Electrochemiluminescence Immunoassay Research Articles

Korea Seroprevalence Study of Monitoring of SARS-COV-2 Antibody Retention and Transmission (K-SEROSMART): findings from national representative sample.

We estimated the population prevalence of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including unreported infections, through a Korea Seroprevalence Study of Monitoring of SARS-CoV-2 Antibody Retention and Transmission (K-SEROSMART) in 258 communities throughout Korea. In August 2022, a survey was conducted among 10,000 household members aged 5 years and older, in households selected through two stage probability random sampling. During face-to-face household interviews, participants self-reported their health status, COVID-19 diagnosis and vaccination history, and general characteristics. Subsequently, participants visited a community health center or medical clinic for blood sampling. Blood samples were analyzed for the presence of antibodies to spike proteins (anti-S) and antibodies to nucleocapsid proteins (anti-N) SARS-CoV-2 proteins using an electrochemiluminescence immunoassay. To estimate the population prevalence, the PROC SURVEYMEANS statistical procedure was employed, with weighting to reflect demographic data from July 2022. In total, 9,945 individuals from 5,041 households were surveyed across 258 communities, representing all basic local governments in Korea. The overall population-adjusted prevalence rates of anti-S and anti-N were 97.6% and 57.1%, respectively. Since the Korea Disease Control and Prevention Agency has reported a cumulative incidence of confirmed cases of 37.8% through July 31, 2022, the proportion of unreported infections among all COVID-19 infection was suggested to be 33.9%. The K-SEROSMART represents the first nationwide, community-based seroepidemiologic survey of COVID-19, confirming that most individuals possess antibodies to SARS-CoV-2 and that a significant number of unreported cases existed. Furthermore, this study lays the foundation for a surveillance system to continuously monitor transmission at the community level and the response to COVID-19.

Association of 25-hydroxyvitamin D levels with lipid profiles in osteoporosis patients: a retrospective cross-sectional study

BackgroundIn the literature, scarce data investigate the link between 25-hydroxyvitamin D (25[OH]D) and blood lipids in the osteoporosis (OP) population. 25(OH)D, as a calcium-regulating hormone, can inhibit the rise of parathyroid hormone, increase bone mineralization to prevent bone loss, enhance muscle strength, improve balance, and prevent falls in the elderly. This retrospective cross-sectional study aimed to investigate the association between serum 25(OH)D levels and lipid profiles in patients with osteoporosis, with the objective of providing insight for appropriate vitamin D supplementation in clinical settings to potentially reduce the incidence of cardiovascular disease, which is known to be a major health concern for individuals with osteoporosis.MethodsThis is a retrospective cross-sectional study from the Affiliated Kunshan Hospital of Jiangsu University, including 2063 OP patients who received biochemical blood analysis of lipids during hospitalization from January 2015 to March 2022. The associations between serum lipids and 25(OH)D levels were examined by multiple linear regression. The dependent variables in the analysis were the concentrations of serum lipoprotein, total cholesterol (TC), triglycerides (TGs), apolipoprotein-A, lipoprotein A, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol (LDL-C). The independent variable was the concentration of blood serum 25(OH)D. At the same time, age, body mass index, sex, time and year of serum analysis, primary diagnosis, hypertension, diabetes, statins usage, beta-C-terminal telopeptide of type I collagen, procollagen type I N-terminal propeptide were covariates. Blood samples were collected in the early morning after the overnight fasting and were analyzed using an automated electrochemiluminescence immunoassay on the LABOSPECT 008AS platform (Hitachi Hi-Tech Co., Ltd., Tokyo, Japan). The generalized additive model was further applied for nonlinear associations. The inception result for smoothing the curve was evaluated by two-piecewise linear regression exemplary.ResultsOur results proved that in the OP patients, the serum 25(OH)D levels were inversely connected with blood TGs concentration, whereas they were positively associated with the HDL, apolipoprotein-A, and lipoprotein A levels. In the meantime, this research also found a nonlinear relationship and threshold effect between serum 25(OH)D and TC, LDL-C. Furthermore, there were positive correlations between the blood serum 25(OH)D levels and the levels of TC and LDL-C when 25(OH)D concentrations ranged from 0 to 10.04 ng/mL. However, this relationship was not present when 25(OH)D levels were higher than 10.04 ng/mL.ConclusionsOur results demonstrated an independent relationship between blood lipids and vitamin D levels in osteoporosis patients. While we cannot establish a causal relationship between the two, our findings suggest that vitamin D may have beneficial effects on both bone health and blood lipid levels, providing a reference for improved protection against cardiovascular disease in this population. Further research, particularly interventional studies, is needed to confirm these associations and investigate their underlying mechanisms.

CORRELATION BETWEEN THYROID FUNCTION AND OBESITY IN TYPE 2 DIABETES INDIVIDUALS

Objectives: In the present study, it is aimed to investigate the prevalence of thyroid dysfunction and blood glucose parameters and their correlation in Type 2 diabetes mellitus (T2DM) obese patients. Methods: The present study was a cross-sectional and observational study conducted for a period of 1 year January 2020–January 2022. The patient demographic data, age, and gender were collected from the medical records. After an overnight fast, venous blood samples were collected in the morning for laboratory tests. Electrochemiluminescence immunoassays were used to assess serum free T3 (FT3), FT4, and thyroid stimulating hormone (TSH). Fasting blood glucose, postprandial blood glucose, and random sugar levels were measured using enzymatic method. Body mass index (BMI) was calculated as weight (kg) divided by squared height (m). Results: In the present study, the mean values of thyroid harmones T3, T4 between the obese and non-obese individuals showed that no much significant variations might be due to low sample size. However, the mean values of TSH values were significantly higher 8.7ng/dl for obese individuals than non-obese individuals. There was a significant positive correlation that was identified for thyroid parameters TSH between obese and non-obese T2DM patients. On the other hand, there was a significant influence of postprandial blood sugar, random blood sugar, hemoglobin A1C, and BMI in obese and non-obese T2DM patients and insignificant influence for thyroid parameters T3 and T4. However, the results also showed that there was a highly significant influence of THS levels in obese T2DM patients. Conclusion: The findings of the present investigation showed a high correlation between thyroid function, mainly TSH levels, and Type 2 diabetes, particularly in obese persons.

Outperformance of interleukin-6 over placental alpha microglobulin-1 in predicting preterm delivery in symptomatic women

Threatened preterm labor is the major cause of hospital admission during the second half of pregnancy. An early diagnosis is crucial for adopting pharmacologic measures to reduce perinatal mortality and morbidity. Current diagnostic criteria are based on symptoms and short cervical length. However, there is a high false-positive rate when using these criteria, which implies overtreatment, causing unnecessary side effects and an avoidable economic burden. This study aimed to compare the use of placental alpha microglobulin-1 and interleukin-6 as vaginal biomarkers combined with cervical length and other maternal characteristics to improve the prediction of preterm delivery in symptomatic women. A prospective observational study was conducted in women with singleton pregnancies complicated by threatened preterm labor with intact membranes at 24+0 to 34+6 weeks of gestation. A total of 136 women were included in this study. Vaginal fluid was collected with a swab for placental alpha microglobulin-1 determination using the PartoSure test, interleukin-6 was assessed by electrochemiluminescence immunoassay, cervical length was measured by transvaginal ultrasound, and obstetrical variables and newborn details were retrieved from clinical records. These characteristics were used to fit univariate binary logistic regression models to predict time to delivery <7 days, time to delivery <14 days, gestational age at delivery ≤34 weeks, and gestational age at delivery ≤37 weeks, and multivariate binary logistic regression models were fitted with imbalanced and balanced data. Performance of models was assessed by their F2-scores and other metrics, and the association of their variables with a risk or a protective factor was studied. A total of 136 women were recruited, of whom 8 were lost to follow-up and 7 were excluded. Of the remaining 121 patients, 22 had a time to delivery <7 days and 31 had a time to delivery <14 days, and 30 deliveries occurred with a gestational age at delivery ≤34 weeks and 55 with a gestational age at delivery ≤37 weeks. Univariate binary logistic regression models fitted with the log transformation of interleukin-6 showed the greatest F2-scores in most studies, which outperformed those of models fitted with placental alpha microglobulin-1 (log[interleukin-6] vs placental alpha microglobulin-1 in time to delivery <7 days: 0.38 vs 0.30; time to delivery <14 days: 0.58 vs 0.29; gestational age at delivery ≤34 weeks: 0.56 vs 0.29; gestational age at delivery ≤37 weeks: 0.61 vs 0.16). Multivariate logistic regression models fitted with imbalanced data sets outperformed most univariate models (F2-score in time to delivery <7 days: 0.63; time to delivery <14 days: 0.54; gestational age at delivery ≤34 weeks: 0.62; gestational age at delivery ≤37 weeks: 0.73). The performance of prediction of multivariate models was drastically improved when data sets were balanced, and was maximum for time to delivery <7 days (F2-score: 0.88±0.2; positive predictive value: 0.86±0.02; negative predictive value: 0.89±0.03). A multivariate assessment including interleukin-6 may lead to more targeted treatment, thus reducing unnecessary hospitalization and avoiding unnecessary maternal-fetal treatment.

The anti-Müllerian hormone: A useful tool for diagnosis of Polycystic Ovary Syndrome.

Polycystic Ovary Syndrome (PCOS) is the most frequent endocrine disorder that affects reproductive-age women with important long-term health implications. As such, the anti-Müllerian hormone (AMH) was proposed as a helpful test to identify women with PCOS. The aim of this study was to determine an AMH cut-off value for the diagnosis of PCOS. This was a two-year cross-sectional study including women of reproductive age, diagnosed with PCOS according to Rotterdam criteria (2003). The control group of healthy women was age-matched. AMH was performed using an electrochemiluminescence immunoassay. AMH levels were compared and evaluated with the receiver operating characteristic curve analysis. A total of 130 women were enrolled in this study. Of these, 65 were diagnosed with PCOS, and 65 were healthy. No significant difference was detected in body mass index between the two groups. AMH levels were significantly higher in women with PCOS (p =<0.001). No significant difference in AMH levels was detected between PCOS phenotypes. A cut-off of 25.1 pmol/L (3.5ng/mL) could discriminate women with PCOS from controls with a sensitivity of 74% and specificity of 72.3%. The area under the curve was 0.811 (95% CI: 0.73-0.88). Our study suggests that AMH had good diagnostic potential as a complement to Rotterdam criteria for PCOS diagnosis in reproductive-age women of Tunisian origin.

A panel of seven protein tumour markers for effective and affordable multi-cancer early detection by artificial intelligence.

155 Background: Cancer early detection aims at reducing cancer deaths. Unfortunately, many established cancer screening technologies are not suitable for use in low- and middle-income countries (LMICs) due to cost, complexity, and dependency on extensive medical infrastructure. Methods: Nearly 10,000 participants [1959 cancer cases (containing more than nine common cancer types) and 7423 non-cancer cases] were divided into one training and two independent validation cohorts. One tube of peripheral blood samples was collected from each participant and quantified using a panel of seven selected protein tumour markers (PTMs) by a common clinical electrochemiluminescence immunoassay analyser. An algorithm named OncoSeek was established using artificial intelligence (AI) to distinguish cancer from non-cancer cases by calculating the probability of cancer (POC) index based on the quantification results of the seven PTMs and clinical information including sex and age of the subjects, and to predict the possible affected tissue of origin (TOO) for those who have been detected with cancer signal. Results: The conventional clinical method relied only on a single threshold for each PTM which would make a big problem when combining the results of those markers, the false positive rate would accumulate as the number of markers increased. Nevertheless, OncoSeek was empowered by AI technology to significantly reduce the false positive rate, increasing the specificity from 56·9% [95% confidence interval (CI): 55·8% to 58·0%] to 92·9% (95% CI: 92·3% to 93·5%). In all cancer types, the overall sensitivity of the OncoSeek test was 51·7% (95% CI: 49·4% to 53·9%). And the performance was generally consistent in the training and the two validation cohorts. The sensitivities ranged from 37·1% to 77·6% for the detection of the nine common cancer types (breast, colorectum, liver, lung, lymphoma, oesophagus, ovary, pancreas, and stomach), which account for ~59·2% of global cancer deaths annually. Furthermore, it has shown excellent sensitivity in several high-mortality cancer types for which there are lacking routine screening tests in the clinic, such as the sensitivity of pancreatic cancer was 77·6% (95% CI: 69·3% to 84·6%). The overall accuracy of TOO prediction in the true positives was 66·8%, which could assist the clinical diagnostic workup. Conclusions: OncoSeek significantly outperforms the conventional clinical method, representing a novel blood-based test for multi-cancer early detection (MCED) which is a non-invasive, easy, efficient, and robust approach. Moreover, the accuracy of TOO facilitates the follow-up diagnostic workup and this method is affordable (less than $25) and accessible requiring nothing more than a blood draw at the screening sites, which makes it acceptable and sustainable in LMICs.

Development and validation of a multiplex electrochemiluminescence immunoassay to evaluate dry eye disease in rat tear fluids

Dry eye disease (DED) is a challenge in ophthalmology. Rat models represent valuable tools to study the pathophysiology and to develop novel treatments. A major challenge in DED research is detecting multiple biomarkers in a low tear volume sample. Multiplex immunoassays for DED rat research are missing. We have developed a multiplex electrochemiluminescence immunoassay (ECLIA) to detect three biomarkers for DED: MMP-9, IL-17 and ICAM-1. Tears, used as matrix, were collected from six healthy Wistar rats. Assays were run based on the U-Plex Meso Scale Diagnostics (MSD) platform, by two independent operators according to the EMA guideline on bioanalytical method validation. Linear mixed, regression models were fit to perform the statistical analysis on the range of concentrations for the chosen analytes. During optimization, it has observed that incubation time, temperature and agitation affected the robustness of the protocol. ECLIA optimum conditions include the use of antibodies at 0.5 µg/ml concentration and 1 h incubation at room temperature with shaking. Precision met the acceptance criteria in the chosen range: 1062–133 pg/ml for ICAM-1, 275–34.4 pg/ml for IL-17, 1750–219 pg/ml for MMP-9. Accuracy and linearity were acceptable for a broader range. This is the first report of a validated ECLIA that allows measurements of three relevant DED biomarkers in rat tear fluids.

Gold Microbeads Enabled Proximity Electrochemiluminescence for Highly Sensitive and Size-Encoded Multiplex Immunoassays.

Developing highly sensitive multiplex immunoassays is urgently needed to guide medical research and improve clinical diagnosis. Here, we report the proximity electrochemiluminescence (ECL) generation enabled by gold microbeads (GMBs) for improving the detection sensitivity and multiplexing capacity of ECL immunoassays (ECLIAs). As demonstrated by microscopy and finite element simulation, GMBs can function as spherical ultramicroelectrodes for triggering ECL reactions in solutions. Employing GMBs as solid carriers in the bead-based ECLIA, the electrochemical oxidation of a coreactant can occur at both the GMB surface and the substrate electrode, allowing the coreactant radicals to diffuse only a short distance of ∼100 nm to react with ECL luminophores that are labeled on the GMB surface. The ECL generation via this proximity low oxidation potential (LOP) route results in a 21.7-fold increase in the turnover frequency of ECL generation compared with the non-conductive microbeads that rely exclusively on the conventional LOP route. Moreover, the proximity ECL generation is not restricted by the diffusion distance of short-lived coreactant radicals, which enables the simultaneous determination of multiple acute myocardial infarction biomarkers using size-encoded GMB-based multiplex ECLIAs. This work brings new insight into the understanding of ECL mechanisms and may advance the practical use of multiplex ECLIAs.

Assessment of alpha-fetoprotein clinical performances in the diagnosis of the hepatocellular carcinoma at Sominé DOLO hospital of Mopti

Serum AFP as a poor clinical performance values especially when it comes to deal with the early and AFP-negative diagnostic of HCC. The aim of this work was to assess the contribution of AFP in the diagnosis of HCC. : A total of 95 subjects was enrolled a prospective observational study by consecutive enrolment and divided in two groups. The first group was made up with subjects in whom the diagnosis of HCC had been retained while the second was the control group which was free of HCC. AFP levels were performed by electrochemiluminescence immunoassay on the cobas e411. Data were captured in Excel and analyzed by Ri386 version 4.1.2 binary for macOS 10.13. The Log of median of AFP in HCC subjects was significantly greater than in non HCC subjects 6.91 ng/mL versus 1.43 ng/mL, Wilcoxon &amp;#60; 0.001. At the cut-off of 200 ng/mL, the clinical performances showed an acceptable sensitivity 97.1% CI 95% [93.7 – 100] but a poor specificity 73,8% CI 95% [64.9 – 82.6] and out of the 34 cases of HCC, one case (2.9%) was AFP-negative HCC. our data show an acceptable sensitivity but a weak specificity of AFP as a biomarker for HCC at cut-off 200 ng/mL. This suggests that AFP should be used with other biomarkers mainly for the early and AFP-negative HCC diagnosis.

The stability of C-peptide and insulin in plasma and serum samples under different storage conditions.

C-peptide and insulin are peptide hormones and their stability is affected by a number of pre-analytical factors. The study aimed to investigate the impact of sample type, storage temperature and time delays before centrifugation and analysis on the stability of C-peptide and insulin. Ten healthy non-diabetic adults in fasting and non-fasting state were enrolled. 40 mL of blood was collected from each participant into SST and dipotassium EDTA tubes. Samples were centrifuged immediately or at timed intervals (8, 12, 48 and 72 h). After baseline measurements on the Roche Cobas e602 analyzer using electrochemiluminescence immunoassays, aliquots were stored at room temperature (RT), 2-8 and-20 °C for 4 h to 30 days. The percentage deviation (PD) from baseline was calculated and a change greater than desirable biological variation total error was considered clinically significant. C-peptide was more stable in separated serum than plasma (PD of-5 vs.-13 %) samples stored at 2-8 °C for 7 days and was most unstable at RT when centrifugation was delayed (PD-46 % in plasma and-74 % in serum after 48 h). Insulin was more stable in plasma than in serum under the different storage conditions with a minimum PD of-1% when stored at-20 °C for 30 days. When samples were kept unspun at RT for 72 h, PD was-23 and-80 % in plasma and serum, respectively. C-peptide was more stable in serum provided the sample was centrifuged immediately and stored in the fridge or freezer while insulin was found to be more stable in EDTA plasma.

Atomically Fe-anchored MOF-on-MOF nanozyme with differential signal amplification for ultrasensitive cathodic electrochemiluminescence immunoassay.

The successful application of electrochemiluminescence (ECL) in immunoassays for clinical diagnosis requires stable electrodes and high-efficient ECL signal amplification strategies. Herein, the authors discovered a new class of atomically dispersed peroxidase-like nanozymes with multiple active sites (CoNi-MOF@PCN-224/Fe), which significantly improved the catalytic performance and uncovered the underlying mechanism. Experimental studies and theoretical calculation results revealed that the nanozyme introduced a Fenton-like reaction into the catalytic system and the crucial synergistic effects of definite active moieties endow CoNi-MOF@PCN-224/Fe strong electron-withdrawing effect and low thermodynamic activation energy toward H2O2. Benefiting from the high peroxidase-like activity of the hybrid system, the resultant ECL electrode exhibited superior catalytic activity in the luminol-H2O2 system and resulted in an ≈17-fold increase in the ECL intensity. In addition, plasmonic Ag/Au core-satellite nanocubes (Ag/AuNCs) were designed as high-efficient co-reactant quenchers to improve the performance of the ECL immunoassay. On the basis of the differential signal amplification strategy (DSAS) proposed, the immunoassay displayed superior detection ability, with a low limit of detection (LOD) of 0.13 pg mL-1 for prostate-specific antigen (PSA). The designed atomically anchored MOF-on-MOF nanozyme and DSAS strategy provides more possibilities for the ultrasensitive detection of disease markers in clinical diagnosis.

Correlation between Hepatitis B Viral Load and Hepatitis B Surface Antigen Levels in Asymptomatic Seropositive Blood Donors

Background and Objectives: Correlation has been shown between hepatitis B surface antigen (HBsAg) and hepatitis B virus (HBV) levels in different patient categories. However, this has not been studied for donors. The aim of this study was to study the relationship between HBV DNA levels and E ratio obtained for HBsAg testing by chemiluminescence immunoassay (CLIA) performed on donor samples. Methods: A prospective, observational study was conducted in the department of transfusion medicine at a large tertiary health-care setup in North India from 2017 to 2021. Serological testing for HBV included HBsAg testing by CLIA. All reactive samples were tested in duplicate by electro CLIA (eCLIA). All samples found to be reactive in all three tests were then tested by a rapid diagnostic test and quantitative polymerase chain reaction. Results: During the study duration, 251 donors were found to be reactive for HBsAg by CLIA and eCLIA in screening. Of these 251, HBV DNA could not be detected in 85 (33.86%) samples, whereas in rest 166 (66.14%) samples, HBV DNA was detected. Mean E ratio for CLIA for all 251 samples was 5177.45, whereas mean viral copies detected were 19645858.66. The correlation for all 251 samples was found to be weak negative. The correlation for sero-reactive samples with the presence of HBV DNA was also found to be weak negative. Conclusion: In conclusion, we found significant but weak correlation between HBsAg results obtained by CLIA and HBV DNA levels for blood donors. The measurement of HBV DNA level is necessary for all apparently healthy donors coming for blood donation and testing reactive for HBsAg in screening assays.

Dual amplification electrochemiluminescence of carbonized polymer dots embedded in the metal-organic framework with low trigger potential and nanoconfinement enhancement for sensitive CYFRA21-1 immunoassay

Developing novel luminophores for electrochemiluminescence (ECL) that could operate smoothly under low-potential excitation while incorporating creative enhancement strategies is a challenging but very attractive initiative to achieve sensitive detection of disease markers. Herein, carbonized polymer dots (L-CPDs) with low cathode excitation potential were successfully synthesized and used for dual amplified sensitive electrochemiluminescence immunoassay of cytokeratin 19 fragment antigen 21–1 (CYFRA21–1). l-CPDs were first used as ECL luminophores and have an unprecedentedly low excitation potential of -0.95 V that has not been equipped for other cathodic carbon-base dots, avoiding side reactions, bioactive damage and electrode polarization due to high potential, thus obtaining excellent sensor performance. In addition, zeolitic imidazolate framework-8 (ZIF-8) synthesized at room temperature as a nanoconfinement carrier encapsulated l-CPDs and reduced the non-radiative energy loss of the luminophore, which led to substantially improved the ECL signal. The ECL efficiency of the encapsulated luminophores is 2.7 times higher than that of monomeric l-CPDs at the same mass concentration. Platinum composite iron oxide (Fe3O4/Pt) was used as a co-reaction acceleration platform to strengthen the ECL response. The sandwich ECL immunosensor fabricated achieved sensitive detection of CYFRA21–1 in the detection range of 150 fg/mL–110 ng/mL with a detection limit of 126 fg/mL. In conclusion, this work provides a consideration direction of developing ideal luminophores complemented by amplification strategies in ECL systems construction to achieve accurate and sensitive detection of targets.

A panel of seven protein tumour markers for effective and affordable multi-cancer early detection by artificial intelligence: a large-scale and multicentre case–control study

A panel of seven protein tumour markers for effective and affordable multi-cancer early detection by artificial intelligence: a large-scale and multicentre case–control study

S-RBD Antibody Titers Following the First and Second Doses of Inactivated SARS-CoV-2 Vaccination (CoronaVac) in Native Participants: A Prospective Cohort Study in Bali, Indonesia

Background: Vaccination has been recognized as an additional option, besides the health protocols practices to control the coronavirus disease 2019 (COVID-19) pandemic, especially with the unknown specific treatment for the disease. This study sought to evaluate the immunogenicity of CoronaVac among the general population in Bali province, a popular tourist spot in Indonesia. Methods: As many as 422 volunteers were recruited from the three vaccination centers, of which 230 volunteers were seronegative and included in the study. CoronaVac was used as vaccine with dose of 0.5 mL or 3 µg at each administration. Blood samples were drawn before vaccination, 21 days after the first dose, and 56 days after second dose, where the interval between the first and second dose vaccination was 28 days. Vaccine immunogenicity was evaluated by the anti-spike receptor-binding domain (anti-S-RBD) IgG titer which was measured using the electrochemiluminescence immunoassay technique. Results: The mean anti-S-RBD levels at 21 days after first dose, and 21 days after the second dose of vaccination are 25.25 ± 59.74 U/mL and 138.77 ± 90.93 U/mL, respectively. The result of the Friedman test was p &lt;0.001 which means that there are significant differences in anti-S-RBD levels between 21 days after first dose and 21 days after second vaccination. Post hoc analysis with the Wilcoxon test also showed significant difference among the three-testing point (p &lt; 0.001). The seroconversion rate from the first dose of CoronaVac was 69.7% and it increased to 99.4% (171/172) on after the second dose. Conclusion: Although the protective level was not totally reached on the first vaccination, the immunogenicity was considered rapid 3 weeks after the first vaccination.

Facile preparation of poly-(styrene-co-maleic anhydride) encapsulated Iridium(III) complexes as highly efficient electrochemiluminescence indicators for sensitive immunoassay of CYFRA 21-1

Exploring facile strategy for developing highly efficient emitters using water-insoluble luminophores has become a vital topic in electrochemiluminescence (ECL) immunoassay. In this work, an ECL-active and water-dispersive iridium(III) complex-based polymer dots (IrPdots) was fabricated by encapsulating water-insoluble tris[1-phenylisoquinolinato-C2, N] iridium(III) complexes [Ir(piq)3] into poly-(styrene-co-maleic anhydride) (PSMA) matrix by a controllable nanoprecipitation process. The obtained IrPdots generated strong ECL signals in the presence of tri-n-propylamine (TPrA) and were used to label detection antibody (Ab2) to act as ECL probes to indicate the signal changes when analyzing target antigen. To construct a sandwich immunosensor, Pd nanoparticles (NPs) decorated MoS2/Ti3C2Tx MXene nanocomposites (MoS2/Ti3C2Tx MXene/Pd) were fabricated as substrates to bind capture antibody (Ab1), which could further amplify ECL signals via a coreaction-accelerating pathway to improve the detection sensitivity. When the cytokeratin 19 fragment 21-1 (CYFRA 21-1) was chosen as model analyte, the developed immunosensor displayed a good linear relationship ranging from 0.1 pg/mL to 50 ng/mL with a low detection limit of 95 fg/mL (S/N = 3) was achieved as well. This research proposed a facile and effective method of fabricating IrPdots as ECL probes for immunoassay using water-insoluble iridium complexes, which expanded the application scope of those water-insoluble luminophores for aqueous bioanalysis.

O-135 Application of AMH determination in preoperative evaluation of micro-TESE in NOA patients

Abstract Study question To investigate the value of anti-Müllerian hormone(AMH) determination for estimating the sperm retrieval rate(SRR) of microdissection testicular sperm extraction(micro-TESE) in non-obstructive azoospermia(NOA) patients. Summary answer NOA with low AMH would have more opportunity to present heterogeneous seminiferous tubules when micro-TESE was performed and had higher SRR, especially in idiopathic cases. What is known already For infertile patients with NOA, micro-TESE is considered to have higher SRR than traditional surgery methods. However, serum inhibin B, follicle-stimulating hormone (FSH) and various clinical parameters are not reliable predictors for the presence of focal spermatogenesis and SRR. In male, AMH is a glycoprotein secreted by Sertoli cells and facilitate the regression of Müllerian structures in the developing foetus. It is still controversial that whether AMH level has value to predict the SRR of micro-TESE. Study design, size, duration This was a retrospective case-control study. From September 2014 to May 2022, 502 NOA patients treated with micro-TESE were divided into different groups according to their surgery outcome and seminiferous tubules appearance. Age, testis volume, serum AMH, FSH and testosterone level were compared between the different groups. The differences of SRR and AMH level in NOA patients with different etiologies were also compared. Participants/materials, setting, methods Micro-TESE was performed at x10 to x20 magnification. An attempt was made to identify seminiferous tubules that were larger and more opaque than others. The procedure was terminated when sperm were retrieved. If all tubules were seen to have an identical appearance, at least three samples (upper, middle, and lower) were extracted. Venous blood samples were drawn from each patient (7–10 AM) after an overnight fast. FSH and AMH were measured by electrochemiluminescence immunoassay. Main results and the role of chance Testicular sperms were successfully retrieved in 270 cases (SRR=53.8%). There were no statistical differences in age, testicular volume, FSH and testosterone levels between the patients who succeeded and failed to obtain sperm (all P&amp;gt;0. 05). The patients who obtained sperms had lower serum AMH level than those without sperm [0.81(0.16, 3.26)μg/L vs.1.37(0.21, 4.84)μg/L, P&amp;lt;0.05]. Patients with orchitis or AZFc deletion, cryptorchidism, KS, idiopathic azoospermia would have different AMH level [0.15(0.01, 0.41)μg/L, 5.71(3.57, 8.26)μg/L, 2.29(1.36, 3.81)μg/L, 0.15(0.05, 0.39)μg/L, 2.46(0.75, 5.49)μg/L, P&amp;lt;0.05]. Idiopathic azoospermia patients who obtained sperms had higher age but lower testosterone and AMH level than those without sperm [(35.2±8.9) years vs. (32.5±5.5) years, P&amp;lt;0.05, (3.1±1.4)μg/L vs. (3.7±2.1)μg/L, P&amp;lt;0.05; 1.63(0.35, 3.84)μg/L vs.3.00(1.20, 6.68)μg/L, P&amp;lt;0.05], there were no statistical differences in testicular volume and FSH level between the two groups (P&amp;gt;0.05). Receiver operating characteristic (ROC) curve showed that cut-off of serum AMH for successful sperm retrieval of idiopathic azoospermia patients was determined to be 2.96, with a sensitivity of 0.710 and specificity of 0.523, area under the curve (AUC) was 0.649. In the cases presenting heterogeneous seminiferous tubules during micro-TESE had lower AMH level and higher SRR than those presenting homogeneous seminiferous tubules [0.55(0.12, 2.05)μg/L vs.2.99(0.76, 6.11)μg/L, 75.9%(236/311)vs. 17.8%(34/191), all P&amp;lt;0.05]. Limitations, reasons for caution Pathology analysis should be involved in the following study. Randomized controlled trial comparing micro-TESE and traditional TESE would demonstrate that whether idiopathic azoospermia patients with higher serum AMH level would have less benefit by microsurgery than patients with lower AMH level. Wider implications of the findings Recently, in our pathologic research, NOA patients with extremely lower serum AMH level were observed to have more opportunity to present severe hyalinization in their seminiferous tubules. Tubules with severe hyalinization have less Sertoli cells and seem very thin. Therefore, tubules with spermatogenesis would be easy to identify during micro-TESE. Trial registration number not applicable

Low total osteocalcin levels are associated with the risk of cardiovascular events among women with hyperglycaemia: a 7.6-year prospective study.

To investigate the association between circulating osteocalcin and incident cardiovascular diseases in a community-based cohort, and further assess whether the association differs by different glycemic stages. This cohort study included 1428 participants (626 men and 802 women) aged 50-80 years, without baseline cardiovascular diseases, and with osteocalcin data available. Circulating total osteocalcin levels were measured by electrochemiluminescence immunoassay. Multivariate Cox proportional hazards models were used to assess the relationship between osteocalcin levels and different glycemic stages with cardiovascular events. At baseline, 437 participants were normoglycaemia and 991 participants were hyperglycaemia. Median circulating osteocalcin levels were 16.43 (13.34-20.19) and 21.66 (17.95-26.11) ng/mL in men and women, respectively. During a mean follow-up of 7.6 years, 144 cases of cardiovascular diseases occurred (10.1%). The risk of incident cardiovascular diseases linearly increased with a decrease in baseline osteocalcin quartiles (quartile 1 versus quartile 4: hazard ratio 2.44, 95% confidence interval 1.07-5.55) in women, while not in men (Pinteraction on sex = 0.028). Subgroup analyses showed that the association was more predominant in participants with baseline hyperglycaemia. Besides, the joint effect of baseline decreased osteocalcin levels and hyperglycaemia resulted in higher risks of future cardiovascular diseases. Low baseline osteocalcin levels were associated with high risks of cardiovascular diseases in middle-aged and elderly women, which were more predominant among those with baseline hyperglycaemia.

1317-P: The Use of NT-proBNP for Risk Stratification of Incident Cardiorenal Complications in Type 2 Diabetes—The Hong Kong Diabetes Biobank

NT-proBNP has emerged as a potential biomarker for cardiovascular complications. We examined the association between NT-proBNP with prevalent and incident diabetes complications, and compared it against prediction based on established risk equations. NT-proBNP was measured using an electrochemiluminescent immunoassay on a Roche cobas e411 analyzer in a subset of baseline samples from the Hong Kong Diabetes Biobank, a multi-centre prospective cohort of individuals with diabetes. All subjects underwent comprehensive assessment for diabetes complications, and were prospectively followed up. Among 1983 subjects with type 2 diabetes (60% male), mean age at recruitment was 61.1±11 years. At baseline, 24.7% of participants had NT-proBNP ≥125pg/ml. Those with NT-proBNP ≥125pg/ml had significantly higher SBP, lower eGFR, and a higher proportion had CHD, PVD and CHF at baseline (all p&amp;lt;0.001). In multivariate logistic regression adjusting for baseline age, sex, DM duration, smoking, BMI, waist, SBP, DBP, HbA1c, lipid traits, lnACR, eGFR and use of DM medications, NT-proBNP was associated with CVD and CKD at baseline. During median follow-up of 5.2 (5.0-5.4) years, baseline NT-proBNP (≥125 vs &amp;lt;125) was associated with increased risk of incident CVD with HR (95%CI) 2.34 (1.41, 3.89), CHF HR 2.60 (1.26, 5.37) and renal complications HR 1.88 (1.20, 2.96)(p &amp;lt;0.01). The cut-off of 125pg/ml showed good performance in differentiating between those with or without incident complications with C-index (95%CI) 0.82 (0.74, 0.89) for CHD, 0.87 (0.80, 0.94) for hospitalization with CHF and 0.86 (0.82, 0.90) for ESRD. Incorporating NT-proBNP improved prediction of CHD, CHF or ESRD compared to using the JADE risk equations alone. Our study highlights the utility of NT-proBNP for risk stratification of cardio-renal complications in T2DM. Disclosure R.C.W.Ma: Advisory Panel; AstraZeneca, Merck &amp; Co., Inc., Other Relationship; Bayer Inc., Boehringer-Ingelheim, Research Support; Tricida, Inc., Roche Diagnostics, Novo Nordisk. C.K.P.Lim: Stock/Shareholder; GemVCare Ltd. J.C.Chan: Board Member; Asia Diabetes Foundation, Consultant; Bayer Inc., Celltrion, Boehringer Ingelheim and Eli Lilly Alliance, Sanofi, Research Support; AstraZeneca, Servier Laboratories, Viatris Inc., Hua Medicine, Merck KGaA, Applied Therapeutics Inc., Lee Powder, Pfizer Inc., Speaker's Bureau; Novartis, Stock/Shareholder; GemVCare Ltd. The hong kong diabetes biobank study group: n/a. C.H.Tam: None. Y.Hou: None. Q.Jin: None. E.S.H.Lau: None. R.Ozaki: None. A.P.Kong: Advisory Panel; Abbott, Kyowa Kirin Co., Ltd., Speaker's Bureau; Abbott, AstraZeneca, Lilly, Bayer Inc., Boehringer Ingelheim Inc. E.Chow: Research Support; Medtronic, Merck KGaA, Speaker's Bureau; Novartis, Bayer Inc., Sanofi. A.Luk: Research Support; Novo Nordisk, Boehringer-Ingelheim, Bayer Inc., Speaker's Bureau; Eli Lilly and Company. Funding Roche Diagnostics (Hong Kong) Limited (to R.C.W.M.); Hong Kong Diabetes Biobank (CUR4012-18); Research Grants Council; (T12-402/13N); Croucher Foundation (to R.C.W.M.)

Procalcitonin for Detecting Culture-Positive Sepsis in Neonates: A Prospective, Multicenter Study

Introduction: It is unclear if serum procalcitonin (PCT) estimated at sepsis suspicion can help detect culture-positive sepsis in neonates. We evaluated the diagnostic performance of PCT in culture-positive sepsis in neonates. Methods: This was a prospective study (February 2016 to September 2020) conducted in four level-3 units in India. We enrolled neonates suspected of sepsis in the first 28 days of life. Neonates with birth weight <750 g, asphyxia, shock, and major malformations were excluded. Blood for PCT assay was drawn along with the blood culture at the time of suspicion of sepsis and before antibiotic initiation. The investigators labeled the neonates as having culture-positive sepsis or “no sepsis” based on the culture reports and clinical course. PCT assay was performed by electrochemiluminescence immunoassay, and the clinicians were masked to the PCT levels while assigning the label of sepsis. Primary outcomes were the sensitivity, specificity, and likelihood ratios to identify culture-positive sepsis. Results: The mean birth weight (SD) and median gestation (IQR) were 2,113 (727) g and 36 (32–38) weeks, respectively. Of the 1,204 neonates with eligible cultures, 155 (12.9%) had culture-positive sepsis. Most (79.4%) were culture-positive within 72 h of birth. The sensitivity, specificity, and positive and negative likelihood ratios at 2 ng/mL PCT threshold were 52.3% (95% confidence interval: 44.1–60.3), 64.5% (60.7–68.1), 1.47 (1.23–1.76), and 0.74 (0.62–0.88), respectively. Adding PCT to assessing neonates with 12.9% pretest probability of sepsis generated posttest probabilities of 18% and 10% for positive and negative test results, respectively. Conclusion: Serum PCT did not reliably identify culture-positive sepsis in neonates.