Comparison of Autolumo A2000 Plus and Architect i2000 for detection of hepatitis B virus serological markers.

Serological detection of hepatitis B virus markers plays a vital role in the diagnosis, treatment, prognosis, and therapeutic surveillance of hepatitis B. To compare the diagnostic performance of Autolumo A2000Plus and Abbott Architect i2000 systems in the detection of hepatitis B infection markers. A total of 6 HBV seroconversion panels and 743 participants were enrolled in this study, including 383 HBV-infected patients and 360 healthy adults. Clinical diagnostic information, laboratory results, and HBV genotyping were collected to evaluate the diagnostic performance of the A2000Plus and i2000 systems in detecting HBV infection markers. The results showed that the total percent agreement of HBV markers was all >90 % in both detection systems among the six seroconversion panels and 743 serum samples from the population. The χ2 values of the Chi-square test among hepatitis B virus serological markers in both analyzers were between 550.7 and 743.0, p < 0.0001. HBV marker consistency test results show perfect consistency between the two analyzers, with Kappa values ranging from 0.854 to 1.000. For specific samples, including Hepatitis B patients with Genotype C, chronic hepatitis B, hepatitis B-related cirrhosis, and hepatocellular carcinoma, spearman correlation analysis showed HBsAg correlation coefficients ranging from 0.8532 to 0.9745, p < 0.001 in both analyzers. In conclusion, Autolumo A2000Plus diagnostic performance in consistency and correlation is comparable to Abbott Architect i2000 when detecting markers of hepatitis B infection. The Autolumo A2000Plus system can be used as a reliable instrument for HBV marker detection.

Evaluation of Salivary Immunoglobulin A Level and Its Correlation with Severity of Early Childhood Caries: An Original Research.

Background and objectives: Early childhood caries (ECC) remains one of the most prevalent diseases mutilating the primary dentition. It is a multifactorial disease that severely affects the quality of life of affected children. One of the risk indicators reported in the literature is the presence of viable mutans streptococci (MS) and protective factors such as salivary immunoglobulin A (SIgA). Hence, it is important to identify such risks and protective factors associated with ECC using simple yet reliable methods supported by advanced technology and a fully automated platform to improve the results. Materials and methods: A retrospective analysis was done on 40 children who were divided into two groups: group I (experimental) and group II (control). Group I comprised 30 healthy children who were further divided into three subgroups of 10 children each. Group IA with decayed, missing, filled teeth/decayed, extracted, filled teeth (dmft/deft) = 1-2, group IB with dmft/deft = 3-4, group IC with dmft/deft ≥5, and group II, comprising 10 healthy children having no caries by using World Health Organization (WHO) 2013 Oral Health Survey criteria. Unstimulated saliva was collected by drooling saliva into a sterile container. The samples were transported to the central research laboratory for SIgA by the immunoturbidimetry method by a fully automated Abbott Architect c system. The data obtained was subjected to statistical analysis. Results: On comparison of SIgA in between varying severities of dental caries and caries-free children between age-group of 3 and 6 years, it was found to be below the grand median 0.20 mg/mL for subgroups IA and control group II. A significant negative statistical correlation (r = -0.948) was present between the SIgA and varying severities of ECC and the control group. Interpretation and conclusion: The low dmft/deft group was found to be relatively closer to the caries-free groups as their mean dmft was 1.50, standard deviation (SD) ± 0.53. A slight change in dmft/deft score and SIgA could be used as a potential biomarker for assessing the severity of ECC in children between age-group of 3 and 6 years. How to cite this article: Sharma V, Bagchi A, Dutta B, et al. Evaluation of Salivary Immunoglobulin A Level and Its Correlation with Severity of Early Childhood Caries: An Original Research. Int J Clin Pediatr Dent 2024;17(3):316-320.

Discrepancies between two total IgE assays and difference in reference intervals in healthy adults.

OBJECTIVE: To compare total immunoglobulin (Ig) E assay performance characteristics between Abbott Architect and Siemens Immulite test systems. Reference intervals were also determined for both platforms in an American population of healthy adults. METHODS: Agreement of the two total IgE assays was evaluated in a cohort of 331 subjects with normal complete blood count (CBC) and comprehensive metabolic panel (CMP) results. Reference intervals were established in 302 subjects after exclusion of atopic individuals on the Abbott Architect and Siemens Immulite test systems. RESULTS: We demonstrated a 32% positive bias for total IgE quantitation on the Siemens Immulite platform compared to the Abbott Architect, despite both methods calibrated against the same WHO international reference material (75/502), Furthermore, the upper limit of the reference interval (95th percentile) was determined to be higher for the Siemens Immulite assay compared to the Abbott Architect (132 and 102 IU/mL, respectively). CONCLUSION: Despite the use of a common WHO reference material for total IgE assay calibration, significant differences in quantitation was observed between two FDA-cleared test systems. Given that, it is warranted for clinical laboratories to verify vendor established reference intervals and adjust accordingly based on internal assessment of the normal range.

Mycelium-Based Composites: Surveying Their Acceptance by Professional Architects.

Mycelium-based composites (MBCs) are biomaterials with scientifically proven potential to improve sustainability in construction. Although mycelium-based products are not entirely new, their use in engineering presents challenges due to the inherent properties of this fungal material. This study investigated professional architects' and interior designers' perceptions of MBCs, focusing on familiarity, aesthetic appeal, and willingness to use. The first phase of the survey explored respondents' views on material-related ecological design principles. In the second phase, respondents evaluated ten small architectural objects crafted from MBCs, focusing on form, detail, and visual appeal. The last phase of the survey measured their interest in using mycelium in their design work. The results revealed that MBCs were relatively unknown among the surveyed professionals; only every second respondent knew this material. Despite this, 90% found MBCs visually appealing after seeing the examples. Interestingly, the natural, unprocessed appearance of the material was assessed as less aesthetically pleasing, with thermal treatment improving its perceived value. Architects were more receptive to using MBCs in their professional projects for customers than for personal use. This observation points to a 'double standard': professional architects are more open to using MBCs in projects not intended for their own use.

Benchmarking Relevance for Hospital Design and Planning: An International Web-Based Survey.

OBJECTIVE: The study aims to investigate what design practitioners and healthcare facility managers deem as important benchmarking metrics worldwide, investigating country differences in benchmarking usage and which metrics are prioritized. BACKGROUND: Benchmarking is a regular practice in the healthcare sector, both for clinical and managerial aspects to compare, measure, and improve standardized processes. However, limited knowledge is available about benchmarking procedures in hospital planning, design, and construction. METHODS: A web-based survey was designed, revised, and pilot-tested in five countries; it was adjusted according to local experts' suggestions and submitted globally via SoSci multilingual platform to persons involved in hospital design, research, construction, and facility management. It was composed of closed questions on 5-point Likert-type scale ranking frequency or importance and open-ended questions divided into six sections. Two hundred and eighty full responses have been collected. Statistical analysis was performed via PowerBI and R-Studio, while qualitative analysis was performed via MAXQDA. RESULTS: The findings reported allow for both specific insights per each country or category as well as enabling general considerations of a practice that is becoming always more international with 30%-50% of respondents working in the international context. The evaluation of the survey highlights the most important benchmarks, among others. For example, for respondents from the top five countries (Sweden, Spain, Germany, Italy, and the United States), the most important metric for benchmark comparability is whether the project was new construction, new construction attached to an existing hospital, or interior renovation. Construction date, client type (public vs. private), and country of location were also generally rated as the most important metrics by respondents. Other metrics that were consistently rated as important globally included inpatient unit layout, walking distances, number of floors, and whether all patient rooms are private. Space-related metrics are considered very important elements in the design and planning of healthcare facilities worldwide. Regarding cost-related metrics, all countries consider the ratio construction cost per building gross area as the most important. CONCLUSIONS: Benchmarking emerges as a relevant tool for hospital design and planning as it can support efficiency, standardization, and confidence; currently, benchmarking is still underutilized due to the challenge of international comparison, access to data outside each specific company, and variation design metrics nationally. Benchmarking strategies should be further investigated to support knowledge exchange and to ensure reliable and comparable information globally.

A new double-antigen sandwich test based on the light-initiated chemiluminescent assay for detecting anti-hepatitis C virus antibodies with high sensitivity and specificity.

Objectives: The aim of this study was to evaluate the performance of a new double-antigen sandwich test that is based on the light-initiated chemiluminescent assay (LiCA®) for detecting anti-hepatitis C virus antibodies (anti-HCV) in comparison to Architect®. Methods: Analytical characteristics and diagnostic performance were tested using seroconversion panels and large pools of clinical samples. Positive results were validated by the strip immunoblot assay (RIBA) and HCV RNA. Results: Repeatability and within-lab imprecision of LiCA® anti-HCV were 1.31%-3.27%. The C5-C95 interval was -5.44%-5.03% away from C50. LiCA® detected seroconversion in an average of 28.9 days and showed a mean of 3.7 (p = 0.0056) days earlier than Architect®. In a pool of 239 samples with known HCV genotypes 1 to 6, both assays correctly detected all subjects. In 16,305 clinical patient sera, LiCA® detected 4 false-negative (0.25‰) and 14 false-positive (0.86‰) anti-HCV cases, while Architect® recorded 6 false-negative (0.37‰) and 138 false-positive (8.46‰) subjects, respectively. Compared to Architect®, LiCA® presented a significantly better performance in specificity (99.91% vs. 99.14%, n = 16,018, p < 0.0001), positive predictive value (95.29% vs. 67.06%, n = 419, p < 0.0001), and overall accuracy (99.89% vs. 99.12%, n = 16,305, p < 0.0001), while no significant difference in sensitivity (98.61% vs. 97.91%, n = 287, p = 0.5217) and negative predictive value (99.98% vs. 99.96%, n = 15,886, p = 0.3021) was seen. An S/Co value of 3.28 was predicted to be the threshold with a positivity ≥95% for the LiCA® anti-HCV assay. Conclusion: LiCA® anti-HCV is a precise and fully automatic chemiluminescent assay with superior sensitivity and specificity. The assay can be used as a valuable tool to supplement the diagnosis of HCV infection.

Pediatric vitamin D: Pseudo-hypervitaminosis.

BACKGROUND: Vitamin D toxicity is rare in pediatric population. Falsely elevated levels of 25-hydroxyvitamin D have been reported as a major challenge with immunoassay methods for quantifying vitamin D metabolites. CASE PRESENTATION AND METHOD: Here, we present two pediatric cases of falsely elevated 25-hydroxyvitamin D that resulted in unnecessary further testing. We also report significant same-day variation in the measurement of 25-hydroxyvitamin D using the Abbott i2000SR immunoassay. Samples were spun twice and their values were confirmed with the gold standard liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for confirmation. CONCLUSION: The addition of a centrifugation step prior to sample testing resolved the variation observed in the measurement of 25-hydroxyvitamin D levels. The patient samples were confirmed with instruments from a different vendor and LC-MS/MS. Re-centrifugation of samples resolved the variation in the 25-hydroxyvitamin D values.

Nano Architect-Based Targeted Delivery Systems for Diabetic Nephropathy: A Review.

Diabetes mellitus is a long-lasting disease that is very common in the age group above 20 years and is characterized by hyperglycemia with other complications like Diabetic Nephropathy (DN). The management of DN focuses on mainly four regions: reduction of cardiovascular risks, control of blood glycemic levels, control of the blood pressure (BP) profile, and the use of therenin-angiotensin system (RAS). Although BP management and RAS-acting agents can postpone the onset of DN, they cannot prevent it. In the modern era, nanotechnological interventions have spread rapidly in the field of medicine. Patient defiance is considered important in diabetes management when long-term or continuous management is required. Nano pharmaceuticals have been shown to increase compliance of diabetic patients by providing multiple ways of drug delivery, controlling release profile, increasing biological steadiness, targeting efficacy, and decreasing toxic profile. Nanoscale formulations of botanical antidiabetic molecules improve clinical efficacy and treatment compliance by overcoming associated biopharmaceutical and pharmacokinetic barriers. Therefore, the development of nanopharmaceuticals can be considered to be a possible answer to attain the finest scientific effect of the plant-based anti-diabetic molecule. Nevertheless, further studies are needed to create clinical research-based and therapeutically effective nanoforms of antidiabetic plant-based molecules to combat the most dreaded disease of diabetes and its known present complications.

How Do Informaticians and IT-Architects Collaborate, or Not? A Case Study from a Public Health Care Provider.

Despite years of work from both informaticians and IT-architects interoperability within healthcare is still low. This explorative case study performed on a well-staffed public health care provider shows that the involved roles were unclear, processes did not include each other, and that tooling was incompatible. However, interest in collaboration was high and technical advances and inhouse development were seen as incentives for increased collaboration.

Comparison of two new HTLV-I/II screening methods, Abbott Alinity i rHTLV-I/II and Diasorin LIAISON® XL murex recHTLV-I/II, to Abbott architect rHTLVI/II assay.

BACKGROUND: Diagnosis of Human T-cell Lymphotropic Virus (HTLV) types I and II infection requires sequencial testing with firstly a screening using an Enzyme immunoassay followed by a confirmatory test. OBJECTIVES: To compare the performances of the Alinity i rHTLV-I/II (Abbott®) and LIAISON® XL murex recHTLV-I/II serological screening tests to the ARCHITECT rHTLVI/II test followed if positive by HTLV BLOT 2.4, MP Diagnostics as the reference. STUDY DESIGN: 119 serum samples from 92 known HTLV-I infected patients and 184 from uninfected patients with HTLV were analyzed in parallel with, Alinity i rHTLV-I/II, LIAISON® XL murex recHTLV-I/II and ARCHITECT rHTLVI/II. RESULTS: Alinity i rHTLV-I/II and LIAISON® XL murex recHTLV-I/II exhibited a total agreement with ARCHITECT rHTLVI/II for both positive and negative samples. Both tests are suitable alternatives for HTLV screening.

Development of an automated chemiluminescent immunoassay for cancer antigen 72-4 and the evaluation of its analytical performance.

Objectives: Cancer antigen (CA) 72-4 assay is widely used for monitoring gastric and ovarian cancers. The antigen is a mucin-like, tumor-associated glycoprotein known as TAG-72. It has been identified and characterized using two different monoclonal antibodies, CC49 and B72.3, which recognize its glycochain epitopes, Galß(1-3) sialyl-Tn and sialyl-Tn antigens, respectively. This study describes the quantitative analytical performance of a newly developed CA 72-4 assay, ARCHITECT CA 72-4. Design: and Methods: The ARCHITECT CA 72-4 assay was developed using the ARCHITECT i2000SRs and three ARCHITECT i1000SRs. The assay performance was evaluated based on guidance from CLSI (Clinical and Laboratory Standards Institute) and correlation against Elecsys CA 72-4. Results: In the total precision study, the minimum coefficient of variation (CV) for Control/Panel samples over 4 U/mL was 1.1%. The measuring interval was from 0.95 to 200 U/mL with good linearity; and limits of blank (LoB), detection (LoD), and quantitation (LoQ) were 0.09, 0.18, and 0.95 U/mL, respectively. High dose hook effect; differences among specimen tube types; and interference of common drugs, potential cross-reactants, and endogenous substances were not observed. Significantly, this assay has high biotin tolerance at 4875 mg/mL and correlates well with the Elecys CA 72-4 assay (correlation coefficient: 0.95). Conclusions: ARCHITECT CA 72-4 is a highly sensitive and precise assay for CA 72-4 measurement in human sera and plasma.

Kinetics of anti-SARS-CoV-2 antibody titer in healthy adults up to 6 months after BNT162b2 vaccination measured by two immunoassays: A prospective cohort study in Japan.

BACKGROUND: Although several assays are used to measure anti-receptor-binding domain (RBD) antibodies induced after severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccination, the assays are not fully comparable in practice. This study evaluated the immunogenicity of the BNT162b2 mRNA vaccine in healthy adults using two immunoassays. METHODS: This prospective cohort study included SARS-CoV-2-naïve adults, predominantly healthcare workers, aged 20-64 years, who received two BNT162b2 vaccine doses between March and May 2021. Blood samples were collected before the first vaccination (S0), before the second vaccination (S1), 4 weeks after the second vaccination (S2), and 6 months after the second vaccination (S3). anti-RBD antibodies were measured using the Architect SARS-CoV-2 IgG II Quant (Abbott Laboratory) and Elecsys anti-SARS-CoV-2 S (Roche Diagnostics) assays. RESULTS: Among the 385 participants, the geometric mean antibody titers (GMTs) on the Architect assay (AU/mL) were 7.5, 693, 7007, and 1030 for S0, S1, S2, and S3, respectively. The corresponding GMTs on the Elecsys assay (U/mL) were 0.40, 24, 928, and 659, respectively. The GMT ratio (S3/S2) was 0.15 on the Architect and 0.71 on the Elecsys assay. The correlation between antibody titers measured with the two assays were strong at all time points after vaccination (Spearman's correlation coefficient: 0.74 to 0.86, P < 0.01 for all). GMT was significantly lower in the older age group after vaccination (P < 0.01), with no significant differences according to sex. Seroprotection (≥5458 AU/mL on the Architect assay and ≥ 753 U/mL on the Elecsys) at each time point was 0 %, 1 %, 67 %, and 1 % on the Architect assay and 0 %, 1 %, 62 %, and 43 % on the Elecsys, respectively. CONCLUSIONS: Two BNT162b2 vaccine doses resulted in adequate anti-RBD antibody response, which varied by age. As the two assays showed different kinetics, the results of single immunoassays should be interpreted with caution.

Comparison of a novel automated DiaSys procalcitonin immunoassay with four different BRAHMS-partnered immunoassays.

Objectives: Procalcitonin (PCT) is an important biomarker of sepsis and respiratory infections. Various automated immunoassays for measuring PCT in patient plasma are available in medical laboratories. However, due to a lack of international reference material for PCT, the assays are not always comparable. Design and methods: In this study, we compared a new turbidimetric immunoassay from DiaSys, measured on the Abbott Architect c16000 and Alinity c, with four BRAHMS-associated chemiluminescence immunoassays (Abbott Architect i2000SR, Alinity i, Roche Cobas e411 and DiaSorin Liaison XL) using 120 random patient plasma samples from the clinical laboratory routine at the University Medical Center Goettingen. Results: The DiaSys assay showed clear differences as compared to the BRAHMS-associated assays when measured on Architect c: i.e. 58% positive mean bias vs. Architect i, 67% vs. Cobas and 23% vs. Liaison. As a result, additional 19% our patients would have a suspected bacterial infection, when using PCT values from the DiaSys assay and commonly accepted decision limits. A crosscheck of the DiaSys calibrator on the BRAHMS-associated systems showed a low recovery of the calibrator material (approx. 50%). Conclusions: Overall, this study shows significant differences between the DiaSys and BRAHMS-associated assays. This could be attributed to a potential DiaSys calibrator problem. This highlights the need for an international reference material for harmonization of the PCT assays.

Evaluation of a batched-extraction method for measurement of sirolimus, tacrolimus, and cyclosporine on the Architect i2000SR.

BACKGROUND: Manual extraction of immunosuppressants is required before measurement on the Architect immunoassay analyzer. The individual extraction of samples places clinical laboratory staff at risk for ergonomic injury. We evaluated the analytical performance of a batched extraction method for measuring sirolimus, tacrolimus, and cyclosporine using the Architect i2000SR. METHODS: Residual whole blood samples from patients receiving immunosuppressant therapy were used for evaluation. The analytical evaluation included imprecision, linearity, and method comparison. Technologist-to-technologist variation was also assessed. RESULTS: Total imprecision ranged from 2.58 to 3.13% for sirolimus, 2.70-3.77% for tacrolimus, and 7.82-12.41% for cyclosporine. Linearity was verified from 0.44-19.49 µg/l for sirolimus, 0.05-26.15 µg/l for tacrolimus, and 0.15-991.55 µg/l for cyclosporine. Deming regression analysis showed slope and intercept were not significant for either technologist-to-technologist comparison or for batched vs. individual processing comparison. Bland-Altman analysis of individual vs. batched processing revealed a mean bias of 1.29% (LLOA: -14.63%, ULOA: 17.21%) for sirolimus, 2.07% (LLOA: -10.87%, ULOA: 15%) for tacrolimus, and -1.56% (LLOA: -20.05%, ULOA: 16.94%) for cyclosporine. The values were not significantly different from the bias and LLOAs observed for technologist-to-technologist comparison. CONCLUSIONS: The imprecision and linearity of batched methods met analytical goals. The batched method also correlated well with the individual extraction methods. The ULOA and LLOA for all drugs tested exceeded a TAE or ± 15%. However, similar range of differences was observed between technologists, suggesting that batch processing did not increase or reduce variability due to manual preparation steps.

Interpretations of SARS-CoV-2 IgM and IgG antibody titers in the seroepidemiological study of asymptomatic healthy volunteers.

INTRODUCTION: The usefulness of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody tests in asymptomatic individuals has not been well validated, although they have satisfied sensitivity and specificity in symptomatic patients. In this study, we investigated the significance of IgM and IgG antibody titers against SARS-CoV-2 in the serum of asymptomatic healthy subjects. METHODS: From June 2020, we recruited 10,039 participants to the project named the University of Tokyo COVID-19 Antibody Titer Survey (UT-CATS), and measured iFlash-SARS-CoV-2 IgM and IgG (YHLO IgM and IgG) titers in the collected serum. For the samples with increased IgM or IgG titers, we performed additional measurements using Elecsys Anti-SARS-CoV-2 Ig (Roche total Ig) and Architect SARS-CoV-2 IgG (Abbott IgG) and investigated the reactivity to N, S1, and receptor binding domain (RBD) proteins. RESULTS: After setting the cutoff value at 5 AU/mL, 61 (0.61%) were positive for YHLO IgM and 104 (1.04%) for YHLO IgG. Few samples with elevated YHLO IgM showed reactivity to S1 or RBD proteins, and IgG titers did not increase during the follow-up in any samples. The samples with elevated YHLO IgG consisted of two groups: one reacted to S1 or RBD proteins and the other did not, which was reflected in the results of Roche total Ig. CONCLUSIONS: In SARS-CoV-2 seroepidemiological studies of asymptomatic participants, sufficient attention should be given to the interpretation of the results of YHLO IgM and IgG, and the combined use of YHLO IgG and Roche total Ig might be more reliable.

Comparative evaluation of ADVIA Centaur® XP chemiluminescence system for screening of HBV, HCV, HIV and syphilis in Indian blood donors.

BACKGROUND: The introduction of chemiluminescent immunoassay (CLIA) in blood donor screening has led to a gradual replacement of enzyme-linked-immunosorbent assay (ELISA) as the former offers automation, higher sensitivity and lower turn-around-time. However, only a few CLIA platforms are used for blood donor screening in India. The present study evaluated one such newer platform viz., Adiva Centaur XP CLIA for screening of HBV, HCV, HIV and syphilis. MATERIAL AND METHODS: Prospective comparative study wherein 4843 whole blood donors were screened for HBsAg, Anti-HCV, HIV Ag-Ab and Anti-treponemal antibodies in both Advia Centaur XP and Architect i2000SR platforms. Additional tests were performed in samples which were reactive in only one of the platforms. The sensitivity, specificity, positive predictive value, negative predictive value, accuracy, false positive rate and false negative rate of both the platforms were compared. Kappa coefficient was calculated to determine the agreement between the testing platforms. RESULTS: The sensitivity of Advia Centaur platform for HBV, HCV, HIV and syphilis detection were 94.9 %, 100 %, 100 % and 100 % respectively as compared to 96.6 %, 100 %, 100 % and 100 % in Architect i2000SR platform. The specificity of both the platforms were 99.8-99.9 % for all the four tests. The agreement between the two platforms was almost perfect for HBV, HCV and syphilis testing; and fair for HIV testing. CONCLUSION: The Advia Centaur CLIA platform was found to be comparable with the Architect CLIA platform for blood donor screening. Unexpected finding was the occurrence of HBV false negatives in both the platforms, possibly due to HBsAg mutations.

Design of Customized TPU Lattice Structures for Additive Manufacturing: Influence on the Functional Properties in Elastic Products.

This work focuses on evaluating and establishing the relationship of the influence of geometrical and manufacturing parameters in stiffness of additively manufactured TPU lattice structures. The contribution of this work resides in the creation of a methodology that focuses on characterizing the behavior of elastic lattice structures. Likewise, resides in the possibility of using the statistical treatment of results as a guide to find favorable possibilities within the range of parameters studied and to predict the behavior of the structures. In order to characterize their behavior, different types of specimens were designed and tested by finite element simulation of a compression process using Computer Aided Engineering (CAE) tools. The tests showed that the stiffness depends on the topology of the cells of the lattice structure. For structures with different cell topologies, it has been possible to obtain an increase in the reaction force against compression from 24.7 N to 397 N for the same manufacturing conditions. It was shown that other parameters with a defined influence on the stiffness of the structure were the temperature and the unit size of the cells, all due to the development of fusion mechanisms and the variation in the volume of material used, respectively.

SARS-CoV-2 Antibody Testing in Health Care Workers: A Comparison of the Clinical Performance of Three Commercially Available Antibody Assays.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies are an excellent indicator of past COVID-19 infection. As the COVID-19 pandemic progresses, retained sensitivity over time is an important quality in an antibody assay that is to be used for the purpose of population seroprevalence studies. We compared 5,788 health care worker (HCW) serum samples by using two serological assays (Abbott SARS-CoV-2 anti-nucleocapsid immunoglobulin G (IgG) and Roche anti-SARS-CoV-2 anti-nucleocapsid total antibody) and a subset of samples (all Abbott assay positive or grayzone, n = 485) on Wantai SARS-CoV-2 anti-spike antibody enzyme-linked immunosorbent assay (ELISA). For 367 samples from HCW with a previous PCR-confirmed SARS-CoV-2 infection, we correlated the timing of infection with assay results. Overall, seroprevalence was 4.2% on Abbott and 9.5% on Roche. Of those with previously confirmed infection, 41% (150/367) and 95% (348/367) tested positive on Abbott and Roche, respectively. At 21 weeks (150 days) after confirmed infection, positivity on Abbott started to decline. Roche positivity was retained for the entire study period (33 weeks). Factors associated (P ≤ 0.050) with Abbott seronegativity in those with previous PCR-confirmed infection included sex (odds ratio [OR], 0.30 male ; 95% confidence interval [CI], 0.15 to 0.60), symptom severity (OR 0.19 severe symptoms; 95% CI, 0.05 to 0.61), ethnicity (OR, 0.28 Asian ethnicity; 95% CI, 0.12 to 0.60), and time since PCR diagnosis (OR, 2.06 for infection 6 months previously; 95% CI, 1.01 to 4.30). Wantai detected all previously confirmed infections. In our population, Roche detected antibodies up to at least 7 months after natural infection with SARS-CoV-2. This finding indicates that the Roche total antibody assay is better suited than Abbott IgG assay to population-based studies. Wantai demonstrated high sensitivity, but sample selection was biased. The relationship between serological response and functional immunity to SARS-CoV-2 infection needs to be delineated. IMPORTANCE As the COVID-19 pandemic progresses, retained sensitivity over time is an important quality in an antibody assay that is to be used for the purpose of population seroprevalence studies. There is a relative paucity of published literature in this field to help guide public health specialists when planning seroprevalence studies. In this study, we compared results of 5,788 health care worker blood samples tested by using two assays (Roche and Elecsys, anti-nucleocapsid antibody) and by testing a subset on a third assay (Wantai enzyme-linked immunosorbent assay [ELISA] anti-spike antibody). We found significant differences in the performance of these assays, especially with distance in time from PCR-confirmed COVID-19 infection, and we feel these results may significantly impact the choice of assay for others conducting similar studies.

Evaluation of Abbott Architect, Siemens Immulite, bioMerieux Vidas, and Euroimmune assays for determination of Epstein-Barr virus serological diagnosis.

Serological tests detecting antibodies for Epstein-Barr virus (EBV) antigens are frequently used to define infection status. Several new automated assays are available for this purpose. We compared the performance of Architect, Immulite, Vidas, and Euroimmune immunofluorescence assays (IFA)/enzyme-linked immunosorbent assays (ELISA) for the detection of EBV viral capsid antigen (VCA) immunoglobulin M (IgM), VCA IgG, Epstein-Barr nuclear antigen (EBNA)-1 IgG. The routine diagnosis of EBV in our laboratory is done by anti-EBV VCA IgM IFT, anti-EBV VCA IgG IFT, and anti-EBNA-1 IgG ELISA (Euroimmune) Kits. Samples were tested with EBV Kits of Architect, Immulite, and Vidas for anti-VCA IgM, anti-VCA IgG, and anti-EBNA-1 IgG. The agreement between assays was calculated for each marker individually and for the determination of the EBV infection profile, based on the combination of three markers. BIOCHIP Sequence EBV (Avidity test) and/or EUROLINE EBV Profile 2 (IgG/IgM) were used as confirmatory assays to resolve discrepancies. The best concordance for VCA IgM detection was between Immulite and Vidas; for VCA IgG and EBNA-1 IgG were between Architect and Vidas. The sensitivities and specificities for VCA IgM were 97% and 88% for IFA, 100% and 94% for Architect, 100% and 99% for Vidas, and 100% and 100% for Immulite, respectively. The most problematic marker was EBNA-1 IgG with a 68.1% specificity by Immulite. Vidas panel had a perfect performance (100%) for determining all EBV profiles. Overall, evaluated assays had comparable performance. There were more discordant VCA IgG and EBNA-1 IgG results than VCA IgM results. The agreement between Architect and Vidas was better than other assays.