Assay For Immunoglobulin Research Articles

Characterization of immunomodulatory B-cells and T-cells to generate extremely targeted immunoassays and vaccines

Introduction: The Rubella virus has worldwide occurrence and congenital Rubella syndrome are widely recognized as emerging infection in several parts of the world. Methodology: We investigated for peptide vaccine with specific T and B-cell epitopes was identified through bioinformatics-based approaches. These were identified utilizing available Rubella virus E1 glycoprotein sequence databases. The outer-membrane glycoprotein, E1 is a target protein for the prediction of best antigens. Results: The bioinformatics online software Bepipred 2 was used for prediction of potential B-cell epitope (pfcntphgqlevqvppdpgd) was identified and it has shown high conversation against E1 glycoprotein and few other bioinformatics online software NetMHCpan, IEDB and NetCTL was used to identify maximum surface-exposed residues. T-Cell epitope (rpvalpral) was identified and shown to be conserved to E1 Glycoprotein. Predicted epitopes were found to had promiscuous class-I major histocompatibility complex binding affinity to major histocompatibility complex super types, antigenicity scores and high proteasomal cleavage. The three-dimensional modelled structures was created using I-TASSER online server for highlighting the predicted T- and B- cell epitopes. Conclusion: The predicted T and B cell epitope could be used for development of immunoglobulin assay and vaccines.

IgG4-IgE complex interferes with measurement of IgE concentration

Background and aimsPatients with immunoglobulin G4 (IgG4)-related disease (IgG4-RD) have elevated immunoglobulin E (IgE) concentration compared to that in healthy individuals, which suggests the occurrence of IgE-mediated allergic reactions. We have previously shown that IgG4 and IgE form a complex in some patients with IgG4-RD. However, it is currently unknown whether and how the presence of the IgG4-IgE complex affects IgE concentration measurements by different assays. Materials and methodsTwenty patients with confirmed presence or absence of IgG4-IgE complex were evaluated. We compared IgE concentrations measured by ST AIA-PACK IgE II (AIA-PACK), Elecsys IgE II Immunoassay (Elecsys), and Iatroace IgE (Iatroace) and evaluated to what extent the IgG4-IgE complex interfered with these measurements. ResultsIn patients with the IgG4-IgE complex, IgE concentrations measured using Iatroace were significantly lower than those measured using Elecsys and tended to be lower than those measured using AIA-PACK. IgE concentrations determined by Iatroace were significantly different in patients with and without the IgG4-IgE complex, whereas no significant differences between these groups were detected when IgE concentrations were measured by AIA-PACK or Elecsys. ConclusionThe formation of the IgG4-IgE complex underestimates measured IgE concentrations depending on the method used. Therefore, caution should be exercised when selecting a specific IgE assay for patients with IgG4-RD.

Prevalence and Variability of Allergen-Specific Immunoglobulin E in Patients with Elevated Tryptase Levels.

BACKGROUND In this paper we report on the link between increased tryptase levels and prevalence of allergen-specific immunoglobulin E (IgE) in patients with anaphylaxis. The main aim of the study was to assess the corelation between elevated tryptase levels and allergen-specific immunoglobulin E (IgE) in anaphylactic reactions, mastocytosis, and other types of allergic reactions. MATERIAL AND METHODS We enrolled 60 adult patients, aged 18-68 years (mean age 45±8 years). The subjects were divided into 3 groups (20 patients in each group) according to the serum tryptase changes: group 1 consisted of patients with anaphylaxis (serum tryptase level ≥11.4 µg/l), group 2 consisted of patients with mastocytosis (serum tryptase level ≥20.0 µg/l), and group 3 consisted of patients with other allergic reactions with no anaphylaxis as an atopic control group (serum tryptase level <11.4 µg/l). The test material was venous blood serum samples. The allergen-specific IgE assay was carried out by immunoblot. Tryptase concentration was determined by immunoenzymatic assay. RESULTS Allergen-specific IgE was found in 73% of all subjects: 75% in the anaphylactic group, 55% in the mastocytosis group, and 90% in the atopic control group. Polysensitization was common and was significantly different among groups. In the atopic group, there were more patients allergic to 4-7 allergens (P<0.05). CONCLUSIONS We did not find a strong correlation between allergen-specific IgE levels and elevated tryptase levels.

Evaluation of the Immunological Efficiency for Some of COVID-19 Vaccines (Pfizer, AstraZeneca and Sinopharm) among Vaccinated People of Wasit Province in Iraq

Background: Coronaviruses (SARS-CoV-2) cause Severe Acute Respiratory Syndrome COVID-19 pandemic in March, 2020. After Chinese scientists published the genome of the virus vaccine manufacturer produced several COVID-19 vaccines that aimed to induce a humoral and cellular immune response to prevent the fatality and harm caused by COVID-19. Existing study aimed to evaluate the immunological activity of some approved vaccines in terms of serological tests for antibodies (IgG and IgM) for the study groups in Wasit Governorate.Methods: The current study sample included (55) individuals who were vaccinated with two doses of one of the three vaccines and did not suffer from chronic health problems, (35) unvaccinated individuals of both genders. Their age ranges from 18-45 years, they were divided into two age ranges (18-31 and 32-45 years) and their vaccination history was confirmed according to a special form. The blood samples were collected from vaccinated individuals 2-4 weeks after the second dose of COVID-19 vaccine for the purpose of conducting immunological assays for immunoglobulins (IgG, IgM) and C- reactive protein (CRP) using ELISA kits.Results: The results of serological immunoassay tests for (IgM) for the vaccinated participants, both age groups and both genders with the three Pfizer, AstraZeneca and Sinopharm vaccines were documented a positive percentage of (47 %), (64 %) and (42 %) and negative (53 %), (36%) and (58%) respectively. Whereas, the (IgG) among vaccinators with the same three vaccines was recorded a positive percentage (100%) and negative (0%) in terms of a significant rise (P≤0.05) in serum antibody levels (IgG) in all the three vaccines (Pfizer, AstraZeneca and Sinopharm) in both age ranges and for both genders compared to the control group (unvaccinated individuals).Conclusions: the findings of the present study, that all three vaccines (Pfizer, AstraZeneca and Sinopharm) have shown a high efficacy and safely against coronavirus disease (COVID-19) in terms of the immune responses of the vaccinators. Current study data indicated a non-significant difference among age ranges (18-31 and 32-45 year) and gender is not associated with IgG levels.

Identification of Immunogenic T and B-Cell Epitope Peptides of Rubella Virus E1 Glycoprotein towards the Development of Highly Specific Immunoassays and Vaccine

Introduction: The Rubella virus has a worldwide occurrence and congenital Rubella syndromes are widely recognized as an emerging infection in several parts of the world. Miscarriage, perinatal mortality, and stillbirth can develop in pregnancy during the first trimester. The most frequent techniques for laboratory diagnosis of Rubella virus infection are IgM and IgG-based serological detection methods. Such emerging viral and bacterial pathogen emphasizes the development of fast diagnostic devices; there is a need for enhanced and quicker methods.&#x0D; Materials and Methods: Search for peptide vaccine with specific T and B-cell epitopes was identified through bioinformatics-based approaches. These were identified utilizing available Rubella virus E1 glycoprotein sequence databases. The outer-membrane glycoprotein, E1 is a target protein for the prediction of best antigens.&#x0D; Results: Using BepiPred2 program, the potential B-cell epitope PFCNTPHGQLEVQVPPDPGD with high conservation among E1 glycoprotein of rubella virus and the maximum surface exposed residues was identified. Using IEDB, NetMHCpan, and NetCTL programs, T-cell epitope RPVALPRAL was identified. Predicted epitopes were found to have promiscuous class-I major histocompatibility complex binding affinity to major histocompatibility complex super types, antigenicity scores, and high proteasomal cleavage. The three-dimensional modeled structures were created using I-TASSER online server for highlighting the predicted T- and B- cell epitopes.&#x0D; Conclusion: The predicted T and B cell epitope could be used for the development of immunoglobulin assay and vaccine candidate peptide.

210.12: Booster Shots and Additional Doses for COVID-19 in Solid Organ Recipients

Introduction: Vaccination against SARS-CoV-2 reduces COVID-19 mortality and complications in solid organ transplant recipients. We evaluated the associated antibody responses and breakthrough infections following vaccination with inactivated SARS-CoV-2 vaccine (CoronaVac, Sinovac) or BNT162b2 mRNA vaccine (Comirnaty, Pfizer-BioNTech) in this high-risk population. Method: This prospective observational study (April 2021-Febbruary 2022) included 10 liver and 38 kidney transplant recipients who received 2 vaccine doses (Sinovac, n = 31; or BioNTech, n = 17) as primary series all of whom provided blood samples (4-6 weeks after second dose) for quantitative antibody tests (Abbott Quant assay forimmunoglobulin G antibodies against SARS-CoV-2 spike protein). Following the end of the primary series, all patients were monitored for the development of infection for 9 months. The booster doses given to the patients throughout the follow-up were also documented. Type I error was α =.05 in all statistical analyses (SPSS, version 25). Results: We analyzed demographic data, antibody responses after 2 doses of SARSCoV-2 vaccine as primary series, booster doses and development of breakthrough infection. Median age was 36.5 and 35 (73%) of them were male. Five patients developed COVID-19 in the first six months after the primary series were completed, four of them had received two doses of Sinovac and one had received two doses of BioNTech. Only one patient has needed hospitalization vaccinated with two doses of Sinovac and her antibody level was 0 AU/mL. The median antibody level in patients who developed COVID-19 was 41,9 AU/mL, while it was 312,0 AU/mL in those who did not. However the difference was not statistically significant (p=0,092). Between the 6th and 9th months, 11 participants tested positive for SARS CoV-2 PCR, with all isolates being Omicron variant. While the rate of positivity was 17% in patients who had at least two booster doses of mRNA vaccine after two consecutive doses of primary series, it was 27% in patients who received just one dose or no booster. Conclusion: Solid-organ transplant recipients demonstrated inadequate vaccine responses. In addition, with the decrease in the immune response developed with the vaccine over time, it is seen that the newly emerged variants significantly increase the need for additional doses. In solid organ transplant patients, the CDC recommends a primary series of three doses at one-month intervals with a booster dose three months later. Despite the small amount of data, the findings of our study support this requirement.

Phase 1/2 study of a novel 24-valent pneumococcal vaccine in healthy adults aged 18 to 64 years and in older adults aged 65 to 85 years

BackgroundPneumococcal diseases remain prevalent despite available polysaccharide and conjugate vaccines. This phase 1/2 study evaluated safety/tolerability and immunogenicity of a novel 24-valent pneumococcal vaccine (ASP3772) based on high-affinity complexing of proteins and polysaccharides. MethodsPneumococcal vaccine–naïve adults aged 18–85 years were randomized to receive either ASP3772 or PCV13 (13-valent conjugate vaccine). Participants received a single intramuscular injection of ASP3772 (1-, 2-, or 5-µg dose per polysaccharide) or PCV13. A separate, nonrandomized group of PCV13-vaccinated participants (65–85 years) received PPSV23 (23-valent polysaccharide vaccine). Assessments were obtained through Day 7 for reactogenicity, through Day 30 for safety and tolerability, and through Month 6 for serious adverse events. Immunogenicity was measured at Day 30 using assays for functional opsonophagocytic activity (OPA) and pneumococcal serotype-specific anticapsular polysaccharide immunoglobulin G for each serotype. ResultsIn both age cohorts, the most frequently reported local reactions were self-limited tenderness and pain after ASP3772 at all dose levels or after PCV13, occurring within 2–3 days. Fatigue, headache, and myalgia were the most frequently reported systemic reactions following either vaccine. Robust OPA responses for all serotypes were observed across all ASP3772 dose groups in both age cohorts. Older adults (aged 65–85 years) who received ASP3772 had significantly higher immune responses to several PCV13 serotypes and all non-PCV13 serotypes than participants who received PCV13. OPA responses to the ASP3772 5-µg dose were significantly higher for several serotypes in naïve participants than in older adults with prior exposure to PCV13 who were administered PPSV23 in this study. ConclusionsThese results demonstrate that ASP3772 is well tolerated, highly immunogenic, and in adults may offer significantly broader protection than existing pneumococcal vaccines.Clinicaltrials.gov: NCT03803202

The Impact of Methenamine Hippurate Treatment on Urothelial Integrity and Bladder Inflammation in Aged Female Mice and Women With Urinary Tract Infections.

Antibiotics are commonly used to treat and prevent urinary tract infection (UTI), but resistance is growing. Nonantibiotic prophylaxis such as methenamine hippurate (MH) shows clinical promise, but its impact on bladder factors influencing recurrent UTIs (rUTIs) is not well described. The aim of the study was to examine the effect of MH on bladder inflammation and barrier function in aged mice and women with rUTI. This study included urine samples from an experimental study involving aged female mice with and without methenamine treatment as well as women with rUTI who received either no prophylaxis, MH alone, vaginal estrogen therapy and/or d-mannose alone, or MH in addition to vaginal estrogen therapy and/or d-mannose. We performed a comprehensive cytopathological analysis, which included enzyme-linked immunosorbent assay for immunoglobulin A (IgA), interleukin 6 (in human samples), and fluorescein isothiocyanate-conjugated-dextran permeability assay (in mice) to assess for urothelial permeability. In the aged mice model, there was a decreased urothelial permeability (as seen by retention of fluorescein isothiocyanate-conjugated-dextran fluorescence in superficial cells) and increased urinary IgA in mice treated with MH compared with controls. There was no significant difference in urothelial shedding (P > 0.05). In human samples, there was significantly increased urinary IgA in those taking MH alone compared with no prophylaxis (830.1 vs 540.1 ng/mL, P = 0.04), but no significant difference in interleukin 6. Methenamine hippurate seems to enhance barrier function as evidenced by decreased urothelial permeability and increased urinary IgA levels, without worsening inflammation. This may reflect another beneficial mechanism by which MH helps prevent rUTI.

Role of Antibodies against SARS-COV-2 in the Detection of Corona Virus, its Transmissibility and Immunological Status Determination among Different Population in Babylon Province

BACKGROUND: The fast worldwide spreading and the elevation of coronavirus disease-2019 (COVID-19) pandemic wave lead to decrease capacity of health-care units. It is important to add serology testing to assess viral transmissibility and the possibility of protection against reinfection. AIM: We aimed to assess the transmissibility of severe acute respiratory syndrome coronavirus-2 in the community and to assess the immunological response, qualitative assay of immunoglobulins (Ig) G and IgM, and the possibility of reinfection. MATERIALS AND METHODS: The present study included a total of 553 patients. We used a rapid test cassette of Biozek Medical Company/Netherland of COVID-19 IgG/IgM. It is a chromatographic immunoassay for the qualitative detection of IgG and IgM antibodies against the COVID-19 virus in human blood. Biozek Medical Company has created this highly accurate, UK approved, COVID-19 test, which provides high accuracy within 15 min. All required information were collected with the patients’ consent. The statistical analysis was performed using the IBM SPSS Statistics, 2016, Armonk, NY: IBM Corp. RESULTS: A total of 320 (57.9%) males and 233 (42.1%) females aged between 2 to 88 years. A significant correlation was found between the age of patients and chronic diseases. While most of the patients did not have any chronic diseases, the patients who had those diseases were mostly aged between their forties to more than 60 of age. A highly significant correlation was found between IgM level in the serum of the patient and the presence of symptoms. A significant correlation was found with chronic diseases and the level of IgG in the serum of patients. Furthermore, a significant correlation was found in patients with previous COVID-19 infections. CONCLUSIONS: Serological testing of IgM and IgG for COVID-19 is very helpful in diagnosing asymptomatic and symptomatic patients, evaluating the immunological status of individuals toward COVID-19 and giving an idea about the spreading of COVID-19 among different populations.

Robust validation and performance comparison of immunogenicity assays assessing IgG and neutralizing antibodies to SARS-CoV-2.

To enable benchmarking of immunogenicity between candidate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines, there is a need for standardized, validated immunogenicity assays. In this article, we report the design and criteria used to validate immunogenicity assays and the outcome of the validation of serologic and functional assays for the evaluation of functional immune response and antibody titers in human serum. A quantitative cell-based microneutralization (MNT) assay, utilizing a reference standard, for detecting anti-SARS-CoV-2 spike protein-neutralizing antibodies in human serum and Meso Scale Discovery’s multiplex electrochemiluminescence (MSD ECL) assay for immunoglobulin G (IgG) antibodies to SARS-CoV-2 spike, nucleocapsid, and receptor-binding domain (RBD) proteins were assessed for precision, accuracy, dilutional linearity, selectivity, and specificity using pooled human serum from coronavirus disease 2019 (COVID-19)-confirmed recovered donors. Both assays met prespecified acceptance criteria for precision, relative accuracy, dilutional linearity, selectivity, and specificity. Both assays demonstrated high specificity for the different SARS-CoV-2 antigens or virus tested, and no significant cross-reactivity with seasonal coronaviruses. An evaluation to compare the neutralizing activity in the MNT assay to the IgG measured using the MSD ECL assay showed a strong correlation between the presence of neutralizing activity and amount of antibodies against the spike and RBD proteins in sera from both convalescent and vaccinated individuals. Finally, the MNT assay was calibrated to the WHO reference standard to enable reporting of results in international units, thus facilitating comparison of immunogenicity data generated by different assays and/or laboratories. The MSD ECL assay has previously been calibrated. In conclusion, these validated assays for the evaluation of functional immune response and antibody titers following SARS-CoV-2 vaccination could provide a relatively simple standardized approach for accurately comparing immune responses to different vaccines and/or vaccination regimens.

Early humoral immune response to two doses of severe acute respiratory syndrome coronavirus 2 vaccine in a diverse group of solid organ transplant candidates and recipients.

Response to two doses of a nucleoside-modified messenger ribonucleic acid (mRNA) vaccine was evaluated in a large solid-organ transplant program. mRNA COVID-19 vaccine was administered to transplant candidates and recipients who met study inclusion criteria. Qualitative anti-SARS-CoV-2 Spike Total Immunoglobulin (Ig) and IgG-specific assays, and a semi-quantitative test for anti-SARS-CoV-2 Spike protein IgG were measured in 241 (17.2%) transplant candidates and 1163 (82.8%) transplant recipients; 55.2% of whom were non-Hispanic White and 44.8% identified as another race. Transplant recipients were a median (IQR) of 3.2 (1.1, 6.8) years from transplantation. Response differed by transplant status: 96.0%versus 43.2% by the anti-SARS-CoV-2 Total Ig (candidates vs. recipients, respectively), 93.5%versus 11.6% by the anti-SARS-CoV-2 IgG assay, and 91.9%versus 30.1% by anti-spike titers after two doses of vaccine. Multivariable analysis revealed candidates had higher likelihood of response versus recipients (odds ratio [OR], 14.6; 95 %CI 2.19, 98.11; P=.02). A slightly lower response was demonstrated in older patients (OR .96; 95 %CI .94, .99; P=.002), patients taking antimetabolites (OR, .21; 95% CI .08, .51; P=.001). Vaccination prior to transplantation should be encouraged.

Performance of Thyroid-Stimulating Immunoglobulin Bioassay and Thyrotropin-Binding Inhibitory Immunoglobulin Assay for the Diagnosis of Graves' Disease in Patients With Active Thyrotoxicosis

ObjectiveGraves' disease (GD) is caused by the stimulation of thyrotropin receptors by autoantibodies. We compared the diagnostic accuracy of the thyroid-stimulating immunoglobulin (TSI) bioassay and thyrotropin-binding inhibitory immunoglobulin (TBII) assay in differentiating GD from other causes of thyrotoxicosis. MethodsWe retrospectively evaluated 493 patients with thyrotoxicosis who were tested with the third-generation TSI and TBII assays simultaneously. Patients were classified according to the clinical, histopathologic, and imaging criteria into the following groups: positive reference group (PRG) (patients with GD), negative reference group (NRG) (patients without GD), and inconclusive group (patients without a definitive diagnosis). ResultsTSI and TBII assays were concordant in 88% of the cases and showed a strong positive correlation (rs = 0.844, P < .01). When analyzed collectively, TSI and TBII assays confirmed the diagnosis of GD in 79% of the PRG cases and excluded GD in 92.5% of patients in NRG. Combined TSI and TBII assays or TBII assay alone showed similar accuracy to the diagnosis of GD (81.4% and 77.5%, respectively). Tests in 40 of 191 patients in PRG were negative for both TSI and TBII assays, whereas 3 of 40 cases in NRG had at least 1 positive thyrotropin receptor antibody test. False-negative cases were associated with subclinical hyperthyroidism, normal radionuclide uptake, longer duration of thyrotoxicosis, and absence of goiter or Graves' ophthalmopathy. ConclusionTSI and TBII assays showed similar performance in differentiating GD from other causes of thyrotoxicosis in a real-world sample of patients with active thyrotoxicosis. In combination, both tests showed little benefit compared with the TBII assay alone. Thyrotropin receptor antibody assay results should be carefully interpreted in patients with mild GD or longstanding disease.

P413 Antibody response to the COVID-19 ChAdOx1nCov-19 and BNT162b2 vaccines in the immunosuppressed (RESCUE)

BackgroundImmunocompromised patients are inherently vulnerable to severe outcomes to vaccine preventable infections compared to the general population. This study aims to investigate the impact of immunosuppression on response to the ChAdOx1nCov-19 and BNT162b2 vaccines to better inform vaccination efforts in this cohort.MethodsA three-armed randomised controlled trial was performed. Patients with autoimmune disorders on immunosuppressive therapies and healthy controls were recruited from two sites. Participants receiving immunosuppression were randomly assigned to either withhold or continue treatment contemporaneous to vaccine administration. Serum SARS-Cov2 immunoglobulin assays were performed at baseline and, 4-weeks following first and second vaccine doses. Between group comparisons were performed to examine differences in vaccine seroconversion and immunogenicity.ResultsA total of, 253 participants of median age, 55 years (IQR:, 45.5–64) including, 193 patients receiving immunosuppression and, 60 healthy controls were studied. Immunosuppressed patients were randomly allocated to continue (n=105) or withhold (n=88) treatment. Of those receiving immunosuppression, 27.08%, 40.63% and, 32.29% of patients were exposed to cDMARDs, bDMARDs and tsDMARDs respectively while rates of BNT162b (Pfizer) vaccination were, 52.33%, 60.67% and, 48.33% among the continue, withhold, and control groups respectively. Post-first dose vaccination seroconversion rates were highest among healthy controls (90%) and patients who temporarily withheld immunosuppressants (76.32%) compared to patients continuing treatment (48.24%) p=0.000. Post-second dose vaccination seroconversion rates were, 100% in both the control and withhold groups and, 86.75% in the continuation (p=0.001). Mean quantitative serum SARS-CoV-2 IgG titres were, 8.58 U/ml, 5.11 U/ml and, 3.29 U/ml (p=0.0001) between the controls, withhold and continue groups respectively following first vaccination. While post-second vaccination mean serum IgG titres were, 96.31 U/ml, 91.86 U/ml, and, 49.73 U/ml (p=0.0066) between these groups. ConclusionCOVID-19 vaccine response in terms of seroconversion and the level of antibody production was highest among healthy controls compared with patients with autoimmune diseases receiving immunosuppression. Temporary cessation of immunosuppressant therapy, contemporaneous to COVID19 vaccination appears to improve vaccine response in this cohort.

Antibody Response to the Coronavirus Disease 2019 Ad26.COV2.S Vaccine Among Maintenance Dialysis Patients

Antibody Response to the Coronavirus Disease 2019 Ad26.COV2.S Vaccine Among Maintenance Dialysis Patients

Antibody Responses to the BNT162b2 mRNA Vaccine in Healthcare Workers in a General Hospital in Japan: A Comparison of Two Assays for Anti-spike Protein Immunoglobulin G.

Objective This study assessed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody responses to the BNT162b2 mRNA vaccine in Japanese healthcare workers. Methods In this prospective cohort study, participants received two doses of the BNT162b2 mRNA vaccine on days 0 and 21 and provided blood for anti-SARS-CoV-2 antibody testing before the first vaccine and on days 21 and 35 after vaccination. Anti-spike protein immunoglobulin G (S-IgG) was measured using Abbott and Fujirebio chemiluminescent immunoassays. Patients One hundred healthcare workers (median age: 39 years old, interquartile range: 30-48 years old), including 6 who had been previously infected with SARS-CoV-2 and 3 individuals taking immunosuppressive drugs, participated in the study. Results The S-IgG antibody titers (AU/mL) measured using both the Abbott and Fujirebio assays increased significantly (p＜0.001) over time, both with a prevalence of 100% at 35 days after the first vaccination. The multivariate log-normal linear regression analysis indicated the effect of immunosuppressant medication using both the Abbott (p=0.013) and Fujirebio (p=0.039) assays on S-IgG levels after complete vaccination. Pearson's correlation coefficient between the Abbott and Fujirebio S-IgG results in all 300 samples collected before and after vaccination and 50 positive controls from patients with coronavirus disease 2019 were 0.963 [95% confidence interval (CI): 0.954-0.970, p＜0.001] and 0.909 (95% CI: 0.845-0.948, p＜0.001), respectively. Conclusion The BNT162b2 mRNA vaccine was effective at increasing S-IgG levels in Japanese immunocompetent healthcare workers. The Fujirebio S-IgG assay showed high diagnostic accuracy, using the Abbott S-IgG assay as the reference test.

Clinical and Epidemiological Characteristics of COVID-19 Patients with SARS-CoV-2 Re-Detected on PCR Test after Discharge from Isolation.

There have been multiple reports of patients with coronavirus disease (COVID-19) testing positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) after discharge; however, information on the characteristics of such cases is limited. In this case report, we aimed to identify clinical and epidemiological characteristics of patients who had a repeat positive polymerase chain reaction (PCR) test for SARS-CoV-2. We analyzed data of 22 COVID-19 patients who tested positive for SARS-CoV-2 on polymerase chain reaction (PCR) testing after two consecutive negative PCR results following discharge from hospitals. The interval between the two positive tests in the episodes of COVID-19 ranged from 4 to 117 days. More than one-third of the cases were healthcare workers (HCWs) and one-third of them had comorbidities. The main symptoms were cough and fever, and we noticed that males experienced more symptoms and signs of COVID-19 than females. Individuals with repeat SARS-CoV-2 positivity tend to experience milder illness during the second episode than the first episode. To confirm the reinfection of SARS-CoV-2, the results of other tests, such as viral culture and immunological assays of immunoglobulin G (IgG) and immunoglobulin M (IgM), need to be considered. Recovered COVID-19 patients should continue social distancing, using face masks, and practicing hand hygiene, especially HCWs who are more likely to be exposed to SARS-CoV-2.

Differences in Antibody Responses Between an Inactivated SARS-CoV-2 Vaccine and the BNT162b2 mRNA Vaccine in Solid-Organ Transplant Recipients.

Vaccination against SARS-CoV-2 may reduce COVID-19 mortality and complications in solidorgan transplant recipients, and we evaluated the associated antibody responses and adverse effects in this high-risk population. This prospective observational study (April-June 2021) included 10 liver and 38 kidney transplant recipients who received 2 vaccine doses (Sinovac, n = 31; or BioNTech, n = 17) and 56 healthy adults (Sinovac), all of whom provided 3 blood samples (prevaccination, 4 weeks after first dose, and 4-6 weeks after second dose) for quantitative tests (Abbott Quant assay forimmunoglobulin G antibodies against SARS-CoV-2 spike protein). Type I error was α = .05 in all statistical analyses (SPSS, version 25). We analyzed demographic data, antibody responses, and adverse events after 2 doses of SARSCoV-2 vaccine, comparedimmune responses from solidorgan transplant recipients (median age, 36.5 years) versus healthy patients (median age, 37.5 years), and observed significantly higher seropositivity in healthy versus transplant patients after Sinovac vaccination (100% vs 67.5%; P = .001). However, we observed no significant seropositive differences for Sinovac versus BioNTech second doses in transplantrecipients. Median SARS-CoV-2 immunoglobulin G level after second dose was significantly higher in BioNTech (1388.6 AU/mL) versus Sinovac patients (136.6 AU/mL) (P = .012). The seropositivity difference between the 2 vaccines was significant in participants 24 to 44 years old (P = .040). The rate of at least 1 side effect was 82.4% (n = 14) for BioNTech vaccine and 32.3% (n = 10) for Sinovac vaccine, and the difference was statistically significant.The most common side effect was arm pain (significantly higher in BioNTech group). Solid-organ transplant recipients demonstrated inadequate vaccine responses (higher risk of complications and mortality) versus healthy patients. Furthermore, immune responses may differ between vaccines. Therefore, additional vaccine doses and strict control measures remain crucial.

Relationship between Serum Thyroid-stimulating Hormone Receptor Autoantibodies and Activity and Severity of Thyroid Eye Disease

Purpose: To study the relationship between the levels of serum thyroid-stimulating hormone (TSH)-receptor autoantibodies (TRAbs) and thyroid eye disease (TED) activity and severity scores.Methods: A cross-sectional study was performed. The medical records of 315 patients diagnosed with TED between March 2014 and December 2019 were reviewed. The clinical activity score (CAS) was used to assess TED activity and a modified NOSPECS score was used for severity grading. The serum TRAb level was measured using two assays: a TSHR binding inhibitory immunoglobulin (TBII) assay and thyroid stimulating immunoglobulin (TSI) bioassay.Results: The TBII and TSI assay results were significantly positively correlated with the CAS (R = 0.113 and 0.211, respectively; &lt;i&gt;p&lt;/i&gt; &lt; 0.05), modified NOSPECS score (R = 0.173 and 0.316, respectively; &lt;i&gt;p&lt;/i&gt; &lt; 0.05), and proptosis (R = 0.136 and 0.167, respectively; &lt;i&gt;p&lt;/i&gt; &lt; 0.05). Both assays demonstrated significant differences in the level of TRAb between patients with and without compressive optic neuropathy or corneal epithelial defects.Conclusions: The levels of TRAbs according to both TBII and TSI assays showed significant correlations with clinical signs of corneal involvement, optic neuropathy, and TED activity and severity.

Compliance withsafety measures andrisk of COVID-19 transmission among healthcare workers.

Aim:This study aimed to determine the compliance of healthcare workers (HCWs) with the hospital safety measures and the prevalence of hospital-acquired COVID-19 infection among them.Methodology:HCWs at King Abdullah University Hospital (KAUH) assigned for COVID-19 patients between 18 March and 10 June 2020 were tested for past infection using total anti-SARS-CoV-2 immunoglobulin assay, demographic data and compliance with safety measures were assessed using a questionnaire.Results:A total of 340 HCWs participated in the study, 260 were close direct care. Three HCWs tested positive for total anti-SARS-CoV-2 immunoglobulin. Close direct care were more compliant with personal protective guidelines than those providing direct care.Conclusion:HCWs compliance with personal protective guidelines might explain the low prevalence of COVID-19 infection in hospital settings.

Spatial Distribution of Plasmodium falciparum and Plasmodium vivax in Northern Ethiopia by Microscopic, Rapid Diagnostic Test, Laboratory Antibody, and Antigen Data.

Determining malaria transmission within regions of low, heterogenous prevalence is difficult. A variety of malaria tests exist and range from identification of diagnostic infection to testing for prior exposure. This study describes the concordance of multiple malaria tests using data from a 2015 household survey conducted in Ethiopia. Blood samples (n=2279) from 3 regions in northern Ethiopia were assessed for Plasmodium falciparum and Plasmodium vivax by means of microscopy, rapid diagnostic test, multiplex antigen assay, and multiplex assay for immunoglobulin G (IgG) antibodies. Geospatial analysis was conducted with spatial scan statistics and kernel density estimation to identify malaria hot spots by different test results. The prevalence of malaria infection was low (1.4% by rapid diagnostic test, 1.0% by microscopy, and 1.8% by laboratory antigen assay). For P. falciparum, overlapping spatial clusters for all tests and an additional 5 unique IgG clusters were identified. For P. vivax, clusters identified with bead antigen assay, microscopy, and IgG partially overlapped. Assessing the spatial distribution of malaria exposure using multiple metrics can improve the understanding of malaria transmission dynamics in a region. The relative abundance of antibody clusters indicates that in areas of low transmission, IgG antibodies are a more useful marker to assess malaria exposure.