Chromotrope FB (Chr FB) is a synthetic azo dye permitted for use in foods and medicines. An acceptable daily intake (ADI) of Chr FB was 0–0.5mg/kg in China. In this study, we synthesized a Chr FB ...hapten with an amino group to prepare its artificial immunogen. Polyclonal antibodies obtained from New Zealand rabbits were applied to develop an indirect competitive chemiluminescent immunoassay (icCLIA) to detect Chr FB in foods. A horseradish peroxidase (HRP)-luminol-H2O2 system was used to yield CL signal with p-iodophenol as an enhancement reagent. The method showed good specificity towards Chr FB and could detect as low as 0.02ngmL−1 Chr FB in buffer, 0.07ngg−1 in yoghurt candy, 0.07ngg−1 in vitamin drink and 0.13ngg−1 in bread. Compared with HPLC method, the proposed method is more sensitive by two orders of magnitude. The accuracy and precision of this method are acceptable and comparable with HPLC method. Therefore, the proposed method could be used for rapid screening of Chr FB in the mentioned foodstuffs.
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•We designed and synthesized Chromotrope FB (Chr FB) hapten with an amino group.•A highly sensitive and specific chemiluminescence immunoassay (CLIA) for Chr FB was developed.•The CLIA method is more sensitive than ELISA and HPLA method.•The method could be successfully used in rapid detection of Chr FB in yoghurt hard candy, vitamin drink and bread.
Background: Coronavirus disease 2019 (COVID-19) influenced the prevalence of other infectious diseases, including congenital cytomegalovirus (CMV) infection. However, the effect of COVID-19 on ...antibody titers has not been reported. This study aimed to explore the influence of COVID-19 on levels of CMV immunoglobulin M (IgM) in pregnant women. Methods: This cross-sectional study included pregnant women who visited the University Hospital due to CMV IgM positivity during the 7th and 8th waves of COVID-19. Data, including maternal characteristics, history of COVID-19, CMV immunoglobulin G (IgG) and IgM index, and IgG avidity index (AI) were collected. Chemiluminescent immunoassay was performed to measure levels of IgG and IgM. Polymerase chain reaction using neonatal urine was performed to confirm congenital infection. Results: Of the 89 pregnant women, 36 (40%) (low IgG AI: n = 10; high IgG AI: n = 26) contracted COVID-19. Among 21 women with low IgG AI, 9 (false IgM positive: n = 8; primary infection: n = 1) had an IgG AI of 0. Among the eight women with false IgM positivity, six (75%) contracted COVID-19. The IgM index of pregnant women with false IgM positivity was 12.6 ± 10.9. Meanwhile, the CMV IgM index of pregnant women with false IgM positivity in the non-COVID-19-infected group was 1.7 ± 0.5. When the IgM indices of women who contracted (n = 36) and did not contract (n = 53) COVID-19 were compared, the IgM index of infected women (4.4 ± 5.7) was higher than those of non-infected women (2.7 ± 3.0) (p = 0.01). Regarding IgM and IgG AI, multiple logistic regression analysis revealed that there were no significantly different variables between the two groups. Conclusions: High prevalence of false IgM positivity was observed among women who contracted COVID-19. The IgM index of pregnant women with false IgM positivity was high. Caution should be exercised in interpreting CMV IgM indices in pregnant women with a history of COVID-19.
Background
Diagnosis of antiphospholipid syndrome (APS) is based on the positivity of laboratory criteria antiphospholipid antibodies (aPLs). Test results for aPLs could be contradictory among ...different detection methods as well as commercial manufacturers. This study aimed to assess and compare the diagnostic and analytic performances of four commercial assays prevalently used in China.
Methods
A total of 313 patients including 100 patients diagnosed with primary APS, 52 with APS secondary to SLE, 71 with SLE, and 90 health controls were recruited. Serum IgG, IgM, and IgA for aCL, and a
β
2GPI antibodies were detected with two ELISA and two CLIA systems, and test system with the best diagnostic value was explored of its correlation with key clinical features.
Results
CLIA by YHLO Biotech Co. was considered as the system with the best predictive power, where 58.55 and 57.89% of APS patients were positive for aCL or a
β
2GPI for at least one antibody (IgG or IgM or IgA). Overall, CLIA showed better performance characteristics than traditional ELISA test systems.
Conclusion
CLIA was considered as a better platform for aPL detection in APS diagnosis. A combination of other detection platforms could assist in differential diagnosis as well as in identifying high-risk patients.
•The CLIA methods for detection of synovial fluid LTF and S100A8 were developed and their analytical performance was verified.•The CLIA methods have wider linear range and are more suitable for the ...detection of LTF and S100A8 in synovial fluid.•Detecting synovial fluid LTF and S100A8 using established CLIA methods can accurately diagnose PJI.•Compared to ELISA, the CLIA methods has the advantages of high automation, short detection time, low detection cost.
Synovial fluid lactoferrin (LTF) and S100 calcium-binding protein A8 (S100A8) have been considered as potential biomarkers for the diagnosis of periprosthetic joint infection (PJI) through our previous research. However, the detection methods of these two proteins are still immature, so a rapid, accurate and cost-effective testing method is warranted.
We developed chemiluminescent immunoassays (CLIA) for the automated detection of synovial fluid LTF and S100A8 and assessed the analytical performance for these two methods. In addition, we recruited 86 patients who were suspected of PJI after total joint replacement (TJA) and examined their synovial fluid using CLIA to explore the clinical application value of these methods and the diagnostic efficiency of synovial fluid LTF and S100A8 for PJI.
Our established CLIA methods have a wide linear range of 20–10,000 ng/mL for LTF detection system and 5–5000 ng/mL for S100A8 detection system. Performance parameters such as precision, specificity, and recovery rate can meet the industry standards. Then, the established methods were used to detect LTF and S100A8 in synovial fluid samples, which showed excellent diagnostic efficiency for PJI, and the areas under ROC curve (AUC) were 0.954 (95 % CI: 0.909–0.999) and 0.958 (95 % CI: 0.918–0.997), respectively.
Our established CLIA methods have the advantages of automation, high throughput, low price, and is expected to be widely popularized in clinical applications. Synovial fluid LTF and S100A8 detected through CLIA had efficient diagnostic potentiality for predicting and diagnosing PJI.
Prostate cancer (PCa) is one of the most frequently diagnosed cancers and the leading cause of cancer death in males worldwide. Although prostate-specific antigen (PSA) screening has considerably ...improved the detection of PCa, it has also led to a dramatic increase in overdiagnosing indolent disease due to its low specificity. This study aimed to develop and validate a multivariate diagnostic model based on the urinary epithelial cell adhesion molecule (EpCAM)-CD9-positive extracellular vesicles (EVs) (uEV
) to improve the diagnosis of PCa.
We investigated the performance of uEV
from urine samples of 193 participants (112 PCa patients, 55 benign prostatic hyperplasia patients, and 26 healthy donors) to diagnose PCa using our laboratory-developed chemiluminescent immunoassay. We applied machine learning to training sets and subsequently evaluated the multivariate diagnostic model based on uEV
in validation sets.
Results showed that uEV
was able to distinguish PCa from controls, and a significant decrease of uEV
was observed after prostatectomy. We further used a training set (N = 116) and constructed an exclusive multivariate diagnostic model based on uEV
, PSA, and other clinical parameters, which showed an enhanced diagnostic sensitivity and specificity and performed excellently to diagnose PCa area under the curve (AUC) = 0.952, P < 0.0001. When applied to a validation test (N = 77), the model achieved an AUC of 0.947 (P < 0.0001). Moreover, this diagnostic model also exhibited a superior diagnostic performance (AUC = 0.917, P < 0.0001) over PSA (AUC = 0.712, P = 0.0018) at the PSA gray zone.
The multivariate model based on uEV
achieved a notable diagnostic performance to diagnose PCa. In the future, this model may potentially be used to better select patients for prostate transrectal ultrasound (TRUS) biopsy.
QuantiFERON-TB Gold Plus (QFT-Plus) is the most widely used interferon gamma release assay (IGRA) for the diagnosis of latent tuberculosis infection (LTBI). The aim of this study was to compare ...QFT-Plus results by enzyme-linked immunosorbent assay (ELISA) on the SkyLab system with those obtained with chemiluminescence immunoassay (CLIA) on the Liaison XL analyzer. Agreement between the two assays was evaluated on 419 QFT-Plus blood samples and was found to be substantial (75.4%); higher agreement was found for positive (95.4%) and negative (80.4%) results, while most discordances were due to ELISA-indeterminate/CLIA-determinate results. According to Italian Clinical Microbiologist Association recommendations, in samples (
= 79) with a borderline result in ELISA (0.20 to 0.70 IU/ml), CLIA median values statistically increased (from 0.29 to 0.59 IU/ml for TB1 and from 0.32 to 0.60 IU/ml for TB2) but remained in the borderline range. Linear regression analysis indicated a substantial correlation between ELISA and CLIA for antigen tubes TB1 (Pearson's
= 0.8666) and TB2 (Pearson's
= 0.8728), but CLIA produced higher values than ELISA. Receiver operating characteristic (ROC) analysis showed that the optimal cutoff value in CLIA was 0.45 IU/ml for TB1 and 0.46 IU/ml for TB2. In conclusion, automated QFT-Plus with CLIA is comparable to QFT-Plus performed by ELISA. Within the linearity range of the test, CLIA detects higher quantitative values than ELISA, resulting in a higher number of determinate results and the conversion of samples that were close to the cutoff into positive borderline results. A higher cutoff for QFT-CLIA needs to be defined based on clinical diagnostic criteria.
The introduction of chemiluminescent immunoassay (CLIA) in blood donor screening has led to a gradual replacement of enzyme-linked-immunosorbent assay (ELISA) as the former offers automation, higher ...sensitivity and lower turn-around-time. However, only a few CLIA platforms are used for blood donor screening in India. The present study evaluated one such newer platform viz., Adiva Centaur XP CLIA for screening of HBV, HCV, HIV and syphilis.
Prospective comparative study wherein 4843 whole blood donors were screened for HBsAg, Anti-HCV, HIV Ag-Ab and Anti-treponemal antibodies in both Advia Centaur XP and Architect i2000SR platforms. Additional tests were performed in samples which were reactive in only one of the platforms. The sensitivity, specificity, positive predictive value, negative predictive value, accuracy, false positive rate and false negative rate of both the platforms were compared. Kappa coefficient was calculated to determine the agreement between the testing platforms.
The sensitivity of Advia Centaur platform for HBV, HCV, HIV and syphilis detection were 94.9 %, 100 %, 100 % and 100 % respectively as compared to 96.6 %, 100 %, 100 % and 100 % in Architect i2000SR platform. The specificity of both the platforms were 99.8−99.9 % for all the four tests. The agreement between the two platforms was almost perfect for HBV, HCV and syphilis testing; and fair for HIV testing.
The Advia Centaur CLIA platform was found to be comparable with the Architect CLIA platform for blood donor screening. Unexpected finding was the occurrence of HBV false negatives in both the platforms, possibly due to HBsAg mutations.
Background
The accurate detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the key to control Coronavirus Disease-2019 (COVID-19). The performance of different antibody ...detection methods for diagnosis of COVID-19 is inconclusive.
Methods
Between 16 February and 28 February 2020, 384 confirmed COVID-19 patients and 142 healthy controls were recruited. 24 different serological tests, including 4 enzyme-linked immunosorbent assays (EIAs), 10 chemiluminescent immunoassays (CLIAs), and 10 lateral flow immunoassays (LFIAs), were simultaneously performed.
Results
The sensitivities of anti-SARS-CoV-2 IgG and IgM antibodies with different reagents ranged from 75 to 95.83% and 46.09 to 92.45%, respectively. The specificities of both anti-SARS-CoV-2 IgG and IgM were relatively high and comparable among different reagents, ranged from 88.03 to 100%. The area under the curves (AUCs) of different tests ranged from 0.733 to 0.984, and the AUCs of EIAs or CLIAs were significantly higher than those of LFIAs. The sensitivities of both IgG and IgM gradually increased with increase of onset time. After 3–4 weeks, the sensitivities of anti-SARS-CoV-2 IgG were maintained at a certain level but the sensitivities of IgM were gradually decreased. Six COVID-19 patients who displayed negative anti-SARS-CoV-2 results were associated with the factors such as older age, having underlying diseases, and using immunosuppressant.
Conclusion
Besides the purpose of assessing the impact of the SARS-CoV-2 pandemic in the population, SARS-CoV-2 antibody assays may have an adjunct role in the diagnosis and exclusion of COVID-19, especially by using high-throughput technologies (EIAs or CLIAs).
Objectives
Analyse alternative methods of intrathecal antibody detection by comparing chemiluminescent immunoassay (CLIA) and enzyme-linked immunosorbent assay (ELISA) techniques to determine if CLIA ...can replace ELISA in the diagnosis of CNS infections.
Methods
A panel of 280 paired samples—cerebrospinal fluid (CSF) and serum—with known antibody reactivities (
Varicella
,
n
= 60;
Measles
,
n
= 120) and negative samples (
n
= 100) were used to evaluate the performance of six serological test kits (Enzygnost, VirClia®, and Serion ELISA (Measles and Variella).
Results
For
Measles virus
IgG, the VirClia® IgG monotest revealed 97% and 94% positive and negative agreement to the Enzygnost as reference test, respectively. In contrast, Serion ELISA kits yielded values of 18% and 90%. For the
Varicella Zoster virus
(VZV) IgG, the VirClia® IgG monotest showed 97% and 90% positive and negative agreement compared to Enzygnost. The Serion ELISA kits showed values of 55% and 86%, respectively. ROC analysis revealed that the areas under the curve for
Measles
and VZV IgGs were 0.7 and 0.852, respectively, using the Serion kit, and 0.963 and 0.955, for Vircell S.L CLIA technique. VirClia® monotest values were calculated using an antibody index cut-off of 1.3.
Conclusion
The findings indicate that CLIA testing can improve antibody detection in CSF samples, aiding the diagnosis of infectious neurological impairments.
Serological diagnosis of infections due to measles and rubella viruses is done by IgM detection. The aim of this study was to comparatively evaluate commercial systems for detecting IgM against both ...viruses, including those of ELISA, in indirect and capture formats, chemiluminescence and electrochemiluminescence.
Seven (for rubella) and six (for measles) assays were studied. One hundred and sixty two samples were included in the study (from 90 rubella and 72 measles cases), and all were analyzed in all the assays.
The ranges of sensitivity, specificity and agreement for rubella were 94.8–100%, 52.4–100% and 75.5–98.1%, respectively. The corresponding ranges for measles assays were 87.0–100%, 53.3–100%, and 73.0–99.4%.
The best-performing assays were chemiluminescence (for measles and rubella IgM), and electrochemiluminescence (for rubella IgM).
El diagnóstico serológico de las infecciones por los virus de la rubéola y del sarampión se realiza por detección de IgM específica. El objetivo de este estudio fue evaluar comparativamente sistemas comerciales para la detección de IgM frente a ambos virus, incluyendo ensayos de ELISA, tanto con metodologías indirectas como de captura, así como quimioluminiscencia y electroquimioluminiscencia.
Se estudiaron 7 ensayos para rubéola y 6 para sarampión. Se emplearon 162 muestras (de 90 casos de rubéola y de 72 de sarampión) que se analizaron en todos los ensayos.
Los rangos de sensibilidad, especificidad y concordancia para los ensayos de rubéola fueron 94,8-100%, 52,4-100% y 75,5-98,1%, respectivamente. Los rangos correspondientes para los ensayos de sarampión fueron 87-100%, 53,3-100% y 73-99,4%, respectivamente.
Los mejores ensayos fueron quimioluminiscencia (para IgM frente a rubéola y a sarampión) y electroquimioluminiscencia (para IgM frente a rubéola).
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