Standard Venipuncture vs a Capillary Blood Collection Device for the Prospective Determination of Abnormal Liver Chemistry

Blood self-sampling devices: innovation, interpretation and implementation in total lab automation

The introduction of the vacuum tube in 1949 revolutionized blood collection, significantly improving sample quality and patient comfort. Over the past 75 years, laboratory diagnostics have evolved drastically, from manual to automated processes, reducing required test volumes by over 1,000 times. Despite these advancements, venous blood collection presents logistical challenges, including centralized scheduling and a large volume of biological waste due to the imbalance between the needed blood volume (often very little) and the collected volume (often in excess). The COVID-19 pandemic further emphasized the need for decentralized healthcare solutions and patient empowerment. Capillary blood collection, widely used in point-of-care testing, offers a promising alternative, particularly for patients facing frequently, or difficulties with, venous sampling. The Leiden University Medical Center in the Netherlands experienced a 15 % reduction in volume of laboratory tests during and after the pandemic, attributed to patient preference for local blood collection and testing. To address these challenges, self-sampling devices are emerging, empowering patients and streamlining sample logistics. However, challenges such as cost, transportation regulations, and sample volume adequacy persists. Robust devices tailored for total lab automation and sustainable practices are crucial for widespread adoption. Despite hurdles, the integration of self-sampling into diagnostic processes is inevitable, heralding a shift towards patient-centered, proactive healthcare. Practical recommendations include robust device design, ease of use, affordability, sustainability, sufficient quality and acceptability by seamless integration into laboratory workflows. Although obstacles remain, self-sampling represents the future of laboratory diagnostics, offering convenience, cost-effectiveness, interoperability and patient empowerment.

Hospital at Home programs: Decentralized inpatient care but centralized laboratory testing?

The Hospital at Home (HaH) program has experienced accelerated growth in major Canadian provinces, driven in part by technological advancements and evolving patient needs during the COVID-19 pandemic. As an increasing number of hospitals pilot or implement these innovative programs, substantial resources have been allocated to support clinical teams. However, it is crucial to note that the vital roles played by clinical laboratories remain insufficiently acknowledged. This mini review aims to shed light on the diverse functions of clinical laboratories, spanning the preanalytical, analytical, and post-analytical phases within the HaH program context. Additionally, the review will explore recent advancements in clinical testing and the potential benefits of integrating new technologies into the HaH framework. Emphasizing the integral role of clinical laboratories, the discussion will address the current barriers hindering their active involvement, accompanied by proposed solutions. The capacity and efficiency of the HaH program hinge on sustained collaborative efforts from various teams, with clinical laboratories as crucial team players. Recognizing and addressing the specific challenges faced by clinical laboratories is essential for optimizing the overall performance and impact of the HaH initiative.

Feasibility, acceptability, and safety of a novel device for self-collecting capillary blood samples in clinical trials in the context of the pandemic and beyond

BACKGROUND

Home blood self-collection devices can enable remote monitoring, but their implementation requires validation. Our objectives were to explore (i) the impact of sampling sites and topical analgesia on capillary blood volume and pain perception and (ii) the safety, acceptability, and failure of capillary self-collection among adults and children using the Tasso-SST device.

METHODS

We conducted a two-phase study. The investigational phase consisted of two on-site cross-sectional studies in healthy adult participants (≥ 12 years) and children (1-17 years) with their accompanying parent. Adults received 4 capillary samplings, where puncture sites and topical analgesia were randomized in a factorial design, and a venipuncture; children (and one parent) had one capillary sampling. The two co-primary outcomes were blood volume and pain. The implementation phase was conducted in two multicentre trials in participants choosing remote visits; blood volume, collection failure, adverse events, and satisfaction were documented.

RESULTS

In the investigational phase, 90 participants and 9 children with 7 parents were enrolled; 15 adults and 2 preschoolers participated in the implementation phase. In the adult investigational study, the device collected a median (25%, 75%) of 450 (250, 550) μl of blood with no significant difference between the puncture site, topical analgesia, and its interaction. Using topical analgesia reduced pain perception by 0.61 (95% CI: 0.97, 0.24; P <0.01) points on the 11-point scale; the pain reduction varied by puncture site, with the lower back showing the most significant decrease. Overall, combining all studies and phases, the median volume collected was 425 (250, 500) μl, and the device failure rate was 4.4%; minor adverse effects were reported in 8.9% of the participants, all were willing to use the device again.

CONCLUSION

Capillary blood self-collection, yielding slightly less than 500 μl, proves to be a safe and relatively painless method for adults and children, with high satisfaction and low failure rates. The puncture site and topical analgesia do not affect blood volume, but topical analgesia on the lower back could reduce pain.

Capillary blood self-collection for high-throughput proteomics

In this study, we sought to compare protein concentrations obtained from a high-throughput proteomics platform (Olink) on samples collected using capillary blood self-collection (with the Tasso+ device) versus standard venipuncture (control). Blood collection was performed on 20 volunteers, including one sample obtained via venipuncture and two via capillary blood using the Tasso+ device. Tasso+ samples were stored at 2°C-8°C for 24-hs (Tasso-24) or 48-h (Tasso-48) prior to processing to simulate shipping times from a study participant's home. Proteomics were analyzed using Olink (384 Inflammatory Panel). Tasso+ blood collection was successful in 37/40 attempts. Of 230 proteins included in our analysis, Pearson correlations (r) and mean coefficient of variation (CV) between Tasso-24 or Tasso-48 versus venipuncture were variable. In the Tasso-24 analysis, 34 proteins (14.8%) had both a correlation r > 0.5 and CV < 0.20. In the Tasso-48 analysis, 68 proteins (29.6%) had a correlation r > 0.5 and CV < 0.20. Combining the Tasso-24 and Tasso-48 analyses, 26 (11.3%) proteins met these thresholds. We concluded that protein concentrations from Tasso+ samples processed 24-48 h after collection demonstrated wide technical variability and variable correlation with a venipuncture gold-standard. Use of home capillary blood self-collection for large-scale proteomics should be limited to select proteins with good agreement with venipuncture.

Enhancing drug development and clinical studies with patient-centric sampling using microsampling techniques: Opportunities, challenges, and insights into liquid chromatography-mass spectrometry strategies

Microsampling has revolutionized pharmaceutical drug development and clinical research by reducing sample volume requirements, allowing sample collection at home or nontraditional sites, minimizing animal and patient burden, and enabling more flexible study designs. This perspective paper discusses the transformative impact of microsampling and patient-centric sampling (PCS) techniques, emphasizing their advantages in drug development and clinical trials. We highlight the integration of liquid chromatography-mass spectrometry (LC-MS) strategies for analyzing PCS samples, focusing on our research experience and a review of current literatures. The paper reviews commercially available PCS devices, their regulatory status, and their application in clinical trials, underscoring the benefits of PCS in expanding patient enrollment diversity and improving study designs. We also address the operational challenges of implementing PCS, including the need for bridging studies to ensure data comparability between traditional and microsampling methods, and the analytical challenges posed by PCS samples. The paper proposes future directions for PCS, including the development of global regulatory standards, technological advancements to enhance user experience, the increased concern of sustainability and patient data privacy, and the integration of PCS with other technologies for improved performance in drug development and clinical studies. By advancing microsampling and PCS techniques, we aim to foster patient-centric approaches in pharmaceutical sciences, ultimately enhancing patient care and treatment efficacy.

Evaluation of Patient-Centric Sample Collection Technologies for Pharmacokinetic Assessment of Large and Small Molecules

Low-volume sampling devices offer the promise of lower discomfort and greater convenience for patients, potentially reducing patient burden and enabling decentralized clinical trials. In this study, we determined whether low-volume sampling devices produce pharmacokinetic (PK) data comparable to conventional venipuncture for a diverse set of monoclonal antibodies (mAbs) and small molecules. We adopted an open-label, non-randomized, parallel-group, single-site study design, with four cohorts of 10 healthy subjects per arm. The study drugs, doses, and routes of administration included: crenezumab (15 mg/kg, intravenous infusion), etrolizumab (210 mg, subcutaneous), GDC-X (oral), and hydroxychloroquine (HCQ, 200 mg, oral). Samples were collected after administration of a single dose of each drug using conventional venipuncture and three low-volume capillary devices: TassoOne Plus for liquid blood, Tasso-M20 for dry blood, both applied to the arm, and Neoteryx Mitra® for dry blood obtained from fingertips. Serum/plasma concentrations from venipuncture and TassoOne Plus samples overlapped and PK parameters were comparable for all drugs, except HCQ. After applying a baseline hematocrit value, the dry blood concentrations and PK parameters for the two monoclonal antibodies were comparable to those obtained from venipuncture. For the two small molecules, two bridging strategies were evaluated for converting dry blood concentrations to equivalent plasma concentrations. A baseline hematocrit correction and/or linear regression-based correction was effective for GDC-X, but not for HCQ. Additionally, the study evaluated the bioanalytical data quality and comparability from the various collection methods, as well as patient preference for the devices.

Optimizing the data in direct access testing: information technology to support an emerging care model

Direct access testing (DAT) is an emerging care model that provides on-demand laboratory services for certain preventative, diagnostic, and monitoring indications. Unlike conventional testing models where health care providers order tests and where sample collection is performed onsite at the clinic or laboratory, most interactions between DAT consumers and the laboratory are virtual. Tests are ordered and results delivered online, and specimens are frequently self-collected at home with virtual support. Thus, DAT depends on high-quality information technology (IT) tools and optimized data utilization to a greater degree than conventional laboratory testing. This review critically discusses the United States DAT landscape in relation to IT to highlight digital challenges and opportunities for consumers, health care systems, providers, and laboratories. DAT offers consumers increased autonomy over the testing experience, cost, and data sharing, but the current capacity to integrate DAT as a care option into the conventional patient-provider model is lacking and will require innovative approaches to accommodate. Likewise, both consumers and health care providers need transparent information about the quality of DAT laboratories and clinical decision support to optimize appropriate use of DAT as a part of comprehensive care. Interoperability barriers will require intentional approaches to integrating DAT-derived data into the electronic health records of health systems nationally. This includes ensuring the laboratory results are appropriately captured for downstream data analytic pipelines that are used to satisfy population health and research needs. Despite the data- and IT-related challenges for widespread incorporation of DAT into routine health care, DAT has the potential to improve health equity by providing versatile, discreet, and affordable testing options for patients who have been marginalized by the current limitations of health care delivery in the United States.

Determination of Capillary Blood TSH and Free Thyroxine Levels Using Digital Immunoassay

Background

The remote performance of thyroid function blood tests is complicated because it requires blood collection.

Objective

To compare TSH and free thyroxine (FT4) levels between capillary and venous blood and assess the adequacy of measuring each value in capillary blood.

Methods

This prospective intervention study was conducted at Ito Hospital and was based on the clinical research method. The participants were 5 healthy female volunteers and 50 patients (41 females and 9 males) between the ages of 23 and 81 years. To measure TSH and FT4 levels in capillary and venous blood, a digital immunoassay (d-IA) method capable of measuring trace samples was used. Chemiluminescence measurements were used as controls. Values obtained for each assay system were compared using Spearman's correlation analysis. Capillary blood was collected using an autologous device (TAP II; not approved in Japan).

Results

Capillary plasma volume obtained using TAP II was 125 µL or more in 26 cases, 25 µL to 124 µL in 24 cases, and less than 25 µL in 5 cases. Strong correlations were noted in the TSH and FT4 levels between capillary and venous blood, with correlation coefficients of rs = 0.99 and rs = 0.97, respectively.

Conclusion

Capillary TSH and FT4 levels strongly correlate with venous blood values. Trace samples can be used in high-precision d-IA methods. These results may promote telemedicine in assessing thyroid function.

Transdermal Blood Sampling for C-Peptide Is a Minimally Invasive, Reliable Alternative to Venous Sampling in Children and Adults With Type 1 Diabetes

OBJECTIVE

C-peptide and islet autoantibodies are key type 1 diabetes biomarkers, typically requiring venous sampling, which limits their utility. We assessed transdermal capillary blood (TCB) collection as a practical alternative.

RESEARCH DESIGN AND METHODS

Ninety-one individuals (71 with type 1 diabetes, 20 control; individuals with type 1 diabetes: aged median 14.8 years [interquartile range (IQR) 9.1-17.1], diabetes duration 4.0 years [1.5-7.7]; control individuals: 42.2 years [38.0-52.1]) underwent contemporaneous venous and TCB sampling for measurement of plasma C-peptide. Participants with type 1 diabetes also provided venous serum and plasma, and TCB plasma for measurement of autoantibodies to glutamate decarboxylase, islet antigen-2, and zinc transporter 8. The ability of TCB plasma to detect significant endogenous insulin secretion (venous C-peptide ≥200 pmol/L) was compared along with agreement in levels, using Bland-Altman. Venous serum was compared with venous and TCB plasma for detection of autoantibodies, using established thresholds. Acceptability was assessed by age-appropriate questionnaire.

RESULTS

Transdermal sampling took a mean of 2.35 min (SD 1.49). Median sample volume was 50 µL (IQR 40-50) with 3 of 91 (3.3%) failures, and 13 of 88 (14.7%) <35 µL. TCB C-peptide showed good agreement with venous plasma (mean venous ln[C-peptide] - TCB ln[C-peptide] = 0.008, 95% CI [-0.23, 0.29], with 100% [36 of 36] sensitivity/100% [50 of 50] specificity to detect venous C-peptide ≥200 pmol/L). Where venous serum in multiple autoantibody positive TCB plasma agreed in 22 of 32 (sensitivity 69%), comparative specificity was 35 of 36 (97%). TCB was preferred to venous sampling (type 1 diabetes: 63% vs. 7%; 30% undecided).

CONCLUSIONS

Transdermal capillary testing for C-peptide is a sensitive, specific, and acceptable alternative to venous sampling; TCB sampling for islet autoantibodies needs further assessment.

Self-sampling of blood using a topper and pediatric tubes; a prospective feasibility study for PSA analysis using 120 prostate cancer patients

OBJECTIVES

Self-collection of blood for diagnostic purposes by blood collection assist devices (BCAD) has gained a lot of momentum. Nonetheless, there are a lack of studies demonstrating the feasibility and reliability of self-collecting capillary blood for routine (immuno)chemistry testing. In this study we describe the topper technology together with pediatric tubes to enable self-collection of blood and investigated its feasibility for PSA testing by prostate cancer patients.

METHODS

A total of 120 prostate cancer patients for which a routine follow-up PSA test was requested, were included in this study. Patients received instruction materials and the blood-collection device consisting of a topper, pediatric tube and base-part, and performed the blood collection procedure themselves. Afterwards a questionnaire was filled-in. Finally, PSA was measured on a Roche Cobas Pro.

RESULTS

The overall self-sampling success rate was 86.7 %. Furthermore, when specified per age category, a 94.7 % success rate for patients under 70 years and a 25 % success rate for patients of 80 years and older was observed. Venous and self-collected PSA were highly comparable when analyzed by Passing-Bablok regression with a slope of 0.99 and intercept of 0.00011, Spearmans correlation coefficient (0.998) and average self-collected PSA recovery of 99.8 %.

CONCLUSIONS

Evidence is presented that self-collected capillary blood by topper and pediatric tube from the finger is feasible, particularly for patients under 70 years. Furthermore, capillary blood self-sampling did not compromise any of the PSA test results. Future validation in a real-world setting, without supervision and including sample stability and logistics, is required.

Decentralized clinical trial design using blood microsampling technology for serum bioanalysis

Background: Alternatives to phlebotomy in clinical trials increase options for patients and clinicians by simplifying and increasing accessibility to clinical trials. The authors investigated the technical and logistical considerations of one technology compared with phlebotomy. Methodology: Paired samples were collected from 16 donors via a second-generation serum gel microsampling device and conventional phlebotomy. Microsamples were subject to alternative sample handling conditions and were evaluated for quality, clinical testing and proteome profiling. Results: Timely centrifugation of blood serum microsamples largely preserved analyte stability. Conclusion: Centrifugation timing of serum microsamples impacts the quality of specific clinical chemistry and protein biomarkers. Microsampling devices with remote centrifugation and refrigerated shipping can decrease patient burden, expand clinical trial populations and aid clinical decisions.

Whole blood cytokine release assays reveal disparity between capillary blood sampling methods

INTRODUCTION

The use of whole blood in rapid cytokine release assays (CRAs) is becoming an established technique for screening immune responses following natural infection or vaccination, especially in the context of the SARS-CoV-2 pandemic. Establishing an accurate capillary blood sampling method to replace the need for venipuncture could make CRAs more accessible. In this study, capillary blood was collected via two different methods alongside traditional venipuncture to investigate whether the method of blood draw affects cytokine quantification when performing CRAs.

METHODS

Adults previously vaccinated with SARS-CoV-2 vaccines donated three blood samples: one by venipuncture, one by finger prick, and one by a microneedle device. Whole blood was aliquoted and incubated overnight with SARS-CoV-2 peptides or left unstimulated. Cytokine release in plasma was measured by multiplex array.

RESULTS

In unstimulated samples, little to no cytokines were detected in blood collected via venipuncture or by microneedle devices. Conversely, capillary blood collected by finger prick showed detectable levels of all cytokines analysed, with significantly inflated levels of TNFα, IL-10 (p < 0.0001), IL-2, GM-CSF, and IL-13 (p < 0.01), and 53% of these samples were also positive for IFN-γ. Following peptide stimulation, 25% of samples collected via finger prick showed dysregulated production of IFN-γ, TNFα, IL-2, and IL-10, with lower cytokine production than unstimulated controls. Contrastingly, this was seen in just 4% of venous blood samples and in none of the microneedle samples.

CONCLUSIONS

Capillary blood draw via a microneedle device results in highly comparable immune responses to those seen via venipuncture at baseline and following peptide stimulation, suggesting this is a viable method for rapid whole blood CRAs. Conversely, differential cytokine production is observed following capillary blood draw via finger prick.

Capillary blood stability and analytical accuracy of 12 analytes stored in Microtainers®

Objectives

The aim of this study was to determine feasibility of collecting capillary blood by traditional fingerstick and next day analysis after transport in Microtainers® at ambient temperature with no plasma separation. This study is pursuing an acceptable alternative to venipuncture for measuring 12 analytes important for health risk assessment.

Design

and Methods: Performance standards of a 12-assay chemistry panel were assessed using a set of paralleled serum and capillary microsamples. The panel included Hemoglobin A1c (HbA1c), Total Cholesterol, Triglycerides, HDL-C, Creatinine, Urea Nitrogen (BUN), Uric Acid, alkaline phosphatase (ALP), ALT (GPT), AST (GOT), gamma-glutamyltransferase (GGT), and total protein. Correlation studies were performed using 31 simultaneous venous and capillary blood collections. Analytical bias, correlation, and medical decision points were calculated to determine equivalency of sample type and the impact of transport conditions. Clinical sensitivity, specificity, and predictive values were evaluated at calculated medical decision points for their usability in health screening initiatives.

Results

Laboratory test results using capillary blood samples stored in Microtainers® under conditions of delayed centrifugation, and mail transport at ambient temperature, showed an acceptable agreement with results obtained using their paired serum samples analyzed using standard methods, except AST.

Conclusions

Capillary blood samples can be self-collected at remote locations using Microtainers® and transported at ambient temperature for 24 h for successful performance of several medical tests important in large-scale health screenings programs.

Painless Capillary Blood Collection: A Rapid Evaluation of the Onflow Device

Blood-based diagnostics are critical for many medical decisions, but mostly rely on venepuncture, which can be inconvenient and painful. The Onflow Serum Gel (Loop Medical SA, Vaud, Lausanne, Switzerland) is a novel blood collection device that utilises needle-free technology to collect capillary blood. In this pilot study, 100 healthy participants were enrolled and provided two Onflow collected specimens and one venous blood specimen. Five chemistry analytes (AST, ALT, LDH, potassium, creatinine) and haemolysis were measured per specimen, and laboratory analyte results were compared. Onflow was found to be more acceptable than venepuncture with lower pain ratings, and 96.5% of participants would use the Onflow method again. All phlebotomists (100%) found Onflow intuitive and user-friendly, with ~1 mL of Onflow blood successfully collected from 99% of participants in <12 min (mean: 6 min, 40 s) and 91% collected on the first attempt. ALT and AST analytes showed no difference in performance, while creatinine generated a negative bias (-5.6 µmol/L), and increased variability was noted with potassium (3.6%CV) and LDH (6.7%CV), although none were clinically relevant. These differences may be due to 35% of Onflow collected specimens having "mild" haemolysis. Onflow is a promising alternative blood collection device that should now be evaluated in participants with expected abnormal chemistries and as an option for self-collection.