Indirect Chemiluminescence Research Articles

Indirect detection of lead(II), cadmium(II) and mercury(II) on a microfluidic electrophoresis chip.

Water environments contaminated by heavy metal ions present significant challenges because these pollutants do not degrade naturally, leading to their gradual bioaccumulation in animals and plants, which ultimately poses an insurmountable threat to human health. Therefore, rapid and accurate detection of heavy metal ions in water is of great significance for environmental protection and disease prevention. In this work, we developed a novel method based on microfluidic electrophoresis coupled with indirect chemiluminescence for the immediate detection of Cd(II), Pb(II) and Hg(II) heavy metal ions. The displacement of the Co(II) ions within the chemiluminescence mixture by the above migrating sample cations caused a measurable reduction in the background signal. The results showed that the detection limits of Cd(II), Pb(II) and Hg(II) ions under the best detection conditions were 5.83 × 10-8 M, 5.38 × 10-8 M and 2.09 × 10-8 M, respectively, which were 1-2 orders of magnitude lower than those of the indirect UV method and 1 order of magnitude lower than that of the indirect laser induced detection method. This method can provide a possibility for the rapid detection of multiple heavy metal ions in actual water environments.

Quantitative determination of prothioconazole in wheat grain, soybean, and pond water based on a polyclonal antibody.

Prothioconazole and its metabolite are considered a potential threat to human health and environmental safety. Thus, the development of a sensitive and rapid detection method for prothioconazole is crucial to ensure the safety of agricultural products. In this study, a new hapten of prothioconazole was designed and synthesized, and a selective polyclonal antibody with high affinity against prothioconazole was produced, which was obtained from immunized New Zealand white rabbits. Based on the polyclonal antibody, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and indirect competitive chemiluminescence enzyme immunoassay (ic-CLEIA) were developed for detecting prothioconazole pesticides. Under optimized experimental conditions, the limit of quantification (LOQ) values for ic-CLEIA and ic-ELISA were 1.8 and 10.7 ng mL-1, respectively. The results demonstrated that the sensitivity (LOQ) achieved by ic-CLEIA was more than five times higher compared to that obtained with ic-ELISA. In addition, the recoveries obtained by adding standard prothioconazole to wheat grain, soybean, and pond water samples were in the range of 81.9 to 104.7% for ic-ELISA and 89.0 to 118.0% for ic-CLEIA.

Preparation of monoclonal antibody and establishment of indirect competitive chemiluminescence enzyme immunoassay for sodium pentachlorophenolate

In this study, three haptens of sodium pentachlorophenolate (PCP-Na) were designed and synthesized, and the monoclonal antibody against PCP-Na with high specificity and affinity was successfully prepared. Based on this monoclonal antibody, a highly sensitive indirect competitive chemiluminescence enzyme immunoassay (ic-CLEIA) was developed for the determination of PCP-Na and its metabolite pentachlorophenol (PCP). The ic-CLEIA method based on optimal conditions showed that the half maximal inhibitory concentration (IC50), linear range (IC20-IC80) and the detection limit (LOD, IC10) for PCP-Na were 0.083 ng/mL, 0.0076–1.5111 ng/mL, and 0.0032 ng/mL, respectively, and 0.29 ng/mL, 0.0983–0.7008 ng/mL, and 0.0192 ng/mL for PCP, respectively. The results of cross reaction showed that the method had no obvious cross reaction with other six chlorophenols compounds (phenol, 2-chlorophenol, 4-chlorophenol, 2, 4-dichlorophenol, 2, 4, 5-trichlorophenol, 2, 4, 6-trichlorophenol) except the metabolite PCP. The average recoveries in chicken, pork and fish samples were 81.3–105.8 %, with coefficient of variation (CV) lower than 7.6 %. In this study, a new highly rapid, sensitive and accurate ic-CLEIA method was established, which can be used for the sensitive detection of PCP-Na and its metabolite PCP in animal tissues.

Clinicopathological Features and Outcomes of IgA Nephropathy with Serum Antineutrophil Cytoplasmic Autoantibody Positivity

Introduction: IgA nephropathy (IgAN) with serum antineutrophil cytoplasmic autoantibody (ANCA) positivity is uncommon. This study analyzed the clinicopathologic features and prognosis of IgAN patients with serum ANCA positivity. Methods: 2,864 IgAN patients were tested for ANCA by the indirect immunofluorescence assay and chemiluminescence immunoassay. Patients with serum ANCA positivity (n = 85) were identified, and their clinical, pathological, and prognostic characteristics were analyzed. They were compared with ANCA-negative IgAN patients (n = 170) and ANCA-associated systemic vasculitis (AAV) with renal involvement patients (n = 85) selected randomly. Results: 2.97% (85/2,864) of IgAN were ANCA positive, and 4 patients were diagnosed as having crescentic IgAN with ANCA positivity. The clinicopathological characteristics of ANCA-positive IgAN patients were comparable to ANCA-negative IgAN patients, but they had higher antinuclear antibody (ANA)-positive rates, lower levels of renal interstitial inflammation, and fewer immune depositions than ANCA-negative IgAN patients. Compared with AAV patients, ANCA-positive IgAN patients were younger and had fewer extrarenal manifestations, milder renal damage, and more immune complex depositions. The renal outcomes were similar between IgAN patients with and without ANCA positivity. Multivariate Cox analysis revealed that in IgAN patients with ANCA positivity, male, ANA positivity, higher serum creatinine and proteinuria, and more severe renal tubular atrophy/interstitial fibrosis were risk factors for adverse renal outcomes. Conclusion: The clinical, pathological features and prognosis of ANCA-positive IgAN patients were similar to those of ANCA-negative IgAN patients except for higher ANA-positive rate, milder renal inflammation, and fewer immune depositions. ANA positivity was an independent risk factor for adverse renal outcomes in ANCA-positive IgAN patients.

Antibody response to SARS-CoV-2 vaccines in patients with relapsing multiple sclerosis treated with evobrutinib: A Bruton’s tyrosine kinase inhibitor

Background: Evobrutinib is an oral, central nervous system (CNS)-penetrant and highly selective covalent Bruton’s tyrosine kinase inhibitor under clinical development for patients with relapsing multiple sclerosis (RMS). Objective: To investigate the effect of evobrutinib on immune responses in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccinated patients with RMS from a Phase II trial (NCT02975349). Methods: A post hoc analysis of patients with RMS who received evobrutinib 75 mg twice daily and SARS-CoV-2 vaccines during the open-label extension (n = 45) was conducted. Immunoglobulin (Ig)G anti-S1/S2-specific SARS-CoV-2 antibodies were measured using an indirect chemiluminescence immunoassay. Results: In the vaccinated subgroup, mean/minimum evobrutinib exposure pre-vaccination was 105.2/88.7 weeks. In total, 43 of 45 patients developed/increased S1/S2 IgG antibody levels post-vaccination; one patient’s antibody response remained negative post-vaccination and the other had antibody levels above the upper limit of detection, both pre- and post-vaccination. Most patients (n = 36/45), regardless of pre-vaccination serostatus, had a 10–100-fold increase of antibody levels pre- to post-vaccination. Antibody levels post-booster were higher versus post-vaccination. Conclusion: These results suggest evobrutinib, an investigational drug with therapeutic potential for patients with RMS, acts as an immunomodulator, that is, it inhibits aberrant immune cell responses in patients with RMS, while responsiveness to foreign de novo and recall antigens is maintained.

A Chemiluminescence Enzyme Immunoassay Based on Biotinylated Nanobody and Streptavidin Amplification for Diazinon Sensitive Quantification

The advantages of genetic modification and preferable physicochemical qualities make nanobody (Nb) easy to develop a sensitive and stable immunosensor platform. Herein, an indirect competitive chemiluminescence enzyme immunoassay (ic-CLEIA) based on biotinylated Nb was established for the quantification of diazinon (DAZ). The anti-DAZ Nb, named Nb-EQ1, with good sensitivity and specificity, was obtained from an immunized library via a phage display technique, where the molecular docking results indicated that the hydrogen bond and hydrophobic interactions between DAZ and complementarity-determining region 3 and framework region 2 in Nb-EQ1 played a critical role in the Nb-DAZ affinity processes. Subsequently, the Nb-EQ1 was further biotinylated to generate a bi-functional Nb-biotin, and then an ic-CLEIA was developed for DAZ determination via signal amplification of the biotin–streptavidin platform. The results showed that the proposed method based on Nb-biotin had a high specificity and sensitivity to DAZ, with a relative broader linear range of 0.12–25.96 ng/mL. After being 2-folds dilution of the vegetable samples matrix, the average recoveries were 85.7–113.9% with a coefficient of variation of 4.2–19.2%. Moreover, the results for the analysis of real samples by the developed ic-CLEIA correlated well with that obtained by reference method GC-MS (R2 ≥ 0.97). In summary, the ic-CLEIA based on biotinylated Nb-EQ1 and streptavidin recognition demonstrated itself to be a convenient tool for the quantification of DAZ in vegetables.

Anti-Covid antibody status in health care professionals of Bangladesh after 3 months of completion of two doses of Covid-19 vaccination

Background: Coronavirus 2019 (COVID-19) is a pandemic disease, where huge number of populations was infected, and massive death occurred worldwide for its rapid spread. Naturally produced antibody or artificially given vaccination can only give protection.This study evaluated the anti-Covid antibody status in health care professionals of Bangladesh after 21 days and 3 months of completion of two doses of Covid-19 vaccination. Methods: This study was conducted at the Department of Laboratory Medicine, BIRDEM, Dhaka. Total 100 respondents who had completed two doses of Covid-19 vaccinationwere enrolled according to inclusion criteria. After taking informed written consent a structured questionnaire was filled up for each subject. First sample (3 ml whole blood) was collected after 21 days of completion of 2nd doses of SARS-CoV-2 vaccination and a 2nd sample (3 ml whole blood) was collected again after 3 months.SARS-CoV-2 IgG was estimated by indirect chemiluminescence assay. Collected data were analyzed by SPSS 22. Results: The mean age of the study subjects was 32.09 ± 7.98. Study subjects were divided into two groups: those with history of past Covid infection (PCR positive) (n=33) and those with no evidence of past infection (n=67). SARS-CoV-2 IgG antibody level was found significantly reduced after 3 months of completion of vaccination, compared to the titer of 21 days of vaccination. A significant difference of mean SARS-CoV-2 IgG antibody level among subjects with and without previous history of Covid 19 infectionwas observedafter 21 days of completion of 2nd dose of Covid 19 vaccination. However, after 3 months of 2nd dose of vaccination no significant differences ofmean SARS-CoV-2 IgG antibody level were observed between the groups. Conclusion: SARS-CoV-2 IgG antibody level was significantly reduced after 3 months of completion of two doses of vaccination. Moreover, antibody level was found significantly higher among the study subjects with previous positive H/O of Covid 19 infection compared to subjects without any H/O previous Covid infection. Therefore, this study recommended that, a third booster dose would be necessary to maintain the effectiveness of vaccines. Bangladesh J Medicine 2023; 34(2): 80-85

Immune Response Following COVID-19 Vaccination (mRNA or Non-mRNA) in Patients with Relapsing Multiple Sclerosis Treated with the Bruton’s Tyrosine Kinase Inhibitor Evobrutinib: An Update (P2-3.017)

Immune Response Following COVID-19 Vaccination (mRNA or Non-mRNA) in Patients with Relapsing Multiple Sclerosis Treated with the Bruton’s Tyrosine Kinase Inhibitor Evobrutinib: An Update (P2-3.017)

S-RBD IgG Response After Second Dose of CoronaVac; Prospective Study on Health Workers

COVID-19 infection causes severe acute respiratory syndrome and requires immediate action. Therefore, developing safe vaccine efficacy and new therapies has become a global priority for achieving herd immunity. Vaccination is expected to form specific antibodies against the SARS-CoV-2 spike protein that can neutralize the virus, thus preventing it from binding to its specific receptor (ACE 2 receptor). This study aimed to analyze the kinetics of antibody response to the CoronaVac vaccine after administration of the second dose vaccine. An observational analytic study with a prospective cohort approach was conducted from January to November 2021 at Dr. Soetomo General Academic Hospital, Surabaya. Two hundred fifty specimens from 50 health workers who met the inclusion criteria were measured for S-RBD IgG levels using the indirect chemiluminescence immunoassay method on the Snibe Maglumi® device. The SARS-CoV-2 S-RBD IgG levels were measured five times, such as before vaccination (day 0) and day 14, day 28, month 3, and month 6 after vaccination of the second dose of CoronaVac. The median (min-max) of S-RBD IgG levels before and after vaccination of the second dose on day 14, day 28, month 3, and month 6 were 0.43 (0.43–4.07); 109,25 (30.71–1619,42); 136,46 (19.38–725,28); 26.56 (7.64–158,65); 13.11 (0.59–8666,00) BAU/mL, respectively. There was a significant difference in S-RBD IgG levels at six months post-vaccination between the group with COVID-19 infection and those without COVID-19 disease (p < 0.001). Vaccination of the second dose of CoronaVac resulted in antibody formation; however, there was a trend of decreasing humoral immunity in the 3rd month after the second dose of CoronaVac vaccination in healthy individuals.

Production of high affinity monoclonal antibody and development of indirect competitive chemiluminescence enzyme immunoassay for gentamicin residue in animal tissues

To determine gentamicin residues in animal tissues, a monoclonal antibody (Mab) was produced and a sensitive indirect competitive chemiluminescent enzyme immunoassay (icCLEIA) was developed. At first, gentamicin was conjugated with bovine serum albumin as immunogens which were used to immunize BALB/c mice. Then, an anti-gentamicin Mab was prepared by hybridoma technology. Finally, a sensitive icCLEIA was developed with an 50% inhibition concentration (IC50) of 0.067 ng/mL for gentamicin. The limit of detection of the icCLEIA was 0.002 ng/mL. The cross reactivity of the Mab with structural analogues were<0.01%. The recoveries of gentamicin ranged from 80 to 101% and coefficient of variation was <6.4% in pork and fish samples. Samples were detected by UPLC-MS/MS for evaluating reliability of the icCLEIA. The results suggested that the prepared anti-gentamicin Mab can be used for rapid and convenient immunoassays to detect gentamicin residues in animal tissues.

Determination of Acetamiprid Residues in Vegetables by Indirect Competitive Chemiluminescence Enzyme Immunoassay.

Acetamiprid (ACE) is widely used in various vegetables to control pests, resulting in residues and posing a threat to human health. For the rapid detection of ACE residues in vegetables, an indirect competitive chemiluminescence enzyme immunoassay (ic-CLEIA) was established. The optimized experimental parameters were as follows: the concentrations of coating antigen (ACE-BSA) and anti-ACE monoclonal antibody were 0.4 and 0.6 µg/mL, respectively; the pre-incubation time of anti-ACE monoclonal antibody and ACE (sample) solution was 30 min; the dilution ratio of goat anti-mouse-HRP antibody was 1:2500; and the reaction time of chemiluminescence was 20 min. The half-maximum inhibition concentration (IC50), the detection range (IC10–IC90), and the detection limit (LOD, IC10) of the ic-CLEIA were 10.24, 0.70–96.31, and 0.70 ng/mL, respectively. The cross-reactivity rates of four neonicotinoid structural analogues (nitenpyram, thiacloprid, thiamethoxam, and clothianidin) were all less than 10%, showing good specificity. The average recovery rates in Chinese cabbage and cucumber were 82.7–112.2%, with the coefficient of variation (CV) lower than 9.19%, which was highly correlated with the results of high-performance liquid chromatography (HPLC). The established ic-CLEIA has the advantages of simple pretreatment and detection process, good sensitivity and accuracy, and can meet the needs of rapid screening of ACE residues in vegetables.

Longitudinal analysis of anti-SARS-CoV-2 S-RBD IgG antibodies before and after the third dose of the BNT162b2 vaccine

Immunosurveillance by evaluating anti-spike protein receptor-binding domain (S-RBD) antibodies represents a useful tool to estimate the long immunity against Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) infection. The aim of this study was to evaluate the kinetics of antibody response in vaccine recipients. We measured anti-S-RBD IgG levels by indirect chemiluminescence immunoassay on Maglumi 800 (SNIBE, California) in 1013 healthy individuals naïve to SARS-CoV2 infection after two and three COVID-19 vaccine doses. We found that anti-S-RBD IgG levels are higher in females than males. Antibody levels gradually decrease to a steady state after four months since the peak, and the decay is independent of age, sex, vaccine doses, and baseline antibodies titer. The third dose induces a high anti-S-RBD IgG reactivity in individuals with previous high responses and triggers a moderate-high anti-S-RBD IgG reactivity. The assessment of anti-S-RBD IgG levels is essential for monitoring long-term antibody response. A third SARS-CoV-2 vaccine dose is associated with a significant immunological response. Thus, our results support the efficacy of the vaccine programs and the usefulness of the third dose.

Postnatal Cytomegalovirus Infection May Increase the Susceptibility of Tuberous Sclerosis Complex to Autism Spectrum Disorders.

ABSTRACTAutism spectrum disorder (ASD), a highly hereditary and heterogeneous neurodevelopmental disorder, is influenced by genetic and environmental factors. Tuberous sclerosis complex (TSC) is a common syndrome associated with ASD. Cytomegalovirus (CMV) infection is an environmental risk factor for ASD. The similarities in pathological and mechanistic pathways of TSC and CMV intrigued us to investigate whether CMV and TSC interacted in ASD’s occurrence. We detected CMV IgG seroprevalence of 308 TSC patients from our prospective cohort (September 2011 to March 2021) and 93 healthy children by magnetic particle indirect chemiluminescence immunoassay. A total of 206 TSC patients enrolled were divided into ASD and non-ASD groups, and the relationship between ASD and CMV seroprevalence was analyzed. Nested PCR and Western blot were used to detect CMV DNAs and proteins in cortical malformations of seven TSC patients with and without ASD. No difference was found in CMV seroprevalence between TSC patients and healthy children (74.0% versus 72.0%, P = 0.704). Univariate analysis showed the seroprevalence in TSC patients with ASD was higher than that in TSC patients without ASD (89.2% versus 75.1%, P = 0.063), and multifactorial analysis showed that CMV seroprevalence was a risk factor for ASD in TSC patients (OR = 3.976, 95% CI = 1.093 to 14.454). Moreover, CMV was more likely to be detected in the cortical malformations in TSC patients with ASD but not in those without ASD. The findings demonstrated that CMV may increase the susceptibility of TSC to ASD.IMPORTANCE CMV is an environmental risk factor for ASD, but its role in syndromic autism with known genetic etiology has been rarely studied. The pathogenesis of ASD is related to the interaction between environmental and genetic factors. This study demonstrated that CMV can contribute to the occurrence of ASD related to TSC, a common genetic syndrome associated with ASD. Our findings provided support for the theory of gene-environment interaction (G × E) in pathogenesis of ASD and a new perspective for the prevention and therapy for TSC related ASD.

A novel high-sensitive indirect competitive chemiluminescence enzyme immunoassay based on monoclonal antibody for tenuazonic acid (TeA) detection

A novel high-sensitive indirect competitive chemiluminescence enzyme immunoassay based on monoclonal antibody for tenuazonic acid (TeA) detection

Direct and Indirect Chemiluminescence: Reactions, Mechanisms and Challenges.

Emission of light by matter can occur through a variety of mechanisms. When it results from an electronically excited state of a species produced by a chemical reaction, it is called chemiluminescence (CL). The phenomenon can take place both in natural and artificial chemical systems and it has been utilized in a variety of applications. In this review, we aim to revisit some of the latest CL applications based on direct and indirect production modes. The characteristics of the chemical reactions and the underpinning CL mechanisms are thoroughly discussed in view of studies from the very recent bibliography. Different methodologies aiming at higher CL efficiencies are summarized and presented in detail, including CL type and scaffolds used in each study. The CL role in the development of efficient therapeutic platforms is also discussed in relation to the Reactive Oxygen Species (ROS) and singlet oxygen (1O2) produced, as final products. Moreover, recent research results from our team are included regarding the behavior of commonly used photosensitizers upon chemical activation under CL conditions. The CL prospects in imaging, biomimetic organic and radical chemistry, and therapeutics are critically presented in respect to the persisting challenges and limitations of the existing strategies to date.

Anti-SARS-CoV-2 S-RBD IgG Antibody Responses after COVID-19 mRNA Vaccine in the Chronic Disorder of Consciousness: A Pilot Study.

Objective: In the last year, a large amount of research has investigated the anti-spike protein receptor-binding domain (S-RBD) antibody responses in patients at high risk of developing severe acute respiratory syndrome because of COVID-19 infection. However, no data are available on the chronic disorder of consciousness (DOC). Methods: Here, we evaluated anti-S-RBD IgG levels after vaccination in chronic DOC patients compared with demographically matched healthy controls (HC) by indirect chemiluminescence immunoassay. All individuals completed a two-dose-cycle vaccination with Pfizer mRNA vaccine (BNT162b2), and antibody responses were evaluated at 30 and 180 days after the administration of the second dose of vaccination. Results: We compared 32 DOC patients with 34 demographically matched healthy controls. Both DOC and HC groups showed a similar antibody response at 30 days, whereas at follow-up (180 days) DOC patients were characterized by lower S-RBD IgG levels with respect to controls. Additional multiple regression analyses including demographical and clinical comorbidities as predictors revealed that age was the only factor associated with the decrease in S-RBD IgG levels at follow-up (180 days). Elderly individuals of both groups were characterized by a reduction in the antibody responses with respect to younger individuals. Conclusions: Our results show an efficacy seroconversion in DOC patients in the first period after vaccination, which significantly declines over time with respect to healthy controls.

1603P SARS-CoV-2 seroconversion among oncology healthcare workers in Brazil

Background: We aimed to estimate the incidence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) seroconversion after baseline screening among oncology healthcare workers (HCW). Methods: This is a prospective longitudinal cohort study of HCW, applied at Centro de Terapia Oncologica (CTO), an Oncology clinic in Petropolis, Brazil. Baseline screening for SARS-CoV-2 occurred between April 9 -29, 2020 using rapid IgM and IgG serological tests for all HCW. Follow-up serology testing took place once between November 5-December 28, 2020 and included retesting with indirect chemiluminescence immunoassay LIAISON SARS-CoV-2 S1/S2 IgG all HCW for seroconversion incidence. Reverse transcriptase–polymerase chain reaction (RT-PCR) testing was offered at baseline and follow-up for all symptomatic staff. The McNemar test was used to assess the change in positive serology incidence in both tests. Results: The study included 60 HCW, with 40 females (66.7%). Mean age was of 43.4 years old (SD =14.5). At baseline SARS-CoV-2 antibody assessment, 57 (95%) were negative and 3 (5%) positive;59 (98%) asymptomatic HCW, and 1 symptomatic (1.6%) tested positive in RT-PCR. A total of 11 RT-PCR were performed since baseline until follow-up in symptomatic HCW, with 9 (81.8%) positive results, all of them with seroconversion. 6 (10%) asymptomatic HCW were seropositive at follow-up screening. None of baseline positive-serology asymptomatic HCW sustained their serology. Seroconversion occurred in 15 (25%) HCW - Table. The incidence of positive serologies in follow-up screening was statistically higher than at baseline (p = 0.008). [Formula presented] Conclusions: Most seroconversions were in symptomatic HCW, although the substantial number of positive serologies in asymptomatic HCW accent the importance and direct impact of regular universal testing. Seropositivity increased five-fold compared to baseline results. This detected increase in infections reflects a national pattern, suggesting community-based and not nosocomial transmission. Legal entity responsible for the study: The authors. Funding: Has not received any funding. Disclosure: All authors have declared no conflicts of interest.

Simultaneous detection of CA15-3 and PGRMC1 on a microfluidic chip for early diagnosis of breast cancer

Simultaneous, rapid, and quantitative detection of multiple tumor markers is extremely important for the prevention and early diagnosis of cancers. In this study, we established a microfluidic-based indirect competitive chemiluminescence enzyme immunoassay for simultaneous detection of cancer antigen 15-3 (CA15-3) and progesterone receptor membrane components 1 (PGRMC1) for diagnosis of breast cancer. CA15-3 and PGRMC1 could be simultaneously detected on the chip. On the chip, the linear ranges of CA15-3 and PGRMC1 were 10 pg/mL–100 ng/mL and 20 pg/mL–358 ng/mL, respectively, whereas the limits of detection (LOD) of CA15-3 and PGRMC1 were 3 pg/mL and 5 pg/mL, respectively. Compared with the enzyme-linked immunosorbent assay (ELISA, LOD = 20 pg/mL for CA15-3; LOD = 10 pg/mL for PGRMC1), our method could simultaneously detect multiple samples with higher sensitivity, which could greatly improve the detection efficiency and meet the requirement for early diagnosis of breast cancer.

Evaluation of Anti-SARS-Cov-2 S-RBD IgG Antibodies after COVID-19 mRNA BNT162b2 Vaccine.

(1) Background: The evaluation of anti-spike protein receptor-binding domain (S-RBD) antibodies represents a useful tool to estimate the individual protection against Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) infection; (2) Methods: We evaluated anti S-RBD IgG levels by indirect chemiluminescence immunoassay on Maglumi 800 (SNIBE, California) in 2248 vaccinated subjects without previous SARS-CoV-2 infection, 91 vaccinated individuals recovered from COVID-19, and 268 individuals recovered from COVID-19 who had not been vaccinated. Among those who were healthy and vaccinated, 352 subjects performed a re-dosing after about 72 days from the first measurement. (3) Results: Anti S-RBD IgG levels were lower in subjects with previous infection than vaccinated subjects, with or without previous infection (p < 0.001). No difference was observed between vaccinated subjects, with and without previous SARS-CoV-2 infection. Overall, anti-RBD IgG levels were higher in females than males (2110 vs. 1341 BAU/mL; p < 0.001) as well as in subjects with symptoms after vaccination than asymptomatic ones (2085 vs. 1332 BAU/mL; p = 0.001) and lower in older than younger subjects. Finally, a significant decrease in anti-RBD IgG levels was observed within a short period from a complete two-dose cycle vaccination. (4) Conclusions: Our results show an efficacy antibody response after vaccination with age-, time- and sex-related differences.

Development of an Indirect Chemiluminescence Immunoassay Using a Multiepitope Recombinant Protein To Specifically Detect Antibodies against Foot-and-Mouth Disease Virus Serotype O in Swine.

Foot-and-mouth disease virus (FMDV) has led to serious losses in animal husbandry worldwide. Seromonitoring of FMDV postvaccination is important for the control and eradication of foot-and-mouth disease (FMD) in regions and countries where vaccination is widespread. However, many commercial kits present high false-positive rates. In this study, a multiepitope-based indirect chemiluminescence immunoassay (ME-CLIA) was developed for specifically detecting antibodies against FMDV serotype O in swine sera. The developed method presented high diagnostic sensitivity and excellent diagnostic specificity, and it could detect a broad spectrum of antibodies against FMDV serotype O. The diagnostic performance, accuracy rate, and analytical sensitivity of ME-CLIA were compared with those of three commercial kits. The immune protection value of multiple-epitope recombinant vaccine detected using ME-CLIA was preliminarily determined by observation of clinical symptoms postimmunization challenge, the results of which indicated that the ME-CLIA can be employed as a matching detection method for evaluating multiple-epitope recombinant vaccine. The percent positive values of ME-CLIA determined using swine vaccinated with inactivated vaccine were significantly positively correlated with the titers of liquid-phase-blocking enzyme-linked immunosorbent assay (ELISA) (LBPE) (r = 0.8361; P < 0.0001). These results indicated that ME-CLIA is suitable for detection of antibodies against FMDV serotype O in swine and for potency evaluation of multiple-epitope and inactivated vaccines.