Evaluation of carbohydrate antigen 50 in human serum using magnetic particle-based chemiluminescence enzyme immunoassay

Detection of serum CC16 by a rapid and ultrasensitive magnetic chemiluminescence immunoassay for lung disease diagnosis

OBJECTIVES

It has been reported that serum Clara cell secreted protein 16 (CC16) is a potential biomarker for lung injury diseases, but currently, there is no other method that is faster, more accurate, or more sensitive being applied in clinical practice apart from ELISA. The current study was designed to established a magnetic nanoparticles chemiluminescence immunoassay (MNPs-CLIA) for highly sensitive automated detection of serum Clara cell secretory protein 16 (CC16), and validated its diagnostic performance for lung disease.

METHODS

The study included the expression of CC16 recombinant protein, the preparation and screening of its monoclonal antibody (MAb), as well as the construction, optimization and analytical evaluation of the MNPs-CLIA method. The clinical application value of this method was investigated by detecting CC16 level in 296 serum samples.

RESULTS

The linear range of the MNPs-CLIA assay system was 0.2-50 ng/mL, and the limit of detection was 0.037 ng/mL. Performance parameters such as specificity, recovery rate, and precision can meet the industry standards of in vitro diagnostic reagents. The established method reveals consistent results with ELISA (R2=0.9962) currently used clinically, and it also exhibits satisfactory diagnostic efficacy of silicosis, chronic obstructive pulmonary disease (COPD), and pulmonary sarcoidosis, with areas under the curve (AUC) of 0.9748, 0.8428 and 0.9128, respectively.

CONCLUSIONS

Our established MNPs-CLIA method has the advantages of automation, high throughput, rapidity, and simplicity, and can be promoted for widely popularized in clinical applications. MNPs-CLIA detection of serum CC16 has efficient diagnostic potentiality for predicting and diagnosing lung diseases.

Overview on the Development of Alkaline-Phosphatase-Linked Optical Immunoassays

The drive to achieve ultrasensitive target detection with exceptional efficiency and accuracy requires the advancement of immunoassays. Optical immunoassays have demonstrated significant potential in clinical diagnosis, food safety, environmental protection, and other fields. Through the innovative and feasible combination of enzyme catalysis and optical immunoassays, notable progress has been made in enhancing analytical performances. Among the kinds of reporter enzymes, alkaline phosphatase (ALP) stands out due to its high catalytic activity, elevated turnover number, and broad substrate specificity, rendering it an excellent candidate for the development of various immunoassays. This review provides a systematic evaluation of the advancements in optical immunoassays by employing ALP as the signal label, encompassing fluorescence, colorimetry, chemiluminescence, and surface-enhanced Raman scattering. Particular emphasis is placed on the fundamental signal amplification strategies employed in ALP-linked immunoassays. Furthermore, this work briefly discusses the proposed solutions and challenges that need to be addressed to further enhance the performances of ALP-linked immunoassays.

Detection of Carbohydrate Antigen 50 Based on a Novel Miniaturized Chemiluminescence Analyzer Enables Large-Scale Cancer Early Screening in Grassroots Community

Early screening of cancer can effectively prolong survival time and reduce cancer mortality. However, the existing health-monitoring devices can only be carried out in professional laboratories, so large-scale early cancer screening in resource-limited settings is hardly achieved. To embrace the challenge, we developed a novel chemiluminescence immunoassay (CLIA) analyzer that does not require a professional operation. Then, it was applied to detect carbohydrate antigen 50 (CA50), a non–organ-specific tumor marker for screening various cancers. As a result, the analyzer exhibited excellent performance that the total assay time was only 15 min, and the detection limit reached 0.057 U ml⁻¹. A coefficient of variance (CV) less than 15% was well-controlled for both intra- and inter-assay precision, and the linear range was 0–500 U ml⁻¹. More importantly, this analyzer can continuously detect 60 samples per hour without any professional paramedic. Finally, this analyzer has been applied to evaluate clinical samples and the detected results showed a good correlation with the clinical test results (correlation coefficient, 0.9958). These characteristics exactly meet large-scale and high-throughput early screening of cancer. Thus, this miniaturized analyzer for CA50 detection is promising to achieve early large-scale screening of cancer in the resource-limited grassroots community.

Tools and Techniques for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)/COVID-19 Detection

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory disease coronavirus 2 (SARS-CoV-2), has led to millions of confirmed cases and deaths worldwide. Efficient diagnostic tools are in high demand, as rapid and large-scale testing plays a pivotal role in patient management and decelerating disease spread. This paper reviews current technologies used to detect SARS-CoV-2 in clinical laboratories as well as advances made for molecular, antigen-based, and immunological point-of-care testing, including recent developments in sensor and biosensor devices. The importance of the timing and type of specimen collection is discussed, along with factors such as disease prevalence, setting, and methods. Details of the mechanisms of action of the various methodologies are presented, along with their application span and known performance characteristics. Diagnostic imaging techniques and biomarkers are also covered, with an emphasis on their use for assessing COVID-19 or monitoring disease severity or complications. While the SARS-CoV-2 literature is rapidly evolving, this review highlights topics of interest that have occurred during the pandemic and the lessons learned throughout. Exploring a broad armamentarium of techniques for detecting SARS-CoV-2 will ensure continued diagnostic support for clinicians, public health, and infection prevention and control for this pandemic and provide advice for future pandemic preparedness.

Performance Evaluation of a New Automated Chemiluminescent Immunoanalyzer-Based Interferon-Gamma Releasing Assay AdvanSure I3 in Comparison With the QuantiFERON-TB Gold In-Tube Assay

BACKGROUND

The interferon-gamma (IFN-γ) releasing assay (IGRA) is widely used for latent tuberculosis infection (LTBI) diagnosis. We evaluated the analytical performance of a new automated chemiluminescent immunoanalyzer-based IGRA (CLIA-IGRA), AdvanSure I3 (LG Life Sciences, Seoul, Korea) and compared it with that of the QuantiFERON-TB Gold In-Tube (QFT-GIT) assay.

METHODS

Repeatability and reproducibility were evaluated at four levels. Detection capability, including limit of blank (LoB), limit of detection (LoD), and limit of quantification (LoQ), was evaluated using IFN-γ standard material (National Institute for Biological Standards and Control code: 87/586). Agreement between the results of two assays was evaluated using 341 blood samples from healthcare workers and patients at a tertiary care hospital. To determine the cut-off value of CLIA-IGRA for diagnosing LTBI, the ROC curve was analyzed.

RESULTS

Repeatability and reproducibility were 4.86-7.00% and 6.36-7.88% CV, respectively. LoB, LoD, and LoQ were 0.022, 0.077, and 0.249 IU/mL, respectively. IFN-γ values between CLIA-IGRA and QFT-GIT showed a strong correlation within the analytical measurable range of both assays, especially when the value was low. Qualitative comparison of the two assays yielded a 99.1% overall agreement (kappa coefficient=0.98). A cut-off value of 0.35 IU/mL was appropriate for diagnosing LTBI.

CONCLUSIONS

CLIA-IGRA is a reliable assay for LTBI diagnosis, with performance similar to that of QFT-GIT.

Serum CA50 levels in patients with cancers and other diseases

Carbohydrate antigen 50 (CA50) is initially reported as a cancer-specific antigen expressed on the surface of human colorectal Colo-205 cancer cells. Subsequently, increased serum CA50 levels are observed in patients not only with colorectal cancers but also other types of cancers. Eventually, serum CA50 is measured clinically as a cancer biomarker. However, serum CA50 level does not always increase in cancer patients but does increase in patients suffering from nonneoplasm diseases, which indicates that serum CA50 is not produced by cancer cells exclusively. Therefore, the serum CA50 levels in patients suffering different types of diseases should be systematically compared in order to comprehend the molecular nature of serum CA50 as a biomarker. In our current study, we measured and analyzed serum CA50 levels from 2113 patients with 14 clinically defined diseases with at least 30 independent tests for each disease in addition to 13,997 serum samples from individuals who attend their annual physical examination as healthy controls. Based on the mean, median, and -Log₁₀p values, we found that patients suffering from pancreatic cancer, cirrhosis, pancreatitis, lung cancer, type 2 diabetes mellitus, and colon cancer had highest levels of serum CA50 while patients suffering from coronary heart disease, gastric cancer, and rectum cancer showed comparable serum CA50 levels to that of healthy controls. Moreover, patients with osteoporosis, anemia, or gastritis had lower serum CA50 levels than that of healthy controls. Furthermore, healthy individuals older than 65 years old had increased serum CA50 levels compared with that of healthy controls. Taken together, these data suggest that serum CA50 is likely to be a system malfunction biomarker, and the serum CA50 levels could be used as diagnostic biomarkers not only for cancers but also for other nonneoplasm diseases.

Detection of urinary survivin using a magnetic particles-based chemiluminescence immunoassay for the preliminary diagnosis of bladder cancer and renal cell carcinoma combined with LAPTM4B

The aim of the present study was to establish a simple step magnetic particles (MPs) based chemiluminescence enzyme immunoassay (CLEIA) for the detection of urinary survivin, and to investigate the diagnostic value of urinary survivin and lysosome-associated protein transmembrane-4β (LAPTM4B) in bladder cancer (BC) and renal cell carcinoma (RCC). The MPs-based CLEIA was developed on the basis of a double antibodies sandwich immunoreaction and luminol-H₂O₂ chemiluminescence system. The parameters of the method were optimized and evaluated. Urine samples were obtained from 200 BC patients, 81 RCC patients and 114 healthy individuals, and the MPs-based CLEIA method was employed to detect their urinary survivin. At the same time, the urinary LAPTM4B levels of the BC patients, RCC patients and the healthy controls were measured. The diagnostic efficiency of urinary survivin and LAPTM4B in BC and RCC was evaluated separately and jointly. A one-step MPs-based CLEIA for the detection of urinary survivin with good accuracy and precision was established. The signals were dependent on survivin concentrations in the range, 0 to 200 ng/ml, and the detection limit was 0.949 ng/ml. The areas under the receiver operating characteristic curves (AUC) were 0.771 in BC and 0.763 in RCC for urinary survivin. Urinary survivin was correlated with the tumor stage (P=0.002), lymph node metastasis (P=0.017), distant metastasis (P=0.005) and tumor size (P=0.02) of BC; however, no association with the clinicopathological parameters in RCC was observed. The AUCs for urinary LAPTM4B were 0.738 in BC and 0.704 in RCC, respectively. The AUCs for them combined were 0.842 in BC and 0.920 in RCC. The MPs-based CLEIA was performed well in the detection of urinary survivin. Urinary survivin and LAPTM4B could serve as potential biomarkers for the preliminary diagnosis of BC and RCC, and in combination they a achieved a greater diagnostic performance.

Evaluation of a magnetic particles-based chemiluminescence enzyme immunoassay for Golgi protein 73 in human serum

BACKGROUND

Golgi protein 73 (GP73) is regarded as a potential serum biomarker for early diagnosis of hepatocellular carcinoma (HCC). We developed a rapid magnetic particles-based chemiluminescence enzyme immunoassay (MPs-CLEIA) for the determination of serum GP73.

METHODS

Fluorescein isothiocyanate (FITC) and alkaline phosphatase (ALP) were used to label 2 different monoclonal antibodies to GP73. Serum GP73 was captured with labeled antibodies and formed a sandwiched immunoreaction. The magnetic particles (MPs) coated with anti-FITC antibody were used as a means of separation of the GP73 protein from other serum proteins. After adding the enzyme substrate solution, the relative light unit (RLU) was measured. A MPs-CLEIA for serum GP73 was established and evaluated.

RESULTS

The RLU was directly proportional to the concentration of GP73. The method linearity was 5-600 μg/l. Limit of the blank was 2.19 μg/l. The intra- and inter-assay imprecision was <3% and <5%, respectively. The average recoveries were between 95% and 105%. The proposed method showed a good correlation with a commercial ELISA assay (r=0.983, p<0.001). We also evaluated the efficiency of serum GP73 measurement for the diagnosis of HCC using this assay. The area under the receiver operating characteristic curve was 0.822 (95% CI, 0.73-0.89), and the sensitivity and specificity, with cut-off value of 115.6 μg/l, were 75.4% and 92.1%, respectively.

CONCLUSIONS

The proposed method demonstrates an acceptable performance for quantifying serum GP73. This assay could be appropriate for routine use in clinical laboratories.

Application of immunomagnetic particles to enzyme-linked immunosorbent assay (ELISA) for improvement of detection sensitivity of HCG

This investigation was aimed at using superparamagnetic particles to enzyme-linked immunosorbent assay (SPIO-ELISA) of human chorionic gonadotropin (hCG) to enhance detection sensitivity of hCG. We found that N-(3-dimethyl aminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) was the best cross-linking reagent to link anti hCG α antibody to superparamagnetic particle (SPIO-anti hCG α antibody immunomagnetic particle). To improve the specificity of the assay, a horse radish peroxidase (HRP)-labeled anti-hCG beta monoclonal antibody was used to detect captured hCG using double antibody sandwich ELISA assay. SPIO-ELISA application to determine hCG increased the sensitivity to 1 mIU/mL, which is a level of sensitivity enabling the diagnosis of pregnancy during the early gestational period.

Comparison of chemiluminescence enzyme immunoassay based on magnetic microparticles with traditional colorimetric ELISA for the detection of serum α-fetoprotein

A chemiluminescence enzyme immunoassay based on magnetic microparticles (MmPs-CLEIA) was developed to evaluate serum α-fetoprotein (AFP) in parallel with traditional colorimetric enzyme-linked immunosorbent assay (ELISA). A systematic comparison between the MmPs-CLEIA and colorimetric ELISA concluded that the MPs-CLEIA exhibited fewer dosages of immunoreagents, less total assay time, and better linearity, recovery, precision, sensitivity and validity. AFP was detected in forty human serum samples by the proposed MPs-CLEIA and ELISA, and the results were compared with commercial electrochemiluminescence immunoassay (ECLIA) kit. The correlation coefficient between MPs-CLEIA and ELISA was obtained with R²=0.6703; however, the correlation between MPs-CLEIA and ECLIA (R²=0.9582) was obviously better than that between colorimetric ELISA and ECLIA (R²=0.6866).

Chemiluminescence enzyme immunoassay based on magnetic nanoparticles for detection of hepatocellular carcinoma marker glypican-3

Glypican-3 (GPC3) is reported as a great promising tumor marker for hepatocellular carcinoma (HCC) diagnosis. Highly sensitive and accurate analysis of serum GPC3 (sGPC3), in combination with or instead of traditional HCC marker alpha-fetoprotein (AFP), is essential for early diagnosis of HCC. Biomaterial-functionalized magnetic particles have been utilized as solid supports with good biological compatibility for sensitive immunoassay. Here, the magnetic nanoparticles (MnPs) and magnetic microparticles (MmPs) with carboxyl groups were further modified with streptavidin, and applied for the development of chemiluminescence enzyme immunoassay (CLEIA). After comparing between MnPs- and MmPs-based CLEIA, MnPs-based CLEIA was proved to be a better method with less assay time, greater sensitivity, better linearity and longer chemiluminescence platform. MnPs-based CLEIA was applied for detection of sGPC3 in normal liver, hepatocirrhosis, secondary liver cancer and HCC serum samples. The results indicated that sGPC3 was effective in diagnosis of HCC with high performance.

Functionalized, biocompatible coating for superparamagnetic nanoparticles by controlled polymerization of a thioglycosidic monomer

It is demonstrated that water-soluble, glucosylated poly(pentafluorostyrene) derivatives revealed favorable coating material properties for magnetic iron oxide nanoparticles. To prepare the coating material in high reproducibility and purity as well as in sufficient amounts, a new route of synthesis is established. The preparation and characterization of the glucosylated, tetrafluorostyryl monomer, by thiol-para-fluorine "click" reaction, and its polymerization, via nitroxide-mediated radical process, is presented in detail. In addition, the coating material and the resulting particle properties are investigated by means of XPS, DLS, TGA, TEM, and cryo-TEM as well as flow cytometry. The glycopolymer acts as an appropriate stabilizing agent for the superparamagnetic nanoparticles by the formation of an approximately 10 nm thick shell, as shown by the XPS analysis. Furthermore, the application of FITC-labeled glycopolymer yielded fluorescent, superparamagnetic nanoparticles, which can be used for monitoring cell-carbohydrate interactions, because these particles show no cytotoxicity toward 3T3 fibroblasts.

Magnetically modulated nanosystems: a unique drug-delivery platform

Magnetic nanoparticles are attractive targets owing to their unique characteristics that are not shared by bulk materials. Magnetic particles, ranging from nanometer-sized to 1 µm in size, are being used in an increasing number of medical applications. The important properties of magnetic particles for medical applications are nontoxicity, biocompatiblilty, injectability and high-level accumulation in the target tissue or organ. Magnetic nanoparticles modified with organic molecules have been widely used for biotechnological and biomedical applications as their properties can be magnetically controlled by applying an external magnetic field. They offer high potential for numerous biomedical applications, such as cell separation, automated DNA extraction, gene targeting, drug delivery, MRI and hyperthermia. When coated with, for example, an antibody, they can be applied in highly sensitive immunoassays or small substance recoveries. Furthermore, a novel application of magnetic nanoparticles and magnetic forces for tissue engineering, termed ‘magnetic force-based tissue engineering’ has been proposed. Particular attention had been paid to the preparation methods that allow the synthesis of particles of nearly uniform size and shape.

Magnetic particle-based chemiluminescence enzyme immunoassay for free thyroxine in human serum

A magnetic particles-based chemiluminescence enzyme immunoassay with high sensitivity, specificity, rapidity, and reproducibility was developed for the determination of free thyroxine in human serum. A competitive assay has been proposed with horseradish peroxidase labeled thyroxine analog. The immunomagnetic particles coated with anti-fluorescein isothiocyanate antibody was used as dispersed solid phase and separation means for the immunoassay. Experimental conditions, such as temperature, the volume of magnetic particles and substrate, incubation time, dilution ratio and other relevant variables upon the immunoassay have been examined and optimized. The proposed method exhibited high performance which the linear range was 1.59-122 pmol L(-1) and the detection limit was 0.25 pmol L(-1). A coefficient of variance of less than 15% was obtained for both intra-assay and inter-assay precision. The present method has been successfully applied to the analysis of free thyroxine in human serum. The diagnostic accordance rate of the method for normal serum, hyperthyroidism and hypothyroidism are satisfactory. Good correlations were obtained between the results by the proposed method and the commercial radioimmunoassay kit. The present method exhibits good potential in the fabrication of FT4 diagnostic kits which could be used in the clinical analysis and facilitated the development of automated operation systems in the clinical practice.

Evaluation of alpha-fetoprotein (AFP) in human serum by chemiluminescence enzyme immunoassay with magnetic particles and coated tubes as solid phases

In this work, the monoclonal antibodies (McAbs) to alpha-fetoprotein (AFP) were immobilized on two different solid phases, i.e., magnetic particles (MP) and coated tubes (CT). Based on this, a MP based chemiluminescence enzyme immunoassay (MP-CLEIA) and a CT based CLEIA (CT-CLEIA) were proposed for the evaluation of AFP in human serum and their analytical merits were studied and compared. By detailed discussion of several performance variants, including the concentration of immobilized McAb, dilution ratio of horseradish peroxidase (HRP) labeled McAb (HRP-McAb), total assay time, substrate volume, chemiluminescent kinetics, and hook effect concentration, the advantages of MP-CLEIA became conspicuously apparent. Moreover, in the presence of MP, the catalytic activity of labeled enzyme was kept to high extent and the stability of immunoreagents was satisfied. Finally, 59 human serum samples were detected by the MP-CLEIA and a good correlation was obtained when comparing the results with that from a commercial electrochemiluminescence immunoassay kit.