Point-of-care Testing Analysis Research Articles

A portable smartphone detection of ctDNA using MnB2 nanozyme and paper-based analytical device

The development of point-of-care testing (POCT) for circulating tumor DNA (ctDNA) is meaningful for the non-invasive cancers screening and diagnosis, particularly in resource-limited settings. The microfluidic paper-based analytical device (μPAD) provides an ideal platform, its application in ctDNA assays remains underexplored. In this work, a multifunctional μPAD was manufactured, which can enhance the efficiency and reduce the cost of ctDNA sensing. Additionally, a smartphone-based application analysis was fabricated for convenient, portable detection and colorimetric signal readout. Moreover, the novel oxidase-like MnB2 nanozyme was introduced in the sandwiches sensing strategy, utilizing its catalytic properties to effectively generate a colorimetric signal. The use of MnB2 nanozyme in sensing application is relatively novel, and its catalytic performance and mechanism was thoroughly evaluated via experiment and density functional theory (DFT) calculations. After optimizing the detection conditions, the proposed biosensor exhibited satisfactory results. Furthermore, the method was successfully used to detect ctDNA in tumor cell lysates and peripheral blood samples from tumor-bearing mice. The results were consistent with standard qPCR method, affirming the reliability of our POCT analysis device in ctDNA detection. Thus, this work not only provides a paper-based POCT device and intelligent analysis tool for portable cancers diagnosis, but it also paves a new application path for MnB2 nanozyme in the sensing filed.

Verification of point-of-care analysers for C-reactive protein, lipid studies and glycated haemoglobin

Due to increased convenience and faster test results, interest in point-of-care testing (PoCT) has grown significantly. Though PoCT may improve the speed and convenience of testing, the devices need to be fit for their intended purpose. Our aim was to verify the performance of Roche cobas b 101 and Abbott Afinion 2 for C-reactive protein (CRP), lipid studies and glycated haemoglobin (HbA1c), and Siemens Atellica DCA for HbA1c. For all PoCT analysers and measurands, accuracy was assessed by method comparison with central laboratory analysers. Passing-Bablok linear regression was performed, and Bland-Altman plots were generated. The proportion of samples within the Royal College of Pathologists of Australasia Quality Assurance Programs Analytical Performance Specifications (RCPAQAP APS) was assessed. Within-run and between-day imprecision was assessed and compared with manufacturer claims and biological variation or clinical guidelines for desirable imprecision. For CRP, both evaluated PoCT analysers had all samples within the RCPAQAP APS and had optimal imprecision according to biological variation. For lipid studies, the Roche cobas b 101 had most samples within the RCPAQAP APS, with two of 22 cholesterol, one of 22 high-density-lipoprotein-cholesterol (HDL-C) and zero of 22 triglyceride comparisons outside the RCPAQAP APS. The Abbott Afinion 2 had a positive bias with all three measured parameters, although the effect was more limited in the calculated parameters cholesterol:HDL-C ratio, non-HDL-C and low-density-lipoprotein-cholesterol (LDL-C). For HbA1c, all analysers had acceptable imprecision for monitoring with coefficient of variation (CV) <3% and minimal bias at the treatment target (HbA1c 53 mmol/mol or 7.0%). However, significant biases were apparent at higher or lower HbA1c for all analysers. All evaluated analysers were fit for purpose for CRP and for serial monitoring of HbA1c, although bias in some analysers was present at extremes of HbA1c. For lipid studies, the Roche cobas b 101 had fewer results outside the RCPAQAP allowable limits, and better precision. The Abbott Afinion 2 had a positive bias on both the cholesterol and HDL-C, but there is limited clinical impact when calculating cholesterol:HDL-C, LDL-C and non-HDL-C.

1253-P: Differences in Screening-Detected Type 2 Diabetes—Evidence from Two Campaign Setups in Denmark

Background: Early detection of type 2 diabetes mellitus (T2DM) increases life expectancy of T2DM patients and reduces societal health care costs. Targeted screening campaigns are used for early detection of T2DM, but different campaign setups may yield different detection results. Methods: Between June and November 2022, the Danish Diabetes Association offered free capillary A1c tests to individuals at high risk of developing diabetes based on the Leicester’s Risk Score questionnaire (score ≥ 16 points). Two campaign setups were applied: a) an event-based community screening campaign in 20 of the largest Danish cities using a portable Point of Care Testing analyzer and b) a social media campaign offering at-home self-sampling tests using mailed Hemoglobin Capillary Collection System. Results: A total of 1,337 and 2,655 individuals at high risk were tested through the community and the social media setup, respectively. The proportion of men and women in both setups were evenly balanced across all age groups. However, compared to the social media setup, in the community setup the proportion of individuals aged below 60 years was 14 percentage points lower, while the proportion of individuals aged 70 years or older was 14 percentage point higher. While 2.6% of the participants in both setups had A1c values ≥ 48 mmol/mol, 8.8% in the community setup and 15.6% in the social media setup had A1c values of 42-47 mmol/mol. The relative difference in the proportion of participants with A1c values of 42-47 mmol/mol was balanced across all age groups. Conclusions: Targeted community and social media screening campaigns are complementary. While older individuals (70 years or above) tend to participate in the community screening campaign, younger individuals (below 60) tend to participate in social media screening campaign. However, social media campaigns for at-home self-sampling prove highly efficient in detecting individuals with A1c values of 42-47 mmol/mol compared to community campaigns. Disclosure N.Cayuelas mateu: Other Relationship; Abbott Diagnostics. T.Thybo: Other Relationship; Abbott Diagnostics.

The Impact of Point-of-Care Testing for Influenza on Antimicrobial Stewardship (PIAMS) in UK Primary Care: Protocol for a Mixed Methods Study

Background Molecular point-of-care testing (POCT) used in primary care can inform whether a patient presenting with an acute respiratory infection has influenza. A confirmed clinical diagnosis, particularly early in the disease, could inform better antimicrobial stewardship. Social distancing and lockdowns during the COVID-19 pandemic have disturbed previous patterns of influenza infections in 2021. However, data from samples taken in the last quarter of 2022 suggest that influenza represents 36% of sentinel network positive virology, compared with 24% for respiratory syncytial virus. Problems with integration into the clinical workflow is a known barrier to incorporating technology into routine care. Objective This study aims to report the impact of POCT for influenza on antimicrobial prescribing in primary care. We will additionally describe severe outcomes of infection (hospitalization and mortality) and how POCT is integrated into primary care workflows. Methods The impact of POCT for influenza on antimicrobial stewardship (PIAMS) in UK primary care is an observational study being conducted between December 2022 and May 2023 and involving 10 practices that contribute data to the English sentinel network. Up to 1000 people who present to participating practices with respiratory symptoms will be swabbed and tested with a rapid molecular POCT analyzer in the practice. Antimicrobial prescribing and other study outcomes will be collected by linking information from the POCT analyzer with data from the patient’s computerized medical record. We will collect data on how POCT is incorporated into practice using data flow diagrams, unified modeling language use case diagrams, and Business Process Modeling Notation. Results We will present the crude and adjusted odds of antimicrobial prescribing (all antibiotics and antivirals) given a POCT diagnosis of influenza, stratifying by whether individuals have a respiratory or other relevant diagnosis (eg, bronchiectasis). We will also present the rates of hospital referrals and deaths related to influenza infection in PIAMS study practices compared with a set of matched practices in the sentinel network and the rest of the network. We will describe any difference in implementation models in terms of staff involved and workflow. Conclusions This study will generate data on the impact of POCT testing for influenza in primary care as well as help to inform about the feasibility of incorporating POCT into primary care workflows. It will inform the design of future larger studies about the effectiveness and cost-effectiveness of POCT to improve antimicrobial stewardship and any impact on severe outcomes. International Registered Report Identifier (IRRID) DERR1-10.2196/46938

Venous blood point-of-care testing (POCT) for paramedics in urgent and emergency care: protocol for a single-site feasibility study (POCTPara).

The COVID-19 pandemic placed the UK healthcare system under unprecedented pressure, and recovery will require whole-system investment in innovative, flexible and pragmatic solutions. Positioned at the heart of the healthcare system, ambulance services have been tasked with addressing avoidable hospital conveyance and reducing unnecessary emergency department and hospital attendances through the delivery of care closer to home. Having begun to implement models of care intended to increase 'see and treat' opportunities through greater numbers of senior clinical decision makers, emphasis has now been placed upon the use of remote clinical diagnostic tools and near-patient or point-of-care testing (POCT) to aid clinical decision making. In terms of POCT of blood samples obtained from patients in the pre-hospital setting, there is a paucity of evidence beyond its utility for measuring lactate and troponin in acute presentations such as sepsis, trauma and myocardial infarction, although potential exists for the analysis of a much wider panel of analytes beyond these isolated biomarkers. In addition, there is a relative dearth of evidence in respect of the practicalities of using POCT analysers in the pre-hospital setting. This single-site feasibility study aims to understand whether it is practical to use POCT for the analysis of patients' blood samples in the urgent and emergency care pre-hospital setting, through descriptive data of POCT application and through qualitative focus group interviews of advanced practitioners (specialist paramedics) to inform the feasibility and design of a larger study. The primary outcome measure is focus group data measuring the experiences and perceived self-reported impact by specialist paramedics. Secondary outcome measures are number and type of cartridges used, number of successful and unsuccessful attempts in using the POCT analyser, length of time on scene, specialist paramedic recruitment and retention, number of patients who receive POCT, descriptive data of safe conveyance, patient demographics and presentations where POCT is applied and data quality. The study results will inform the design of a main trial if indicated.

Real-life evaluation of hypersensitive I-troponin on a point-of care analyser in an emergency unit

European Society of Cardiology (ESC) guidelines allow to perform rapid rule-in and rule-out algorithm with rapid troponin kinetics for the management of suspected Non ST-elevation acute coronary syndrome. These recommendations allow the use of point-of-care testing (POCT) systems provided that they have sufficient analytical performance. The aim of our study was to evaluate in real life the feasibility and performance of using a high sensitivity cardiac troponin I POCT system assay (hs-cTnI, Atellica® VTLi, Siemens) compared to high sensitivity cardiac troponin T values (hs-cTnT, e602®, Roche) obtained for patients admitted to emergency department. Analytical verification showed a coefficient of variation below 10% for hs-cTnI. Comparison of both troponins was moderate (r=0.7). The study included 117 patients with a median age of 65 years, 30% had renal failure and 36% presented with chest pain. In this study, the hs-cTnT value was, more often, higher than the 99th percentile than the hs-cTnl value, even for an age-adjusted 99th percentile hs-cTnT value. The concordance of the results was moderate (Cohen's Kappa: 0.54), age remaining the most important explanatory value of discordance. Only hs-cTnT had a predictive value for hospitalization. We did not observe any interpretation discrepancies for patients who had troponin kinetics. This study confirms the feasibility of using a POCT analyzer in the emergency department, provided that it performs high sensitivity troponin. However, some data are missing to be able to use it in the framework of rapid algorithm. Finally, the implementation of POCT requires collaboration between biologists and emergency physicians in terms of organization and interpretation of values, for the overall benefit of the patient.

A label-free electrochemical aptasensor based on Bi-Sb alloy materials for potential POCT of HER-2.

As a prognostic biomarker for breast cancer, human epidermal growth factor receptor 2 (HER-2) is of crucial diagnostic value. Here, a label-free electrochemical aptasensor was established for the ultrasensitive detection of HER-2 using a modified electrode of Bi-Sb alloy materials (Bi-Sb AMs). The performance of the aptasensor was enhanced greatly due to the introduction of Bi-Sb alloy materials (Bi-Sb AMs) with high conductivity. Furthermore, by integrating the aptasensor with the Sensit Smart U-disk electrochemical analyzer, the point-of-care testing (POCT) for HER-2 was realized. Under the optimal experimental parameters, the POCT analyzer showed a wide linear response from 0.01 pg mL-1 to 100 ng mL-1, with a low detection limit (LOD) of 5.96 fg mL-1 for the detection of HER-2. The presented POCT analyzer exhibited good specificity, stability, and reproducibility. Benefiting from the simple operation and rapid testing, the developed analyzer will have potential application in the prognostic diagnosis and treatment of breast cancer.

Comparison of blood gas results obtained on Abbott i-Stat® and on Radiometer ABL 800 Flex® analyzers Impact for the clinical decision

Point of care testing (POCT) tests are needed to assess severity and to help for triage in hospital and in prehospital settings. Before their use, the analytical performances of POCTs have to be compared with central laboratory reference methods. In this study, we describe the comparability of results obtained by either the Abbott i-STAT® System POCT handheld device or the blood gases analyzer of the central laboratory of our hospital. Sample blood from 37 septic patients admitted to the intensive care unit (ICU) were assayed by Abbott i-STAT® System POCT and Radiometer ABL800 Flex® lab analyzer. Studied parameters were as follows: pH, pO2, pCO2, base excess (BE), HCO3-and lactate. Comparability was evaluated using Bland-Altman method. The clinical value for possible mismatch issued of values differences was also assessed. Quite acceptable correlations in results of POCT and laboratory analyzer were observed with R²most of time above 0.85. Bland-Altman analysis showed a bias of 1.26% for Abbott i-STAT® System POCT vs laboratory. Abbott i-STAT® System POCT handheld device is comparable to Radiometer ABL800 Flex® lab analyzer and concordant with laboratory analysis. Abbott i-STAT® System POCT handled device could be used in the prehospital settings in order to evaluate the severity of sepsis.

Lateral flow assays (LFA) for detection of pathogenic bacteria: A small point-of-care platform for diagnosis of human infectious diseases.

Up-to-date diagnostics is globally improved by point-of-care testing (POCT) analysis and bedside research works. Development in POCT analysis has been provided mostly by forward-looking engineering technology for biosensing and sensing assessments. Lately, lateral flow assays (LFAs) have attracted a lot of interest as a result of their noteworthy benefits including cost-effectiveness, better portability, being operator friendly and rapid detection. This technique has been employed broadly for monitoring diverse biomarkers linked to ultrasensitive detection of pathogenic bacteria, ecological monitoring, consumer protection, and infectious diseases. LFA analyses established on qualitative and optical outcomes have boosted the objectivity and data efficiency of the assessments. Therefore, developing novel methods with the capability of providing reliable and quantitative information regarding a target analyte in a model and preserving the qualities of LFAs is of great necessity. In this review, the main principles of LFAs, challenges, and prospects for more development in this field in sensing pathogenic bacteria have been summarized. Subsequently, visually-read LFAs improvement to further progressive platforms have been explored by considering the prospects of this very flexible method for ultrasensitive detection of pathogenic bacteria. In addition, novel labeling methodologies, electrochemical and optical transducers are described. Also, recent developments in these detection methods elements in combination with other considered approaches have been highlighted.

Comparison of POCT glucose meters and analysis of the interference factor

Abstract Objectives Not many reports have covered large-scale point of care testing (POCT) blood glucose comparisons, and many interfering factors affect detection. This study aims to verify the performance of POCT blood glucose meters and discusses the factors that interfere with detection. Methods Accuracy and precision verification in five glucose concentration groups-high 1 (H1), High 2 (H2), medium 1 (M1), medium 2 (M2), and low (L); comparison of different test methods and specimens; and also the influence of iodophor was investigated in a dilution experiment. Results A total of 58 out of 64 Accu-Chek Inform II POCT blood glucose meters (ACI II) qualified for testing. A proportional significant difference in the relative bias was observed with the POCT instruments in the intermediate and high glucose concentration groups (H=15.364, p=0.02). There were significant differences among the five groups with compliance rates (χ 2=21.03, p=0.00); Group L showed higher values than groups H1 and H2. The precision verification met the requirements issued by the Consensus. Significant differences were found between the three detection methods. The measurement of the Glucose Oxidase Method (Cobas B 123) was lower than that of the HITACHI Plasma Hexokinase Method and the Glucose Dehydrogenase Method on the ACI II (p=0.005 and 0.003) in the preliminary study. No differences were seen among the three types of specimens (p&gt;0.05). The glucose results were incorrect in the presence of iodophor interference. Conclusions The ACI II and Cobas B123 (with a slightly negative bias) provide sufficiently accurate measurements, and all types of blood specimens can be applied. Iodophor, a disinfectant, interferes with glucose measurement.

Soft Electrochemical/Electronic Devices and Their Applications in Point-of-Care Testing

Using soft materials (e.g., paper, hydrogel) to replace the traditional hard materials (e.g., glass, silicon) as substrates have become a recent trend in developing point-of-care testing (POCT) platforms. And through integration of the soft materials with electrochemical or electric devices can further extend the applications of POCT. In our recent work, we used four kinds of soft materials, including paper, PDMS, hydrogel and liquid marble, as the new soft substrates of POCT platforms and realized their new applications in POCT. For example, by integration of the electrodes and hydrophobic channels on paper through simply writing method using home-made pens, the fabricated paper-based electrochemical devices have been successfully applied to detect glucose in artificial urine and melamine in sample solutions. By fabrication of MWNTs/PDMS fibers as multifunctional sensors and integration them on a glove, the measurement of gesture recognition and temperature have been realized by the “smart” glove. Through injection of liquid metal into the 3D helical structure of hydrogel and combination the hydrogel with electronic sensing device, the temperature, UV sensing and EMG signal detections have been performed by the wearable, multifunctional hydrogel device. By using liquid marble as a separator and small device for isoelectric focusing, the POCT separation and analysis of proteins have been realized. The proposed new soft platforms show wide application potential in POCT.

Photothermometric analysis of bismuth ions using aggregation-induced nanozyme system with a target-triggered surface cleaning effect.

The development of nanozyme-based photothermometric sensing for point-of-care testing (POCT) heavy metal ions is of great significance for disease diagnosis and health management. Considering the low catalytic activity of most nanozymes at physiological pH, we found bismuth ions (Bi3+) could effectively enhance the peroxidase (POX)-like activity of cetyltrimethylammonium bromide and citrate-capped octahedral gold nanoparticle (CTAB/Cit-AuNP) nanozymes. It is mainly based on Bi3+ions being able to trigger the surface cleaning effect of CTAB/Cit-AuNPs. Because the more active Bi3+ ions could effectively bind with citrate on the gold surface and competitively destroy the electrostatic interaction between citrate and CTAB, resulting in the removal of CTAB ligands from the gold surface. Without the ligand protection, CTAB/Cit-AuNPs aggregated immediately, and further resulted in a significant activation of the POX-like activity of AuNP nanozymes. Based on this principle, we introduced the enzyme substrate 3,3',5,5'-tetramethylbenzidine (TMB) into this aggregation-induced nanozyme system, and rationally designed a photothermometric platform to quickly and sensitively detect Bi3+ ions by using the good photothermal effect of the oxidation product of TMB (oxTMB). The developed photothermometric method only using a common thermometer has a limit of detection (LOD) as low as 45.7nM for POCT analysis of Bi3+ ions. This study not only provides a more accurate understanding ofthe aggregation-induced nanozymes based on the surface cleaning principle, but also shows the potential applications of aggregation-induced nanozymes in the POCT field.

Effects of regular testing as a sort of Covid-19 filter, by identifying, isolating and thus filtering out currently infected persons, using antigenic tests among healthcare workers in three hospitals in the South of Italy

The use of antigen tests is proposed as a substitute for the molecular test in some conditions and the Italian Regions are preparing for massive provision. This method has been introduced and tested in the local health authority ASL BT - Puglia (Italy) and then integrated with the regional health surveillance protocol for health workers thanks to the preliminary results. In the Puglia Region there has been an Integrated Health and Safety Management System SGSL (SiRGISL) since pre-COVID times, which has standardized procedures and protocols as regards to Integrated Health and Safety for the prevention of hospital worker risks. Where the method was first tested, a screening test was introduced on 2,500 health workers operating in the three hospitals of the BT district, weekly. The nasopharyngeal swabs were carried out by the coordinators (workers safety representatives in Puglia Region SGSL), the swabs were sent to the PoCT (Point of Care Testing) analysis laboratory with immediate reading of the antigen test following by molecular test method confirmation. The study was performed in a Puglia district with high virus circulation. About 12 thousand swabs were performed, mainly in the period, which identified 192 cases of positivity to SARS CoV2 among asymptomatic operators not detected symptomatic by the usually temperature control method at the hospital entrance. During the third week a peak of cases (79) with a subsequent decline was revealed, otherwise the infection trend of the population district maintained a constant growth. Early identification and removal of asymptomatic hospital workers, by means of frequent use of rapid tests, acts as a filter and reduces the chances of contagion by cutting the chains at the origin. During a time featured by high viral circulation, the amount and the speed of the tests should be privileged over more accurate methods, difficult to manage with a very high demand. In Puglia Region, the presence of Integrated Health and Safety Management System (SiRGISL) makes the organizational structures efficiently adaptable to the rapid change of the pandemic framework by choosing suitable technologies and methods in order to anticipate the change of the pandemic curve instead of following it. Asymptomatic subjects detecting is a major problem in the management of epidemics even in controlled environments such as hospitals.

Effects of regular testing as a sort of Covid-19 filter, by identifying, isolating and thus filtering out currently infected persons, using antigenic tests among healthcare workers in three hospitals in the South of Italy

The use of antigen tests is proposed as a substitute for the molecular test in some conditions and the Italian Regionsare preparing for massive provision. This method has been introduced and tested in the local health authority ASLBT - Puglia (Italy) and then integrated with the regional health surveillance protocol for health workers thanks to thepreliminary results. In the Puglia Region there has been an Integrated Health and Safety Management System SGSL(SiRGISL) since pre-COVID times, which has standardized procedures and protocols as regards to Integrated Healthand Safety for the prevention of hospital worker risks.Where the method was first tested, a screening test was introduced on 2,500 health workers operating in the threehospitals of the BT district, weekly. The nasopharyngeal swabs were carried out by the coordinators (workers safetyrepresentatives in Puglia Region SGSL), the swabs were sent to the PoCT (Point of Care Testing) analysis laboratorywith immediate reading of the antigen test following by molecular test method confirmation. The study was performedin a Puglia district with high virus circulation.About 12 thousand swabs were performed, mainly in the period, which identified 192 cases of positivity to SARS CoV2among asymptomatic operators not detected symptomatic by the usually temperature control method at the hospitalentrance.During the third week a peak of cases (79) with a subsequent decline was revealed, otherwise the infection trend ofthe population district maintained a constant growth.Early identification and removal of asymptomatic hospital workers, by means of frequent use of rapid tests, acts as afilter and reduces the chances of contagion by cutting the chains at the origin.During a time featured by high viral circulation, the amount and the speed of the tests should be privileged over moreaccurate methods, difficult to manage with a very high demand.In Puglia Region, the presence of Integrated Health and Safety Management System (SiRGISL) makes theorganizational structures efficiently adaptable to the rapid change of the pandemic framework by choosing suitabletechnologies and methods in order to anticipate the change of the pandemic curve instead of following it.Asymptomatic subjects detecting is a major problem in the management of epidemics even in controlled environmentssuch as hospitals.

Performance Evaluation of Four Commercial Point-of-Care Testing Urine Analyzers for Diagnosing Urinary Tract Infection.

Urinalysis is used as a screening tool in case of a clinical suspicion of urinary tract infection (UTI). The purpose of this study is to evaluate the analytical performance, agreement, and screening value of four commercial point-of-care testing (POCT) urine analyzers for UTI. The following four POCT analyzers were evaluated: Clinitek Status+, BW-200, Hipee S2, and URS-14K. The agreement of the four analyzers with the laboratory standard was assessed. The diagnostic indicators of the screening tests performed using POCT analyzers for UTI were calculated against the bacterial culture as the gold standard. Overall agreement of the four analyzers was good. For nitrite and leukocytes, all the analyzers showed substantial or excellent agreement with the laboratory reference standard, whereas agreement for erythrocytes varied from moderate to excellent. With each POCT analyzer, combined detection of nitrite, leukocytes, and erythrocytes provided better diagnostic performance than individual detection. Combined detection had higher sensitivity and negative predictive value, while the specificity and positive predictive value were higher for single detection of nitrite. Present findings demonstrate that the overall performance of the four POCT urine analyzers was sufficient for routine use for screening UTI. A result positive for nitrite is helpful for early diagnosis of UTI, and a result negative for the combination of nitrite, leukocytes, and erythrocytes is helpful for early elimination of UTI.

Value Added Impact of Both Point-of-Care and Laboratory Lactic Acid Analysis When Emergently Evaluating Cancer Patients.

IntroductionCancer patients are immunosuppressed and may present to an emergency department with atypical symptoms. In the emergency setting, it is important ascertain rapidly if lactic acid levels are high, either due to sepsis or tumor lysis syndrome, to effectively manage symptoms. Therefore, it is critical to determine the blood lactic acid level to timely identify who is at risk of sepsis and provide early intervention. We have compared blood lactic acid concentrations (BLAC) in cancer patients obtained by point-of-care testing (POCT) and those measured by laboratory analysis in blood samples drawn within a short time of each other.MethodsThis was a retrospective study in cancer patients whose BLAC had been determined by POCT and laboratory analysis. Only those patients who had blood withdrawn for both testing methods within a 2-h timeframe were included in the study. Regressions were performed together with an analysis categorizing the BLAC from both testing methods.ResultsA total of 274 patients met the criteria for the study. The BLAC from POCT correlated well with the values from laboratory testing (R = 0.925). Categorization of BLAC showed that 88.32% of the patients had BLAC that directly matched between the two tests; 28 (10.22%) patients had a normal BLAC according to laboratory analysis but a high BLAC on POCT; and four (1.46%) patients had a high BLAC according laboratory analysis but normal BLAC on POCT.ConclusionsThere was a high correlation between POCT and laboratory analysis values of BLAC in cancer patients, with the results from both testing methods agreeing 96% of the time. This finding suggests that POCT would suffice in most cases. Importantly, in 2% of the cancer patients who presented emergently, BLAC determined by POCT and laboratory analysis did not agree. Therefore, in subsequent decision-making, we recommend that if sepsis is suspected and BLAC determined by POCT is normal, nucleic acids, proteins, circulating cells, and interleukin-3 levels should also be obtained by POCT to confirm sepsis and/or rule out tumor lysis syndrome in patients with cancer.Electronic Supplementary MaterialThe online version of this article (10.1007/s40487-020-00118-0) contains supplementary material, which is available to authorized users.

Soft Electrochemical/Electronic Devices and Their Applications in Point-of-Care Testing

Using soft materials (e.g., paper, hydrogel) to replace the traditional hard materials (e.g., glass, silicon) as substrates have become a recent trend in developing point-of-care testing (POCT) platforms. And through integration of the soft materials with electrochemical or electric devices can further extend the applications of POCT. In our recent work, we used four kinds of soft materials, including paper, PDMS, hydrogel and liquid marble, as the new soft substrates of POCT platforms and realized their new applications in POCT. For example, by integration of the electrodes and hydrophobic channels on paper through simply writing method using home-made pens, the fabricated paper-based electrochemical devices have been successfully applied to detect glucose in artificial urine and melamine in sample solutions. By fabrication of MWNTs/PDMS fibers as multifunctional sensors and integration them on a glove, the measurement of gesture recognition and temperature have been realized by the “smart” glove. Through injection of liquid metal into the 3D helical structure of hydrogel and combination the hydrogel with electronic sensing device, the temperature, UV sensing and EMG signal detections have been performed by the wearable, multifunctional hydrogel device. By using liquid marble as a separator and small device for isoelectric focusing, the POCT separation and analysis of proteins have been realized. The proposed new soft platforms show wide application potential in POCT.

A new microchannel capillary flow assay (MCFA) platform with lyophilized chemiluminescence reagents for a smartphone-based POCT detecting malaria

There has been a considerable development in microfluidic based immunodiagnostics over the past few years which has greatly favored the growth of novel point-of-care-testing (POCT). However, the realization of an inexpensive, low-power POCT needs cheap and disposable microfluidic devices that can perform autonomously with minimum user intervention. This work, for the first time, reports the development of a new microchannel capillary flow assay (MCFA) platform that can perform chemiluminescence based ELISA with lyophilized chemiluminescent reagents. This new MCFA platform exploits the ultra-high sensitivity of chemiluminescent detection while eliminating the shortcomings associated with liquid reagent handling, control of assay sequence and user intervention. The functionally designed microchannels along with adequate hydrophilicity produce a sequential flow of assay reagents and autonomously performs the ultra-high sensitive chemiluminescence based ELISA for the detection of malaria biomarker such as PfHRP2. The MCFA platform with no external flow control and simple chemiluminescence detection can easily communicate with smartphone via USB-OTG port using a custom-designed optical detector. The use of the smartphone for display, data transfer, storage and analysis, as well as the source of power allows the development of a smartphone based POCT analyzer for disease diagnostics. This paper reports a limit of detection (LOD) of 8 ng/mL by the smartphone analyzer which is sensitive enough to detect active malarial infection. The MCFA platform developed with the smartphone analyzer can be easily customized for different biomarkers, so a hand-held POCT for various infectious diseases can be envisaged with full networking capability at low cost.

A novel naphthofluorescein-based probe for ultrasensitive point-of-care testing of zinc(II) ions and its bioimaging in living cells and zebrafishes.

The combination of fluorescence method with paper-based diagnostic device is quite suitable in point-of-care testing (POCT). Herein, we designed a novel hybrid fluorescein-based probe ZN-2 and investigated its fluorescent properties thoroughly in the detection of Zn2+. In comparison with the fluorescein-based probe ZN-1, ZN-2 displayed better sensitivity, long-wavelength and faster response to Zn2+ within 20min. Interestingly, we could achieve ultrasensitive, high-throughput and visual detection in the POCT analysis of Zn2+ by anchoring this probe ZN-2 on the paper-based device. This device with satisfied performance for Zn2+ detection was achieved in real samples including cytochylema, serum and lake water. Finally, the probe ZN-2 was further applied to visualize and monitor the level changes of Zn2+ in the living cells and zebrafishes.

Performance Evaluation of Cardiac Troponin I Assay: A Comparison Between the Point-of-care Testing Radiometer AQT90 FLEX and the Central Laboratory Siemens Advia Centaur Analyzer.

BackgroundTo validate the point of care testing (POCT) Trop-I analyzer and compare it with a central laboratory-based chemiluminescence immunoassay, in order to evaluate its performance for use in critical care areas. Moreover, for clinical decision-making, it is imperative to know the extent to which patient stratification will differ based on the analytic method being used. In particular, the aim of this study was to evaluate the analytical performance of the point-of-care analyzer and demonstrate the agreement with the central laboratory measurements in patients presenting to the emergency department (ED) with chest pain and suspected acute coronary syndrome (ACS).MethodsThis cross-sectional study was performed at the section of chemical pathology, department of pathology and laboratory medicine, the Aga Khan University (AKU), Karachi, from October to November 2017. Samples from patients and the quality control material of Trop-I were analyzed for imprecision, linearity, and method comparison on Advia Centaur (Siemens Diagnostics, CA, USA), and the AQT90 FLEX analyzer (Radiometer Medical ApS, Brønshøj, Denmark) with photometric detection at the section of chemical pathology, AKU. Statistical analysis was done using Microsoft Excel (Microsoft Corporation, Washington, United States) and EP Evaluator version 10.3.0.556 (Data Innovations, LLC, VT, US). Quantitative variables were represented in terms of mean ± SD. For precision, the computed SD was compared with allowable random error. Furthermore, Cohen’s kappa was applied to observe the agreement between the two methods.ResultsThe Trop-I Precision study on the POCT analyzer showed a coefficient of variation (CV) of 2.4% using a pooled patient sample with a mean Trop-I of 2.15 ± 0.05 ng/ml. Three standards ranging from 0.034 to 1.316 ng/ml were run in triplicate to verify accuracy and linearity. The allowable systematic error (SEa) was 10.0%. The maximum deviation for a mean recovery from 100% was 4.1%. All three of the mean recoveries were accurate and within the allowable error limits. The results were linear with slope 1.04, intercept 0.0. On a method comparison, Trop-I showed good agreement, yielding a kappa value of 0.95.ConclusionThis study has validated the performance of a POCT Trop-I assay against a central laboratory immunoassay and found acceptable results. POCT assays for cTnI should be implanted in emergency settings to ensure the fast triage of patients with chest pain, as well as timely diagnosis.