Immunoassay Assay Research Articles

Exploring the Role of Intraoperative Prolactin Levels in Surgical Management of Prolactinomas: Predicting Operative Success and Enhancing Surgical Decision-Making

Objective: Prolactinomas comprise half of all pituitary adenomas. This study explores the significance of measuring intraoperative (IO) prolactin (PRL) levels in guiding surgical decision making and predicting operative success. Methods: Retrospective cohort study design of consecutive patients with prolactinomas who underwent TSS resection from June 2021 to May 2023. Intraoperative prolactin was measured after tumor resection was completed. Remission was defined as normalization of prolactin levels during follow-up without medication. Outcomes included factors associated with remission, utilizing significance thresholds at p<0.05. Results: Thirteen patients were included with a 5.3-month median follow-up (range, 3-15 months). Most of the tumors were microadenomas (61%), with a median preoperative PRL level of 116 ng/mL (range, 25-471 ng/mL). Gross total resection (GTR) was achieved in 69% of patients, all of whom attained remission. The median IO PRL was 19.8 ng/mL (range, 1-329), the postoperative day 1 (POD1) PRL of 3.6 ng/mL (range, 1-203 ng/mL) and the latest PRL at 9.3 ng/mL (range, 1-137 ng/mL). A ≥40% decline in IO PRL from baseline was identified as the optimal cut-off for predicting biochemical remission, with 89% sensitivity, 75% specificity, and 85% accuracy. Conclusions: Monitoring prolactin levels intraoperatively may be a useful biomarker aiding surgeon’s assessment of the extent of tumor resection and guiding surgical decision-making. Further refinement of the immunoassay assay and clinical testing with more extensive prospective studies are needed.

Novel solid-phase extraction promotes simultaneous colloidal gold immunochromatographic assay of malachite green, leuco-malachite green, chloramphenicol, and semi-carbazone metabolites in aquatic products.

Solid phase extraction (SPE) using traditional column materials offers several advantages, but its ability to simultaneously extract and purify commonly used veterinary drugs, such as chloramphenicol, malachite green, leuco-malachite green and semi-carbazone, remains unproven.Therefore, in the present study, a rapid analytical method based on ultrasound-assisted SPE combined with colloidal gold test strips was developed and applied herein to determine the residues of these veterinary drugs in common aquatic products. Under optimized conditions, the method achieved a limit of detection in the range of 0.01-0.5μg/kg, inter-day RSDs of the spiked samples in the ranges of 0.99-5.58% and 1.6-7.2%, and absolute recoveries in the range of 84.2-112.9% using the colloidal gold immunoassay and enzyme-linked immunosorbent assay methods, respectively. The SPE column efficiently enriched the four veterinary drugs simultaneously, showing considerable potential for determining common veterinary drug residues in aquatic products.

ADNI Biomarker Core: A review of progress since 2004 and future challenges.

We describe the Alzheimer's Disease Neuroimaging Initiative (ADNI) Biomarker Core major activities from October 2004 to March 2024, including biobanking ADNI cerebrospinal fluid (CSF), plasma, and serum biofluid samples, biofluid analyses for Alzheimer's disease (AD) biomarkers in the Biomarker Core and various non-ADNI laboratories, and continuous assessments of pre-analytics. Validated immunoassay and mass spectrometry-based assays were performed in CSF with a shift to plasma, a more accessible biofluid, as qualified assays became available. Performance comparisons across different CSF and plasma AD biomarker measurement platforms have enriched substantially the ADNI participant database enabling method performance determinations for AD pathology detection and longitudinal assessments of disease progression. Close collaboration with academic and industrial partners in the validation and implementation of AD biomarkers for early detection of disease pathology in treatment trials and ultimately in clinical practice is a key factor for the success of the work done in the Biomarker Core. Describe ADNI Biomarker Core biobanking and sample distribution from 2007 to 2024. Discuss validated mass spectrometry and immunoassay methods for ADNI biofluid analyses. Review collaborations with academic and industrial partners to detect AD and progression. Discuss major challenges, and progress to date, for co-pathology detection. Implementation in the ATN scheme: co-pathology and modeling disease progression.

Correlation of Eight (8) Polymorphisms and Their Genotypes with the Risk Factors of Cardiovascular Disease in a Black Elderly Population.

Single nucleotide polymorphisms (SNPs) have been associated with the development of cardiovascular diseases (CVDs). This study correlated eight SNPs with the risk factors of CVD in a black elderly population. Genotyping was used to detect eight polymorphisms; rs675 (ApoA-IV), rs699 (Angiotensinogen (AGT)), rs247616 and rs1968905 (Cholesteryl ester transfer protein (CETP)), rs1801278 (Insulin receptor substrate 1 (IRS-1)), rs1805087 (Methylenetetrahydrofolate reductase (MTHFR)) and rs28362286 and rs67608943 (Proprotein convertase subtilisin/kexin type 9 (PCSK9)), as well as their genotypes in deoxyribonucleic acid (DNA) extracted from peripheral blood. The cardiovascular risk (CVR) measurements were conducted on a Konelab 20i Thermo Scientific autoanalyzer and an enzyme-linked immunoassay (ELISA) assay. International Business Machines Corporation (IBM)® Statistical Package for the Social Sciences ® (SPSS) version 28 was used for statistical analysis. The heterozygous and homozygous genotypes of the eight polymorphisms were detected with the corresponding CVD risk factors. Subgroup analysis indicated that certain genotype carriers exhibited variations in their concentrations of CVR factors compared to others; however, these differences did not reach statistical significance. For example, carriers of the G genotype of the rs699 polymorphism showed marginally different blood pressure readings compared to the AG genotype carriers. The multiple linear regression analysis indicated that the only significant association was between PCSK9 and the rs28362286 (p = 0.029) polymorphism. The findings of our study show that single nucleotide polymorphisms are disseminated across the human genome. The heterozygous and homozygous genotypes of the SNPs require further investigation as they may have independent and possible collective roles in increasing the risk of CVDs.

Detection of Epstein-Barr virus (EBV) among thyroid disorders patients using enzyme-linked immunoassay (ELISA) and indirect immunofluorescence assay (IFA) in Mosul city, Iraq

Detection of Epstein-Barr virus (EBV) among thyroid disorders patients using enzyme-linked immunoassay (ELISA) and indirect immunofluorescence assay (IFA) in Mosul city, Iraq

Immunogenicity and Efficacy of Combined mRNA Vaccine Against Influenza and SARS-CoV-2 in Mice Animal Models.

Background. The combined or multivalent vaccines are actively used in pediatric practice and offer a series of advantages, including a reduced number of injections and visits to the doctor, simplicity of the vaccination schedule and minimization of side effects, easier vaccine monitoring and storage, and lower vaccination costs. The practice of widespread use of the combined vaccines has shown the potential to increase vaccination coverage against single infections. The mRNA platform has been shown to be effective against the COVID-19 pandemic and enables the development of combined vaccines. There are currently no mRNA-based combined vaccines approved for use in humans. Some studies have shown that different mRNA components in a vaccine can interact to increase or decrease the immunogenicity and efficacy of the combined vaccine. Objectives. In the present study, we investigated the possibility of combining the mRNA vaccines, encoding seasonal influenza and SARS-CoV-2 antigens. In our previous works, both vaccine candidates have shown excellent immunogenicity and efficacy profiles in mice. Methods. The mRNA-LNPs were prepared by microfluidic mixing, immunogenicity in mice was assessed by hemagglutination inhibition assay, enzyme-linked immunoassay and virus neutralization assay. Immunological efficacy was assessed in a mouse viral challenge model. Results. In this work, we demonstrated that the individual mRNA components of the combined vaccine did not affect the immunogenicity level of each other. The combined vaccine demonstrated excellent protective efficacy, providing a 100% survival rate when mice were infected with the H1N1 influenza virus and reducing the viral load in the lungs. Four days after the challenge with SARS-CoV-2 EG.5.1.1., no viable virus and low levels of detectable viral RNA were observed in the lungs of vaccinated mice. Conclusions. The combination does not lead to mutual interference between the individual vaccines. We believe that such a combined mRNA-based vaccine could be a good alternative to separated human vaccinations for the prevention of COVID-19 and influenza.

Ultrafast and high-throughput immunoassay assay to detect anti-SARS-CoV-2 IgG antibodies in dogs and cats.

The fact that SARS-CoV-2 has reportedly infected companion, livestock and wildlife animals may constitute a significant risk for virus reservoirs, ground for emerging variants and potential for novel reverse zoonosis. Hence, SARS-CoV-2 surveillance in animal species is crucial to prevent emerging variants which may spread to humans. The present study aimed to develop a simple, high-throughput and ultrafast magnetic bead immunoassay to detect anti-SARS-CoV-2 nucleocapsid and spike reactive IgG antibodies in dog and cat serum samples. The assays were validated using serum from eleven dogs and cats which had SARS-CoV-2 infections confirmed by real-time RT-PCR. The negative cohort consisted of pre-pandemic dog and cat samples. The assays performed at 73-82% sensitivity and 97.5-98% specificity for dogs and 71% sensitivity and 92-94% specificity for cats. The lower assay specificity for cats is explained by the fact that cat pre-pandemic sera showed high levels of cross-reactive with SARS-CoV-2 Nucleocapsid and Spike, supporting that these animals have been exposed to other coronavirus sharing structural similarities with SARS-CoV-2. These assays described in this work are now being used for SARS-CoV-2 surveillance and research purposes.

Rotavirus Vaccine Effectiveness Against Severe Acute Gastroenteritis: 2009-2022.

Rotavirus was the leading cause of acute gastroenteritis among US children until vaccine introduction in 2006, after which, substantial declines in severe rotavirus disease occurred. We evaluated rotavirus vaccine effectiveness (VE) over 13 years (2009-2022). We analyzed data from the New Vaccine Surveillance Network using a test-negative case-control design to estimate rotavirus VE against laboratory-confirmed rotavirus infections among children seeking care for acute gastroenteritis (≥3 diarrhea or ≥1 vomiting episodes within 24 hours) in the emergency department (ED) or hospital. Case-patients and control-patients were children whose stool specimens tested rotavirus positive or negative, respectively, by enzyme immunoassay or polymerase chain reaction assays. VE was calculated as (1-adjusted odds ratio)×100%. Adjusted odds ratios were calculated by multivariable unconditional logistic regression. Among 16 188 enrolled children age 8 to 59 months, 1720 (11%) tested positive for rotavirus. Case-patients were less often vaccinated against rotavirus than control-patients (62% versus 88%). VE for receiving ≥1 dose against rotavirus-associated ED visits or hospitalization was 78% (95% confidence interval [CI] 75%-80%). Stratifying by a modified Vesikari Severity Score, VE was 59% (95% CI 49%-67%), 80% (95% CI 77%-83%), and 94% (95% CI 90%-97%) against mild, moderately severe, and very severe disease, respectively. Rotavirus vaccines conferred protection against common circulating genotypes (G1P[8], G2P[4], G3P[8], G9P[8], and G12[P8]). VE was higher in children <3 years (73% to 88%); protection decreased as age increased. Rotavirus vaccines remain highly effective in preventing ED visits and hospitalizations in US children.

Evaluation of the novel ALK5 inhibitor EW-7197 on therapeutic efficacy in renal fibrosis using a three-dimensional chip model.

EW-7197, a potent oral ALK5 inhibitor, was assessed for its impact on transforming growth factor beta 1 (TGF-β1)-induced fibrosis in a three-dimensional (3D) renal fibrosis-on-a-chip and a mouse model. The evaluation included tubular epithelial-mesenchymal transition, angiogenesis, and inflammatory cytokine expression. In a 3D renal fibrosis-on-a-chip model, three cell types (kidney fibroblasts, human proximal tubular cell line, and human umbilical vein endothelial cells) were cultured and treated with TGF-β1 and EW-7197. Expression of alpha smooth muscle actin (α-SMA) and keratin 8 (KRT-8) was assessed, angiogenesis was observed via confocal microscopy, and cytokine levels were measured using real-time polymerase chain reaction, immunoassay, and enzyme-linked immunosorbent assay. In a cisplatin-induced renal fibrosis mouse model, blood urea nitrogen levels, TGF-β, and Smad 2/3 were determined, and renal fibrosis was assessed with Masson's trichrome stain. The α-SMA expression was significantly lower in the EW-7197 group than in the TGF-β fibrosis group. TGF-β decreased the expression of the epithelial marker KRT-8, an effect that was reversed by EW-7197 and SB431542. In the TGF-β-induced fibrosis model, the length of the thick vessels was reduced, and the diameter of both thick and thin vessels was decreased, but EW-7197 reversed these effects. EW-7197 significantly reduced the messenger RNA expression of TGF-β and increased the levels of vascular endothelial growth factor receptor 2, interleukin (IL)-10, and IL-6. EW-7197 reduced the levels of secretory cytokines TGF-β1, TGF-β3, IL-1β. In the cisplatin-induced renal fibrosis mouse model, EW-7197 reduced renal fibrosis by down-regulating TGF-β signaling. EW-7197 attenuated the TGF-β1-induced fibrotic cellular response in the 3D chip model and animal model. These findings indicate the potential effect of EW-7197 in attenuating renal fibrosis.

Elevated plasma hepcidin concentrations are associated with an increased risk of mortality and nonfatal cardiovascular events in patients with type 2 diabetes: a prospective study

BackgroundThe effect of plasma hepcidin concentrations on the long-term risk of developing adverse cardiovascular outcomes in people with type 2 diabetes mellitus (T2DM) is unclear.MethodsWe followed for a median of 55.6 months 213 outpatients with established T2DM (45.5% women, mean age 69 ± 10 years; BMI 28.7 ± 4.7 kg/m2; median diabetes duration 11 years). Baseline plasma ferritin and hepcidin concentrations were measured with an electrochemiluminescence immunoassay and mass spectrometry-based assay, respectively. The primary study outcome was a composite of all-cause mortality or incident nonfatal cardiovascular events (inclusive of myocardial infarction, permanent atrial fibrillation, ischemic stroke, or new hospitalization for heart failure).Results42 patients developed the primary composite outcome over a median follow-up of 55.6 months. After stratifying patients by baseline hepcidin tertiles [1st tertile: median hepcidin 1.04 (IQR 0.50–1.95) nmol/L, 2nd tertile: 3.81 (IQR 3.01-4-42) nmol/L and 3rd tertile: 7.72 (IQR 6.37–10.4) nmol/L], the risk of developing the primary composite outcome in patients in the 3rd tertile was double that of patients in the 1st and 2nd tertile combined (unadjusted hazard ratio [HR] 2.32, 95%CI 1.27–4.26; p = 0.007). This risk was not attenuated after adjustment for age, sex, adiposity measures, smoking, hypertension, statin use, antiplatelet medication use, plasma hs-C-reactive protein and ferritin concentrations (adjusted HR 2.53, 95%CI 1.27–5.03; p = 0.008).ConclusionsIn outpatients with T2DM, higher baseline hepcidin concentrations were strongly associated with an increased long-term risk of overall mortality or nonfatal cardiovascular events, even after adjustment for established cardiovascular risk factors, plasma ferritin concentrations, medication use, and other potential confounders.

Changes in Circulating Adipokine Levels in COVID-19 Patients.

Objective: The COVID-19 pandemic has posed significant global health challenges. Despite extensive research efforts, the inflammatory response triggered by SARS-CoV-2 remains to be further explored and understood. Our study aims to examine the changes in serum concentrations of pro-inflammatory adipokines-visfatin and leptin-in COVID-19 patients in relation to a healthy control group. Patients/Materials/Subjects and Methods: The study consisted of forty COVID-19 patients and twenty-four healthy patients in the control group. Two serum samples were collected: upon admission and on the seventh day of hospitalization. Concentrations of visfatin and leptin in the serum, alongside routine biochemical parameters, were measured using enzyme immunoassay or enzyme-linked immunosorbent assay kits. The Shapiro-Wilk test was used to assess normality. Differences between independent groups were compared using the Mann-Whitney U test and Kruskal-Wallis ANOVA. Correlations were evaluated with Spearman's rank correlation coefficient. Results: Our findings revealed significantly lower visfatin levels in COVID-19 patients compared to the control group upon admission (4.29 ng/mL, (3.0-6.88 ng/mL) vs. 37.16 ng/mL (24.74-50.12 ng/mL), p < 0.001 for visfatin 1 and 52.05 ng/mL, (31.2-69.66 ng/mL) vs. 37.16 ng/mL (24.74-50.12 ng/mL), p = 0.048 for visfatin 2). The visfatin level of COVID-19 patients returned to the normal levels, established in the control group. However, there was no significant difference in leptin levels between the two groups (p = 0.270 for leptin 1 and p = 0.129 for leptin 2). There was a positive correlation between BMI and leptin concentration (r = 0.66 and p = 0.00). Moreover, it was discovered that COVID-19 independently reduces visfatin levels during the first day of illness. Conclusions: The results of our research suggest that the onset of COVID-19 infection is correlated to visfatin levels. Association with leptin levels remains inconclusive. Further research is imperative to elucidate the intricate role of visfatin and leptin in SARS-CoV-2 infection and their potential as biomarkers for COVID-19 severity and prognosis.

Management of Heparin-Induced Thrombocytopenia: A Contemporary Review.

Heparin-induced thrombocytopenia (HIT) is a life- and limb-threatening immune-mediated emergency classically associated with heparin therapy. This review focuses on type II HIT, characterized by the development of antibodies against platelet-factor 4 (PF4) bound to heparin after exposure, causing life-threatening thrombocytopenia, arterial thrombosis, and/or venous thrombosis. The high morbidity and mortality rates emphasize the need for early recognition and urgent intervention with discontinuation of heparin and initiation of non-heparin anticoagulation. We discuss the management of HIT with an emphasis on recent developments: (i) incorporating the phases of HIT (i.e., suspected, acute, subacute A and B, and remote) into its management, categorized according to platelet count, immunoassay, and functional assay results and (ii) direct-acting oral anticoagulants (DOACs), which are increasingly used in appropriate cases of acute HIT (off-label). In comparison to parenteral options (e.g., bivalirudin and danaparoid), they are easier to administer, are more cost-effective, and obviate the need for transition to an oral anticoagulant after platelet recovery. We also identify the knowledge gaps and suggest areas for future research.

Study protocol: diagnostic accuracy study comparing Cy-Tb and STANDARD F TB-Feron FIA tests for tuberculosis infection diagnosis in Vietnam

IntroductionThe large reservoir of tuberculosis (TB) infections is one of the main reasons for the persistent incidence of TB. Accurate diagnostic tests are crucial to correctly identify and treat people...

HIV Diagnostic Algorithms in A Resource-Limited Setting: A Comparative Study

Background: Adoption of appropriate HIV testing algorithm is essential for quality HIV diagnostic results. Whether rapid enzyme immunoassay (rEIA) or combination of rapid enzyme immunoassay and enzyme-linked immunosorbent assay (rEIA-ELISA) alternative confirmatory algorithm is enough to make accurate HIV diagnosis has been a subject of controversies. Recent evaluation of national algorithm for HIV testing presented some discrepancies in results. Again, current guideline prescribed discontinuity of Western blot supplemental test and its replacement with Geenius HIV-1/ HIV-2 differentiation test followed by nucleic acid testing. The objective of this study is to compare HIV-1 testing algorithms using ELISA-NAT algorithm as the gold standard for HIV-1 diagnosis, and rEIA-Western blot and ELISA-Western blot as alternative confirmatory algorithms for HIV-2 diagnosis. Methods: This is a comparative study involving a cohort of 173 (98.9%) HIV-positive subjects and two (1.1%) HIV-negative subjects initially diagnosed on the basis of rEIA algorithm. Plasma samples separated from ethylene diamine tetra-acetic acid anticoagulated blood were used for further analyses. Fourth generation HIV antigen-antibody kit was used for further testing to make up rEIA-ELISA algorithm. Analyses with Western blot 1 and 2 assays were done as supplemental tests to make up alternative rEIA-Western blot and ELISA-Western blot confirmatory algorithms. Research subjects were further tested for HIV-RNA under PEPFAR plan. The sensitivity, specificity, positive predictive value and negative predictive value of algorithms were compared using the descriptive statistics of the SPSS version 17. Results: The HIV testing analyses showed 100% sensitivity, specificity, positive predictive value and negative predictive value from algorithm to algorithm especially for HIV-1 diagnosis. Use of combined ELISA-NAT confirmatory algorithm validated outcomes of rEIA-Western blot and ELISA-Western blot alternative confirmatory algorithms for HIV-1 diagnosis. Among HIV-1 positive samples tested, 50.0-60.7% HIV-2 Western blot indeterminate result was obtained and 7.1-10.7% HIV-1/HIV-2 co-infections were observed. Conclusion: The rEIA or national algorithm and its combination with enzyme-linked immunosorbent assay are reliable alternative confirmatory algorithms for the diagnosis of established HIV-1infection in resource-limited settings but not for HIV-2. Diagnosing acute HIV infection with current algorithm is limited and still require further review.

Quantitative Detection of the CP4-EPSPS Protein in Genetically Modified Soybeans Using a Novel Fluorescence Immunoassay Assay.

Protein-based detection methods, enzyme-linked immunosorbent assays (ELISAs) and lateral flow strips, have been widely used for rapid, specific, and sensitive detection of genetically modified organisms (GMOs). However, the traditional ELISA method for the quantitative detection of GMOs has certain limitations. Herein, a quantum dot (QD)-based fluorescence-linked immunosorbent assay was developed using QDs as fluorescent markers for the detection of glyphosate-resistant protein (CP4-EPSPS) in the MON89788 soybean. The end-point fluorescent detection system was carried out using QDs conjugated with a goat anti-rabbit secondary antibody. Compared with the conventional sandwich ELISA method, the newly developed fluorescence-linked immunosorbent assay was highly sensitive and accurate for detecting the CP4-EPSPS protein. The quantified linearity was achieved in the range of 0.05-5% (w/w) for the MON89788 soybean sample. The recovery of protein extracted from mixed MON89788 soybean samples ranged from 87.67% to 116.83%. The limits of detection and limits of quantification were 0.7101 and 2.152 pg/mL, respectively. All of the results indicated that the QD-based fluorescence-linked immunosorbent assay was a highly specific and sensitive method for monitoring the CP4-EPSPS protein in GMOs.

Reference Ranges and Comparison of Pepsinogen by Chemiluminescence Immunoassay and Enzyme-Linked Immunosorbent Assay in Chinese Population.

Serum pepsinogen (PG) is a good indicator of atrophic changes in the gastric mucosa. Gastric mucosal atrophy is a high-risk factor for gastric cancer. Serological testing for PG combined with endoscopy can help to improve gastric cancer screening. In this study, we established the reference ranges of serum PG-I, PG-II, and the PG-I/II ratio (PGR) in the Chinese population by chemiluminescence immunoassay (CLIA) and enzyme-linked immunosorbent assay (ELISA). Besides, in the real world, doctors are often confused by the results of different testing platforms. Thus, a comparison of methods CLIA and ELISA was performed. 2904 individuals were enrolled from six regions in China as part of the Chinese Adult Digestive Diseases Surveillance (2016) program. The individuals completed questionnaires and volunteered to undergo examinations, including gastroscopy, urea breath test, abdominal ultrasound examination and routine serologic tests. Serum was collected to measure PGs (including PG-I, PG-II and PGR) by CLIA and ELISA. Participants who were found obvious abnormalities or absent from the examinations were excluded. Ultimately, 747 healthy individuals were enrolled in this study. The Kolmogorov-Smirnov test was used to assess the distribution of variables. The Kruskal-Wallis H or Mann-Whitney U-tests were used to compare different sex, age, and geographical groups. The 95% reference ranges of PGs obtained by the two methods were established according to document CLSI-EP28-A3, with covariates of sex, age, and region. Spearman correlation analysis, linear regression analysis and allowable total error (ATE) zone analysis were utilized for comparing the two methods. On overall, the 95% reference ranges of PG-I, PG-II, and PGR measured by CLIA were 23.00-110.64 ng/mL, 2.50-19.13 ng/mL, and 3.87-13.30, respectively. Meanwhile, the reference ranges of PG-I, PG-II, and PGR measured by ELISA were 36.93-205.06 ng/mL, 1.65-17.96 ng/mL, and 7.50-33.60, respectively. Both PG-I and PG-II levels measured by the two platforms were found to be influenced by sex and age. PGR measured by CLIA was influenced by age but not by sex, while PGR measured by ELISA was not affected by either age or sex. Regional factors did not significantly impact the PG results, except for PG-I detected by ELISA. Ultimately, reference ranges for PGs were established based on age and sex stratification. Additionally, the Spearman correlation analysis revealed that the correlation coefficients for PG-I, PG-II, and PGR detected by the two methods were 0.899, 0.887, and 0.777, respectively, indicating a strong correlation between the two methods. The regression equation for the PG levels detected by two methods was obtained through linear regression analysis. The ATE analysis provided a visual depiction of the consistency between the two methods, clearly indicating the poor agreement between them. This study established the reference ranges of PGs by strict and intact enrollment standard. In addition, the results indicated a strong linear relationship between the two methods, yet with a clear bias, which was valuable for laboratory interpretation.

Fabrication of dextran-grafted magnetic polymer microspheres with low nonspecific protein adsorption as carriers for chemiluminescence immunoassays

Inhibiting the nonspecific protein adsorption on the surface of magnetic microspheres has become a pressing challenge for immunoassays. In this paper, a novel dextran-modified sandwich-type magnetic polymer microsphere was developed and demonstrated to be a promising carrier for chemiluminescence immunoassay (CLIA). Dextran-modified sandwich-type magnetic polymer microspheres (PFS-PGDN) were synthesized by surface-initiated atom transfer radical polymerization (SI-ATRP) and ring-opening reaction of epoxy and aminodextran on the surface of magnetic P(GMA-MMA)-NH2@Fe3O4@SiO2 (PFS) microspheres. Then, carboxylated dextran-modified sandwich-type magnetic polymer microspheres (PFS-PGDC) were prepared by the surface carboxylation of the microspheres, which allowed the prepared microspheres to better couple with nucleic acids or antibodies. It is found that after grafting dextran, magnetic PFS-PGDC microspheres could significantly reduce the nonspecific protein adsorption by over 90 %. The chemiluminescence immunoassay assay showed a reduction of the background value to a very low level, indicating that the magnetic spheres showed significant advantages in improving the sensitivity of the chemiluminescence assay. Moreover, the chemiluminescence sensitivity and signal values of the synthesized magnetic microspheres have reached high levels. Therefore, the magnetic microspheres synthesized here hold great promise for applications in the field of CLIA.

Seroprevalence and molecular detection of Toxoplasma gondii and Neospora caninum in beef cattle and goats in Hunan province, China

BackgroundToxoplasma gondii and Neospora caninum are closely related protozoan parasites that are considered important causes of abortion in livestock, causing huge economic losses. Hunan Province ranks 12th in the production of beef and mutton in China. However, limited data are available on the seroprevalence, risk factors and molecular characterization of T. gondii and N. caninum in beef cattle and goats in Hunan province, China.MethodsSera of 985 beef cattle and 1147 goats were examined for the presence of specific antibodies against T. gondii using indirect hemagglutination test (IHAT) and anti-N. caninum IgG using competitive-inhibition enzyme-linked immunoassay assay (cELISA). Statistical analysis of possible risk factors was performed using PASW Statistics. Muscle samples of 160 beef cattle and 160 goats were examined for the presence of T. gondii DNA (B1 gene) and N. caninum DNA (Nc-5 gene) by nested PCR. The B1 gene-positive samples were genotyped at 10 genetic markers using the multilocus nested PCR-RFLP (Mn-PCR-RFLP).ResultsSpecific IgG against T. gondii were detected in 8.3% (82/985) and 13.3% (153/1147) and against N. caninum in 2.1% (21/985) and 2.0% (23/1147) of the beef cattle and goats, respectively. Based on statistical analysis, the presence of cats, semi-intensive management mode and gender were identified as significant risk factors for T. gondii infection in beef cattle. Age was a significant risk factor for T. gondii infection in goats (P < 0.05), and age > 3 years was a significant risk factor for N. caninum infection in beef cattle (P < 0.05). PCR positivity for T. gondii was observed in three beef samples (1.9%; 3/160) and seven chevon samples (4.4%; 7/160). Genotyping of PCR positive samples identified one to be ToxoDB#10. The N. caninum DNA was observed in one beef sample (0.6%; 1/160) but was negative in all chevon samples.ConclusionsTo our knowledge, this is the first large-scale serological and molecular investigation of T. gondii and N. caninum and assessment of related risk factors in beef cattle and goats in Hunan Province, China. The findings provide baseline data for executing prevention and control of these two important parasites in beef cattle and goats in China.Graphical

Detection of intrathecal IgG antibody for varicella and measles diagnosis by evaluation and comparison of a commercial IgG chemiluminescent immunoassay with two ELISAs.

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. 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). 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 theVaricella 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. The findings indicate that CLIA testing can improve antibody detection in CSF samples, aiding the diagnosis of infectious neurological impairments.

Ferritin: A Biomarker Requiring Caution in Clinical Decision.

To determine the ferritin inter-assay differences between three "Conformité Européenne" (CE) marked tests, the impact on reference intervals (RI), and the proportion of individuals with iron deficiency (ID), we used plasma and serum from healthy blood donors (HBD) recruited in three different Switzerland regions. Heparinized plasma and serum from HBD were obtained from three different transfusion centers in Switzerland (Fribourg, Geneva, and Neuchatel). One hundred forty samples were recruited per center and per matrix, with a gender ratio of 50%, for a total of 420 HBD samples available per matrix. On both matrices, ferritin concentrations were quantified by three different laboratories using electrochemiluminescence (ECL), latex immunoturbidimetric assay (LIA), and luminescent oxygen channeling immunoassay (LOCI) assays, respectively. The degree of agreement between matrices and between the three sites/methods was assessed by Passing-Bablok and we evaluated the proportion of individuals deemed to have ID per method. Overall, no difference between serum and heparinized plasma ferritin values was observed according to Passing-Bablok analyses (proportional bias range: 1.0-3.0%; maximum constant bias: 1.84 µg/L). Significant median ferritin differences (p < 0.001 according to Kruskal-Wallis test) were observed between the three methods (i.e., 83.6 µg/L, 103.5 µg/L, and 62.1 µg/L for ECL, LIA, and LOCI in heparinized plasma, respectively), with proportional bias varying significantly between ±16% and ±32% on serum and from ±14% to ±35% on plasma with no sign of gender-related differences. Affecting the lower end of RI, the proportion of ID per method substantially varied between 4.76% (20/420) for ECL, 2.86% (12/420) for LIA, and 9.05% (38/420) for LOCI. Serum and heparinized plasma are exchangeable for ferritin assessment. However, the order of magnitude of ferritin differences across methods and HBD recruitment sites could lead to diagnostic errors if uniform RI were considered. Challenging the recently proposed use of uniform ferritin thresholds, our results highlight the importance of method- and region-specific RI for ferritin due to insufficient inter-assay harmonization. Failing to do so significantly impacts ID diagnosis.