechanisms that influence birth outcomes.

Validation of Dried Blood Spots for Maternal Biomonitoring of Nonessential Elements in an Artisanal and Small-Scale Gold Mining Area of Tanzania

Biomonitoring studies of vulnerable populations in low- and middle-income countries are limited because traditional sampling methods are challenging to implement in low-resource settings. The present study examined the feasibility, precision, and accuracy of dried blood spots (DBS) for human biomonitoring of nonessential elements (cadmium [Cd], mercury [Hg], and lead [Pb]) in an area of northern Tanzania with artisanal and small-scale gold mining activities. Pregnant women (n = 44) were recruited in Geita during antenatal clinic visits, and DBS from capillary blood were collected on filter paper. As a gold-standard comparison, venous blood was sampled from the same participants and compared with the DBS. Venous blood, DBS, and quality control samples were analyzed for chemical elements by inductively coupled plasma mass spectrometry. Field blanks were very clean for most elements, generally only twice as high as corresponding laboratory filter blanks. No significant differences were found between duplicate DBS samples taken from the same participants, with near perfect intraclass correlation coefficients (0.99) for Cd, Hg, and Pb, indicating excellent reliability. Moreover, correlation was strong (r² > 0.9) and significant (p < 0.0001) between DBS and the quantitative venous blood, with regression line slopes close to 1.0 (0.847, 0.976, and 0.969 for Cd, Hg, and Pb, respectively), indicating high accuracy of the DBS method compared with the gold-standard approach. The DBS method is minimally invasive and was a feasible, precise, and accurate means of measuring exposure to Cd, Hg, and Pb in pregnant women in a low-resource setting. Environ Toxicol Chem 2019;38:1285-1293. © 2019 SETAC.

The Consequences of Foster Care Versus Institutional Care in Early Childhood on Adolescent Cardiometabolic and Immune Markers: Results From a Randomized Controlled Trial

OBJECTIVE

Children exposed to institutional rearing often exhibit problems across a broad array of developmental domains. We compared the consequences of long-term, high-quality foster care versus standard institution-based care, which began in early childhood on cardiometabolic and immune markers assessed at the time of adolescence.

METHODS

The Bucharest Early Intervention Project is a longitudinal investigation of children institutionalized during early childhood (ages 6 to 30 months at baseline) who were subsequently randomized to either high-quality foster care or continued institutional care. At the age of 16 years, 127 respondents participated in a biomarker collection protocol, including 44 institutionalized children randomly assigned to receive care as usual, 41 institutionalized children randomized to be removed from institutional care and placed in high-quality foster care in infancy, and a control group of 42 demographically matched children raised in biological families. Outcomes included body mass index (BMI), systolic and diastolic blood pressure, C-reactive protein, interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor α, glycosylated hemoglobin A1c, and Epstein-Barr virus antibody titers.

RESULTS

Early institutional rearing was not associated with differences in cardiometabolic or immune markers. Randomization to foster care and age of placement into foster care were also unrelated to these markers, with the exception of BMI z-score, where children assigned to care as usual had lower BMI z-scores relative to children assigned to foster care (-0.23 versus 0.08, p = .06), and older age at placement was associated with lower BMI (β = -0.07, p = .03).

CONCLUSIONS

The impact of institutional rearing on measures of cardiometabolic health and immune system functioning is either absent or not evident until later in development. These findings provide new insights into the biological embedding of adversity and how it varies developmentally and across regulatory systems and adversity type.

CLINICAL TRIAL REGISTRATION

NCT00747396.

Regulation of inflammation during gestation and birth outcomes: Inflammatory cytokine balance predicts birth weight and length

OBJECTIVES

The maternal environment during gestation influences offspring health at birth and throughout the life course. Recent research has demonstrated that endogenous immune processes such as dysregulated inflammation adversely impact birth outcomes, increasing the risk for preterm birth and restricted fetal growth. Prior analyses examining this association suggest a relationship between maternal C-reactive protein (CRP), a summary measure of inflammation, and offspring anthropometric outcomes. This study investigates pro- and anti-inflammatory cytokines, and their ratio, to gain deeper insight into the regulation of inflammation during pregnancy.

METHODS

IL6, IL10, TNFɑ, and CRP were quantified in dried blood spots collected in the early third trimester (mean = 29.9 weeks) of 407 pregnancies in Metropolitan Cebu, Philippines. Relationships between these immune markers and offspring anthropometrics (birth weight, length, head circumference, and sum of skinfold thicknesses) were evaluated using multivariate regression analyses. Ratios of pro- to anti-inflammatory cytokines were generated.

RESULTS

Higher maternal IL6 relative to IL10 was associated with reduced offspring weight and length at birth. Individual cytokines did not predict birth outcomes.

CONCLUSIONS

Consistent with the idea that the relative balance of cytokines with pro- and anti-inflammatory effects is a key regulator of inflammation in pregnancy, the IL6:IL10 ratio, but neither cytokine on its own, predicted offspring birth outcomes. Our findings suggest that prior reports of association between CRP and fetal growth may reflect, in part, the balance between pro- and anti-inflammatory cytokines, and that the gestational environment is significantly shaped by cytokine imbalance.

Ankle brachial index (ABI) in a cohort of older women in the Philippines: Prevalence of peripheral artery disease and predictors of ABI

OBJECTIVE

Cardiovascular disease (CVD) is rising in low and middle-income countries, but studies of CVD epidemiology in such settings often focus on risk factors rather than measures of disease progression. Here we use the ankle brachial index (ABI) to assess the prevalence of peripheral artery disease (PAD) among older women living in Metropolitan Cebu, Philippines, and relationships between ABI and CVD risk factors and body composition.

METHODS

ABI was measured using the Doppler technique in 538 female participants in the 2015 Cebu Longitudinal Health and Nutrition Survey (mean age 58 years, range 47-78 years). ABI was related to a panel of CVD risk factors measured in 2005 and 2012, and to 2012 body composition measures.

RESULTS

The prevalence of PAD (1.8%) was among the lowest reported in any comparably-aged sample, and only 9.9% of participants had an ABI indicating borderline PAD risk. Smoking (P < 0.011) and use of CVD medications (P < 0.0001) predicted lower ABI (indicating higher PAD risk), which was also lower in relation to 2012 systolic blood pressure (P < 0.054). ABI was unrelated to other CVD risk factors. An apparent protective relationship between body mass index (BMI) and ABI, noted in previous studies, was found to be confounded by protective relationships between ABI and fat free mass, height, and grip strength (all P < 0.05).

CONCLUSIONS

The prevalence of PAD is low in Cebu Longitudinal Health and Nutrition Survey participants, and ABI was related to few CVD risk factors. Past reports of lower PAD risk in relation to BMI may reflect confounding by lean mass, which has protective relationships with ABI.

Dried blood spot compared to plasma measurements of blood-based biomarkers of brain injury in neonatal encephalopathy

BACKGROUND

Data correlating dried blood spots (DBS) and plasma concentrations for neonatal biomarkers of brain injury are lacking. We hypothesized that candidate biomarker levels determined from DBS can serve as a reliable surrogate for plasma levels.

METHODS

In the context of a phase II multi-center trial evaluating erythropoietin for neuroprotection in neonatal encephalopathy (NE), DBS were collected at enrollment ( < 24 h), day 2, 4, and 5. Plasma was collected with the first and last DBS. The relationship between paired DBS-plasma determinations of brain-specific proteins and cytokines was assessed by correlation and Bland-Altman analyses. For analytes with consistent DBS-plasma associations, DBS-derived biomarker levels were related to brain injury by MRI and 1-year outcomes.

RESULTS

We enrolled 50 newborns with NE. While S100B protein, tumor necrosis factor α, interleukin (IL)1 β, IL-6, IL-8 demonstrated significant DBS-plasma correlations, Bland-Altman plots demonstrated that the methods are not interchangeable, with a 2 to 4-fold error between measurements. No significant relationships were found between DBS levels of TNFα, IL-6, and IL-8 and outcomes.

CONCLUSION

Further work is needed to optimize elution and assay methods before using DBS specimens as a reliable surrogate for plasma levels of candidate brain injury biomarkers in NE.

Stability of glyoxal- and methylglyoxal-modified hemoglobin on dried blood spot cards as analyzed by nanoflow liquid chromatography tandem mass spectrometry

Blood sampling by the dried blood spot (DBS) technique has become commonly applied in newborn screening. It is often used for analysis of small molecules, such as metabolites. Recently, DBS sampling has been applied for quantification of post-translational protein modifications. Glyoxal and methylglyoxal are two simple oxoaldehydes released from glycated proteins in the Maillard reaction. They are widely distributed in the environment (e.g. cigarette smoke) and found in foods and beverages. Glyoxal and methylglyoxal are shown to react with biomolecules including DNA and proteins. In this laboratory, we previously identified the sites of modification by these two oxoaldehydes in human hemoglobin and found that the extents of modification at certain sites of lysine and arginine residues are significantly higher in type 2 diabetes mellitus patients than in nondiabetic individuals. In this study, we examine the stability of these modifications of hemoglobin stored on DBS cards at room temperature or 4 °C in the ambient air. After hemoglobin was extracted from the DBS cards, it was digested by trypsin and analyzed by nanoflow liquid chromatography coupled with nanospray ionization tandem mass spectrometry. The results show that the extents of all these PTMs are stable within 14 and 21 days when stored on DBS at room temperature and at 4 °C, respectively. Extraction of globin from DBS cards is mostly advantageous for hemolytic blood samples. This assay is sensitive as only a quarter of a DBS card containing ca. 12 μL of blood is required. Thus, it is practically useful to measure the extents of glyoxal- and methylglyoxal-induced hemoglobin modifications from DBS cards.

Psychobiological Factors of Sexual Functioning in Aging Women - Findings From the Women 40+ Healthy Aging Study

Background: A variety of biological and psychosocial factors are associated with women’s sexual health in midlife and older age. Evidence suggests a decline in sexual functioning in the context of aging and the menopausal transition, including changes in sexual desire, arousal, lubrication, orgasm, pain, and/or contentment. However, not all women in midlife and older age experience such a decline, and it remains unclear how the endocrine environment and psychosocial aspects contribute to the maintenance of healthy sexual functioning. Therefore, the aim of this study was to examine psychobiological predictors of sexual functioning in healthy middle-aged and elderly females.

Methods: A total of 93 healthy, sexually active women aged 40–73 years completed a battery of validated psychosocial questionnaires, including measures of sexual functioning (Female Sexual Function Index) and of protective psychological traits and interpersonal variables. The steroid hormones estrogen, testosterone, progesterone and dehydroepiandrosterone sulfate were determined in saliva samples, while follicle-stimulating hormone, luteinizing hormone and sex hormone-binding globulin were determined in dried blood spots. The findings were statistically adjusted for multiple testing.

Results: Age and postmenopausal status were negatively associated with overall sexual functioning, arousal, and lubrication. Regression analyses revealed that relationship satisfaction, emotional support, self-esteem, optimism, and life satisfaction each significantly predicted overall sexual functioning or specific aspects of sexual functioning, including arousal, contentment, orgasm, and pain (all p < 0.029). For desire and lubrication, no associations were found with the tested psychosocial factors. In terms of steroid hormones, testosterone was positively linked to orgasm (p = 0.012). In this sample, 79.6% reported to have healthy sexual functioning according to the questionnaires’ cutoff. Younger age (OR = 0.911, 95% CI 0.854–0.970, p = 0.004) and a higher level of emotional support (OR = 1.376, 95% CI 1.033–1.833, p = 0.029) were associated with the presence of healthy sexual functioning.

Discussion: Although aging and menopause negatively affected aspects of sexual functioning, the accompanying endocrine correlates were not predictive for sexual functioning in this healthy sample of middle-aged and older females. Instead, our findings suggest that sexual functioning is highly dependent on psychosocial aspects related to well-being. Accordingly, personality traits such as optimism, and interpersonal aspects such as emotional support and relationship satisfaction were identified as important predictors of sexual functioning.

Galectin-9 and CXCL10 as Biomarkers for Disease Activity in Juvenile Dermatomyositis: A Longitudinal Cohort Study and Multicohort Validation

Objective

Objective evaluation of disease activity is challenging in patients with juvenile dermatomyositis (DM) due to a lack of reliable biomarkers, but it is crucial to avoid both under‐ and overtreatment of patients. Recently, we identified 2 proteins, galectin‐9 and CXCL10, whose levels are highly correlated with the extent of juvenile DM disease activity. This study was undertaken to validate galectin‐9 and CXCL10 as biomarkers for disease activity in juvenile DM, and to assess their disease specificity and potency in predicting the occurrence of flares.

Methods

Levels of galectin‐9 and CXCL10 were measured by multiplex immunoassay in serum samples from 125 unique patients with juvenile DM in 3 international cross‐sectional cohorts and a local longitudinal cohort. The disease specificity of both proteins was examined in 50 adult patients with DM or nonspecific myositis (NSM) and 61 patients with other systemic autoimmune diseases.

Results

Both cross‐sectionally and longitudinally, galectin‐9 and CXCL10 outperformed the currently used laboratory marker, creatine kinase (CK), in distinguishing between juvenile DM patients with active disease and those in remission (area under the receiver operating characteristic curve [AUC] 0.86–0.90 for galectin‐9 and CXCL10; AUC 0.66–0.68 for CK). The sensitivity and specificity for active disease in juvenile DM was 0.84 and 0.92, respectively, for galectin‐9 and 0.87 and 1.00, respectively, for CXCL10. In 10 patients with juvenile DM who experienced a flare and were prospectively followed up, continuously elevated or rising biomarker levels suggested an imminent flare up to several months before the onset of symptoms, even in the absence of elevated CK levels. Galectin‐9 and CXCL10 distinguished between active disease and remission in adult patients with DM or NSM (P = 0.0126 for galectin‐9 and P < 0.0001 for CXCL10) and were suited for measurement in minimally invasive dried blood spots (healthy controls versus juvenile DM, P = 0.0040 for galectin‐9 and P < 0.0001 for CXCL10).

Conclusion

In this study, galectin‐9 and CXCL10 were validated as sensitive and reliable biomarkers for disease activity in juvenile DM. Implementation of these biomarkers into clinical practice as tools to monitor disease activity and guide treatment might facilitate personalized treatment strategies.

Puberty and the Evolution of Developmental Science

In recent decades, theoretical and methodological advances have operated synergistically to advance understanding of puberty and prompt increasingly comprehensive models that engage with the temporal, psychosocial, and biological dimensions of this maturational milepost. This integrative overview discusses these theoretical and methodological advances and their implications for research and intervention to promote human development in the context of changing maturational schedules and massive ongoing social transformations.

Pathways linking caesarean delivery to early health in a dual burden context: Immune development and the gut microbiome in infants and children from Galápagos, Ecuador

OBJECTIVES

Global increases in caesarean deliveries are exposing more infants to perinatal environments that are evolutionarily novel and potentially increasing their risks for inflammatory conditions. Yet, the pathways linking caesareans to later health outcomes are not well understood, particularly in dual burden contexts. We test two of the hypothesized pathways, altered immune function and gut microbiota, which may link delivery mode to later health outcomes and test whether these associations persist when controlling for postnatal nutritional and pathogenic exposures.

METHODS

Data come from infants, aged 0 to 2 (n = 41), and young children, aged 2 to 11 (n = 135), from the Galápagos, Ecuador. Differences in morbidity, C-reactive protein (CRP), and gut microbiota by delivery type were tested using linear and logistic regression models adjusted for nutritional and pathogenic exposures and infant age.

RESULTS

Over half of infants and over 40% of children were delivered by caesarean. Morbidity and CRP did not differ between infants or children born by caesarean or vaginally. Microbial taxa abundance differed by delivery mode. Infants born by caesarean had a higher abundance of Firmicutes and a lower relative abundance of Bacteroidales. Children born by caesarean had a higher abundance of Proteobacteria and Enterobacteriales. These differences remained after adjustment for environmental exposure.

CONCLUSIONS

Caesarean delivery is associated with differences in gut microbiota across childhood even in this dual burden context. Our results highlight the importance of examining caesarean delivery across diverse contexts to better understand the impact of perinatal interventions on short- and longer-term health outcomes.

Social Integration and Quality of Social Relationships as Protective Factors for Inflammation in a Nationally Representative Sample of Black Women

Social integration and supportive relationships protect against cardiovascular disease (CVD). However, prior studies have examined heterogeneous samples which may obscure unique relationships within groups. We investigate the association between social relationships and inflammation-a known CVD risk factor-in Black women, a population with higher rates of CVD and CVD mortality. Secondary data from wave 4 of the National Longitudinal Study of Adolescent to Adult Health (Add Health) were analyzed. The sample was comprised of 1829 Black women aged 24-34 years. Social integration was a z-score standardized measure of four items (marital/cohabitation status, church attendance, volunteerism, close friendships). Data on the quality of three relationship types was available: perceived happiness with a romantic relationship and perceived closeness to mother and father figure. Inflammation was measured via high-sensitivity C-reactive protein (hs-CRP) in which levels were categorized based on clinical cut-points for risk of CVD (< 1 mg/L = low risk-reference, 1-3 mg/L = moderate risk, > 3-10 mg/L = high risk, > 10 mg/L = very high risk). Multivariable logistic regression was conducted accounting for the complex survey design and wave 4 control measures (e.g., body mass index, smoking, medications, acute illness, overall health, sociodemographic factors). No significant associations were found between level of social integration and hs-CRP levels. With respect to relationship quality, women who reported they were very happy with their romantic relationship were less likely than those who were only fairly happy or unhappy to have hs-CRP levels in the moderate- (AOR = 0.36, 95% CI = 0.17, 0.75), high (AOR = 0.20, 95% CI = 0.08, 0.49), or very high CVD-risk category (AOR = 0.36, 95% CI = 0.16, 0.80). Women who reported they were somewhat/quite/very close to their mother figure (AOR = 0.48, 95% CI = 0.25, 0.92) and those who reported having no mother figure (AOR = 0.25, 95% CI = 0.08, 0.77) were less likely than women reporting being not very close/not close at all with their mother figure to have hs-CRP levels in the moderate- vs. low-risk category. No statistically significant associations were found between father-figure relationship and hs-CRP CVD risk category. In summary, social integration and the quality of specific social relationships were significantly associated with inflammation in young adult Black women. Thus, interventions designed to enhance social connectedness and positive social relationships among Black women may have the potential to be protective for CVD risk. Further researches with the longitudinal social relationship and inflammatory measures are needed to better understand how changes in social relationships may influence CVD risk over the life course.

In-Transit Electroextraction of Small-Molecule Pharmaceuticals from Blood

An electrokinetic platform was developed for extracting small-molecule pharmaceuticals from a dried blood spot. Through the exclusion of liquid reagents and use of low field strength (6 V cm^-1 ), the electroextraction of a drug from a dried blood spot, deposited on a polymer inclusion membrane (PIM), could be realised while in transit in the mail. In transit sample preparation provides a potential solution to in situ sample degradation and may accelerate the workflow upon arrival of a patient sample at the analytical facility. The electroextraction method was enabled through our discovery of the use of 15-20 μm thin PIMs as electrophoretic separation medium in absence of liquid reagents. Here, a PIM consisting of cellulose triacetate as polymer base, 2-nitrophenyl octyl ether as plasticizer and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide as carrier was used. The PIM, was packaged with two 12 V batteries to supply the separation voltage. A blood spot containing berberine chloride was deposited and dried before the applying the separation potential, allowing for the electroextraction while the packaged device was shipped in internal mail. Upon arrival in the analytical laboratory, the PIM was analysed using a fluorescence microscope with photon multiplier tube, quantifying the berberine extracted away from the sample matrix. This platform represents a new opportunity for processing clinical samples during transport to the laboratory, saving time and manual handling to accelerate the time to result.

Protein measurements in venous plasma, earlobe capillary plasma and in plasma stored on filter paper

In this study, levels of inflammatory protein biomarkers in venous plasma, plasma derived from capillary blood from the earlobe, and capillary plasma stored as dried plasma spots (DPS) were compared. Samples from 12 male individuals were assessed with a panel of 92 inflammation-related proteins using multiplex proximity extension assay. Correlations between sample types varied greatly between analytes. A high correlation of ρ > 0.8 was observed between capillary plasma and DPS for 32 analytes. At this level of correlation, 13 analytes correlated between venous and capillary plasma and 5 analytes in the comparison of venous blood with DPS.

Change in Cardiometabolic Risk Among Blacks, Whites, and Hispanics: Findings From the Health and Retirement Study

Background

Blacks experience greater multisystem physiological dysregulation, or cumulative biological risk, which is associated with poor cardiometabolic health and mortality. In this study, we assess race differences in change in risk over 4 years among older whites, blacks, and Hispanics.

Method

We examined race differences in 4-year change in individual biomarkers and a cumulative measure of risk-cardiometabolic risk (CMR)-using data for each respondent from two waves of the Health and Retirement Study's biomarker assessment (n = 5,512). CMR is a count of high-risk cardiovascular and metabolic biomarkers. We estimated mean CMR at baseline and follow-up by race/ethnicity, and used logistic regression to determine whether race differences exist in 4-year transitions between high- and low-risk states for individual biomarkers.

Results

Blacks had higher baseline CMR than whites and Hispanics and experienced an increase in risk over 4 years; conversely, CMR decreased among whites and Hispanics. Blacks were more likely to develop high-risk pulse pressure and high-risk hemoglobin A1c, which contributed to increases in CMR. Whites and Hispanics were more likely to become low-risk on C-reactive protein and high-density lipoprotein cholesterol which contributed to declines in CMR. Race differences in transitions between risk states remained after controlling for social, behavioral, and health care-related factors. However, the racial patterning of these differences was influenced by disease diagnosis and medication use.

Conclusions

We show that the cardiometabolic health of older blacks worsens as they age both absolutely and relative to that of whites and Hispanics because of poor blood pressure control and diabetes prevention.

Metabolic Signature of Dietary Iron Overload in a Mouse Model

Iron is an essential co-factor for several metabolic processes, including the Krebs cycle and mitochondrial oxidative phosphorylation. Therefore, maintaining an appropriate iron balance is essential to ensure sufficient energy production and to avoid excessive reactive oxygen species formation. Iron overload impairs mitochondrial fitness; however, little is known about the associated metabolic changes. Here we aimed to characterize the metabolic signature triggered by dietary iron overload over time in a mouse model, where mice received either a standard or a high-iron diet. Metabolic profiling was assessed in blood, plasma and liver tissue. Peripheral blood was collected by means of volumetric absorptive microsampling (VAMS). Extracted blood and tissue metabolites were analyzed by liquid chromatography combined to high resolution mass spectrometry. Upon dietary iron loading we found increased glucose, aspartic acid and 2-/3-hydroxybutyric acid levels but low lactate and malate levels in peripheral blood and plasma, pointing to a re-programming of glucose homeostasis and the Krebs cycle. Further, iron loading resulted in the stimulation of the urea cycle in the liver. In addition, oxidative stress was enhanced in circulation and coincided with increased liver glutathione and systemic cysteine synthesis. Overall, iron supplementation affected several central metabolic circuits over time. Hence, in vivo investigation of metabolic signatures represents a novel and useful tool for getting deeper insights into iron-dependent regulatory circuits and for monitoring of patients with primary and secondary iron overload, and those ones receiving iron supplementation therapy.

Detection of anti-hepatitis C virus and hepatitis C virus RNA in dried blood spot specimens using Whatman No. 1 filter paper

Purpose

Dried blood spot (DBS) specimen simplifies blood collection, processing, storage and shipment and may reduce the cost of testing for hepatitis C virus (HCV) infection. We wanted to see if DBS using a cheap filter paper is reliable alternative to serum for detection of anti-HCV and HCV RNA.

Materials and Methods

At a tertiary care hospital in Northeast India, we collected 91 paired DBS and serum specimens from patients at risk of HCV infection from July 2014 to June 2015. DBS was collected on Whatman No. 1 filter paper. After processing, the specimens were subjected to anti-HCV detection by a third-generation Enzyme-Linked Immunosorbent Assay (ELISA). The reactive DBS and serum specimens were further subjected to HCV RNA detection by polymerase chain reaction. The results were analysed in paired screen-positive study design.

Results

Anti-HCV was detected in 9 (9.9%) DBS specimens and 10 (10.9%) serum specimens. There was statistically significant (P < 0.0001) correlation between the optical density values of DBS and serum specimens (Pearson r = 0.9181, 95% confidence interval: 0.8781-0.9453). HCV RNA was detected in 5/9 (55.6%) reactive DBS and 9/10 (90.0%) reactive serum specimens. There was no correlation between HCV RNA levels in the DBS and the serum specimens. The relative sensitivity rate and the relative false-positive rate of DBS anti-HCV ELISA were 0.89 and 1.00, respectively.

Conclusions

DBS using Whatman No. 1 filter paper is quite reliable as serum for detection of anti-HCV. It can be useful in effective surveillance. However, it is not suitable for confirmation of chronic HCV infection.

Reinventing (Bio)chemical Analysis with Paper

This paper focuses on one of the most commonly encountered materials in our society, namely paper. Paper is an inherently complex material, yet its use provides for chemical analysis approaches that are elegant in their simplicity of execution. In the first half of the previous century, paper in scientific research was used mainly for filtration and chromatographic separation. While its use decreased with the rise of modern elution chromatography, paper remains a versatile substrate for low-cost analytical tests. Recently, we have seen renewed interest to work with paper in (bio)analytical science, a result of the growing demand for inexpensive, portable analysis. Dried blood spotting, paper microfluidics, and paper spray ionization are areas in which paper is (re)establishing itself as an important material. These research areas all exploit several properties of paper, including stable sample storage, passive fluid movement and manipulation, chromatographic separation/extraction, modifiable surface and/or volume, easily altered shape, easy transport, and low cost. We propose that the real, and to date underexploited, potential of paper lies in utilizing its combined characteristics to add new dimensions to paper-based (bio)chemical analysis, expanding its applicability. This article provides the reader with a short historical perspective on the scientific use of paper and the developments that led to the establishment of the aforementioned research areas. We review important characteristics of paper and place them in a scientific context in this descriptive, yet critical, assessment of the achieved and the achievable in paper-based analysis. The ultimate goal is the exploration of integrative approaches at the interface between the different fields in which paper is or can be used.

Web-Delivered Multimedia Training Materials for the Self-Collection of Dried Blood Spots: A Formative Project

Background

The use of dried blood spots (DBS) in biomedical research has been increasing as an objective measure for variables that are typically plagued by self-report, such as smoking status and medication adherence. The development of training materials for the self-collection of DBS that can be delivered through the Web would allow for broader use of this methodology.

Objective

The objective of this study was to evaluate the acceptability and feasibility of the self-collection of DBS using newly developed multimedia training materials that were delivered through the Web. We also aimed to assess the usability of the collected DBS samples.

Methods

We recruited participants through Facebook advertising for two distinct studies. The first study evaluated the acceptability of our newly developed DBS training materials, while the second assessed the implementation of this protocol into a larger Web-based study.

Results

In the first study, participants (N=115) were aged, on average, 26.1 (SD 6.4) years. Training materials were acceptable (113/115, 98.2%, of participants were willing to collect DBS again) and produced usable samples (110/115, 95.7%, collected DBS were usable). In the second study, response rate was 25.0% (41/164), with responders being significantly younger than nonresponders (20.3 [SD 0.2] vs 22.0 [SD 0.4]; P<.001), and 92% (31/41) of collected DBS samples were usable by the laboratory.

Conclusions

Overall, while the protocol is acceptable, feasible, and produced usable samples, additional work is needed to improve response rates.

Quantification of HIV-1 RNA Among Men Who Have Sex With Men Using an At-Home Self-Collected Dried Blood Spot Specimen: Feasibility Study

BACKGROUND

Suboptimal antiretroviral therapy (ART) adherence and disengagement in care present significant public health challenges because of the increased probability of HIV transmission. In the United States, men who have sex with men (MSM) continue to be disproportionately affected by HIV, highlighting a critical need to engage high-risk MSM living with HIV who are not engaged or retained in care.

OBJECTIVE

The aim of the study was to assess the feasibility of at-home blood self-collection and laboratory quantification of HIV-1 RNA viral load (VL) to report laboratory-based VL outcomes and compare self-reported and laboratory-reported VL.

METHODS

Between 2016 and 2017, 766 US HIV-positive MSM enrolled in a Web-based behavioral intervention were invited to participate in an at-home dried blood spot (DBS) collection study using HemaSpot-HF kits (Spot On Sciences, Inc, Austin, TX) for laboratory-quantified VL.

RESULTS

Of those invited to participate, 72.3% (554/766) enrolled in the DBS study. Most (79.2%, 439/554) men enrolled reported attempting to collect their blood, 75.5% (418/554) of participants mailed a DBS specimen to the research laboratory, and 60.8% (337/554) had an adequate blood sample for VL testing. Of the 337 specimens tested for VL by the laboratory, 52.5% (177/337) had detectable VL (median: 3508 copies/mL; range: 851-1,202,265 copies/mL). Most men (83.9%, 135/161) who returned a DBS specimen with laboratory-quantified detectable VL self-reported an undetectable VL during their last clinical visit.

CONCLUSIONS

Home collection of DBS samples from HIV-positive MSM is feasible and has the potential to support clinical VL monitoring. Discrepant laboratory HIV-1 RNA values and self-reported VL indicate a need to address perceived VL status, especially in the era of treatment as prevention. Most participants were willing to use an at-home DBS kit in the future, signaling an opportunity to engage high-risk MSM in long-term HIV care activities.

Optimization of kidney dysfunction prediction in diabetic kidney disease using targeted metabolomics

AIMS

Metabolomics have been used to evaluate the role of small molecules in human disease. However, the cost and complexity of the methodology and interpretation of findings have limited the transference of knowledge to clinical practice. Here, we apply a targeted metabolomics approach using samples blotted in filter paper to develop clinical-metabolomics models to detect kidney dysfunction in diabetic kidney disease (DKD).

METHODS

We included healthy controls and subjects with type 2 diabetes (T2D) with and without DKD and investigated the association between metabolite concentrations in blood and urine with eGFR and albuminuria. We also evaluated performance of clinical, biochemical and metabolomic models to improve kidney dysfunction prediction in DKD.

RESULTS

Using clinical-metabolomics models, we identified associations of decreased eGFR with body mass index (BMI), uric acid and C10:2 levels; albuminuria was associated to years of T2D duration, A1C, uric acid, creatinine, protein intake and serum C0, C10:2 and urinary C12:1 levels. DKD was associated with age, A1C, uric acid, BMI, serum C0, C10:2, C8:1 and urinary C12:1. Inclusion of metabolomics increased the predictive and informative capacity of models composed of clinical variables by decreasing Akaike's information criterion, and was replicated both in training and validation datasets.

CONCLUSIONS

Targeted metabolomics using blotted samples in filter paper is a simple, low-cost approach to identify outcomes associated with DKD; the inclusion of metabolomics improves predictive capacity of clinical models to identify kidney dysfunction and DKD-related outcomes.