Sample Collection Procedures Research Articles

Cutaneous Bacteria in the Gut Microbiome as Biomarkers of Systemic Malodor and People Are Allergic to Me (PATM) Conditions: Insights From a Virtually Conducted Clinical Trial

Background The skin is a dynamic ecosystem of microbes and the source of many chemical compounds that affect human health. Skin-microbiome interactions can cause persistent, psychosocially devastating body smell despite good hygiene. Since odor production is often transient, malodors may not be perceptible during medical examinations. Therefore, having odor complaints can be diagnosed as body dysmorphic disorder and referred for psychological evaluations. Development of simple at-home tests and virtual care programs could improve the diagnosis and management of socially debilitating malodor conditions. Objective The aim of this study was to assess potential effectiveness of at-home gut microbiome testing in the diagnosis and management of idiopathic body and breath odor and in people are allergic to me (PATM) syndrome. Methods We contacted participants of prior metabolic body odor (MEBO) and PATM studies and online support groups by email or social media. Individuals who consented to participate were mailed test kits for at-home collection of gut microbiome samples. Participants completed an online survey (specially developed for this study) addressing their symptoms and other quality-of-life indicators at baseline and after sampling. Participants collected stool samples after flare-ups or symptom improvements and mailed them to the laboratory to be processed and analyzed. We evaluated between-group differences in symptom severity, as well as symptom improvement observations for the same individuals. For differential abundance testing of microbial taxa, we performed nonparametric statistical analyses using Mann-Whitney U tests for unpaired samples and Wilcoxon signed rank test for paired samples. Results A total of 112 individuals from 21 countries consented to participate. About half the participants had been tested for the metabolic disorder trimethylaminuria, and about half of those tested were diagnosed with the disorder. The levels of bacteria previously associated with cutaneous body odor were significantly elevated in gut samples. For the combination of species from Anaerococcus, Corynebacterium, Campylobacter, and Propionibacterium genera, the differences were P=.002 for active (73 participants, 182 samples) versus regression or remission groups (30 participants, 51 samples); P=.01 for those experiencing symptoms most or all of the time (46 participants, 88 samples) versus those who had symptoms sometimes, rarely, or never (25 participants, 74 samples); and P<.001 for improvement of symptoms in the same individuals (22 participants, 43 sets of matched samples). Changes in microbial diversity were significant for between- but not within-participant comparisons. Conclusions Changes in the gut microbiome composition affect MEBO and PATM severity. In particular, an increase in intestinal bacteria producing odor when in skin flexures was associated with increased intensity of self-reported symptoms. The changes were consistent in the within-group and between-group analyses. Our findings support the feasibility of remote and decentralized clinical studies of malodor conditions. Supplementary sample collection procedures may help to meet established research quality standards. Trial Registration ClinicalTrials.gov NCT03582826; http://clinicaltrials.gov/ct2/show/NCT03582826 International Registered Report Identifier (IRRID) RR2-10.1101/2020.08.21.20179242

Rapid Fabrication of Sterile Medical Nasopharyngeal Swabs by Stereolithography for Widespread Testing in a Pandemic.

The 3D printing of nasopharyngeal swabs during the COVID‐19 pandemic presents a central case of how to efficiently address a break in the global supply chain of medical equipment. Herein a comprehensive study of swab design considerations for mass production by stereolithography is presented. The retention and comfort performance of a range of novel designs of 3D‐printed swabs are compared with the standard flocked‐head swab used in clinical environments. Sample retention of the 3D swab is governed by the volume, porosity density, and void fraction of the head as well as by the pore geometry. 3D‐printed swabs outperform conventional flock‐head swabs in terms of sample retention. It is argued that mechanically functional designs of the swab head, such as corkscrew‐shaped heads and negative Poisson ratio heads, maximize sample retention and improve patient comfort. In addition, available designs of swab shafts for an optimized sample collection procedure are characterized. The study is conducted in vitro, using artificial mucus, covering the full range of human mucus viscosities in a 3D‐printed model of a nasal cavity. The work sets the path for the resilient supply of widespread sterile testing equipment as a rapid response to the current and future pandemics.

Experience on how to implement a preanalytical and POCT unit in Madrid's IFEMA field hospital during this unprecedented COVID-19 emergency.

To fight the virus SARS-CoV-2 spread to Europe from China and to give support to the collapsed public health system, the Spanish Health Authorities developed a field hospital located in the facilities of Madrid exhibition centre (IFEMA) to admit and treat patients diagnosed with SARS-CoV-2 infectious disease (COVID-19). The Department of Laboratory Medicine of La Paz University Hospital in Madrid (LMD-HULP) was designated to provide laboratory services. Due to the emergency, the IFEMA field hospital had to be prepared for patient admission in less than 1 week and the laboratory professionals had to collaborate in a multidisciplinary group to assure that resources were available to start on time. The LMD-HULP participated together with the managers in the design of the tests portfolio and the integration of the healthcare information systems (IS) (hospital IS, laboratory IS and POCT management system). Laboratorians developed a strategy to quickly train clinicians and nurses on test requests, sample collection procedures and management/handling of the POCT blood gas analyser both by written materials and training videos. The IFEMA´s preanalytical unit managed 3782 requests, and more than 11,000 samples from March 27th to April 30th. Furthermore, 1151 samples were measured by blood gas analysers. In conclusion, laboratory professionals must be resilient and have to respond timely in emergencies as this pandemic. The lab’s personnel selection, design and monitoring indicators to maintain and further improve the quality and value of laboratory services is crucial to support medical decision making and provide better patient care.

Best practice recommendations for the measurement and interpretation of salivary proinflammatory cytokines in biobehavioral research

Despite the integration of salivary inflammatory cytokines into research across the biobehavioral, psychological, clinical, and health-related disciplines, there is little guidance regarding the biospecimen collection, handling, and storage practices that maximize the quality and validity of salivary cytokine data. Furthermore, associations between salivary cytokines and measures related to oral health are rarely assessed and accounted for in studies outside the oral health fields. To address these gaps, we examine the sensitivity of salivary interleukin-1β (IL-1β), IL-6, IL-8, and tumor necrosis factor-α (TNF-α) to changes in saliva sample collection technique and cold chain management procedures. Using subsets of saliva samples collected from 150 healthy adults, we measure salivary IL-1β, IL-6, IL-8, TNF-α, and other oral health-related indices (i.e., blood contamination [transferrin], and salivary matrixmallotprotienase-8). In addition to examining changes in cytokine levels associated with sample collection technique and cold chain management procedures, we assess relations between cytokine concentrations and levels of other oral health-related measures. We found that IL-1β, IL-6, and IL-8 were more robust to changes in sample collection and cold chain management procedures than TNF-α, and all cytokines were positively associated with other oral health-related measures. Based on our findings, we recommend analyte-specific guidance for measuring and interpreting salivary cytokine concentrations.

Effects of Relaxation Therapy Using Music on Breast Milk Production in Postpartum Mothers

Introduction: Low milk production is one of the main reasons mothers do not provide breast milk exclusively. Relaxation therapy interventions are expected to help increase milk production. Purpose: The purpose of this scoping review is to map available evidence related to the effect of relaxation therapy interventions on breast milk production in postpartum mothers. Methods: In this scoping review, the authors identify studies that explain the effect of relaxation therapy on breast milk production in postpartum mothers from three databases (PubMed, Wiley, and Science Direct). Searches are limited to studies published in English and present data for the period 2010-2019. The identified study was reviewed using the PRISMA Flowchart. Studies with quantitative designs related to the effect of relaxation therapy on the production of breast milk are then selected for review. Results: From a total of four articles that have been reviewed two sub-themes are found, relaxation therapy increases milk production (increased success of breastfeeding, increased milk secretion and fat content in breast milk) and relaxation therapy decreases maternal stress levels (decreases stress scores and cortisol levels). Conclusion: From this review, some evidences shows music therapy is effective in significantly increase milk production. All studies included in the review have limitations related to the research design or sample collection procedures. The method of relaxation therapy is simple, inexpensive, and easy to use without the involvement of hospital staff. Regarding the intervention, all the intervention groups in this study showed a significant effect compared to the control group.
 Keywords: Music Therapy, Relaxation Therapy, Breastfeeding, Lactating

An efficient method for simultaneously screening for HIV, syphilis, and HCV based on one dried blood spot sample

ObjectiveThe aim of this study was to optimize the parameters of a dried blood spot (DBS)-based ELISA method to simultaneously screen for anti-HIV, anti-hepatitis C virus (HCV) and anti-treponema pallidum (TP) antibodies, and investigate the assay performance. MethodsExperiments were performed to establish optimized parameters for a DBS-based ELISA method to simultaneously screen for anti-HIV, anti-HCV, and anti-TP antibodies. Then, 429 paired plasma and DBS samples were collected to evaluate the performance of the assay with optimized parameters. Plasma test results were used as the reference standard. ResultsThe optimized assay conditions were: blood volume, 70–100 μL; DBS size, whole spot; eluent volume, 500 μL; eluent, PBS with 1‰ Tween20; elution time, 4 h; elution temperature, room temperature. The overall prevalence of HIV, HCV, and TP was 6.06% (95% confidence interval [CI]: 4.07–8.87%), 27.74% (95% CI: 23.60–32.28%), and 14.92% (95% CI: 11.75–18.73%). The clinical sensitivity of the assay for anti-HIV, anti-HCV, and anti-TP antibodies was 88.46%, 98.32%, and 92.19%, respectively. The assay was 100% specificity for each analyte. The assay positive predictive value for each analyte was 100%, and the negative predictive values were >98%. Of the 429 samples, 9 DBS results were different than the plasma results; in these samples the plasma signal-to-cutoff rations were low (range, 1.40–7.81). ConclusionThe DBS-based ELISA method demonstrated good performance for simultaneously screening for anti-HIV, anti-HCV, and anti-TP antibodies. DBS samples are a promising method to screen for HIV, HCV, and TP infections. ImportanceDBS samples are a promising alternative to plasma samples, with the advantages of good sample stability, smaller blood volume, simpler storage, and easier transport. DBS sample testing is used for the diagnosis of a wide variety of pathogens, including HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV). The performance of DBS samples for the serological diagnosis of HIV, HCV, and Treponema pallidum (TP) has been demonstrated to be good in many studies, and therefore DBS is regarded as an ideal choice to screen for HIV, HCV, and TP infections, especially in difficult-access or resource-limited settings. There is no generally accepted procedure for sample collection and processing of DBS samples and there are few studies on simultaneous detection of anti-HIV, anti-HCV and anti-TP using a single DBS.

Microbial contamination risk in hematopoietic stem cell products: retrospective analysis of 1996–2016 data

AbstractQuality assurance and safety of hematopoietic stem cells (HSC) with special emphasis on bacterial and fungal contamination is the prerequisite for any transplantation procedure. The aim was to determine the incidence rate of such contamination during processing of transplantation material with regard to HSC source: peripheral blood stem cell (PBSC), bone marrow (BM), or cord blood (CB). Analysis involved autologous and allogenic products dedicated for patients and comprised in all 4135 donations, including 112 BM (2.70%), 3787 PBSC (91.60%), and 236 CB (5.70%) processed in cell bank over the period 1996–2016. Aerobic and anaerobic contamination was determined.Analysis of the 20-year data revealed 42 contaminated products: 25 PBSC (0.66% of tested units) and 17 CB (7.20% of tested units). No microbial contamination of BM products was detected. Overall percentage of contaminated products was 1.01%, mostly with Staphylococcus epidermidis (61.36%). Bacterial contamination rate at cell bank is relatively low and processing in a closed system does not seem as crucial as might be expected. This is particularly true for BM components. Equally important are evaluation of donor’s medical status and condition of the puncture site for collection of source material. Implementation of appropriate sample collection procedures should help minimize the risk of false-positive results due to environmental contamination.

Changes in microbiome and metabolomic profiles of fecal samples stored with stabilizing solution at room temperature: a pilot study

The gut microbiome is related to various host health conditions through metabolites produced by microbiota. Investigating their relationships involves association analysis of the population-level microbiome and metabolome data, which requires the appropriate collection, handling, and storage of specimens. Simplification of the specimen handling processes will facilitate such investigations. As a pilot study for population-level studies, we collected the fecal samples from three volunteers and tested whether a single sample collection procedure, particularly using OMNIgene-GUT, can be used to reliably obtain both microbiome and metabolome data. We collected fecal samples from three young and healthy Korean adults, stored them at room temperature with and without OMNIgene-GUT solution up to three weeks, and analyzed their microbiome and metabolite profiles. We found that the microbiome profiles were stably maintained in OMNIgene-GUT solution for 21 days, and the abundance relationships among metabolites were well preserved, although their absolute abundances slightly varied over time. Our results show that a single sampling procedure suffices to obtain a fecal sample for collecting gut microbiome and gut metabolome data of an individual. We expect that the health effects of gut microbiome via fecal metabolites can be further understood by increasing the sampling size to the population level.

Comparative Evaluation of the Role of Nonbronchoscopic and Bronchoscopic Techniques of Distal Airway Sampling for the Diagnosis of Ventilator-Associated Pneumonia.

Background:The diagnosis of ventilator-associated pneumonia (VAP) remains a challenge, with clinicians mainly relying on clinical, radiological, and bacteriologic strategies to manage patients with VAP.Aims:To compare the results of non-bronchoscopic and bronchoscopic techniques of distal airway sampling for the diagnosis of VAP.Settings and Design:This was a single-center prospective diagnostic accuracy study done in the 14-bedded intensive care unit of a tertiary care referral hospital.Materials and Methods:Patients aged ≥18 years, on mechanical ventilation for ≥48 h, and with clinical suspicion of VAP (fever, leukocytosis, and increased tracheal secretions) either on admission or during their stay were included. Every patient underwent both procedures for sample collection, first non-bronchoscopic protected bronchoalveolar lavage (NP-BAL) and then bronchoscopic BAL (B-BAL). Clinical Pulmonary Infection Score (CPIS) was calculated for each patient and the collected samples were evaluated in laboratory using standard microbiological techniques.Statistical Analysis Used:The sensitivity, specificity, positive predictive value, and negative predictive value of NP-BAL and B-BAL for the diagnosis of VAP were calculated taking CPIS score of >6 as index test for the diagnosis of VAP.Results:Sixty patients were included in the study. Both NP-BAL and B-BAL had concordance with the CPIS at 69.1%. The concordance between NP-BAL and B-BAL was better at 67.6% with a kappa coefficient of 0.064 (P = −0.593). The yield and sensitivity of NP-BAL were comparable to that of B-BAL.Conclusions:The blind NP-BAL is an equally effective method of airway sampling and could be a better alternative to replace more invasive B-BAL for microbiologic diagnosis of VAP.

Measurement of soil water characteristic curve using HYPROP2

Soil water characteristic curve (SWCC) has an important application in drainage, irrigation, soil physical behavior, and modeling hydrology and nutrient transport. However, measurement of the SWCC is often very time consuming, inaccurate and requires a lot of effort. In order to determine an accurate SWCC, we used HYPROP2. This method article extensively describes the topics which were not covered well by the instrument's manual such as collecting soil samples, use of the HYPROP refill unit, degassing water prior to degassing the tensio shafts and other procedures. Advice is provided in terms of better handling of the equipment to receive all four phases of an optimal measuring curve. Following the step-by-step procedure mentioned in this article would provide a high-quality SWCC. Our measurements were performed on both clay loam and sandy loam soils to show differences in the SWCC. We found that the upper tensio shaft took longer to cavitate for sandy loam soil compared to the clay loam soil.•This paper describes an efficient and accurate method to determine the SWCC using HYPROP2.•This method showed quick and reliable measurements of SWCC for a clay loam and sandy loam soil.•This method includes procedure for soil sample collection and laboratory analysis with HYPROP2.

Evaluation of data input in a rabies testing request form for herbivores

ABSTRACT: Bovines and equines are the domestic animals with the highest incidence of rabies in Brazil. This study evaluated the data input in testing request forms for rabies in herbivores accompanying samples sent to a certified laboratory of rabies diagnosis in the state of Rio Grande do Sul, Brazil. Information was obtained systematically from all forms sent to the laboratory in 2013 and 2014 using a collection instrument that listed variables about the kind of form used, municipality of origin, description of the suspected animal, clinical signs, sample collection, and conservation procedure. The 11 most relevant variables (municipality of origin, geographic coordinates, species, gender, breed, age, herd size, clinical signs, persistence of clinical signs, biological material, and sample conservation) were assessed for the quality of the data entered, and percentage data input was calculated per form. In total, 603 forms were sent to the laboratory. The most used form was the FORM SN, (82.0%, 497/603). “Excellent” and “good” data inputs were observed only for one variable describing the location of suspected rabies cases or outbreaks and animals (species, gender, biological material). Quality of data input of variables describing geographic coordinates, age, breed, herd size, clinical signs, persistence of signs, and sample conservation method varied between “average” and “poor”. The data input in testing request forms for herbivores are not dully supplied in suspected cases neurological syndromes, pointing to the need to increase awareness and improve training of field staff.

P3 - Optimization of the sample collection procedures for selective BCRP inhibitor, KO143, in rodents

P3 - Optimization of the sample collection procedures for selective BCRP inhibitor, KO143, in rodents

Deaf ACCESS: Adapting Consent Through Community Engagement and State-of-the-Art Simulation.

One of the most understudied health disparity populations in the United States is the Deaf community, a sociolinguistic minority group of more than 500,000 individuals who communicate via American Sign Language. Research on Deaf health disparities is lacking due to inaccessible recruitment, sampling, and data collection procedures, as well as the fundamental disconnect between medical and cultural views of Deaf people. A potential starting place for addressing inaccessible research methods and mistrust of the biomedical research community is the careful reconsideration of the traditional informed consent process, often a Deaf individual's first point of contact with the research world. Yet, most Deaf individuals experience obstacles to engaging in informed consent due to differences in language and development compared to hearing individuals. In response to these issues, our team led a three-phase, formative, community-engaged approach to adapt the informed consent process and train research staff in the updated method so that all required components are properly communicated and understood. The goals of our work were to promote Deaf engagement in research about the Deaf community, increase the number of Deaf individuals who participate in general population biomedical research, and generalize our findings to improve research accessibility for the general population.

Correlates of longitudinal leukocyte telomere length in the Costa Rican Longevity Study of Healthy Aging (CRELES): On the importance of DNA collection and storage procedures.

The objective is to identify cofactors of leukocyte telomere length (LTL) in a Latin American population, specifically the association of LTL with 36 socio-demographic, early childhood, and health characteristics, as well as with DNA sample collection and storage procedures. The analysis is based on longitudinal information from a subsample of 1,261 individuals aged 60+ years at baseline from the Costa Rican Study of Longevity and Healthy Aging (CRELES): a nationally representative sample of elderly population. Random effects regression models for panel data were used to estimate the associations with LTL and its longitudinal changes. Sample collection procedures and DNA refrigerator storage time were strongly associated with LTL: telomeres are longer in blood collected in October-December, in DNA extracted from <1-year-old blood cells, and in DNA stored at 4°C for longer periods of time up to five years. The data confirmed that telomeres are shorter at older ages, as well as among males, and diabetic individuals, whereas telomeres are longer in the high-longevity Nicoya region. Most health, biomarkers, and early childhood indicators did not show significant associations with LTL. Longitudinal LTL variation over approximately two years was mainly associated with baseline LTL levels, as found in other studies. Our findings suggest that if there is unavoidable variability in season of sample collection and DNA storage time, these factors should be controlled for in all demographic and epidemiologic studies of LTL. However, due to unobserved components of measurement variation, statistical control may be inadequate as compared to standardization of data collection procedures.

The role of Kisspeptin levels in polycystic ovary syndrome: a systematic review and meta-analysis.

Polycystic ovarian syndrome (PCOS) is a complex and not fully elucidated pathology. This prevalent endocrinopathy affects patients in reproductive age, impacts on estrogen-dependent diseases, as well as in infertility. In this context, Kisspeptin (KP) may be considered a potential biomarker for PCOS diagnosis and follow-up. Here, we aimed to verify the levels of KP in obese and non-obese patients with PCOS, their relationship with other hormones, in comparison to healthy controls. A systematic review and meta-analysis were performed according to the PRISMA guidelines. We searched MEDLINE, EMBASE, PsycINFO, Global Health, The Cochrane Library, Health Technology Assessment Database, and Web of Science for eligible studies. A random effects model meta-analysis of standardized mean difference (SMD) was conducted and the I2 was used to assess heterogeneity. Meta-regression was conducted through mixed-effects model. A total of 12 studies were included, comprising 660 PCOS patients and 600 controls. The KP levels were lower in the control group (0.76: 0.17-1.35; 95% CI). In the subgroup analyses, patients were divided in non-overweight/obese (BMI < 25) and overweight/obese (BMI ≥ 25) groups. The meta-regression revealed a difference between the obese and non-obese groups (z = 2.81; p = 0.0050). PCOS patients showed higher KP levels than control, and obese non-PCOS patients also showed altered KP levels. All studies had poor descriptions of sample collection, pre-analytical and analytical procedures, which is critical considering structural characteristics of the KP molecule.

Pilot test of an educational intervention to improve self-management of diabetes in persons living with HIV

People living with a diagnosis of HIV (PLWH) and type 2 diabetes (T2DM) can experience a synergistic negative impact on their vascular and immune systems if their conditions are poorly controlled. The purpose of this study was to adapt a community-based diabetes self-management intervention for people living with HIV and test the feasibility of administering the intervention with PLWH+T2DM who are low-income, predominantly minority, vulnerable population. The intervention was 12 weeks long with 6 h of educational instruction followed by 6 weekly support telephone calls to reinforce training and problem solve. The study used a one-group pretest–posttest design. Participants were a convenience sample of 25 adults diagnosed with HIV + T2DM. Diabetes knowledge, HIV knowledge, and self-management skills were measured. Analyses comprised descriptive statistics and correlations. Participants completed an average of 2.7 of 6 h of instruction and an average of 3 of 6 possible telephone calls. There was a 34% increase in diabetes self-management skills from pretest to posttest, but there were no changes in knowledge about HIV or diabetes. Based on this pilot study, next steps will include a multi-modal educational intervention, with in-person, at-home, and teleconference components. Blood sample collection procedure will be coordinated with study visits to decrease participants’ burden, and the updated diabetes knowledge instrument with a higher reported internal consistency will be used.

Lack of FGF21 Promotes NASH-HCC Transition via Hepatocyte-TLR4-IL-17A Signaling

Fibroblast growth factor (FGF21) holds great promise as an effective therapeutic means for treating nonalcoholic steatohepatitis (NASH) which is a potential precursor for hepatocellular carcinoma (HCC). We aimed to explore the potential mechanism(s) of FGF21 during NASH-HCC transition using a FGF21 knockout (KO) mouse model. Lack of FGF21 caused significant up-regulation of the hepatocyte derived IL-17A via Toll-like receptor 4 (TLR4) and NF-κB signaling. Restoration of FGF21 alleviated the high NAFLD activity score (NAS) and attenuated the TLR4 triggered hepatocyte-IL-17A expression. The HCC nodule number and tumor size were significantly alleviated by treatments of anti-IL-17A antibody. Down-regulated FGF21 but up-regulated IL-17A expression was also found in the HCC samples from our clinical patients and consistent with data analysis of Gene Expression Profiling Interactive Analysis (GEPIA). In conclusion, lack of FGF21 contributed to FFA mediated induction of hepatocyte-TLR4 signal to up-regulate IL-17A expression in hepatocytes. The potential anti-inflammatory effect of FGF21 could be through a negative feedback on the hepatocyte-TLR4 signaling to inhibit IL-17A production in the liver. The negative feedback loop on the hepatocyte-TLR4 -IL-17A axis could be a potential anti-carcinogenetic mechanism for FGF21 to prevent NASH-HCC transition. Funding: Research reported in this publication was supported partly by an Institutional Development Award (IDeA) from the NIGMS of the National Institutes of Health under grant number P20GM113226. Declaration of Interest: The authors declare that they have no competing interests. Ethical Approval: The animal procedures were approved by the Institutional Animal Care and Use Committee of University of Louisville, which is certified by the American Association for Accreditation of Laboratory Animal Care. All the human sample collection procedures for this study were approved by the Institutional Review Board for Human Study at the University of Louisville.

Qualitative methods in implementation research: An introduction

Qualitative methods are a valuable tool in implementation research because they help to answer complex questions such as how and why efforts to implement best practices may succeed or fail, and how patients and providers experience and make decisions in care. This article orients the novice implementation scientist to fundamentals of qualitative methods and their application in implementation research, describing: 1) implementation-related questions that can be addressed by qualitative methods; 2) qualitative methods commonly used in implementation research; 3) basic sampling and data collection procedures; and 4) recommended practices for data analysis and ensuring rigor. To illustrate qualitative methods decision-making, a case example is provided of a study examining implementation of a primary care-based collaborative care management model for women Veterans with anxiety, depression, and PTSD.

Official International Association for Therapeutic Drug Monitoring and Clinical Toxicology Guideline: Development and Validation of Dried Blood Spot-Based Methods for Therapeutic Drug Monitoring.

Dried blood spot (DBS) analysis has been introduced more and more into clinical practice to facilitate Therapeutic Drug Monitoring (TDM). To assure the quality of bioanalytical methods, the design, development and validation needs to fit the intended use. Current validation requirements, described in guidelines for traditional matrices (blood, plasma, serum), do not cover all necessary aspects of method development, analytical- and clinical validation of DBS assays for TDM. Therefore, this guideline provides parameters required for the validation of quantitative determination of small molecule drugs in DBS using chromatographic methods, and to provide advice on how these can be assessed. In addition, guidance is given on the application of validated methods in a routine context. First, considerations for the method development stage are described covering sample collection procedure, type of filter paper and punch size, sample volume, drying and storage, internal standard incorporation, type of blood used, sample preparation and prevalidation. Second, common parameters regarding analytical validation are described in context of DBS analysis with the addition of DBS-specific parameters, such as volume-, volcano- and hematocrit effects. Third, clinical validation studies are described, including number of clinical samples and patients, comparison of DBS with venous blood, statistical methods and interpretation, spot quality, sampling procedure, duplicates, outliers, automated analysis methods and quality control programs. Lastly, cross-validation is discussed, covering changes made to existing sampling- and analysis methods. This guideline of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology on the development, validation and evaluation of DBS-based methods for the purpose of TDM aims to contribute to high-quality micro sampling methods used in clinical practice.

The effect of sampling procedures and day-to-day variations in metabolomics studies of biofluids

Metabolomics analysis of biofluids is a feasible tool for disease characterization and monitoring due to its minimally invasive nature. To reduce unwanted variation in biobanks and clinical studies, it is important to determine the effect of external factors on metabolic profiles of biofluids. In this study we examined the effect of sample collection and sample processing procedures on NMR measured serum lipoproteins and small-molecule metabolites in serum and urine, using a cohort of men diagnosed with either prostate cancer or benign prostatic hyperplasia. We determined day-to-day reliability of metabolites by systematic sample collection at two different days, in both fasting and non-fasting conditions. Study participants received prostate massage the first day to assess the differences between urine with and without prostate secretions. Further, metabolic differences between first-void and mid-stream urine samples, and the effect of centrifugation of urine samples before storage were assessed. Our results show that day-to-day reliability is highly variable between metabolites in both serum and urine, while lipoprotein subfractions possess high reliability. Further, fasting status clearly influenced the metabolite concentrations, demonstrating the importance of keeping this condition constant within a study cohort. Day-to-day reliabilities were however comparable in fasting and non-fasting samples. Urine sampling procedures such as sampling of first-void or mid-stream urine, and centrifugation or not before sample storage, were shown to only have minimal effect on the overall metabolic profile, and is thus unlikely to constitute a confounder in clinical studies utilizing NMR derived metabolomics.