RESUMO
BACKGROUND: The diagnosis of hypercortisolism requires multiple biochemical investigations, due to variations in cortisol production during the 24-hour circadian cycle. Midnight serum cortisol is difficult to interpret since the threshold value is dependent on the analytical method used and is often not provided by the manufacturer. Second-generation assays are more specific than first-generation assays and may have lower threshold values. OBJECTIVES: The aim of this study was to determine a novel threshold value of midnight serum cortisol for the biochemical diagnosis of hypercortisolism, using the Roche Cobas Cortisol® second-generation assay. METHODS: This study was performed in adult patients hospitalized in the endocrinology unit of a university hospital. Patients had a complete assessment of their 24-hour cortisol cycle, i.e., a serum cortisol test every four hours and at least two first-line tests: late night salivary cortisol, dexamethasone suppression test and/or 24-hour urinary free cortisol. First-line tests were used to identify patients with hypercortisolism. Serum samples were analyzed by second-generation electrochemiluminescence immunoassays (ECLIA) from Roche Cobas Cortisol®. RESULTS: Midnight serum cortisol samples were obtained from 175 hospitalized patients. The novel threshold value obtained was 157 nmol/L with a sensitivity of 82.9% (68.6 to 94.3%) and a specificity of 90.0% (85.0 to 95.0%). CONCLUSION: Our study confirms that the threshold value of midnight serum cortisol is not comparable between first- and second-generation Roche Cobas Cortisol® assays and that the threshold value is lower with the second-generation assay.
Assuntos
Síndrome de Cushing/diagnóstico , Hidrocortisona/normas , Imunoensaio/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Hidrocortisona/análise , Masculino , Pessoa de Meia-Idade , Valores de Referência , Estudos Retrospectivos , Saliva/química , Adulto JovemAssuntos
Teste para COVID-19/normas , COVID-19/diagnóstico , Imunoensaio/normas , Programas de Rastreamento/normas , Autoteste , COVID-19/epidemiologia , COVID-19/prevenção & controle , Teste para COVID-19/instrumentação , Teste para COVID-19/estatística & dados numéricos , Humanos , Imunoensaio/instrumentação , Imunoensaio/estatística & dados numéricos , Programas de Rastreamento/métodos , Programas de Rastreamento/estatística & dados numéricos , Sensibilidade e EspecificidadeRESUMO
Lateral flow immunoassays are low cost, rapid and highly efficacious point-of-care devices, which have been used for SARS-CoV-2 antibody testing by professionals. However, there is a lack of understanding about how self-administered tests are used by the general public for mass testing in different environmental settings. The purpose of this study was to assess the user experience (UX) (including usability) of a self-testing kit to identify COVID-19 antibodies used by a representative sample of the public in their cars, which included 1544 participants in Northern Ireland. The results based on 5-point Likert ratings from a post-test questionnaire achieved an average UX score of 96.03% [95% confidence interval (CI) 95.05-97.01%], suggesting a good degree of user experience. The results of the Wilcoxon rank sum tests suggest that UX scores were independent of the user's age and education level although the confidence in this conclusion could be strengthened by including more participants aged younger than 18 and those with only primary or secondary education. The agreement between the test result as interpreted by the participant and the researcher was 95.85% [95% CI 94.85-96.85%], Kappa score 0.75 [95% CI 0.69-0.81] (indicating substantial agreement). Text analysis via the latent Dirichlet allocation model for the free text responses in the survey suggest that the user experience could be improved for blood-sample collection, by modifying the method of sample transfer to the test device and giving clearer instructions on how to interpret the test results. The overall findings provide an insight into the opportunities for improving the design of SARS-CoV-2 antibody testing kits to be used by the general public and therefore inform protocols for future user experience studies of point-of-care tests.
Assuntos
Anticorpos Antivirais/análise , Teste para COVID-19/estatística & dados numéricos , Imunoensaio/estatística & dados numéricos , Adolescente , Adulto , Anticorpos Antivirais/imunologia , Criança , Escolaridade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Sistemas Automatizados de Assistência Junto ao Leito , Autoadministração , Sensibilidade e Especificidade , Adulto JovemRESUMO
Serology or antibody tests for COVID-19 are designed to detect antibodies (mainly Immunoglobulin M (IgM) and Immunoglobulin G (IgG) produced in response to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS CoV-2) infection. In this study, 30 lateral flow immunoassays were tested using serum or plasma from patients with confirmed SARS CoV-2 infection. Negative serological controls were accessed from a well-characterised bank of sera which were stored prior to February 2020. Operational characteristics and ease of use of the assays are reported. 4/30 (13%) of kits (Zheihang Orient Gene COVID-19 IgG/IgM, Genrui Novel Coronavirus (2019-nCoV) IgG/IgM, Biosynex COVID-19 BSS IgG/IgM, Boson Biotech 2019-nCoV IgG/IgM) were recommended for SAHPRA approval based on kit sensitivity. Of these, only the Orientgene was recommended by SAHPRA in August 2020 for use within the approved national testing algorithm while the remaining three received limited authorization for evaluation. All kits evaluated work on the same basic principle of immunochromatography with minor differences noted in the shape and colour of cartridges, the amount of specimen volume required and the test duration. Performance of the lateral flow tests were similar to sensitivities and specificities reported in other studies. The cassettes of the majority of kits evaluated (90%) detected both IgG and IgM. Only 23% of kits evaluated contained all consumables required for point-of-care testing. The study highlights the need for thorough investigation of kits prior to implementation.
Assuntos
Anticorpos Antivirais/isolamento & purificação , Teste Sorológico para COVID-19/instrumentação , COVID-19/diagnóstico , Imunoensaio/instrumentação , Kit de Reagentes para Diagnóstico/estatística & dados numéricos , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , COVID-19/sangue , COVID-19/imunologia , COVID-19/virologia , Teste de Ácido Nucleico para COVID-19/estatística & dados numéricos , Teste Sorológico para COVID-19/estatística & dados numéricos , Humanos , Imunoensaio/estatística & dados numéricos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina G/isolamento & purificação , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Imunoglobulina M/isolamento & purificação , Testes Imediatos/estatística & dados numéricos , RNA Viral/sangue , RNA Viral/isolamento & purificação , SARS-CoV-2/genética , SARS-CoV-2/imunologia , SARS-CoV-2/isolamento & purificação , Sensibilidade e EspecificidadeRESUMO
ABSTRACT: The 17 Provincial Institutes of Health and Environment (PIHEs) in Korea use HIV antibody, antigen, and Western blot assays for confirmatory testing of HIV infection. The Korea Disease Control and Prevention Agency (KDCA) has further included p24 antigen neutralization and nucleic acid tests (NATs) since 2015. Our study aimed to investigate the effect of this new testing algorithm on the confirmation rate of HIV infection.Annual changes, from 2012 through 2017, in positive or indeterminate HIV confirmatory results were compared for the two algorithms between the PIHEs and the KDCA. Fiebig stages and Western blot p31 band were used to identify the diagnostic proportions of acute or early chronic HIV for the two algorithms.The number of positive cases in the samples requested from PIHEs for reconfirmation by the KDCA has steadily increased from 10.3% in 2014 to 33.3% in 2017. However, the number of indeterminate cases dropped sharply, from 71.9% in 2014 to 14.0% in 2017. The results for the p31 reactive band were 27.4% and 88.4% for the KDCA and PIHEs, respectively. Of positive cases reported by the KDCA, 22.9% were in the early acute stage and Fiebig stages I to II.The new testing algorithm has improved the diagnosis of HIV infections in the early acute stage. Early confirmatory diagnosis can prevent secondary transmission of HIV and provide early treatment opportunities for people living with HIV infection.
Assuntos
Algoritmos , Western Blotting/estatística & dados numéricos , Infecções por HIV/diagnóstico , Imunoensaio/estatística & dados numéricos , Técnicas de Amplificação de Ácido Nucleico/estatística & dados numéricos , Diagnóstico Precoce , HIV/imunologia , Anticorpos Anti-HIV/análise , Antígenos HIV/análise , Infecções por HIV/epidemiologia , Humanos , República da Coreia/epidemiologia , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: A number of immunoassays have been developed to measure antibodies specific to SARS-CoV-2. More data is required on their comparability, particularly among those with milder infections and in the general practice population. The aim of this study was to compare four high-throughput automated anti-SARS-CoV-2 assays using samples collected from hospitalized patients and healthcare workers with confirmed SARS-CoV-2 infection. In addition, we collected general practice samples to compare antibody results and determine seroprevalence. METHODS: Samples were collected from 57 hospitalized patients and nine healthcare workers at 14 days and at 28 days following confirmed SARS-CoV-2 infection. Samples were also collected from 225 patients presenting to general practice. Four assays were used: Abbott Architect IgG, Beckman Coulter DxI 800 IgG, Roche Cobas e801 total antibody and Siemens Advia Centaur XPT total antibody. RESULTS: All four assays showed concordance at 14 days in 83.9% of hospitalized patients and in 66.7% of healthcare workers. All four assays showed concordance at 28 days in 88.4% of hospitalized patients and 77.8% of healthcare workers. The sensitivity to detect recent infection was higher for the IgG assays than the total assays. All four assays showed concordance of 95.1% in the general practice population. Seroprevalence ranged from 4.9 to 5.8% depending on the assay used. CONCLUSIONS: All four assays showed excellent comparability, but it may be possible to obtain a negative result for any of the anti-SARS-CoV-2 assays in patients with confirmed previous SARS-CoV-2 infection. An equivocal range would be useful for all anti-SARS-CoV-2 assays.
Assuntos
Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , COVID-19/imunologia , SARS-CoV-2/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/sangue , COVID-19/epidemiologia , Teste Sorológico para COVID-19/estatística & dados numéricos , Feminino , Medicina Geral , Pessoal de Saúde , Ensaios de Triagem em Larga Escala/métodos , Ensaios de Triagem em Larga Escala/estatística & dados numéricos , Hospitalização , Humanos , Imunoensaio/métodos , Imunoensaio/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Pandemias , Estudos Soroepidemiológicos , Reino Unido/epidemiologia , Adulto JovemRESUMO
Our objective was to estimate the diagnostic accuracy of real-time polymerase chain reaction (RT-PCR) and lateral flow immunoassay (LFIA) tests for coronavirus disease 2019 (COVID-19), depending on the time after symptom onset. Based on the cross-classified results of RT-PCR and LFIA, we used Bayesian latent-class models, which do not require a gold standard for the evaluation of diagnostics. Data were extracted from studies that evaluated LFIA (immunoglobulin G (IgG) and/or immunoglobulin M (IgM)) assays using RT-PCR as the reference method. The sensitivity of RT-PCR was 0.68 (95% probability interval (PrI): 0.63, 0.73). IgG/M sensitivity was 0.32 (95% PrI :0.23; 0.41) for the first week and increased steadily. It was 0.75 (95% PrI: 0.67; 0.83) and 0.93 (95% PrI: 0.88; 0.97) for the second and third weeks after symptom onset, respectively. Both tests had a high to absolute specificity, with higher point median estimates for RT-PCR specificity and narrower probability intervals. The specificity of RT-PCR was 0.99 (95% PrI: 0.98; 1.00). and the specificity of IgG/IgM was 0.97 (95% PrI: 0.92, 1.00), 0.98 (95% PrI: 0.95, 1.00) and 0.98 (95% PrI: 0.94, 1.00) for the first, second, and third weeks after symptom onset. The diagnostic accuracy of LFIA varies with time after symptom onset. Bayesian latent-class models provide a valid and efficient alternative for evaluating the rapidly evolving diagnostics for COVID-19, under various clinical settings and different risk profiles.
Assuntos
Teste de Ácido Nucleico para COVID-19/estatística & dados numéricos , Teste Sorológico para COVID-19/estatística & dados numéricos , COVID-19/diagnóstico , Imunoensaio/estatística & dados numéricos , Reação em Cadeia da Polimerase em Tempo Real/estatística & dados numéricos , Anticorpos Antivirais/sangue , Teorema de Bayes , COVID-19/imunologia , Humanos , Análise de Classes Latentes , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Sensibilidade e Especificidade , Fatores de TempoRESUMO
Preexisting cross-reactivity to SARS-CoV-2 occurs in the absence of prior viral exposure. However, this has been difficult to quantify at the population level due to a lack of reliably defined seroreactivity thresholds. Using an orthogonal antibody testing approach, we estimated that about 0.6% of nontriaged adults from the greater Vancouver, Canada, area between May 17 and June 19, 2020, showed clear evidence of a prior SARS-CoV-2 infection, after adjusting for false-positive and false-negative test results. Using a highly sensitive multiplex assay and positive/negative thresholds established in infants in whom maternal antibodies have waned, we determined that more than 90% of uninfected adults showed antibody reactivity against the spike protein, receptor-binding domain (RBD), N-terminal domain (NTD), or the nucleocapsid (N) protein from SARS-CoV-2. This seroreactivity was evenly distributed across age and sex, correlated with circulating coronaviruses' reactivity, and was partially outcompeted by soluble circulating coronaviruses' spike. Using a custom SARS-CoV-2 peptide mapping array, we found that this antibody reactivity broadly mapped to spike and to conserved nonstructural viral proteins. We conclude that most adults display preexisting antibody cross-reactivity against SARS-CoV-2, which further supports investigation of how this may impact the clinical severity of COVID-19 or SARS-CoV-2 vaccine responses.
Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , COVID-19/imunologia , SARS-CoV-2/imunologia , Adulto , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Colúmbia Britânica/epidemiologia , COVID-19/sangue , COVID-19/diagnóstico , COVID-19/prevenção & controle , Teste Sorológico para COVID-19/estatística & dados numéricos , Vacinas contra COVID-19/administração & dosagem , Reações Cruzadas/imunologia , Estudos Transversais , Feminino , Geografia , Voluntários Saudáveis , Humanos , Imunidade Humoral , Imunoensaio/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , SARS-CoV-2/isolamento & purificação , Índice de Gravidade de DoençaRESUMO
The emergence of COVID-19 has emphasised that biological assay data must be analysed quickly to develop safe, effective and timely vaccines/therapeutics. For viruses such as SARS-CoV-2, the primary way of measuring immune correlates of protection is through assays such as the pseudotype microneutralisation (pMN) assay, thanks to its safety and versatility. However, despite the presence of existing tools for data analysis such as PRISM and R the analysis of these assays remains cumbersome and time-consuming. We introduce an open-source R Shiny web application and R library (AutoPlate) to accelerate data analysis of dose-response curve immunoassays. Using example data from influenza studies, we show that AutoPlate improves on available analysis software in terms of ease of use, flexibility and speed. AutoPlate (https://philpalmer.shinyapps.io/AutoPlate/) is a tool for the use of laboratories and wider scientific community to accelerate the analysis of biological assays in the development of viral vaccines and therapeutics.
Assuntos
COVID-19/diagnóstico , Imunoensaio/estatística & dados numéricos , Vírus da Influenza A/fisiologia , Influenza Humana/diagnóstico , SARS-CoV-2/fisiologia , Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/metabolismo , Interpretação Estatística de Dados , Relação Dose-Resposta a Droga , Humanos , Imunoensaio/normas , Controle de Qualidade , SoftwareAssuntos
Autoanticorpos/sangue , Dermatomiosite/complicações , Neoplasias/epidemiologia , Fatores de Transcrição/imunologia , Adolescente , Adulto , Idoso , Autoanticorpos/imunologia , Autoanticorpos/isolamento & purificação , Dermatomiosite/sangue , Dermatomiosite/imunologia , Feminino , Humanos , Imunoensaio/métodos , Imunoensaio/estatística & dados numéricos , Imunoprecipitação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Neoplasias/sangue , Neoplasias/diagnóstico , Neoplasias/imunologia , Prevalência , Estudos Retrospectivos , Adulto JovemRESUMO
Influenza is associated with increased morbidity, healthcare costs, hospitalization rates, and mortality in children. Rapid immunochromatography assay (ICA), a test with low sensitivity, is often used as point-of-care (POC) test. Recently, the rapid syndromic molecular test FilmArray has become available. This observational study aims to evaluate whether the use of FilmArray would decrease the use of antivirals and hospitalization rates among children presenting to the emergency room (ER) with influenza-like illness (ILI) symptoms. Nasopharyngeal swabs were prospectively collected from children, aged 0-16 years, presenting with ILI at the ER of a tertiary hospital during the peak endemic period. Patients were allocated to be tested by either FilmArray or ICA. The use of antivirals and hospitalization rates were noted. Logistic regression models were used to investigate the impact of testing methods on decision-making. Overall, 80 children were included (mean age: 5 years). Admissions were more likely to occur if an ICA test was performed (OR, 3.16; 95% CI, 1.01-9.82; p = .046). Oseltamivir administration was more likely among children who had undergone the ICA test (OR, 4.67; 95% CI, 1.06-20.43; p = .041). The implementation of rapid molecular test had no impact on complementary diagnostic testing or antibacterial prescription. The use of FilmArray significantly reduced both hospitalization and oseltamivir administration in children. Further knowledge on the use of POC tests is required to improve current management of children presenting with ILI and decrease associated healthcare costs.
Assuntos
Antivirais/uso terapêutico , Hospitalização/estatística & dados numéricos , Técnicas de Diagnóstico Molecular/estatística & dados numéricos , Oseltamivir/uso terapêutico , Testes Imediatos/estatística & dados numéricos , Viroses/diagnóstico , Adolescente , Criança , Pré-Escolar , Serviço Hospitalar de Emergência/estatística & dados numéricos , Feminino , Custos de Cuidados de Saúde , Humanos , Imunoensaio/normas , Imunoensaio/estatística & dados numéricos , Lactente , Recém-Nascido , Influenza Humana/diagnóstico , Influenza Humana/virologia , Masculino , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/normas , Testes Imediatos/normas , Estudos Prospectivos , Viroses/virologiaRESUMO
OBJECTIVE: Because of the rapidly emerging SARS-CoV-2 pandemic and its wide public health challenges, rapid diagnosis is essential to decrease the spread. Antigen-based rapid detection tests are available; however, insufficient data about their performance are available. METHODS: The lateral-flow immunochromatographic BIOCREDIT COVID-19 antigen test was evaluated using nasopharyngeal swabs in a viral transport medium from patients with confirmed infection, contacts, and exposed healthcare professionals at Fayoum University Hospital in Egypt. Test performance was determined in comparison to the SARS-CoV-2 real-time reverse-transcription polymerase chain reaction (RT-PCR) test. RESULTS: Three hundred ten specimens from 3 categories-patients with confirmed diagnoses of COVID-19, contacts, and exposed healthcare professionals-were included; 188 specimens were RT-PCR-positive, from which 81 were detected by rapid antigen test. Overall sensitivity was 43.1%. Sensitivity was significantly higher in specimens with high viral loads. CONCLUSION: Poor sensitivity of the BIOCREDIT COVID-19 test does not permit its use for diagnosis, and it can only be used in conjunction with RT-PCR for screening.
Assuntos
Teste Sorológico para COVID-19 , COVID-19/diagnóstico , Imunoensaio/estatística & dados numéricos , Adulto , Egito , Feminino , Humanos , MasculinoRESUMO
BACKGROUND: The tetravalent dengue vaccine (CYD-TDV) has been shown to provide protection against dengue disease over 5-year follow-up in participants with previous dengue infection, but increased the risk of dengue hospitalisation and severe dengue during long-term follow-up in those without previous dengue infection. WHO recommended pre-vaccination screening to identify those with previous dengue infection (ie, dengue seropositive) who would benefit from vaccination. We re-evaluated CYD-TDV efficacy in those identified as dengue seropositive using five commercially available immunoassays, and assessed immunoassay performance. METHODS: We included participants in the immunogenicity subsets of the phase 3 CYD14 (NCT01373281) and CYD15 (NCT01374516) CYD-TDV efficacy trials, which enrolled children aged 2-16 years in 2011-12 in five countries in the Asia-Pacific region (CYD14) and five Latin American countries (CYD15). Participants assessed had received at least one injection of study drug (CYD-TDV or placebo) and had baseline samples available. We tested baseline samples by IgG-based immunoassays to classify baseline dengue serostatus, using two ELISAs (EUROIMMUN and Panbio) and three rapid diagnostic tests (RDTs; TELL ME FAST, SD BIOLINE, and OnSite). Vaccine efficacy in preventing symptomatic, hospitalised, and severe virologically confirmed dengue was determined for participants who tested positive by each immunoassay. The specificity and sensitivity of each immunoassay was determined as percentage negative and positive agreement compared with the reference algorithm, which used dengue plaque reduction neutralisation test with 50% and 90% cutoffs and non-structural protein 1 IgG ELISA results to assign baseline serostatus. FINDINGS: Samples were available for 3967 participants, 2735 (69·0%) of whom were classified as seropositive by the reference algorithm. Vaccine efficacy against symptomatic virologically confirmed dengue in immunoassay-positive participants was high across all five immunoassays (EUROIMMUN ELISA 88·2% [95% CI 77·3 to 93·9], Panbio ELISA 87·6% [76·7 to 93·4], TELL ME FAST RDT 88·8% [67·0 to 96·2], SD BIOLINE RDT 82·8% [66·9 to 91·1], and OnSite RDT 89·7% [64·6 to 97·0]), as was vaccine efficacy against hospitalised virologically confirmed dengue (EUROIMMUN-ELISA 72·8% [38·9 to 87·9], Panbio ELISA 77·5% [52·8 to 89·3], TELL ME FAST RDT 92·4% [37·8 to 99·1], SD BIOLINE RDT 87·2% [54·5 to 96·4], and OnSite RDT 73·7% [-5·1 to 93·4]) and severe virologically confirmed dengue (EUROIMMUN ELISA 86·9% [-16·8 to 98·5], Panbio ELISA 91·3% [27·6 to 99·0], TELL ME FAST RDT 100·0% [not estimable to 100·0%], SD BIOLINE RDT 89·4% [9·6 to 98·8], and OnSite RDT 73·4% [-193·7 to 97·6]). The immunoassays exhibited high specificity (≥98·8% for all immunoassays apart from SD BIOLINE RDT) but variable sensitivities, with higher sensitivities observed for the ELISAs (EUROIMMUN 89·2% [87·9 to 90·3] and Panbio 92·5 [91·4 to 93·5]) than the RDTs (TELL ME FAST 52·5% [50·6 to 54·4], SD BIOLINE 71·1% [69·3 to 72·8], and OnSite 47·6% [45·7 to 49·5]). INTERPRETATION: Our findings suggest that these immunoassays could be used for pre-vaccination screening for CYD-TDV as tools to assist risk stratification until more sensitive and convenient tests become available. FUNDING: Sanofi Pasteur.
Assuntos
Vacinas contra Dengue/efeitos adversos , Vírus da Dengue/imunologia , Dengue/diagnóstico , Imunoensaio/instrumentação , Programas de Rastreamento/instrumentação , Adolescente , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/isolamento & purificação , Criança , Pré-Escolar , Ensaios Clínicos Fase III como Assunto , Dengue/imunologia , Dengue/prevenção & controle , Dengue/virologia , Vacinas contra Dengue/administração & dosagem , Feminino , Humanos , Imunoensaio/estatística & dados numéricos , Masculino , Programas de Rastreamento/estatística & dados numéricos , Testes de Neutralização/instrumentação , Testes de Neutralização/estatística & dados numéricos , Seleção de Pacientes , Kit de Reagentes para Diagnóstico/estatística & dados numéricos , Reprodutibilidade dos Testes , Estudos RetrospectivosRESUMO
BACKGROUND: Commercially available SARS-CoV-2 serological assays based on different viral antigens have been approved for the qualitative determination of anti-SARS-CoV-2 antibodies. However, there are limited published data associating the results from commercial assays with neutralizing antibodies. METHODS: Sixty-six specimens from 48 patients with PCR-confirmed COVID-19 and a positive result by the Roche Elecsys Anti-SARS-CoV-2, Abbott SARS-CoV-2 IgG, or EUROIMMUN SARS-CoV-2 IgG assays and 5 control specimens were analyzed for the presence of neutralizing antibodies to SARS-CoV-2. Correlation, concordance, positive percent agreement (PPA), and negative percent agreement (NPA) were calculated at several cutoffs. Results were compared in patients categorized by clinical outcomes. RESULTS: The correlation between SARS-CoV-2 neutralizing titer (EC50) and the Roche, Abbott, and EUROIMMUN assays was 0.29, 0.47, and 0.46, respectively. At an EC50 of 1:32, the concordance kappa with Roche was 0.49 (95% CI; 0.23-0.75), with Abbott was 0.52 (0.28-0.77), and with EUROIMMUN was 0.61 (0.4-0.82). At the same neutralizing titer, the PPA and NPA for the Roche was 100% (94-100) and 56% (30-80); Abbott was 96% (88-99) and 69% (44-86); and EUROIMMUN was 91% (80-96) and 81% (57-93) for distinguishing neutralizing antibodies. Patients who were intubated, had cardiac injury, or acute kidney injury from COVID-19 infection had higher neutralizing titers relative to those with mild symptoms. CONCLUSIONS: COVID-19 patients generate an antibody response to multiple viral proteins such that the calibrator ratios on the Roche, Abbott, and EUROIMMUN assays are all associated with SARS-CoV-2 neutralization. Nevertheless, commercial serological assays have poor NPA for SARS-CoV-2 neutralization, making them imperfect proxies for neutralization.
Assuntos
Anticorpos Neutralizantes/análise , Anticorpos Antivirais/análise , Teste Sorológico para COVID-19/estatística & dados numéricos , COVID-19/imunologia , Imunoensaio/estatística & dados numéricos , SARS-CoV-2/imunologia , Idoso , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/epidemiologia , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Correlação de Dados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fosfoproteínas/imunologia , Curva ROC , SARS-CoV-2/química , Índice de Gravidade de Doença , Glicoproteína da Espícula de Coronavírus/imunologiaRESUMO
The clinical performances of six molecular diagnostic tests and a rapid antigen test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were clinically evaluated for the diagnosis of coronavirus disease 2019 (COVID-19) in self-collected saliva. Saliva samples from 103 patients with laboratory-confirmed COVID-19 (15 asymptomatic and 88 symptomatic) were collected on the day of hospital admission. SARS-CoV-2 RNA in saliva was detected using a quantitative reverse transcription-PCR (RT-qPCR) laboratory-developed test (LDT), a cobas SARS-CoV-2 high-throughput system, three direct RT-qPCR kits, and reverse transcription-loop-mediated isothermal amplification (RT-LAMP). The viral antigen was detected by a rapid antigen immunochromatographic assay. Of the 103 samples, viral RNA was detected in 50.5 to 81.6% of the specimens by molecular diagnostic tests, and an antigen was detected in 11.7% of the specimens by the rapid antigen test. Viral RNA was detected at significantly higher percentages (65.6 to 93.4%) in specimens collected within 9 days of symptom onset than in specimens collected after at least 10 days of symptoms (22.2 to 66.7%) and in specimens collected from asymptomatic patients (40.0 to 66.7%). Self-collected saliva is an alternative specimen option for diagnosing COVID-19. The RT-qPCR LDT, a cobas SARS-CoV-2 high-throughput system, direct RT-qPCR kits (except for one commercial kit), and RT-LAMP showed sufficient sensitivities in clinical use to be selectively used in clinical settings and facilities. The rapid antigen test alone is not recommended for an initial COVID-19 diagnosis because of its low sensitivity.
Assuntos
Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Imunoensaio , Técnicas de Amplificação de Ácido Nucleico , Pneumonia Viral/diagnóstico , Saliva/virologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos Virais/análise , Betacoronavirus/genética , Betacoronavirus/isolamento & purificação , COVID-19 , Teste para COVID-19 , Técnicas de Laboratório Clínico/métodos , Técnicas de Laboratório Clínico/normas , Técnicas de Laboratório Clínico/estatística & dados numéricos , Feminino , Humanos , Imunoensaio/métodos , Imunoensaio/normas , Imunoensaio/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Amplificação de Ácido Nucleico/normas , Técnicas de Amplificação de Ácido Nucleico/estatística & dados numéricos , Pandemias , RNA Viral/análise , RNA Viral/genética , SARS-CoV-2 , Sensibilidade e Especificidade , Manejo de Espécimes , Adulto JovemRESUMO
BACKGROUND: Health-care workers constitute a high-risk population for acquisition of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Capacity for acute diagnosis via PCR testing was limited for individuals with mild to moderate SARS-CoV-2 infection in the early phase of the COVID-19 pandemic and a substantial proportion of health-care workers with suspected infection were not tested. We aimed to investigate the performance of point-of-care and laboratory serology assays and their utility in late case identification, and to estimate SARS-CoV-2 seroprevalence. METHODS: We did a prospective multicentre cohort study between April 8 and June 12, 2020, in two phases. Symptomatic health-care workers with mild to moderate symptoms were eligible to participate 14 days after onset of COVID-19 symptoms, as per the Public Health England (PHE) case definition. Health-care workers were recruited to the asymptomatic cohort if they had not developed PHE-defined COVID-19 symptoms since Dec 1, 2019. In phase 1, two point-of-care lateral flow serological assays, the Onsite CTK Biotech COVID-19 split IgG/IgM Rapid Test (CTK Bitotech, Poway, CA, USA) and the Encode SARS-CoV-2 split IgM/IgG One Step Rapid Test Device (Zhuhai Encode Medical Engineering, Zhuhai, China), were evaluated for performance against a laboratory immunoassay (EDI Novel Coronavirus COVID-19 IgG ELISA kit [Epitope Diagnostics, San Diego, CA, USA]) in 300 samples from health-care workers and 100 pre-COVID-19 negative control samples. In phase 2 (n=6440), serosurveillance was done among 1299 (93·4%) of 1391 health-care workers reporting symptoms, and in a subset of asymptomatic health-care workers (405 [8·0%] of 5049). FINDINGS: There was variation in test performance between the lateral flow serological assays; however, the Encode assay displayed reasonable IgG sensitivity (127 of 136; 93·4% [95% CI 87·8-96·9]) and specificity (99 of 100; 99·0% [94·6-100·0]) among PCR-proven cases and good agreement (282 of 300; 94·0% [91·3-96·7]) with the laboratory immunoassay. By contrast, the Onsite assay had reduced sensitivity (120 of 136; 88·2% [95% CI 81·6-93·1]) and specificity (94 of 100; 94·0% [87·4-97·8]) and agreement (254 of 300; 84·7% [80·6-88·7]). Five (7%) of 70 PCR-positive cases were negative across all assays. Late changes in lateral flow serological assay bands were recorded in 74 (9·3%) of 800 cassettes (35 [8·8%] of 400 Encode assays; 39 [9·8%] of 400 Onsite assays), but only seven (all Onsite assays) of these changes were concordant with the laboratory immunoassay. In phase 2, seroprevalence among the workforce was estimated to be 10·6% (95% CI 7·6-13·6) in asymptomatic health-care workers and 44·7% (42·0-47·4) in symptomatic health-care workers. Seroprevalence across the entire workforce was estimated at 18·0% (95% CI 17·0-18·9). INTERPRETATION: Although a good positive predictive value was observed with both lateral flow serological assays and ELISA, this agreement only occurred if the pre-test probability was modified by a strict clinical case definition. Late development of lateral flow serological assay bands would preclude postal strategies and potentially home testing. Identification of false-negative results among health-care workers across all assays suggest caution in interpretation of IgG results at this stage; for now, testing is perhaps best delivered in a clinical setting, supported by government advice about physical distancing. FUNDING: None.
Assuntos
Betacoronavirus , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Doenças Profissionais/diagnóstico , Pneumonia Viral/diagnóstico , Sistemas Automatizados de Assistência Junto ao Leito , Adulto , COVID-19 , Teste para COVID-19 , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Ensaio de Imunoadsorção Enzimática/estatística & dados numéricos , Feminino , Pessoal de Saúde , Humanos , Imunoensaio/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Doenças Profissionais/epidemiologia , Doenças Profissionais/virologia , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , Valor Preditivo dos Testes , Estudos Prospectivos , Reprodutibilidade dos Testes , SARS-CoV-2 , Sensibilidade e Especificidade , Estudos Soroepidemiológicos , Reino Unido/epidemiologiaAssuntos
Pérnio/epidemiologia , Técnicas de Laboratório Clínico/estatística & dados numéricos , Infecções por Coronavirus/diagnóstico , Imunoensaio/estatística & dados numéricos , Pneumonia Viral/diagnóstico , Adolescente , Adulto , Betacoronavirus/imunologia , Betacoronavirus/isolamento & purificação , Viés , COVID-19 , Teste para COVID-19 , Pérnio/sangue , Pérnio/diagnóstico , Pérnio/etiologia , Infecções por Coronavirus/complicações , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Feminino , Humanos , Masculino , Pandemias , Pneumonia Viral/complicações , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , SARS-CoV-2 , Pele/imunologia , Pele/patologia , Adulto JovemRESUMO
BACKGROUND: Due to a lack of reliable reference intervals (RIs) for Kenya, we set out to determine RIs for 40 common chemistry and immunoassay tests as part of the IFCC global RI project. METHODS: Apparently healthy adults aged 18-65 years were recruited according to a harmonized protocol and samples analyzed using Beckman-Coulter analyzers. Value assigned serum panels were measured to standardize chemistry results. The need for partitioning reference values by sex and age was based on between-subgroup differences expressed as standard deviation ratio (SDR) or bias in lower or upper limits (LLs and ULs) of the RI. RIs were derived using a parametric method with/without latent abnormal value exclusion (LAVE). RESULTS: Sex-specific RIs were required for uric acid, creatinine, total bilirubin (TBil), total cholesterol (TC), ALT, AST, CK, GGT, transferrin, transferrin saturation (TfSat) and immunoglobulin-M. Age-specific RIs were required for glucose and triglyceride for both sexes, and for urea, magnesium, TC, HDL-cholesterol ratio, ALP, and ferritin for females. LAVE was effective in optimizing RIs for AST, ALT, GGT iron-markers and CRP by reducing influence of latent anemia and metabolic diseases. Thyroid profile RIs were derived after excluding volunteers with anti-thyroid antibodies. Kenyan RIs were comparable to those of other countries participating in the global study with a few exceptions such as higher ULs for TBil and CRP. CONCLUSIONS: Kenyan RIs for major analytes were established using harmonized protocol from well-defined reference individuals. Standardized RIs for chemistry analytes can be shared across sub-Saharan African laboratories with similar ethnic and life-style profile.
Assuntos
Variação Biológica da População , Análise Química do Sangue/normas , Imunoensaio/normas , Adolescente , Adulto , Idoso , Biomarcadores/sangue , Análise Química do Sangue/estatística & dados numéricos , Interpretação Estatística de Dados , Feminino , Voluntários Saudáveis , Humanos , Imunoensaio/estatística & dados numéricos , Quênia , Masculino , Pessoa de Meia-Idade , Padrões de Referência , Valores de Referência , Fatores Sexuais , Adulto JovemRESUMO
Objectives Acute kidney injury (AKI) is common in critically ill children, but current biomarkers are suboptimal. Proenkephalin A 119-159 (PENK) is a promising new biomarker for AKI in adults, but pediatric data is lacking. We determined PENK reference intervals for healthy children, crucial for clinical implementation, and explored concentrations in critically ill infants aged under 1 year. Methods Observational cohort study in healthy infants and critically ill children aged 0-1 years. Reference values were determined using generalized additive models. Plasma PENK concentrations between healthy children and critically ill children with and without AKI, were compared using linear mixed modelling. The performance of PENK as AKI biomarker was compared to cystatin C (CysC) and ß-trace protein (BTP) using receiver-operating-characteristic (ROC) analysis. Results PENK concentrations in 100 healthy infants were stable during the first year of life (median 517.3 pmol/L). Median PENK concentrations in 91 critically ill children, were significantly higher in those with AKI (n=40) (KDIGO Stage 1 507.9 pmol/L, Stage 2 704.0 pmol/L, Stage 3 930.5 pmol/L) than non-AKI patients (n=51, 432.2 pmol/L) (p < 0.001). PENK appeared to relate better to AKI diagnosis than CysC and BTP (AUROC PENK 0.858, CysC 0.770 and BTP 0.711) in the first 24 h after recruitment. Conclusions PENK reference values are much higher in young infants than adults, but clearly discriminate between children with and without AKI, with comparable or better performance than CysC and BTP. Our results illustrate the importance of establishing age-normalized reference values and indicate PENK as a promising pediatric AKI biomarker.