Capillary Samples Research Articles

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.

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. 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. 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. 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.

Assessing EPO stability in urine and comparing recombinant EPO detectability in matched urine, venous serum, and capillary serum following a controlled epoetin alfa administration.

The instability of erythropoietin receptor agonists (ERAs, i.e., EPO) in urine presents a challenge to their detectability in doping control samples; however, this issue is not often seen in blood (serum) samples. With the anti-doping field beginning to transition into alternative blood collection technologies, it is important to understand recombinant EPO (rEPO) detectability in serum samples collected from one such capillary collection device, the Tasso+ SST. Twelve individuals were administered a single, 40 IU/kg dose of rEPO (epoetin alfa, EPOGEN®). Following administration, matched urine, venous serum, and capillary serum samples were concurrently collected. Urine aliquots were subject to various storage times and temperatures mimicking shipping conditions of doping control urine samples to assess EPO stability, while other urine aliquots, venous serum, and capillary serum aliquots were frozen until analysis to understand rEPO detectability across all three matrices. EPO and rEPO instability was identified in urine collected from 8 of 12 participants, especially in aliquots stored at room temperature and 37°C. In some of these unstable samples, rEPO was still detectable, while in others, no recombinant nor endogenous EPO was detectable and would have resulted in negative sample reports. Analyzing the concurrently collected urine, venous, and capillary serum samples, rEPO detectability was identical across the three matrices. In most cases, rEPO was detectable for at least 168 h post-administration. Noting greater stability in blood compared with urine, it is recommended that anti-doping authorities utilize this novel capillary serum collection technology to improve overall ERA detectability in doping control samples.

Is blood blood? Comparing quantitation of endogenous steroids and luteinizing hormone in concurrently collected venous serum and Tasso+ SST capillary serum samples.

The monitoring of endogenous steroids in urine has been an important component of the Athlete Biological Passport (ABP) for the last decade. Recently, the quantitation of endogenous steroids in blood has been incorporated into the ABP to increase sensitivity in circumstances where the excretion of urinary ABP biomarkers is low. Current ABP guidelines mandate the use of venous blood draws for blood steroid sample collections, however, recent efforts have focused on investigating the use of less invasive sample collection methods, such as capillary blood collected from the upper arm. The focus of this study was to compare the analytical results of venous and capillary blood collected weekly from 20 individuals, 10 males and 10 females, over six weeks. The two primary biomarkers of the blood steroid ABP module, testosterone (T) and the testosterone/androstenedione (T/A4) ratio, were compared, as well as luteinizing hormone (LH) and the T/LH ratio in male participants, two biomarkers known to be responsive to T use. All biomarkers showed excellent agreement between venous and capillary blood. Longitudinal stability between sample types within individuals was also comparable for all biomarkers. Finally, storage of simultaneously collected capillary samples at room temperature and frozen conditions was compared with evaluate the potential impact of non-cold chain shipping conditions. Most biomarkers showed excellent agreement between frozen and room temperature storage conditions. These results indicate capillary blood collections represent a promising alternative to venous blood collections for the blood steroid module of the ABP.

#2624 Point of care creatinine for early detection of community acquired acute kidney injury in a primary health care centre in Nigeria

Abstract Background and Aims Community acquired Acute kidney injury (AKI) and leads to poor outcomes in low and middle-income countries due to delayed diagnosis however its epidemiology is poorly studied due to lack of biochemical diagnosis. Supported by the International Society of Nephrology, we evaluated the accuracy of point of care creatinine (POC Cr) technology using capillary samples [1] and its use implementing a clinical algorithm to select patients at risk of AKI for POC Cr testing in the Hospital Emergency Department in Port Harcourt in Nigeria. In this phase of the project POC Cr was used in a large primary care health centre for early detection and management of community acquired AKI. Method The study is conducted in Ozuoba Model Comprehensive Primary Health Care Centre. The centre has 4148 patient attendances per month (20.3% medical, 18.8% obstetrics and 60.8% paediatrics) with 11.1% considered acute requiring short admission at the centre usually for intravenous fluids. Historically, decision making is based largely on clinical judgement and renal function tests when requested from external laboratories are reported in &amp;gt; 48 hours. During this project POC Cr was offered on high-risk patients based on the clinical algorithm from the previous stage (Fig. 1) and patients with detected AKI were offered short admission for intravenous fluids and antibiotics. Results To date 54 patients have been screened with POC Cr. Median age is 25.5 years, minimum 2 months, maximum 85 years, interquartile range (48-10), 62% are females, 57% presented with malaria diagnosis and 9% with gastroenteritis. Mean (standard deviation) of POC Cr was 105 (54) µmol/L. There were 5 cases (9%) of AKI (Cr &amp;gt;150 µmol) detected in patients aged 5 months, 13 months, 7 years, 19 years and 31 years. All were treated with short admission and intravenous fluids and were discharged after clinical improvement. Knowledge of the presence of AKI altered management in all patients prompting short admission. Conclusion Community acquired AKI is common in young patients with malaria and early biochemical diagnosis can improve outcomes. The study continues to recruit and aims to investigate the characteristics of community acquired AKI in Africa and to contribute to the design of optimal and sustainable pathway for early detection and management of AKI.

A pharmacokinetic randomised interventional study to optimise dihydroartemisinin-piperaquine dosing for malaria preventive treatment in Malawian infants: A protocol for the OPTIMAL study

Background A newer malaria preventive treatment, dihydroartemisinin-piperaquine (DP), has been identified as an effective alternative to sulfadoxine-pyrimethamine, to which malaria parasites are increasingly becoming resistant. However, how best to dose DP to safely prevent malaria in infants when aligned with routine health facility visits remains unresolved. As infants are usually excluded from participating in early dose optimisation clinical trials, the present study seeks to shift the paradigm and develop optimised DP dosing strategies for malaria preventive treatment in infants. Methods A randomised, single-blind, placebo-controlled, two-arm, interventional study will be conducted in southern Malawi. At 10 weeks (2.5 months) of age, 220 eligible infants will be randomised to receive DP (intervention group, n=110) or placebo (control group, n=110) with routine vaccines. They will be followed until 12 months of age and receive three further DP or placebo treatment courses at 14 weeks, six- and nine months. Infants in the intervention group will contribute capillary samples for piperaquine concentrations pre-dose and at three-, seven-, 14- and 28-days post-DP dosing as well as capillary samples pre-dose and on day 28 post-DP to quantify malaria parasitaemia using microscopy and quantitative PCR. In the control group, infants will contribute capillary blood samples for malaria parasitaemia at the same time points as the intervention group. Malaria incidence and adverse events will be compared between the two groups. Population pharmacokinetic-pharmacodynamic modelling techniques will be applied to derive feasible, optimised, efficacious, and safe DP dosing strategies for malaria preventive treatment in infancy. Conclusions The findings will provide the much-needed evidence to inform DP dosing for malaria preventive treatment in infants when administered with routine health facility visits. Additionally, they will help inform optimal DP dosing for malaria treatment in infants. The trial was registered with the Pan African Clinical Trials Registry; (PACTR202211575727659) on 8 November 2022. Protocol version 3.1, dated 29 September 2022.

Comparing Integrative Respiratory and Renal Acid-Base Acclimatization in Lowlanders and Tibetan Highlanders During Incremental Ascent to 4,300m

During sustained exposure to high altitude, integrated respiratory and renal acclimatization protects blood oxygenation and acid-base homeostasis, respectively. A sustained and augmented hypoxic ventilatory response (HVR) protects blood oxygenation with ascent (i.e., ventilatory acclimatization). However, the HVR elicits hypocapnia and respiratory alkalosis. A subsequent renally-mediated compensatory metabolic acidosis partially returns pH back to baseline values, with a high degree of variability, and capacity for full compensation limited to approximately 4000-4500m. In convenience samples of fully-acclimatized participants, indigenous highlanders of Tibetan ancestry (TH; i.e., Sherpa) have been reported to have (a) similar ventilatory acclimatization but, (b) improved renal compensation than lowlanders (LL) at 4300m. However, little work has been performed on the differences in renal acclimatization between LL and TH during acclimatization with incremental ascent to high altitude over a similar ascent profile. We assessed renal acclimatization between acclimatizing LL and TH, and hypothesized that (a) TH would have similar ventilatory acclimatization to LL but (b) larger magnitude renal compensation than LL during incremental ascent from 1400m to 4300m. Age- and sex-matched groups of 15 unacclimatized LL (8F) and 14 unacclimatized TH of confirmed Tibetan ancestry (7F) were recruited at 1400m. Utilizing an average of two finger capillary blood draw samples and a blood gas analyzer, we compared renally-mediated acid-base acclimatization (PCO2, [HCO3−], pH) in both groups before (1400m) and following day 8-9 of incremental ascent to 4300m. We found that following ascent, LL had significantly lower PCO2 (p&lt;0.0001) and [HCO3-] (p&lt;0.0001), and higher pH (P=0.0037), suggesting respiratory alkalosis and only partial renal compensation. However, TH had significantly lower PCO2 (p&lt;0.0001) and [HCO3−] (p&lt;0.0001), but unchanged pH (P=0.1), suggesting full renal compensation. At 4300m, TH had significantly lower PCO2 (P=0.01), [HCO3−] (p&lt;0.0001) and pH (P=0.005) than LL. These data suggest that TH have larger magnitude and more rapid time-course ventilatory and renal mechanisms compared to LL, resulting in fully-compensated pH in TH during incremental ascent to high altitude, despite a larger hypocapnic stimulus. To our knowledge, this is the first study to demonstrate these integrated respiratory-renal responses between acclimatizing LL and TH. MRU, NSERC, NSF. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Volumetric dried blood spots for determination of phosphatidylethanol: Validation of a liquid chromatography tandem masspectrometry method and clinical application.

Phosphatidylethanol (PEth) measurement in whole blood samples is established as a specific alcohol biomarker with clinical and forensic applications. Establishment of dried blood spots (DBSs) as a specimen for PEth determination offers several advantages and was the focus of this work. A liquid chromatography tandem mass spectrometry method using a 96-well format for sample preparation was developed and validated. PEth was extracted from DBSs by using isopropanol containing PEth-d5 as internal standard. The blood sampling used a commercial volumetric DBS device having a phosholipase D inhibitor incorporated to stop continuous PEth formation. The method quantified PEth in the range of 0.05-10μmol/L, with a bias and imprecision of less than 15%. In a clinical study (n = 25) using fingerprick blood, the volumetric device offered more precise quantifications (CV 4.6%) compared with the Whatman 903 Protein Saver card device (CV 16.6%). In another clinical study (n = 48), the use of dried venous and capillary blood, and liquid venous blood was compared under real-life conditions with samples sent by postal service. The capillary and venous DBS samples gave identical results while the liquid blood gave slightly higher values. Calculation of elimination half-life (PEth 16:0/18:1) in 31 cases based on two consecutive samples with 2-9days in between gave results (mean 6.2days) that agree with literature but several cases with values over 10days. In conclusion, this study demonstrates that volumetric DBS is a valid specimen for determination of PEth blood concentrations, offering several advantages.

Umbilical Cord Blood as an Alternative to Neonatal Blood for Complete Blood Count: A Comparison Study

ObjectiveTo assess concordance between umbilical cord blood (UCB) and neonatal blood (NB) laboratory test results at birth. Study designThis retrospective study considered very preterm neonates (<32 weeks' gestational age) admitted to a tertiary neonatal intensive care unit from 2012 to 2023. Inclusion criteria required neonates with a complete blood count measured in both UCB and NB drawn within 2 hours after birth. Median hemoglobin (Hb) and hematocrit (Hct) concentrations were compared between UCB (venous samples) and NB (venous, arterial, or capillary samples). ResultsA total of 432 neonates with paired UCB and NB values were included in the study. Hb concentration in UCB was 14.7 g/dL (interquartile range [IQR] 13.5-16.1 g/dL) compared with 14.8 g/dL (IQR 12.6-19.3 g/dL) in venous NB samples, 13.9 g/dL (IQR 12.9-15.3 g/dL) in arterial NB and 18.7 g/dL (IQR 16.6-20.8 g/dL) in capillary NB. The regression equation showed a correction factor of 1.08 for converting Hb values from UCB to venous NB. Median Hct concentration in UCB was 0.45 L/L (IQR: 0.41-0.49 L/L) compared with 0.48 L/L (IQR 0.43-0.54 L/L) in venous NB, 0.42 L/L (IQR 0.38-0.45 L/L) in arterial NB and 0.57 L/L, (IQR 0.51-0.63 L/L) in capillary NB. ConclusionsHb and Hct concentrations measured in UCB are similar to those measured in venous blood in very preterm infants and are valid alternatives for NB tests at birth. Hb and Hct concentrations in arterial and capillary NB are respectively lower and higher compared with UCB measurements.

Reflex strategy to ensure accurate total testosterone results from consumer initiated, self-collected capillary samples

BackgroundSelf-collected capillary samples are convenient for direct access testing (DAT), but exogenous testosterone use may cause falsely elevated total testosterone (TT) results.We designed a quality assurance workflow to differentiate between accurate or erroneous supraphysiological TT concentrations. MethodsClinical samples with TT > 1500 ng/dL were reflexed to luteinizing hormone (LH) and follicle stimulating hormone (FSH) and screened for exogenous testosterone use. Samples (n = 120) with normal TT were reflexed to LH/FSH as a control. ResultsA total of 8572 TT samples were evaluated, of which 533 (6.2 %) had TT > 1500 ng/dL and were reflexed. Of these, 441 (82.7 %) had significantly decreased LH/FSH (<0.85/<0.7mIU/mL, respectively), 72 (13.5 %) had normal or borderline normal LH/FSH, and 20 (3.8 %) had insufficient plasma volume. In patients with TT > 1500 ng/dL, injectable exogenous testosterone use was most commonly accompanied by significantly decreased LH/FSH, while topical testosterone use was most commonly accompanied by detectable LH/FSH. Control samples were almost all (99.2 %) within or above the LH/FSH reference intervals. Unique patients ordered 351 TT tests where at least one TT result was > 1500 ng/dL. Based on TT and LH/FSH results, we hypothesized that patients were intermittently or consistently overusing exogenous testosterone, resolved elevated TT with recollection, or repeatedly contaminated their sample. ConclusionSelf-collected capillary specimens are acceptable for TT testing. A quality assurance reflex to LH/FSH can determine the validity of supraphysiological TT results in a consumer initiated/DAT population.

Sickle cell disease in French Guiana: assessing 30 years of neonatal screening (1992-2021)

Sickle cell disease is one of the most common genetic diseases in France. In French Guiana, neonatal screening was introduced in 1992, at the same time as other screening programs for childhood diseases. The aim of this study is to describe the organization of newborn screening for sickle cell disease in French Guiana. We used several data sources: data collected from hospital records since 2005, activity reports from the national neonatal screening program and data from screening campaigns organized by the Drepaguyane association between 2010 and 2021 on 1,300 subjects. Blood samples from newborns are collected by capillary or venous sampling and absorbed on blotting paper (Guthrie) at the same time as those for other neonatal screenings. The dried papers are sent to the inter-regional laboratory in Lille, for further processing. In Saint-Laurent-du-Maroni, in order to reduce the proportion of people lost to follow-up, a double screening is carried out and the results are returned before discharge from the maternity hospital. All data were entered into an anonymous Excel file. The data were analyzed using STATA software. Among the 175,593 screened neonates between 1992 and 2021, screening detected 823 infants with sickle cell disease and 17,950 heterozygotes. Sickle cell genotypes include 493 SS (60%), 302 SC (37%) and 28 S-Beta-thalassemia (3%). The incidence of sickle cell disease was 1/213, 95% CI [1/236-1/204], and that of heterozygotes 1/10, IC 95% [1/12-1/8]. The majority of these children (52%) were from the Maroni region. The delay between screening and test results was 7 days. Only pathological results (homozygous, heterozygous) were communicated to parents and/or the attending physician by post. These data confirm the upward trend in the number of children screened for sickle cell disease in French Guiana. Data from screening campaigns organized by the Drepaguyane association have enabled to describe the distribution of the various abnormal hemoglobin fractions, and to confirm that HbS is more frequent in Western French Guiana. In Cayenne, in 2021, the active file comprised 699 patients, including 266 children under 18 years old. This study provides valuable data on 30 years of neonatal screening for sickle cell disease in French Guiana, and on the evolution of sickle cell disease patients. It confirms that French Guiana is the French territory with the highest incidence of sickle cell disease. This incidence continues to rise over time. The study reveals the improvement in the organization of sickle cell disease management in French Guiana between 1992, when screening was introduced, and the present day. It highlights the role of patient associations in the fight against this disease, by organizing awareness and screening campaigns. These data will be used to guide public health policies in the pursuit of improved care and primary prevention.

Detection of Islet Autoantibodies in Whole Blood by Antibody Detection by Agglutination-PCR (ADAP) Technology Is Sensitive and Suitable for General Population Screening Programs

Background. Detection of type 1 diabetes (T1D) at the preclinical stage is possible by detecting islet autoantibodies (IAs) years before the appearance of symptomatic diabetes. The Antibody Detection Israeli Research is a general population screening program searching for children with multiple IAs who are at risk of developing T1D. IAs are measured in capillary or venous whole blood (WB) samples using the novel ultrasensitive antibody detection by agglutination-PCR (ADAP) technology. Objective. To assess the accuracy and reliability of the ADAP assay in venous and capillary WB. Materials and Methods. In total, 50 children with T1D and 50 healthy controls participated in the study. Venous and capillary blood samples were drawn from participants with T1D, while only venous blood was drawn from the controls. The ADAP assay in venous and capillary blood was compared to the currently used assays in their ability to detect glutamic acid decarboxylase (GADA), islet antigen-2 (IA-2A), and insulin autoantibodies (IAAs). Results. The area under the curve using the receiver operating characteristic curves was comparable between the ADAP assay in WB and standard enzyme-linked immunosorbent assay (ELISA)/radioimmunoassay (RIA) for all three IAs GADA 0.946 (95% CI: 0.900–0.991) vs. 0.949 (0.906–0.992), P=0.873; IA-2A 0.747 (0.649–0.844) vs. 0.666 (0.587–0.744), P=0.106; IAA 1.000 (1.000–1.000) vs. 1.000 (1.000–1.000), P=1.000. The correlation between the levels of IA in venous and capillary WB using ADAP was R2 = 0.958 (P &lt;0.01), R2 = 0.943 (P &lt;0.01), and R2 = 0.711 (P &lt;0.01) for GADA, IA-2A, and IAA, respectively. IA levels in venous and capillary WB using ADAP were comparable without a proportional bias in Bland–Altman’s plots of agreement, suggesting the two methods may be used interchangeably. Conclusions. The ADAP assay is reliable in detecting IA in venous and capillary WB samples with comparable performance to standard RIA and ELISA. These findings open avenues for widespread use of the ADAP assay in future general population screening programs to detect children at risk of developing T1D.

Point-of-Care Capillary Compared to Venous Bilirubin Measurement in Neonates

AbstractWe aimed to evaluate the agreement between the point-of-care (POC) capillary bilirubin measurement with POC venous samples and the reference laboratory measurement. We conducted a prospective comparative study, including neonates ≥ 34 weeks of gestational age, and ≥ 72 h of age. The agreement between POC (Calmark Neo-Bilirubin, Sommargatan, Karlstad, Sweden) capillary, POC venous, and laboratory venous bilirubin was examined with the Bland–Altman plot and the Passing-Bablok regression analyses. The mean bilirubin was 13.54 (2.79) mg/dL in the POC capillary samples, 13.45 (2.69) mg/dL in the POC venous samples, and 12.68 (2.33) mg/dL in reference samples. Bland–Altman plots showed optimal agreement between the POC capillary and venous methods, and with the reference venous method. The bias between the POC capillary and venous methods was 0.094 [levels of agreement (− 3.118)− 3.306], between the POC capillary and the reference venous methods 0.865 [levels of agreement (− 2.283)− 4.014], and between the POC venous and the reference venous methods 0.771 [levels of agreement (− 1.814)− 3.357]. The POC capillary and venous bilirubin levels were in optimal agreement with each other, and with the reference venous measurements, supporting the POC Calmark Neo-Bilirubin capillary measurement as an alternative for a less-invasive, more rapid evaluation of bilirubin.

Sendaway capillary NT-proBNP in pulmonary hypertension

BackgroundN-terminal pro-B-type natriuretic peptide (NT-proBNP) is a biomarker of cardiac ventricular wall stress that is incorporated into pulmonary hypertension (PH) risk stratification models. Sendaway sampling may enable patients to perform...

3D Printed Devices for the Separation of Blood Plasma from Capillary Samples.

Sample preparation is a critical requirement for many clinical tests and diagnostic procedures, but it is difficult to perform on a lab-on-a-chip platform. The analytical side of microfluidic technologies has been gradually catching up with laboratory methods in terms of sensitivity, selectivity, and reliability. There is a growing need for the development of sample preparation modules that can either be connected or embedded into such devices and extract blood plasma in a fast, safe, and automated way. Achieving this functionality is an important step towards creating commercially viable products that can one day become part of everyday life. In this study, a range of simple, yet effective, 3D printed sample preparation devices was developed. The devices rely on snap-fit mechanisms and "resin-bonding" methods to fasten two layers and integrate a plasma separation membrane in between. The devices have excellent usability, with only one step required for their operation without any waiting time for the user, and could extract an average of 56.88% of the total available plasma from 50 μL capillary blood samples in 87 s without inducing any haemolysis. The manufacturing process is quick and straightforward, requiring only low-cost equipment and minimal training. The devices can either be used as a stand-alone device or integrated into an existing lab-on-a-chip system to provide blood filtration capabilities.

Effect of Arterialization on Venous Blood Glucose Concentrations and Implications for Observed Continuous Glucose Monitoring Accuracy.

Background: Heating of the arm and/or hand ("arterialization") is sometimes used in continuous glucose monitoring (CGM) performance studies with the reported aim of reducing differences between venous and capillary glucose concentrations. In this study, the effect of heating on venous glucose concentrations and CGM accuracy was investigated. Methods: A heating pad set to 50°C (122°F) was used with 20 participants to heat either the dominant or nondominant arm and hand. Venous and capillary samples were obtained every 15 min on both arms throughout each of three 6-h glucose challenges. CGM sensors were worn on each upper arm for each of the three visits. Results: Heating of the arm led to a median increase in venous glucose concentrations of +1.4%. No similar effect on capillary concentrations was observed. As a result, the median capillary to venous difference decreased from +5.9% in the nonheated arm to +4.2% in the heated arm. CGM accuracy observed in this study was affected by the selection of heated venous, nonheated venous, or capillary glucose concentrations as comparator data. The heating effect was more pronounced with rapidly decreasing glucose concentrations. Temperatures on the skin did not exceed 40°C (104°F). No adverse events or protocol deviations were associated with the use of the heating pad. Conclusions: Heating of the arm led to a small increase in venous glucose concentrations, but venous concentrations did not reach the level of capillary glucose concentrations. CGM accuracy observed in this study varied depending on the selected comparator data. This study was registered at the German Clinical Trials Register (DRKS00031197).

A practical approach for complete blood count analysis following acute exercise: Capillary vs. venous blood sampling

BackgroundVenipuncture is the standard technique for blood sample acquisition but requires expertise, larger volumes of blood, and can be challenging in special populations. Capillary sampling may provide an alternative, but its reliability is unclear for assessing hematological parameters, especially following acute exercise. ObjectivesThe purpose of the study was to compare the agreement and accuracy of complete blood counts (CBC) from capillary and venous blood sampled before, immediately after a single bout of aerobic exercise, and into recovery. An exploratory purpose was to examine potential biological sex differences within the CBC between blood sampling sites. MethodsRecreationally active healthy adults (N = 13 male and N = 13 female) completed three visits including familiarization, graded exercise testing, and a 40-minute exercise bout at 90–98% of ventilatory threshold. Venous and capillary blood samples were collected simultaneously at rest, immediately post-exercise (0 h) and 30-minutes into recovery (0.5 h). ResultsWhite blood cells (WBC), lymphocytes (LYM), and neutrophils (NEUT) were strongly correlated at all timepoints (r > 0.8, p < 0.05) with low bias, and moderate level of agreement (LOA). Mixed cells (MXD), hemoglobin (HGB), and hematocrit (HCT) were strongly correlated at baseline (r > 0.7, p < 0.05), but showed weaker correlations following exercise. There were no differences in mobilization or egress of CBC outcomes between sites by sex except for lymphocyte egress. Males had lower lymphocyte egress in venous versus capillary sampling whereas females had higher lymphocyte egress in venous versus capillary sampling. DiscussionThese data indicate capillary sampling is an accurate alternative to venous sampling following acute exercise based on LOA and reliability data.

Home capillary sampling and screening for type 1 diabetes, celiac disease, and autoimmune thyroid disease in a Swedish general pediatric population: the TRIAD study.

To screen a general pediatric population for type 1 diabetes (T1D), celiac disease (CD), and autoimmune thyroid disease (AITD) after home capillary sampling. Swedish schoolchildren between 6-9 years and 13-16 years of age were invited to screening by taking a capillary sample at home. Samples were returned by mail and assessed for autoantibodies associated with T1D, CD, and AITD. Persistently autoantibody-positive children were referred for clinical follow-up. Of 19,593 invited, 3,527 (18.0%) consented to participate and 2,315/3,527 (65.6%) returned a blood sample of sufficient volume. Hemolysis occurred in 830/2,301 (36.1%) samples. After exclusion of 42 children with previously known T1D, CD, or AITD, and two autoantibody-positive children who declined a confirmatory sample, 2,271/19,593 (11.6%) were included. 211/2,271 (9.3%) had persistent autoantibodies: 60/2,271 (2.6%) with T1D autoantibodies, 61/2,271 (2.7%) with CD autoantibodies, and 99/2,271 (4.4%) with AITD autoantibodies; 9/2,271 (0.4%) were autoantibody positive for ≥1 disease. After clinical follow-up, 3/2,271 (0.1%) were diagnosed with T1D, 26/2,271 (1.1%) with CD, and 6/2,271 (0.3%) with AITD. Children with a first-degree relative (FDR) with T1D, CD, and/or AITD, had higher occurrence of autoantibodies compared to children without an FDR (63/344, 18.3%, vs. 148/1,810, 8.2%) (p < 0.0001, OR 2.52, 95% CI 1.83-3.47), and higher occurrence of screening-detected diagnosis (14/344, 4.1%, vs. 21/1,810, 1.2%) (p < 0.0001, OR 3.61, 95% CI 1.82-7.18). Half of these children screened positive for another disease than the FDR. Screening for T1D, CD, and AITD by home capillary sampling in a Swedish general pediatric population detected autoimmunity in 9.3% and undiagnosed disease in 1.5%.

Performance analysis of point-of-care testing haemoglobin concentration methods with automated haematology analyser amongst blood donors

Abstract Background: In terms of rapidness, testing methodology and sensitivity, point-of-care (POC) testing devices provide quality in haemoglobin (Hb) check for safe donation of blood. Methods: This was a prospective observational study in a tertiary care centre. Capillary finger-prick samples obtained from 100 blood donors were analysed prior to donation using reagent-free cuvettes (DiaSpect Tm), digital haemoglobinometer (True Hb) and Hb photometer (HemoCue 301). Venous samples were drawn for analysis on haematology analyser. Donors were accepted based on copper sulphate method acceptance criteria. The performance of the devices was evaluated considering automated haematology analyser (Sysmex XN 1000) as the gold standard. Results: The mean Hb value using Sysmex XN 1000, HemoCue 301, DiaSpect Tm and True Hb were 14.8 ± 1.1 g/dL, 15.4 ± 1.8 g/dL, 15.3 ± 1.8 g/dL and 18.6 ± 2.8 g/dL, respectively. The sensitivity of True Hb, DiaSpect Tm, HemoCue 301 and copper sulphate method were 96.8%, 96.8%, 3.7% and 98.9%, respectively. DiaSpect Tm had a specificity of 60% whereas specificity of True Hb and copper sulphate method were 20% each. True Hb, HemoCue 301, DiaSpect Tm and copper sulphate had a positive predictive value of 95.8%, 94.7%, 97.9% and 95.9% and accuracy of 93%, 89%, 95% and 95%, respectively. The mean turnaround time was 1 sec for DiaSpect Tm whereas 35.3 sec and 2.6 sec for True Hb and HemoCue 301, respectively. The copper sulphate test provided the highest rate of donor’s acceptance, despite unacceptable Hb levels. Conclusions: DiaSpect Tm has the advantage of rapid turnaround time, high specificity and accuracy when compared to gold standard method.

Paclitaxel and Therapeutic Drug Monitoring with Microsampling in Clinical Practice.

Paclitaxel is an anticancer agent efficacious in various tumors. There is large interindividual variability in drug plasma concentrations resulting in a wide variability in observed toxicity in patients. Studies have shown the time the concentration of paclitaxel exceeds 0.05 µM is a predictive parameter of toxicity, making dose individualization potentially useful in reducing the adverse effects. To determine paclitaxel drug concentration, a venous blood sample collected 24 h following the end of infusion is required, often inconvenient for patients. Alternatively, using a microsampling device for self-sampling would facilitate paclitaxel monitoring regardless of the patient's location. We investigated the feasibility of collecting venous and capillary samples (using a Mitra® device) from cancer patients to determine the paclitaxel concentrations. The relationship between the venous plasma and whole blood and venous and capillary blood (on Mitra®) paclitaxel concentrations, defined by a Passing-Bablok regression, were 0.8433 and 0.8569, respectively. Demonstrating a clinically acceptable relationship between plasma and whole blood paclitaxel concentration would reduce the need to establish new target concentrations in whole blood. However, in this study, comparison of venous and capillary blood using Mitra® for sampling displayed wide confidence intervals suggesting the results from the plasma and whole blood on this device may not be interchangeable.

Comparison of capecitabine concentrations determined by microsampling versus plasma concentrations for therapeutic drug monitoring: a pilot study.

Therapeutic drug monitoring allows personalized dosing of chemotherapy, but is not well established for capecitabine. The aim of this study was to compare the concentrations of capecitabine and its metabolites obtained simultaneously by microsampling with plasma sampling and their acceptability to patients. Adults taking capecitabine for cancer had paired (duplicate) microsampling at steady state (hour 2 post dose) using Mitra® devices and venous blood samples for analysis. Capecitabine and metabolites were measured using a validated mass spectrometry assay. Correlation between the sampling methods was determined. Patients' preferences were elicited using a Likert numeric rating scale and pain by a Visual Analog Scale (range, 0-10). Capecitabine concentrations from 10 patients (60 paired samples) by microsampling and plasma sampling were highly correlated (Pearson correlation: 0.97, Coefficients of determination: 0.94, P < 0.0001). Capecitabine concentrations in capillary sampling were consistently lower than the paired plasma concentration (median capecitabine capillary/plasma concentration ratio = 2851/3846 μg/l 75%). The agreement between sampling matrices showed a 28% bias (95% Cl, 4.02-52.00). Participant ratings showed microsampling was the preferred method by all 10 patients. Most participants reported no pain with microsampling (median 0, range 0-1). Capecitabine concentration measured by microsampling and plasma sampling were highly correlated, but consistently lower in microsampling. Microsampling was the preferred method with minimal pain.