The impact of new trends in POCTs for companion diagnostics, non-invasive testing and molecular diagnostics

[Barriers for Implementation of PGx Testing in Psychiatric Hospitals in Germany: Results of the FACT-PGx Study]

OBJECTIVE

The FACT-PGx study was conducted to analyze barriers to implementation of pharmacogenetic testing in psychiatric hospitals in Germany and to propose solutions for its faster and easier implementation in all hospitals.

METHODS

104 patients (50% female) were genotyped and participated in the study. 67 completed a survey. To analyze the correlation between continuous data (age) of the survey, the wilcoxon rank test and for categorial data (education level, history of treatment and episodes), t-test was used.

RESULTS

No patient declined to be genotyped. 99% believed that genotyping could help to shorten their hospital stay. Patients >40 years of age and with higher educational levels were willing to pay for the PGx (p=0.009). On average, patients were willing to pay 117.42€ +/-140.49€ and to wait 15.83+/- 8.92 days for the results. Processes differed significantly between routine laboratory screening and PGx testing which could be a barrier for implementation.

CONCLUSION

Patients are not barriers to but enablers of an implementation of PGx. New process flows can be barriers, but can be overcome by optimization.

Integrated nucleic acid purification technology based on amino-modified centrifugal microfluidic chip

Nucleic acid detection is an important tool for clinical diagnosis. The purification of the sample is the most time-consuming step in the nucleic acid testing process and will affect the results of the assay. Here, we developed a surface modification-based nucleic acid purification method and designed an accompanying set of centrifugation equipment and chips to integrate the steps of nucleic acid purification on a single platform. The results of experiments with HeLa cells and HPV type 16 as samples showed that the mentioned method had good nucleic acid purification capability and the accompanying equipment greatly simplified the operation of the experimenters in the whole process. Overall, our equipment can improve the efficiency of nucleic acid purification and is suitable for application in larger-scale clinical assays.

Instant Preparation of Ultraclean Gold Nanothorns under Ambient Conditions for SERS Kit-Enabled Mobile Diagnosis

Availability of surface-enhanced Raman scattering (SERS) substrates with good stability, high sensitivity, and a clean surface is crucial for the practical usefulness of the SERS technology in biochemical sensing, especially for point-of-care testing (POCT). Hereby, we develop a "ready-to-use" SERS kit, which requires only 20 s to fabricate ultraclean gold nanothorn (AuNT)-based SERS chips under ambient conditions with simple solution processing steps. By varying the thickness of the pre-coated platinum (Pt) nanolayer, we can control the size and number density of the grown AuNT. Taking advantage of the ultraclean surface of the instantly obtained fresh AuNT, Raman reporter molecules can also be immediately modified, by means of which specific detection of three analytes including H₂O₂, NO₂^-, and ClO^- is realized. Furthermore, we propose the concept of an SERS kit and apply it to smartphone-based Raman analysis for POCT applications. This on-site preparation method solves the long-standing challenges hindering the practical use of SERS substrates, such as complicated fabrication processes, interference of residual surfactants, poor surface stability, and easy contamination. Besides performing SERS analysis conveniently and quickly, this SERS kit-enabled POCT technology can integrate remote data terminals and medical resources, which shows great potential for environmental protection or online-healthcare systems.

Recent advances and challenges of biosensing in point-of-care molecular diagnosis

Molecular diagnosis, which plays a major role in infectious disease screening with successful understanding of the human genome, has attracted more attention because of the outbreak of COVID-19 recently. Since point-of-care testing (POCT) can expand the application of molecular diagnosis with the benefit of rapid reply, low cost, and working in decentralized environments, many researchers and commercial institutions have dedicated tremendous effort and enthusiasm to POCT-based biosensing for molecular diagnosis. In this review, we firstly summarize the state-of-the-art techniques and the construction of biosensing systems for POC molecular diagnosis. Then, the application scenarios of POCT-based biosensing for molecular diagnosis were also reviewed. Finally, several challenges and perspectives of POC biosensing for molecular diagnosis are discussed. This review is expected to help researchers deepen comprehension and make progresses in POCT-based biosensing field for molecular diagnosis applications.

Health Economic Evidence of Point-of-Care Testing: A Systematic Review

OBJECTIVE

Point-of-care testing (POCT) has become an essential diagnostic technology for optimal patient care. Its implementation, however, still falls behind. This paper reviews the available evidence on the health economic impact of introducing POCT to assess if poor POCT uptake may be related to lacking evidence.

STUDY DESIGN

The Scopus and PubMed databases were searched to identify publications describing a health economic evaluation of a point-of-care (POC) test. Data were extracted from the included publications, including general and methodological characteristics as well as the study results summarized in either cost, effects or an incremental cost-effectiveness ratio. Results were sorted into six groups according to the POC test's purpose (diagnosis, screening or monitoring) and care setting (primary care or secondary care). The reporting quality of the publications was determined using the CHEERS checklist.

RESULTS

The initial search resulted in 396 publications, of which 44 met the inclusion criteria. Most of the evaluations were performed in a primary care setting (n = 31; 70.5%) compared with a secondary care setting (n = 13; 29.5%). About two thirds of the evaluations were on POC tests implemented with a diagnostic purpose (n = 28; 63.6%). More than 75% of evaluations concluded that POCT is recommended for implementation, although in some cases only under specific circumstances and conditions. Compliance with the CHEERS checklist items ranged from 20.8% to 100%, with an average reporting quality of 72.0%.

CONCLUSION

There were very few evaluations in this review that advised against the implementation of POCT. However, the uptake of POCT in many countries remains low. Even though the evaluations included in this review did not always include the full long-term benefits of POCT, it is clear that health economic evidence across a few dimensions of value already indicate the benefits of POCT. This suggests that the lack of evidence on POCT is not the primary barrier to its implementation and that the low uptake of these tests in clinical practice is due to (a combination of) other barriers. In this context, aspects around organization of care, support of clinicians and quality management may be crucial in the widespread implementation of POCT.

LAMP Diagnostics at the Point-of-Care: Emerging Trends and Perspectives for the Developer Community

Introduction: Over the past decade, loop-mediated isothermal amplification (LAMP) technology has played an important role in molecular diagnostics. Amongst numerous nucleic acid amplification assays, LAMP stands out in terms of sample-to-answer time, sensitivity, specificity, cost, robustness, and accessibility, making it ideal for field-deployable diagnostics in resource-limited regions.Areas covered: In this review, we outline the front-end LAMP design practices for point-of-care (POC) applications, including sample handling and various signal readout methodologies. Next, we explore existing LAMP technologies that have been validated with clinical samples in the field. We summarize recent work that utilizes reverse transcription (RT) LAMP to rapidly detect SARS-CoV-2 as an alternative to standard PCR protocols. Finally, we describe challenges in translating LAMP from the benchtop to the field and opportunities for future LAMP assay development and performance reporting.Expert opinion: Despite the popularity of LAMP in the academic research community and a recent surge in interest in LAMP due to the COVID-19 pandemic, there are numerous areas for improvement in the fundamental understanding of LAMP, which are needed to elevate the field of LAMP assay development and characterization.

Demonstration of a fast and easy sample-to-answer protocol for tuberculosis screening in point-of-care settings: A proof of concept study

We sought to develop a smooth and low cost sample preparation and DNA extraction protocol, streamlined with a ready-to-use qPCR in a portable instrument to overcome some of the existing hurdles. Several solutions were evaluated as to their ability to liquefy a mucin-based matrix. Each liquefied matrix, supplemented with either Mycobacterium tuberculosis (MTB) H37Rv strain DNA or intact cells, was aliquoted onto a filter paper embedded with solubilizing agents, and was subsequently dried up. Most of the nucleic acids, including genomic DNA from the bacilli and the host, binds to the filter paper. Next, several protocols were evaluated to elute the DNA from the paper, using qPCR to detect the insertion sequence IS6110, a M. tuberculosis complex genomic marker. The limit of detection (LOD) of the best protocol was then evaluated using parallel seeding and colony counting. The protocol was also evaluated using seventeen sputum samples, previously characterized by the GeneXpert or culture. Two instruments (the ABI7500 Standard and the Q3-Plus system) and two reagents storage formats (frozen or ready-to-use) were evaluated. Solutions containing guanidine isothiocyanate exerted the best liquefying effect on the mucin-based matrix extracted from one 6-mm punches, followed by a brief incubation at 95°C. The resulting DNA contained impurities, but a simple 1:10 dilution elicited the detection of MTB and human genomic targets. The described protocol presented an apparent LOD of 02 CFU/mL of MTB. Challenging the protocol with previously characterized samples showed substantial agreement with GeneXpert MTB/RIF results (sensitivity of 90%, agreement of 88.9%, kappa coefficient of 0.77), and moderate agreement with culture results (sensitivity of 100%, agreement of 78.9%, kappa coefficient of 0.58). This work presents a sensitive proof–of-concept protocol for sputum liquefaction and decontamination followed by a simple DNA extraction procedure, in which the extraction steps are streamlined with a ready-to-use qPCR in a portable instrument that can be employed in low infrastructure settings.

Evaluation of commercial methods to separate nucleic acids from intestinal tissues of pigs for diagnosis of porcine epidemic diarrhea

The article presents the results of evaluating commercial methods for extracting nucleic acids from pig intestinal tissues for the diagnosis of PED. The study was based on samples of small intestine tissues and faeces from 3–5 day old pigs which died from PED. Nucleic acid extraction was performed using commercial kits with different nucleic acid separation strategies based on: silicon-sorbent; silicate membrane fixed in a microcentrifuge column and magnetic balls. The studies were conducted in two stages. The first was a comparison of the results of the amplification of the obtained nucleic acid extracts from the homogenate of the intestines of piglets by using the above-mentioned commercial kits for the extraction of nucleic acids. For this purpose, samples of homogenate were used which in weight corresponded to the guideline for the application of the test kits. The second step was directed to determining the efficiency of extraction of DNA and RNA from homogenate samples with a weight of 10, 50, 100 and 200 mg. Determination of the optimal methodological strategy of nucleic acid extraction for the diagnosis of porcine epidemic diarrhea by PCR has been investigated. The results of the PCR studies of RNA of the PED virus and a unique pig DNA fragment indicate that the extraction of nucleic acids by commercial kits has different levels of efficiency and depends on different factors. According to the research, it was found that the most important of them are the adsorption capacity of the solid-phase sorbent, its configuration and nature, which binds RNA and DNA molecules, the type of sample from which extraction takes place, its volume, or the tissue mass used for extraction. Based on the obtained results, it has been found that the most effective PED virus RNA extraction is by “ArtBioTech”, “Bio Extract Column”, and “Viral DNA/RNA Extraction Kit”, and pig genomic DNA extraction by the “ArtBioTech” and “Viral DNA / RNA extraction Kit”.

Clinical Utility of Advanced Microbiology Testing Tools

Advanced microbiology technologies are rapidly changing our ability to diagnose infections, improve patient care, and enhance clinical workflow. These tools are increasing the breadth, depth, and speed of diagnostic data generated per patient, and testing is being moved closer to the patient through rapid diagnostic technologies, including point-of-care (POC) technologies.

Advanced microbiology technologies are rapidly changing our ability to diagnose infections, improve patient care, and enhance clinical workflow. These tools are increasing the breadth, depth, and speed of diagnostic data generated per patient, and testing is being moved closer to the patient through rapid diagnostic technologies, including point-of-care (POC) technologies. While select stakeholders have an appreciation of the value/importance of improvements in the microbial diagnostic field, there remains a disconnect between clinicians and some payers and hospital administrators in terms of understanding the potential clinical utility of these novel technologies. Therefore, a key challenge for the clinical microbiology community is to clearly articulate the value proposition of these technologies to encourage payers to cover and hospitals to adopt advanced microbiology tests. Specific guidance on how to define and demonstrate clinical utility would be valuable. Addressing this challenge will require alignment on this topic, not just by microbiologists but also by primary care and emergency room (ER) physicians, infectious disease specialists, pharmacists, hospital administrators, and government entities with an interest in public health. In this article, we discuss how to best conduct clinical studies to demonstrate and communicate clinical utility to payers and to set reasonable expectations for what diagnostic manufacturers should be required to demonstrate to support reimbursement from commercial payers and utilization by hospital systems.

Gold nanoprobe-based non-crosslinking hybridization for molecular diagnostics: an update

INTRODUCTION

An update on the uses and applications of the non-cross-linking (NCL) hybridization assay based on the spectral modulation of gold nanoparticles (AuNPs) are presented, emphasizing DNA and RNA detection. Areas covered: Nanotechnology is strongly impacting the way we address diagnostics and therapeutics. In fact, nanoscale devices and particles have been used in a variety of platforms for improved biosensing and, more interestingly, for molecular diagnostics. AuNPs have been used in a great diversity of DNA and RNA detection strategies that are based on their nanoscale properties. Their unique optical properties have put them at the forefront of colorimetric sensing platforms. Among these, those relying on the NCL mechanism using DNA-modified AuNPs have shown remarkable versatility and simplicity for molecular detection of human pathogens, identification of single base alterations at the basis of human disease, gene expression, among others. Application of the NCL assay to molecular diagnostics will be discussed considering the challenges for validation and clinically relevant targets. Expert commentary: Integration of the NCL approach using AuNPs into chip biosensing platforms, projecting miniaturization and portability, will be addressed in terms of the future, i.e. clinical validation and translation to market.

Verification of the qLabs international normalized ratio point-of-care device for monitoring of patients attending an anticoagulation clinic

INTRODUCTION

In the developing world, point-of-care (POC) testing for international normalized ratio (INR) plays an important role in the monitoring of patients on long-term warfarin therapy with limited access to healthcare ensuring safe and effective anticoagulation. A newly developed POC device for INR measurement by healthcare workers is the handheld qLabs POC device^® (Micropoint Biotechnologies Incorporated, Guangdong, China).

METHODS

The qLabs POC device^® was evaluated in 262 patients attending an anticoagulation clinic with regards to accuracy and precision of the INR results. The results were compared to the results obtained on the Stago STA R Max^® coagulation analyzer (Stago Diagnostica, Paris, France) on a wide range of normal and abnormal results of clinical relevance.

RESULTS

The mean laboratory INR (2.50 ± 1.08) was significantly higher than the qLabs POC device^® INR (2.38 ± 1.07) (P < .0001). The correlation coefficient (r) was .88, the slope coefficient was 1.0 (CI, 0.8-1.2), and the intercept was -0.10 (CI, -0.50 to 0.30). The mean of the differences was -0.13% (CI, -0.19 to -0.06). Dosage concordance was 85.46% and clinical agreement was 92.37%. However, clinical agreement was 42.42% in the subgroup above the target range (>3.5). The imprecision was within acceptable limits (<5%) and the error message rate was 4.38%.

CONCLUSION

In conclusion, the qLabs POC device^® is accurate and precise with high levels of dosage concordance and clinical agreement for INR values within and below the target range.

Current Nucleic Acid Extraction Methods and Their Implications to Point-of-Care Diagnostics

Nucleic acid extraction (NAE) plays a vital role in molecular biology as the primary step for many downstream applications. Many modifications have been introduced to the original 1869 method. Modern processes are categorized into chemical or mechanical, each with peculiarities that influence their use, especially in point-of-care diagnostics (POC-Dx). POC-Dx is a new approach aiming to replace sophisticated analytical machinery with microanalytical systems, able to be used near the patient, at the point of care or point of need. Although notable efforts have been made, a simple and effective extraction method is still a major challenge for widespread use of POC-Dx. In this review, we dissected the working principle of each of the most common NAE methods, overviewing their advantages and disadvantages, as well their potential for integration in POC-Dx systems. At present, it seems difficult, if not impossible, to establish a procedure which can be universally applied to POC-Dx. We also discuss the effects of the NAE chemicals upon the main plastic polymers used to mass produce POC-Dx systems. We end our review discussing the limitations and challenges that should guide the quest for an efficient extraction method that can be integrated in a POC-Dx system.

Portable devices and mobile instruments for infectious diseases point-of-care testing

INTRODUCTION

Rapidity, simplicity, and portability are highly desirable characteristics of tests and devices designed for performing diagnostics at the point of care (POC), either near patients managed in healthcare facilities or to offer bioanalytical alternatives in external settings. By reducing the turnaround time of the diagnostic cycle, POC diagnostics can reduce the dissemination, morbidity, and mortality of infectious diseases and provide tools to control the global threat of antimicrobial resistance. Areas covered: A literature search of PubMed and Google Scholar, and extensive mining of specialized publications, Internet resources, and manufacturers' websites have been used to organize and write this overview of the challenges and requirements associated with the development of portable sample-to-answer diagnostics, and showcase relevant examples of handheld devices, portable instruments, and less mobile systems which may or could be operated at POC. Expert commentary: Rapid (<1 h) diagnostics can contribute to control infectious diseases and antimicrobial resistant pathogens. Portable devices or instruments enabling sample-to-answer bioanalysis can provide rapid, robust, and reproducible testing at the POC or close from it. Beyond testing, to realize some promises of personalized/precision medicine, it will be critical to connect instruments to healthcare data management systems, to efficiently link decentralized testing results to the electronic medical record of patients.

Multiplex SNP genotyping in whole blood using an integrated microfluidic lab-on-a-chip

Pharmacogenetics has often been touted as a cornerstone for precision medicine as detailed knowledge of a specific genetic makeup may allow for accurate predictions of a patient's individual drug response. Still, the widespread use of genetic tests is limited as they remain expensive and cumbersome, requiring sophisticated tools and highly trained personnel. In order for pharmacogenetics to reach its full potential, more cost-effective and easily accessible genotyping methods are desired. To meet these challenges, we present a silicon-based integrated microsystem for the detection of multiple single nucleotide polymorphisms (SNPs) directly from human blood. The device combines a blood lysis chamber, a cross-flow filter, a T-junction mixer, and a microreactor for quantitative polymerase chain reaction (qPCR). Using this device, successful on-chip genotyping of two clinically relevant SNPs in human CYP2C9 gene was demonstrated with TaqMan assays, starting from blood. The two SNPs were detected simultaneously by introducing a sequence of plugs, each containing a different set of primers and probes. The method can be easily extended to detect several SNPs. The microsystem described here offers a rapid, reproducible, and accurate sample-to-answer technology enabling multiplex SNP profiling in point-of-care settings, bringing pharmacogenetics-based precision medicine a step closer to reality.

Challenges of development and implementation of point of care pharmacogenetic testing

INTRODUCTION

Just as technology was the underlying driver of the sequencing of the human genome and subsequent generation of volumes of genome sequence data from healthy and affected individuals, animal, plant, and microbial species alike, so too will technology revolutionize diagnostic testing. One area of intense interest is the use of genetic data to inform decisions regarding drug selection and drug dosing, known as pharmacogenetic (PGx) testing, to improve likelihood of successful treatment outcomes with minimal risks.

AREAS COVERED

This commentary will provide an overview of implementation research of PGx testing, the benefits of point-of-care (POC) testing and overview of POC testing platforms, available PGx tests, and barriers and facilitators to the development and integration of POC-PGx testing into clinical settings. Sources include the published literature, and databases from the Centers for Medicaid and Medicare Services, Food and Drug Administration. Expert commentary: The utilization of POC PGx testing may enable more routine test use, but the development and implementation of such tests will face some barriers before personalized medicine is available to every patient. In particular, provider training, availability of clinical decision supports, and connectivity will be key areas to facilitate routine use.

Novel developments in mobile sensing based on the integration of microfluidic devices and smartphones

Portable electronic devices and wireless communication systems enable a broad range of applications such as environmental and food safety monitoring, personalized medicine and healthcare management. Particularly, hybrid smartphone and microfluidic devices provide an integrated solution for the new generation of mobile sensing applications. Such mobile sensing based on microfluidic devices (broadly defined) and smartphones (MS(2)) offers a mobile laboratory for performing a wide range of bio-chemical detection and analysis functions such as water and food quality analysis, routine health tests and disease diagnosis. MS(2) offers significant advantages over traditional platforms in terms of test speed and control, low cost, mobility, ease-of-operation and data management. These improvements put MS(2) in a promising position in the fields of interdisciplinary basic and applied research. In particular, MS(2) enables applications to remote in-field testing, homecare, and healthcare in low-resource areas. The marriage of smartphones and microfluidic devices offers a powerful on-chip operating platform to enable various bio-chemical tests, remote sensing, data analysis and management in a mobile fashion. The implications of such integration are beyond telecommunication and microfluidic-related research and technology development. In this review, we will first provide the general background of microfluidic-based sensing, smartphone-based sensing, and their integration. Then, we will focus on several key application areas of MS(2) by systematically reviewing the important literature in each area. We will conclude by discussing our perspectives on the opportunities, issues and future directions of this emerging novel field.

Issues in the practical implementation of POCT: overcoming challenges

There are many challenges in implementing a successful point-of-care testing (POCT) program. When compared to traditional testing, POCT results are faster and allow for rapid patient treatment. Unfortunately, the excitement of this technology is often lost due to an assortment of practical obstacles. Implementation of POCT requires consideration of the regulatory complexity and amount of documentation to be compliant. As more tests move to the site of patient care, the number of operators that need to be trained and assessed will grow. An effective POCT program rests solely on the foundation of education and training of each operator, but assuring regular competency updates for a large number of staff can be a management issue. Discussed in this article are several of the key obstacles to implementing a POCT program including laboratory quality regulations, compliance documentation and operational management challenges.