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1.
IntroductionThe data on the coronavirus disease (COVID-19) in solid-organ transplant recipients (SOTRs) in Croatia is unknown. The aim of this study was to analyze the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Croatian SOTRs.Materials and methodsFrom 7 September to 27 November 2020 (beginning of the second COVID-19 pandemic wave), a cross-sectional screening for COVID-19 was performed in the adult outpatient liver (LTRs; N = 280) and kidney transplant recipients (KTRs; N = 232). Serum samples were initially tested for SARS-CoV-2 IgG antibodies using a commercial enzyme-linked immunosorbent assay (ELISA; Vircell Microbiologists, Granada, Spain). All positive samples were confirmed using a virus neutralization test (VNT). Data on risk exposure and COVID-19 related symptoms were collected using a questionnaire.ResultsThe transplanted cohort’s seroprevalence detected by ELISA and VNT was 20.1% and 3.1%, respectively. Neutralizing (NT) antibodies developed in 15.6% of anti-SARS-CoV-2 ELISA IgG positive SOTRs. The difference in seropositivity rates between LTRs and KTRs was not statistically significant (ELISA 21.1% vs. 19.0%, P = 0.554; VNT 3.6% vs. 2.6%, P = 0.082). Overall VNT positivity rates were higher in patients who reported participation in large community events (5.9% vs. 1.0%; P = 0.027) as well as in patients who reported COVID-19 related symptoms in the past six months. In addition, symptomatic VNT positive patients showed significantly higher (P = 0.031) NT antibody titers (median 128, interquartile range (IQR) = 32-128) compared to asymptomatic patients (median 16, IQR = 16-48).ConclusionsThis study showed that 15.6% of anti-SARS-CoV-2 ELISA positive Croatian SOTRs developed NT antibodies indicating protective immunity. Further studies are needed to determine the dynamic of NT antibodies and COVID-19 immunity duration in immunocompromised populations such as LTRs and KTRs.  相似文献   

2.
Coronavirus disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a global health problem, India being the second most affected country. The kinetics of antibody response to SARS-CoV-2 in Indian population is not studied yet. To understand serological response in relation to age, gender, time period and severity of disease, Roche Elecsys anti-SARS-CoV-2 test was used which analysed both IgM and IgG. One hundred and three COVID-19 patients were enrolled. Seropositivity was seen in 64% of patients, with 33% at ≤ 7 days, 62% between 8 and 15 days and 81% at ≥ 16 days from the time of admission. Men (65%) showed higher antibody response than women (59%), whereas no difference was observed in seropositivity with respect to age of the patients. Dynamics of antibody responses revealed individual variations. Patients in ICU had higher antibody reactivity with 67% positivity as compared to 60% positivity in non-ICU patients. Kinetics of antibody response during COVID-19 disease varied in relation to gender, age, time period and severity and these factors might play an important role in treatment and control of COVID-19.  相似文献   

3.
Upon SARS CoV-2 infection, humoral immune system triggers production of anti-SARS CoV-2 IgM and IgG antibodies. Currently, antibodies against SARS CoV-2 spike protein receptor binding domain play a central role in disease protection, making them potential target for in vitro diagnostics applications. This study determines the expression level and sustainability of anti-receptor binding domain (RBD) SARS CoV-2 IgG in post COVID-19 patients. Anti-RBD SARS CoV-2 IgG antibodies in patient serum were analysed by standardised indirect ELISA using SARS CoV-2 spike receptor binding domain protein and HRP conjugated anti-human IgG antibody (anti-h IgG). The study was conducted using 35 adult patient samples with confirmed SARS CoV-2 infection. Additionally, correlation between antibody response after each stage and disease symptoms in post COVID-19 patients were studied. Maximum antibody titre was seen at Day 40 and decreased relatively to Day 180 in antibody positive samples when compared with controls. Overall, more IgG antibody expression is observed in patients who suffered from loss of smell and taste at Day 40. 71% of the positive subjects in this study showed high SARS CoV-2 IgG antibody concentration of above 10 ng/mL and 37% showed strong antibody concentration above 20 ng/mL at the peak of seroconversion.  相似文献   

4.
Early detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and diagnosis of coronavirus disease 2019 (COVID-19) are priorities during the pandemic. Symptomatic and suspected asymptomatic individuals should be tested for COVID-19 to confirm infection and to be excluded from social interactions. As molecular testing capacity is overloaded during the pandemic, rapid antigen tests, such as lateral flow immunoassays (LFIAs), can be a useful tool as they allow greater test availability and obtain results in a very short time. This short review aims to present the analytical properties of LFIAs in the detection of SARS-CoV-2 in nasopharyngeal swabs. Lateral flow immunoassay is a method that combines thin-layer chromatography and indirect immunochemical sandwich method and allows the detection of a specific SARS-CoV-2 antigen in nasopharyngeal swabs. Swab specimens should be adequately collected and tested as soon as possible. Users should pay attention to quality control and possible interferences. Antigen tests for SARS-CoV-2 show high sensitivity and specificity in cases with high viral loads, and should be used up to five days after the onset of the first symptoms of COVID-19. False positive results may be obtained when screening large populations with a low prevalence of COVID-19 infection, while false negative results may happen due to improper specimen collection or insufficient amount of antigen in the specimen. So as to achieve reliable results, a diagnostic accuracy study of a specific rapid antigen test should be performed.  相似文献   

5.
In December 2019, Wuhan city in the Hubei province of China reported for the first time a cluster of patients infected with a novel coronavirus, since then there has been an outburst of this disease across the globe affecting millions of human inhabitants. Severe acute respiratory syndrome coronavirus type-2 (SARS-CoV-2), is a member of beta coronavirus family which upon exposure caused a highly infectious disease called novel coronavirus disease-2019 (COVID-19). COVID-19, a probably bat originated disease was declared by World Health Organization (WHO) as a global pandemic in March 2020. Since then, despite rigorous global containment and quarantine efforts, the disease has affected nearly 56,261,952 laboratory confirmed human population and caused deaths of over 1,349,506 lives worldwide. Virus passes in majority through respiratory droplets and then enters lung epithelial cells by binding to angiotensin converting enzyme 2 (ACE2) receptor and there it undergoes replication and targeting host cells causing severe pathogenesis. Majority of human population exposed to SARS-CoV-2 having fully functional immune system undergo asymptomatic infection while 5–10% are symptomatic and only 1–2% are critically affected and requires ventilation support. Older people or people with co-morbidities are severely affected by COVID-19. These categories of patients also display cytokine storm due to dysfunctional immune response which brutally destroys the affected organs and may lead to death in some. Real time PCR is still considered as standard method of diagnosis along with other serology, radiological and biochemical investigations. Till date, no specific validated medication is available for the treatment of COVID-19 patients. Thus, this review provides detailed knowledge about the different landscapes of disease incidence, etiopathogenesis, involvement of various organs, diagnostic criteria’s and treatment guidelines followed for management of COVID-19 infection since its inception. In conclusion, extensive research to recognize novel pathways and their cross talk to combat this virus in precarious settings is our future positive hope.  相似文献   

6.
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7.
COVID-19 has emerged as a global pandemic. It is mainly manifested as pneumonia which may deteriorate into severe respiratory failure. The major hallmark of the disease is the systemic inflammatory immune response characterized by Cytokine Storm (CS). CS is marked by elevated levels of inflammatory cytokines, mainly interleukin-6 (IL-6), IL-8, IL-10, tumour necrosis factor-α (TNF-α) and interferon-γ (IFN-γ). Of these, IL-6 is found to be significantly associated with higher mortality. IL-6 is also a robust marker for predicting disease prognosis and deterioration of clinical profile. In this review, the pivotal role played by IL-6 in the immuno-pathology of COVID-19 has been illustrated. The role of IL-6 as a pleiotropic cytokine executing both pro and anti-inflammatory activities has been reviewed. ADAM 10, a metalloproteinase switches the anti-inflammatory pathway of IL-6 to pro inflammatory hence blocking the action of ADAM 10 could be a new therapeutic strategy to mitigate the proinflammatory action of IL-6. Furthermore, we explore the role of anti-IL6 agents, IL-6 receptor antibodies which were being used for autoimmune diseases but now are being repurposed for the therapy of COVID-19.  相似文献   

8.
IntroductionSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serological tests have been suggested as an additional diagnostic tool in highly suspected cases with a negative molecular test and determination of seroprevalence in population. We compared the diagnostic performance of eight commercial serological assays for IgA, IgM, and IgG antibodies to the SARS-CoV-2 virus.Materials and methodsThe comparison study was performed on a total of 76 serum samples: 30 SARS-CoV-2 polymerase chain reaction (PCR)-negative and 46 SARS-CoV-2 PCR-positive patients with asymptomatic to severe disease and symptoms duration from 3-30 days. The study included: three rapid lateral flow immunochromatographic assays (LFIC), two enzyme-linked immunosorbent assays (ELISA), and three chemiluminescence immunoassays (CLIA).ResultsAgreement between IgM assays were minimal to moderate (kappa 0.26 to 0.63) and for IgG moderate to excellent (kappa 0.72 to 0.92). Sensitivities improved with > 10 days of symptoms and were: 30% to 89% for IgM; 89% to 100% for IgG; 96% for IgA; 100% for IgA/IgM combination; 96% for total antibodies. Overall specificities were: 90% to 100% for IgM; 85% to 100% for IgG; 90% for IgA; 70% for IgA/IgM combination; 100% for total antibodies. Diagnostic accuracy for IgG ELISA and CIA assays were excellent (AUC ≥ 0.90), without significant difference. IgA showed significantly better diagnostic accuracy than IgM (P < 0.001).ConclusionThere is high variability between IgM assays independently of the assay format, while IgG assays showed moderate to perfect agreement. The appropriate time for testing is crucial for the proper immunity investigation.  相似文献   

9.
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10.
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the etiological agent of coronavirus disease-2019 (COVID-19), is a highly contagious pathogenic coronavirus to emerge and spread in human populations. Although substantial exertions have been laid to avert spread of COVID-19 by therapeutic and preventive countermeasures, but emergence of SARS-CoV-2 variants as a result of mutations make the infection more ominous. New viral confers a higher nasopharyngeal viral load, increased viral transmissibility, higher infectiousness, immune escape, increased resistance to monoclonal/polyclonal antibodies from convalescence sera/vaccine, and an enhanced virulence. Thus, it is pertinent to monitor evolving mutations and genetic diversity of SARS-CoV-2 as it is decisive for understanding the viral variants. In this review we provide an overview of colloquial nomenclature and the genetic characteristics of different SARS-CoV-2 variants in the context of mutational changes of the circulating strains, transmissibility potential, virulence and infectivity.  相似文献   

11.
Humankind is facing its worst pandemic of the twenty-first century, due to infection of a novel coronavirus named as SARS-CoV2, started from Wuhan in China. Till now, 15 million people are infected, causing more than 600,000 deaths. The disease, commonly known as, COVID-19, was initially thought to be associated with ARDS only, but later on revealed to have many unexplained and atypical clinical features like coagulopathy and cytokinemia, leading to multi-organ involvements. The patients also suffer from ‘Silent Hypoxemia’, where there is no immediate respiratory signs and symptoms even though alarmingly low SpO2 level. We hypothesize that this covert hypoxemia may lead to molecular changes exacerbating coagulopathy and cytokine storm in COVID19 patients, which again, in turn, causes a vicious cycle of more hypoxemia/hypoxia and progression of the infection to more severe stages through HIF-1α dependent pathway. Although molecular mechanisms are yet to be substantiated by scientific evidence, hypoxemia remains an independent worsening factor in serious COVID 19 patients. Keeping all in mind, we propose that even in the early and asymptomatic cases, prophylactic oxygen therapy to be initiated to break the vicious cycle and to reduce the mortality in COVID 19 to save precious human lives.  相似文献   

12.
International Guidelines have voted for PCR as the Gold Standard in COVID diagnosis. Nasoparyngeal swab is the preferred specimen for PCR. It has a high probability of diagnosing early infection. But the diagnostic sensitivity of nasopharyngeal PCR decreases with increase in lapse between the infection and presentation to hospital. This might lead to dire consequences of labelling these patients as false negative, though such patients have been proved to be potentially infective since viral shedding occurs through other body fluids (stools) for long. COVID infection reveals that the IgM antibodies start to appear as early as 5th day of infection and switches over to IgA within 2–3 days. The aim of the study was to see if COVID antibody testing be coupled with PCR for diagnosis especially in patients presenting late (more than 14 days) of onset of infection? And if the antibodies are giving values, hence can them be reported quantitatively rather than in qualitative fashion? The second objective was to see if the COVID antibody levels be used to monitor the disease severity? And if the antibody levels of SARS CoV 2 be used an indicator to monitor the recovery?  相似文献   

13.
宗喆  鲁俊群 《科技管理研究》2021,41(17):162-169
梳理欧美相关法律中的相关条款,专注于分析疫情爆发初期主要国家采用科技抗疫的案例,提出在疫情等公共安全事件突发时,各国应在内部明确数据保护与公共利益优先的临界点,并尽快建立平衡数据保护与公共利益的国际合作机制.  相似文献   

14.
IntroductionThe COVID-19 pandemic has posed several challenges to clinical laboratories across the globe. Amidst the outbreak, errors occurring in the preanalytical phase of sample collection, transport and processing, can further lead to undesirable clinical consequences. Thus, this study was designed with the following objectives: (i) to determine and compare the blood specimen rejection rate of a clinical laboratory and (ii) to characterise and compare the types of preanalytical errors between the pre-pandemic and the pandemic phases.Materials and methodsThis retrospective study was carried out in a trauma-care hospital, presently converted to COVID-19 care centre. Data was collected from (i) pre-pandemic phase: 1st October 2019 to 23rd March 2020 and (ii) pandemic phase: 24th March to 31st October 2020. Blood specimen rejection rate was calculated as the proportion of blood collection tubes with preanalytical errors out of the total number received, expressed as percentage.ResultsTotal of 107,716 blood specimens were screened of which 43,396 (40.3%) were received during the pandemic. The blood specimen rejection rate during the pandemic was significantly higher than the pre-pandemic phase (3.0% versus 1.1%; P < 0.001). Clotted samples were the commonest source of preanalytical errors in both phases. There was a significant increase in the improperly labelled samples (P < 0.001) and samples with insufficient volume (P < 0.001), whereas, a significant decline in samples with inadequate sample-anticoagulant ratio and haemolysed samples (P < 0.001).ConclusionIn the ongoing pandemic, preanalytical errors and resultant blood specimen rejection rate in the clinical laboratory have significantly increased due to changed logistics. The study highlights the need for corrective steps at various levels to reduce preanalytical errors in order to optimise patient care and resource utilisation.  相似文献   

15.
《Research Policy》2022,51(1):104393
In this paper we draw a parallel between the insights developed within the framework of the current COVID-19 health crisis and the views and insights developed with respect to the long term environmental crisis, the implications for science, technology and innovation (STI) policy, Christopher Freeman analyzed already in the early 90′s. With at the time of writing, the COVID-19 pandemic entering in many countries a third wave with a very differentiated implementation path of vaccination across rich and poor countries, drawing such a parallel remains of course a relatively speculative exercise. Nevertheless, based on the available evidence of the first wave of the pandemic, we feel confident that some lessons from the current health crisis and its parallels with the long-term environmental crisis can be drawn. The COVID-19 pandemic has also been described as a “syndemic”: a term popular in medical anthropology which marries the concept of ‘synergy’ with ‘epidemic’ and provides conceptually an interesting background for these posthumous Freeman reflections on crises. The COVID-19 crisis affects citizens in very different and disproportionate ways. It results not only in rising structural inequalities among social groups and classes, but also among generations. In the paper, we focus on the growing inequality within two particular groups: youngsters and the impact of COVID-19 on learning and the organization of education; and as mirror picture, the elderly many of whom witnessed despite strict confinement in long-term care facilities, high mortality following the COVID-19 outbreak. From a Freeman perspective, these inequality consequences of the current COVID-19 health crisis call for new social STI policies: for a new “corona version” of inclusion versus exclusion.  相似文献   

16.
IntroductionEvaluation of thyroid function is often requested and therefore defining paediatric reference intervals (RIs) is of vital importance. Currently, there is a distinct lack of paediatric RIs for thyroid function tests in Croatia. Thus, we established RIs for thyroid stimulating hormone (TSH), total triiodothyronine (TT3), total thyroxine (TT4), free triiodothyronine (FT3) and free thyroxine (FT4) in the Croatian paediatric population.Materials and methodsReference intervals were calculated from 397 apparently healthy children, aged from 2 days to < 19 years. Serum samples were analysed for thyroid function tests on the Abbott Architect i2000. Age- and sex-specific 95% RIs with 90% confidence intervals were established according to Clinical and Laboratory Standards Institute guidelines. To express the magnitude of sex and age variation, standard deviation ratio (SDR) was calculated using two-level nested ANOVA. The criterion for considering partitioning reference values was set to SDR > 0.3.ResultsAll thyroid function tests required age partitioning, confirmed by SDR above 0.3. There was no need for sex partitioning, confirmed by SDR below 0.3. Still, FT3 was partitioned due to visually noticeable sex related difference for the oldest group (12 years to < 19 years).ConclusionThis is the first study to establish RIs for thyroid function tests in the Croatian paediatric population. We propose RIs for widely used Abbott platform, thus giving laboratories method- and population-specific paediatric RIs for thyroid function tests that should improve clinical test interpretation.  相似文献   

17.
本文基于已公布的新冠病毒(COVID-19)疫苗专利或文献,分析了我国目前研发的新型冠状病毒疫苗核心免疫原,着重关注其中可能涉及的S-2P知识产权风险,并对我国利用该技术发展相关疫苗提出了建议。  相似文献   

18.
Minks are raised in many countries and have transmitted severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to humans. However, the biologic properties of SARS-CoV-2 in minks are largely unknown. Here, we investigated and found that SARS-CoV-2 replicates efficiently in both the upper and lower respiratory tracts, and transmits efficiently in minks via respiratory droplets; pulmonary lesions caused by SARS-CoV-2 in minks are similar to those seen in humans with COVID-19. We further found that a spike protein-based subunit vaccine largely prevented SARS-CoV-2 replication and lung damage caused by SARS-CoV-2 infection in minks. Our study indicates that minks are a useful animal model for evaluating the efficacy of drugs or vaccines against COVID-19 and that vaccination is a potential strategy to prevent minks from transmitting SARS-CoV-2.  相似文献   

19.
In December 2019, coronavirus disease 2019 became a pandemic affecting more than 200 countries and territories. Millions of lives are still affected because of mandatory quarantines, which hamstring economies and induce panic. Immunology plays a major role in the modern field of medicine, especially against virulent infectious diseases. In this field, neutralizing antibodies are heavily studied because they reflect the level of infection and individuals'' immune status, which are essential when considering resumption of work, flight travel, and border entry control. More importantly, it also allows evaluating the antiviral vaccine efficacy as vaccines are still known for being the ultimate intervention method to inhibit the rapid spread of virulent infectious diseases. In this Review, we first introduce the host immune response after the infection of SARS-CoV-2 and discuss the latest results using conventional immunoassays. Next, as an enabling platform for detection with sufficient sensitivity while saving analysis time and sample size, the progress of microfluidic-based immunoassays is discussed and compared based on surface modification, microfluidic kinetics, signal output, signal amplification, sample matrix, and the detection of anti-SARS-CoV-2 antibodies. Based on the overall comparison, this Review concludes by proposing the future integration of visual quantitative signals on microfluidic devices as a more suitable approach for general use and large-scale surveillance.  相似文献   

20.
Mutations and transient conformational movements of the receptor binding domain (RBD) that make neutralizing epitopes momentarily unavailable present immune escape routes for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To mitigate viral escape, we developed a cocktail of neutralizing antibodies (NAbs) targeting epitopes located on different domains of spike (S) protein. Screening of a library of monoclonal antibodies generated from peripheral blood mononuclear cells of COVID-19 convalescent patients yielded potent NAbs, targeting the N-terminal domain (NTD) and RBD domain of S, effective at nM concentrations. Remarkably, a combination of RBD-targeting NAbs and NTD-binding NAbs, FC05, enhanced the neutralization potency in cell-based assays and an animal model. Results of competitive surface plasmon resonance assays and cryo-electron microscopy (cryo-EM) structures of antigen-binding fragments bound to S unveil determinants of immunogenicity. Combinations of immunogens, identified in the NTD and RBD of S, when immunized in rabbits and macaques, elicited potent protective immune responses against SARS-CoV-2. More importantly, two immunizations of this combination of NTD and RBD immunogens provided complete protection in macaques against a SARS-CoV-2 challenge, without observable antibody-dependent enhancement of infection. These results provide a proof of concept for neutralization-based immunogen design targeting SARS-CoV-2 NTD and RBD.  相似文献   

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