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1.
Clin Infect Dis ; 73(12): 2155-2162, 2021 12 16.
Article in English | MEDLINE | ID: covidwho-1592795

ABSTRACT

BACKGROUND: Assessing the duration of immunity following infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a first priority to gauge the degree of protection following infection. Such knowledge is lacking, especially in the general population. Here, we studied changes in immunoglobulin isotype seropositivity and immunoglobulin G (IgG) binding strength of SARS-CoV-2-specific serum antibodies up to 7 months following onset of symptoms in a nationwide sample. METHODS: Participants from a prospective representative serological study in the Netherlands were included based on IgG seroconversion to the spike S1 protein of SARS-CoV-2 (N = 353), with up to 3 consecutive serum samples per seroconverted participant (N = 738). Immunoglobulin M (IgM), immunoglobulin A (IgA), and IgG antibody concentrations to S1, and increase in IgG avidity in relation to time since onset of disease symptoms, were determined. RESULTS: While SARS-CoV-2-specific IgM and IgA antibodies declined rapidly after the first month after disease onset, specific IgG was still present in 92% (95% confidence interval [CI], 89%-95%) of the participants after 7 months. The estimated 2-fold decrease of IgG antibodies was 158 days (95% CI, 136-189 days). Concentrations were sustained better in persons reporting significant symptoms compared to asymptomatic persons or those with mild upper respiratory complaints only. Similarly, avidity of IgG antibodies for symptomatic persons showed a steeper increase over time compared with persons with mild or no symptoms (P = .022). CONCLUSIONS: SARS-CoV-2-specific IgG antibodies persist and show increasing avidity over time, indicative of underlying immune maturation. These data support development of immune memory against SARS-CoV-2, providing insight into protection of the general unvaccinated part of the population. CLINICAL TRIALS REGISTRATION: NL8473 (the Dutch trial registry).


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Netherlands/epidemiology , Prospective Studies
2.
J Nippon Med Sch ; 88(4): 380-383, 2021 Sep 01.
Article in English | MEDLINE | ID: covidwho-1551292

ABSTRACT

We assessed the association of severity of coronavirus disease 2019 (COVID-19) with acute respiratory syndrome coronavirus 2 (SARS-CoV-2) load, IgG antibody level, and prognostic indicators.Twenty-one patients hospitalized with COVID-19 were classified as having severe or mild disease on the basis of average respiratory rate during hospitalization (severe: ≥22 breaths/min; mild: <22 breaths/min). Viral load in nasopharyngeal samples, blood levels of C-reactive protein (CRP), lymphocytes, and D-dimer on admission and plasma immunoglobulin G (IgG) index on Day 7±2 after symptom onset were compared in relation to disease severity. Seven patients had severe disease and 14 had mild disease. Those with severe disease had a significantly higher IgG index (median: 3.75 vs 0.56, p=0.01) and CRP (median: 8.6 vs 1.0 mg/dL, p<0.001) and D-dimer levels (median: 1.65 vs 0.75 µg/mL; p=0.002) and a significantly lower lymphocyte count (median: 1,176 vs 666 cells/µL, p=0.005) and viral load (median: 8.7×106 vs 2.3×104 copies/mL, p=0.005). Furthermore, time from symptom onset to virus disappearance was significantly longer in severe patients (median: 24 vs 17 days, p=0.03). A high IgG index in the early phase of the disease was associated with severe disease and might serve as a prognostic indicator.


Subject(s)
Antibodies, Viral/blood , COVID-19 Nucleic Acid Testing , COVID-19 Serological Testing , COVID-19/diagnosis , Immunoglobulin G/blood , SARS-CoV-2/pathogenicity , Viral Load , Adult , Aged , Biomarkers/blood , COVID-19/blood , COVID-19/drug therapy , COVID-19/therapy , COVID-19/virology , Female , Hospitalization , Host-Pathogen Interactions , Humans , Japan , Male , Middle Aged , Oxygen Inhalation Therapy , Predictive Value of Tests , Prognosis , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Severity of Illness Index , Time Factors
3.
Transpl Int ; 34(10): 1908-1913, 2021 10.
Article in English | MEDLINE | ID: covidwho-1268132

ABSTRACT

Solid organ transplant recipients might be at greater risk for acquisition and mortality because of SARS-CoV-2. There are no data regarding SARS-CoV-2 seroprevalence among liver transplant (LT) recipients, and whether it is different from that of the general population or other immunosuppressed groups. We evaluated the prevalence of IgG SARS-CoV-2 antibodies among LT recipients to estimate the frequency of asymptomatic SARS-CoV-2 infection using serological assays in our outpatient clinic. We conducted a cross-sectional analysis from 10 May to 26 October 2020 of all adult (>18 years) LT recipients that underwent a routine laboratory test for the outpatient clinic follow-up at the Hospital Universitari Vall d'Hebron (Barcelona) in which we included serological testing for SARS-CoV-2. Nine out of 294 LT recipients (3.1%) tested positive for anti-SARS-CoV-2 IgG antibodies. Five of them (55.5%) had suffered clinically symptomatic SARS-CoV-2 infection confirmed by RT-PCR, four (44.4%) had presented compatible symptoms but without microbiological confirmation and only one patient (1/9, 11.1%) tested positive without any previous symptom. SARS-CoV-2 seroprevalence among LT recipients in an area highly affected by the pandemic is lower than in the general population in the same area. These results render the possibility of asymptomatic infection in LT recipients very unlikely.


Subject(s)
COVID-19 , Liver Transplantation , Adult , Antibodies, Viral , Cross-Sectional Studies , Humans , SARS-CoV-2 , Seroepidemiologic Studies
4.
J Med Virol ; 93(4): 2227-2233, 2021 04.
Article in English | MEDLINE | ID: covidwho-1217375

ABSTRACT

The coronavirus disease 2019 (COVID-19) is a pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, little is known about the durability of the antibody response during COVID-19 convalescent phase. We investigated the prevalence of anti-SARS-CoV-2 specific antibodies including immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies and the dynamic changes in antibody levels in convalescent COVID-19 patients. A total of 159 blood samples were collected from 52 recovered COVID-19 patients up to six months after symptom onset for longitudinal serological tests. The positive rate of IgG and IgM antibodies was 92.3% and 90.4% in the first month after symptom onset, and the seropositivity of IgG antibody remained high at all follow-up time points, whereas the seropositivity of IgM antibody decreased to 22.73% by the sixth months after symptom onset. The level of IgG antibody was stable, the level of IgM antibody decreased slightly in the early convalescent phase and was detected in only five patients in the sixth month after symptom onset. The level of IgG antibody was higher in the severe and critical group than in the moderate group. The anti-SARS-CoV-2 specific antibodies have a long-term persistence in convalescent COVID-19 patients, whether they have long-term protection need to be further investigated.


Subject(s)
Antibodies, Viral/blood , COVID-19/immunology , SARS-CoV-2/immunology , Adult , Antibodies, Viral/biosynthesis , Antibody Formation , COVID-19/blood , COVID-19/diagnosis , COVID-19 Testing/methods , Female , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Male , Middle Aged , Serologic Tests/methods
5.
Pract Lab Med ; 25: e00227, 2021 May.
Article in English | MEDLINE | ID: covidwho-1203246

ABSTRACT

BACKGROUND: Recently many serological assays for detection of antibodies to SARS-COV-2 virus were introduced on the market. Aim of this study was to assess the diagnostic performance of an automated CLIA for quantitative detection of anti-SARS-CoV-2 IgM and IgG antibodies. METHODS: A total of 354 sera, 89 from consecutive patients diagnosed with COVID-19 (43 mild, 32 severe and 13 critical) and 265 from asymptomatic and negative on rRT-PCR testing healthcare workers, were evaluated for IgM and IgG anti-SARS-CoV-2 antibodies with MAGLUMI immunoassay. RESULTS: The overall sensitivity and specificity were 86.5% (95%CI: 77.6-92.8) and 98.5% (95%CI:96.2-99.6), respectively. PPV, PPN, LR+, LR- and OR were 95.1 (95%CI: 87.8-98.6), 95.6 (95%CI: 92.4-97.7), 57.3 (95%CI: 21.6-152.1), 7.3 (95%CI: 4.31-12.4) and 418.6 (95%CI: 131.2-1335.2), respectively. The levels of SARS-CoV-2 IgM and IgG antibodies were 1.22 â€‹± â€‹1.2 AU/mL and 15.86 â€‹± â€‹24.83 AU/mL, 2.86 â€‹± â€‹2.4 AU/mL and 69.3 â€‹± â€‹55.5 AU/mL, 2.47 â€‹± â€‹1.33 AU/mL and 83.9 â€‹± â€‹83.9 AU/mL in mild, severe and critical COVID-19 groups, respectively. A significant difference in antibody levels between mild and severe/critical subjects has been shown. CONCLUSIONS: The CLIA assay showed good diagnostic performance and a significant association between antibody levels and severity of the disease was found.

6.
J Med Virol ; 93(3): 1810-1813, 2021 03.
Article in English | MEDLINE | ID: covidwho-1196504

ABSTRACT

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vertical transmission is an open issue. Recent reports call into question in utero or peripartum viral transmission to the offspring. Few data are available on immunoglobulin G (IgG) and/or IgM in newborns. Insufficient evidence is available regarding passive immunity in neonates born from SARS-CoV-2 infected women. We report a case of a neonate showing the presence of blood specific IgG and the absence of IgM and negative nasopharyngeal swab. He was born from an asymptomatic SARS-CoV-2-infected mother with positive IgG and IgM. The transplacental passage of specific IgG antibodies from the affected mother to the unaffected fetus highlights neonatal passive immunity.


Subject(s)
Antibodies, Viral/blood , COVID-19/transmission , Immunity, Maternally-Acquired/immunology , Infectious Disease Transmission, Vertical , SARS-CoV-2/immunology , Adult , COVID-19/diagnosis , Female , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Infant, Newborn , Male , Pregnancy , Pregnancy Complications, Infectious/virology
7.
J Clin Microbiol ; 59(5)2021 04 20.
Article in English | MEDLINE | ID: covidwho-1195818

ABSTRACT

In this study, we comprehensively analyzed multispecific antibody kinetics of different immunoglobulins in hospitalized patients with acute severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Three hundred fifty-four blood samples longitudinally obtained from 81 IgG-seroconverting progressed coronavirus disease 2019 (CoVID-19) patients were quantified for spike 1 (S1), S2, and nucleocapsid protein (NCP)-specific IgM, IgA, IgG, and total Ig antibodies using a microarray, 11 different enzyme-linked immunosorbent assays (ELISAs)/chemiluminescence immunoassays (CLIAs), and 1 rapid test by seven manufacturers. The assays' specificity was assessed in 130 non-CoVID-19 pneumonia patients. Using the microarray, NCP-specific IgA and IgG antibodies continuously displayed higher detection rates during acute CoVID-19 than S1- and S2-specific ones. S1-specific IgG antibodies, however, reached higher peak values. Until the 26th day post-symptom onset, all patients developed IgG responses against S1, S2, and NCP. Although detection rates by ELISAs/CLIAs generally resembled those of the microarray, corresponding to the target antigen, sensitivities and specificities varied among all tests. Notably, patients with more severe CoVID-19 displayed higher IgG and IgA levels, but this difference was mainly observed with S1-specific immunoassays. In patients with high SARS-CoV-2 levels in the lower respiratory tract, we observed high detection rates of IgG and total Ig immunoassays with a particular rise of S1-specific IgG antibodies when viral concentrations in the tracheal aspirate subsequently declined over time. In summary, our study demonstrates that differences in sensitivity among commercial immunoassays during acute SARS-CoV-2 infection are only partly related to the target antigen. Importantly, our data indicate that NCP-specific IgA and IgG antibodies are detected earlier, while higher S1-specific IgA antibody levels occur in severely ill patients.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , Immunoassay/methods , Coronavirus Nucleocapsid Proteins/immunology , Humans , Immunoglobulin A/immunology , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Kinetics , Phosphoproteins/immunology , SARS-CoV-2 , Sensitivity and Specificity , Spike Glycoprotein, Coronavirus/immunology
8.
Emerg Microbes Infect ; 10(1): 905-912, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1191602

ABSTRACT

Without an effective vaccine against SARS-CoV-2, the build-up of herd immunity through natural infection has been suggested as a means to control COVID-19. Although population immunity is typically estimated by the serological investigation of recovered patients, humoral immunity in asymptomatic subjects has not been well studied, although they represent a large proportion of all SARS-CoV-2 infection cases. In this study, we conducted a serosurvey of asymptomatic infections among food workers and performed serological and cellular response analyses of asymptomatic subjects in Wuhan, the original epicenter of the COVID-19 outbreak. Our data showed that up to 5.91% of the food workers carried SARS-CoV-2 IgG antibodies asymptomatically; however, in 90.4% of them, the antibody level declined over a 2-week period. IgM and IgG antibodies, including neutralizing antibodies, were significantly lower in asymptomatic subjects than in recovered symptomatic patients with similar disease courses. Furthermore, the asymptomatic subjects showed lymphopenia and a prominent decrease in the B-cell population, as well as a low frequency of antibody-secreting cells and a low cytokine response. These factors probably contributed to the low and unsustained antibody levels in asymptomatic subjects. Our results show that asymptomatic subjects are likely to be vulnerable to SARS-CoV-2 reinfection, and neither the proportion of population immunity nor the breadth of immune responses is sufficient for herd immunity.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Asymptomatic Infections , COVID-19 Serological Testing , COVID-19/immunology , Immunoglobulin G/blood , Immunoglobulin M/blood , Pandemics , SARS-CoV-2/immunology , Antibodies, Neutralizing/biosynthesis , Antibodies, Viral/biosynthesis , B-Lymphocytes , COVID-19/epidemiology , COVID-19 Nucleic Acid Testing , China/epidemiology , Convalescence , Cytokines/blood , Disease Susceptibility , Enzyme-Linked Immunosorbent Assay , Follow-Up Studies , Food Handling , Genome, Viral , Humans , Immunity, Herd , Immunoglobulin G/biosynthesis , Immunoglobulin M/biosynthesis , Lymphocyte Count , Lymphopenia/etiology , Phylogeny , RNA, Viral/blood , Real-Time Polymerase Chain Reaction , SARS-CoV-2/genetics , Seroepidemiologic Studies , Sputum/virology
9.
J Orthop Sci ; 2021 Apr 17.
Article in English | MEDLINE | ID: covidwho-1188813

ABSTRACT

BACKGROUND: Elective orthopaedic surgery has been severely curtailed because of coronavirus disease, 2019. There is scant scientific evidence to guide surgeons in assessing the protocols that must be implemented before resuming elective orthopaedic surgery safely after the second wave of the coronavirus disease, 2019. METHODS: A retrospective review of elective orthopaedic surgeries performed between May 15, 2020, and November 20, 2020, was conducted. A screening questionnaire was used, and reverse transcription-polymerase chain reaction and severe acute respiratory syndrome coronavirus-2 immunoglobulin G and IgM antibodies testing were assessed in all admitted patients. Screening and testing data for coronavirus disease was reviewed for all patients. RESULTS: Of 592 patients tested for severe acute respiratory syndrome coronavirus-2 during the study period, 21 (3.5%) tested positive. There were 2 patients (0.3%) with positive reverse transcription-polymerase chain reaction tests, 3 (0.5%) with positive IgG and IgM antibodies, 13 (2.2%) with positive IgG antibodies, and 10 (1.7%) with positive IgM antibodies. Among these 21 patients, 20 (95.2%) were asymptomatic. CONCLUSIONS: Our findings suggest that most elective orthopaedic surgery patients with severe acute respiratory syndrome coronavirus-2 are asymptomatic. In the second wave of coronavirus disease, 2019, universal testing of all patients should be strongly considered as an important measure to prevent clusters of in-hospital transmission of the disease.

11.
PLoS One ; 16(3): e0249247, 2021.
Article in English | MEDLINE | ID: covidwho-1175427

ABSTRACT

OBJECTIVES: We aimed to estimate the seroprevalence of COVID-19 in a rural district of South India, six months after the index case. METHODOLOGY: We conducted a cross-sectional study of 509 adults aged more than 18 years. From all the four subdistricts, two grampanchayats (administrative cluster of 5-8 villages) were randomly selected followed by one village through convenience. The participants were invited for the study to the community-based study kiosk set up in all the eight villages through village health committees. We collected socio-demographic characteristics and symptoms using a mobile application-based questionnaire, and we tested samples for the presence of IgG antibodies for SARS CoV-2 using an electro chemiluminescent immunoassay. We calculated age-gender adjusted and test performance adjusted seroprevalence. RESULTS: The age-and gender-adjusted seroprevalence was 8.5% (95% CI 6.9%- 10.8%). The unadjusted seroprevalence among participants with hypertension and diabetes was 16.3% (95% CI:9.2-25.8) and 10.7% (95% CI: 5.5-18.3) respectively. When we adjusted for the test performance, the seroprevalence was 6.1% (95% CI 4.02-8.17). The study estimated 7 (95% CI 1:4.5-1:9) undetected infected individuals for every RT-PCR confirmed case. Infection Fatality Rate (IFR) was calculated as 12.38 per 10000 infections as on 22 October 2020. History of self-reported symptoms and education were significantly associated with positive status (p < 0.05). CONCLUSION: A significant proportion of the rural population in a district of south India remains susceptible to COVID-19. A higher proportion of susceptible, relatively higher IFR and a poor tertiary healthcare network stress the importance of sustaining the public health measures and promoting early access to the vaccine are crucial to preserving the health of this population. Low population density, good housing, adequate ventilation, limited urbanisation combined with public, private and local health leadership are critical components of curbing future respiratory pandemics.


Subject(s)
COVID-19/epidemiology , Rural Population/statistics & numerical data , Adult , Female , Humans , India/epidemiology , Male , Middle Aged , Seroepidemiologic Studies , Young Adult
12.
PLoS One ; 16(4): e0249449, 2021.
Article in English | MEDLINE | ID: covidwho-1171683

ABSTRACT

OBJECTIVES: To determine the seroprevalence of anti-SARS-CoV-2 IgG and IgM antibodies in symptomatic Japanese COVID-19 patients. METHODS: Serum samples (n = 114) from 34 COVID-19 patients with mild to critical clinical manifestations were examined. The presence and titers of IgG antibody for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were determined by a chemiluminescent microparticle immunoassay (CMIA) using Alinity i SARS-CoV-2 IgG and by an immunochromatographic (IC) IgM/IgG antibody assay using the Anti-SARS-CoV-2 Rapid Test. RESULTS: IgG was detected by the CMIA in 40%, 88%, and 100% of samples collected within 1 week, 1-2 weeks, and 2 weeks after symptom onset in severe and critical cases, and 0%, 38%, and 100% in mild/moderate cases, respectively. In severe and critical cases, the positive IgG detection rate with the IC assay was 60% within one week and 63% between one and two weeks. In mild/moderate cases, the positive IgG rate was 17% within one week and 63% between one and two weeks; IgM was positive in 80% and 75% of severe and critical cases, and 42% and 88% of mild/moderate cases, respectively. On the CMIA, no anti-SARS-CoV-2 IgG antibodies were detected in COVID-19 outpatients with mild symptoms within 10 days from onset, whereas 50% of samples from severe inpatients were IgG-positive in the same period. The IC assay detected higher IgM positivity earlier from symptom onset in severe and critical cases than in mild/moderate cases. CONCLUSIONS: A serologic anti-SARS-CoV-2 antibody analysis can complement PCR for diagnosing COVID-19 14 days after symptom onset.


Subject(s)
Antibodies, Viral/blood , COVID-19 Serological Testing , COVID-19 , Immunoglobulin G/blood , Immunoglobulin M/blood , SARS-CoV-2/metabolism , Adult , Aged , Aged, 80 and over , COVID-19/blood , COVID-19/diagnosis , COVID-19/epidemiology , Female , Humans , Immunoassay , Japan/epidemiology , Male , Middle Aged
13.
J Clin Med ; 10(7)2021 Apr 04.
Article in English | MEDLINE | ID: covidwho-1167630

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence in cancer patients may vary widely dependent on the geographic area and this has significant implications for oncological care. The aim of this observational, prospective study was to assess the seroprevalence of SARS-CoV-2 IgM/IgG antibodies in solid cancer patients referred to the academic institution of the Marche Region, Italy, between 1 July and 26 October 2020 and to determine the accuracy of the rapid serological test. After performing 3767 GCCOV-402a rapid serological tests on a total of 949 patients, seroconversion was initially observed in 13 patients (1.4%). Ten (77% of the total positive) were IgG-positive, 1 (8%) were IgM-positive and 2 (15%) IgM-positive/IgG-positive. However, only 7 out of 13 were confirmed as positive at the reference serological test (true positives), thus seroprevalence after cross-checking was 0.7%. No false negatives were reported. The kappa value of the consistency analysis was 0.71. Due to rapid serological test high false positive rate, its role in assessing seroconversion rate is limited, and the standard serological tests should remain the gold standard. However, as rapid test negative predictive value is high, GCCOV-402a may instead be useful to monitor patient immunity over time, thus helping to assist ongoing vaccination programs.

14.
Int J Environ Res Public Health ; 18(7)2021 04 05.
Article in English | MEDLINE | ID: covidwho-1167591

ABSTRACT

Coronavirus disease 2019 (COVID-19) has become a serious public health problem worldwide. In general, healthcare workers are considered to be at higher risk of COVID-19 infection. However, the prevalence of COVID-19 among healthcare workers in Japan is not well characterized. In this study, we aimed to examine the seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antibodies among 2160 healthcare workers in hospitals and clinics that are not designated to treat COVID-19 patients in Japan. The prevalence of SARS-CoV-2 immunoglobulin G was 1.2% in August and October 2020 (during and after the second wave of the pandemic in Japan), which is relatively higher than that in the general population in Japan (0.03-0.91%). Because of the higher risk of COVID-19 infection, healthcare workers should be the top priority for further social support and vaccination against SARS-CoV-2.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Viral , Health Personnel , Hospitals, General , Humans , Japan/epidemiology , Seroepidemiologic Studies
15.
Int J Occup Med Environ Health ; 34(2): 203-209, 2021 May 27.
Article in English | MEDLINE | ID: covidwho-1140809

ABSTRACT

OBJECTIVES: Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome virus 2 (SARS-CoV-2) had spread worldwide since December 2019 and became a pandemic in March 2020. The diagnosis of an active infection is based on the real-time reverse transcriptase-polymerase chain reaction (RT-PCR) from the nasopharyngeal swab specimen. The aim of the current analysis was to assess the usefulness of the rapid serological tests for diagnosing SARS-CoV-2 infections. MATERIAL AND METHODS: The rapid serological tests detecting IgG/IgM antibodies for SARS-CoV-2 were voluntarily performed in asymptomatic employees of 2 companies. The examination was conducted at the date and time selected online by the study participants. The testing team consisted of 2 nurses collecting the samples and 1 doctor who interpreted the results. Each positive rapid test result was verified by an RT-PCR examination from a nasopharyngeal swab. The testing kits named Vazyme: 2019-nCoV IgG/IgM Detection Kit (Colloidal Gold-Based) were provided by the employer along with the manual and certificates. RESULTS: The overall interest in testing among employees was below the employer's expectations and reached 30% and 20% in each of the 2 companies, respectively. A total of 516 participants were included in the analysis. Ten positive results of the rapid tests were documented, including 7 for IgM and 3 for IgG antibodies. No positive result was confirmed by the detection of the genetic material of the SARS-CoV-2 by the RT-PCR examination. CONCLUSIONS: Herein, the authors demonstrated the uselessness of rapid serological tests performed in asymptomatic volunteers for diagnosing SARS-CoV-2 infections. Int J Occup Med Environ Health. 2021;34(2):203-9.


Subject(s)
Antibodies, Viral/analysis , COVID-19/epidemiology , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Pandemics , SARS-CoV-2/immunology , Adult , COVID-19/immunology , COVID-19/virology , Female , Humans , Immunoglobulin M/immunology , Male , Middle Aged
16.
Biology (Basel) ; 10(3)2021 Mar 10.
Article in English | MEDLINE | ID: covidwho-1125483

ABSTRACT

Several hundred millions of people have been diagnosed of coronavirus disease 2019 (COVID-19), causing millions of deaths and a high socioeconomic burden. SARS-CoV-2, the causative agent of COVID-19, induces both specific T- and B-cell responses, being antibodies against the virus detected a few days after infection. Passive immunization with hyperimmune plasma from convalescent patients has been proposed as a potentially useful treatment for COVID-19. Using an in-house quantitative ELISA test, we found that plasma from 177 convalescent donors contained IgG antibodies specific to the spike receptor-binding domain (RBD) of SARS-CoV-2, although at very different concentrations which correlated with previous disease severity and gender. Anti-RBD IgG plasma concentrations significantly correlated with the plasma viral neutralizing activity (VN) against SARS-CoV-2 in vitro. Similar results were found using an independent cohort of serum from 168 convalescent health workers. These results validate an in-house RBD IgG ELISA test in a large cohort of COVID-19 convalescent patients and indicate that plasma from all convalescent donors does not contain a high enough amount of anti-SARS-CoV-2-RBD neutralizing IgG to prevent SARS-CoV-2 infection in vitro. The use of quantitative anti-RBD IgG detection systems might help to predict the efficacy of the passive immunization using plasma from patients recovered from SARS-CoV-2.

17.
Arch Immunol Ther Exp (Warsz) ; 69(1): 5, 2021 Mar 06.
Article in English | MEDLINE | ID: covidwho-1118194

ABSTRACT

Coronaviruses share conservative spike protein (S) on their enveloped membrane surface, where S1 subunit recognizes and binds the cellular receptor, and the S2 subunit mediates membrane fusion. This similarity raises the question: does coronaviral infection by one create protection to others? Convalescent SARS-CoV-2 (COVID-19) sera were tested for cross reactivity with peptides from Middle East respiratory syndrome coronavirus (MERS-CoV) which shares 74% homology. Our results showed significant cross-reactivity with a peptide of the heptad repeat 2 (HR2) domain of the MERS-CoV spike protein. Sera samples of 47 validated seropositive convalescent COVID-19 patients and 40 sera samples of control patients, collected in pre-COVID time were used to establish cross-bind reactivity with the MERS-CoV peptide. Significantly stronger binding (p < 0.0001) was observed for IgG antibodies in convalescent COVID-19 patients compared to the control group. In ELISA, MERS-CoV peptide helps to discriminate post-COVID-19 populations and non-infected ones by the presence of antibodies in blood samples. This suggests that polyclonal antibodies established during SARS-CoV-2 infection can recognize and probably decrease severity of MERS-CoV and other coronaviral infections. The high homology of the spike protein domain also suggests that the opposite effect can be true: coronaviral infections produce cross-reactive antibodies effective against SARS-CoV-2. The collected data prove that despite the core HR2 region is hidden in the native viral conformation, its exposure during cell entry makes it highly immunogenic. Since inhibitory peptides to this region were previously described, this opens new possibilities in fighting coronaviral infections and developing vaccines effective even after possible viral mutations.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , Convalescence , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Cross Reactions , Humans , Middle East Respiratory Syndrome Coronavirus/immunology , SARS Virus/immunology
18.
Perioper Med (Lond) ; 10(1): 7, 2021 Mar 02.
Article in English | MEDLINE | ID: covidwho-1112453

ABSTRACT

BACKGROUND: Health care workers (HCW) such as anesthesiologists, surgeons, and intensivists face high rates of exposure to SARS-CoV-2 through direct contact with COVID-19 patients. While there are initial reports of the prevalence of COVID-19 antibodies among the general population, there are few reports comparing the seroprevalence of IgM/IgG COVID-19 antibodies in HCW of different exposure levels as well as different HCW professions. METHODS: A convenience sample of health care workers provided blood for COVID-19 antibody testing and a review of medical history and work exposure for correlative analyses. RESULTS: Overall, 474 HCW were enrolled in April 2020 including 102 front-line physicians (e.g., anesthesiologists, surgeons, intensivists, emergency medicine), 91 other physicians, 135 nurses, 134 other clinical staff, and 12 non-clinical HCW. The prevalence of IgM or IgG antibodies to SARS-CoV-2 was 16.9% (95% CI 13.6-20.6) (80/474). The proportion of positive antibodies in the PCR + group was significantly higher than health care workers without symptoms (84.6% [95% CI 54.6-98.1] vs. 12.3% [95% CI 8.5-17.2], p < 0.001). No significant differences in proportions of COVID-19 antibodies were observed among the different exposure groups (e.g., high vs minimal/no exposure) and among the different HCW professionals. CONCLUSIONS: Despite exposure to COVID-19 patients, the prevalence of antibodies in our HCW was similar to what has been reported for the general population of New York State (14%) and for another New York HCW cohort (13.7%). Health care workers with higher exposure rates were not more likely to have been infected with COVID-19. Therefore, these data suggest that infection of HCW may result from exposure in the community rather than at work. TRIAL REGISTRATION: This investigator-initiated study was observational; therefore, no registration was required. Not applicable.

19.
BMC Immunol ; 22(1): 14, 2021 02 17.
Article in English | MEDLINE | ID: covidwho-1088580

ABSTRACT

BACKGROUND: SARS-CoV-2 is a novel coronavirus first recognized in late December 2019 that causes coronavirus disease 19 (COVID-19). Due to the highly contagious nature of SARS-CoV-2, it has developed into a global pandemic in just a few months. Antibody testing is an effective method to supplement the diagnosis of COVID-19. However, multicentre studies are lacking to support the understanding of the seroprevalence and kinetics of SARS-CoV-2 antibodies in COVID-19 epidemic regions. METHOD: A multicentre cross-sectional study of suspected and confirmed patients from 4 epidemic cities in China and a cohort study of consecutive follow-up patients were conducted from 29/01/2020 to 12/03/2020. IgM and IgG antibodies elicited by SARS-CoV-2 were tested by a chemiluminescence assay. Clinical information, including basic demographic data, clinical classification, and time interval from onset to sampling, was collected from each centre. RESULTS: A total of 571 patients were enrolled in the cross-sectional study, including 235 COVID-19 patients and 336 suspected patients, each with 91.9%:2.1% seroprevalence of SARS-CoV-2 IgG and 92.3%:5.4% seroprevalence of SARS-CoV-2 IgM. The seroprevalence of SARS-CoV-2 IgM and IgG in COVID-19 patients was over 70% less than 7 days after symptom onset. Thirty COVID-19 patients were enrolled in the cohort study and followed up for 20 days. The peak concentrations of IgM and IgG were reached on the 10th and 20th days, respectively, after symptom onset. The seroprevalence of COVID-19 IgG and IgM increased along with the clinical classification and treatment time delay. CONCLUSION: We demonstrated the kinetics of IgM and IgG SARS-CoV-2 antibodies in COVID-19 patients and the association between clinical classification and antibodies, which will contribute to the interpretation of IgM and IgG SARS-CoV-2 antibody tests and in predicting the outcomes of patients with COVID-19.


Subject(s)
COVID-19/immunology , SARS-CoV-2/physiology , Adult , Antibodies, Viral/blood , Antibody Formation , COVID-19/diagnosis , China , Cross-Sectional Studies , Disease Progression , Female , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Male , Middle Aged , Prognosis , Seroepidemiologic Studies
20.
Sci Rep ; 11(1): 3461, 2021 02 10.
Article in English | MEDLINE | ID: covidwho-1078603

ABSTRACT

Despite ongoing efforts to characterize the host response toward SARS-CoV-2, a major gap in our knowledge still exists regarding the magnitude and duration of the humoral response. Analysis of the antibody response in mild versus moderate/severe patients, using our new developed quantitative electrochemiluminescent assay for detecting IgM/IgA/IgG antibodies toward SARS-CoV-2 antigens, revealed a rapid onset of IgG/IgA antibodies, specifically in moderate/severe patients. IgM antibodies against the viral receptor binding domain, but not against nucleocapsid protein, were detected at early stages of the disease. Furthermore, we observed a marked reduction in IgM/IgA antibodies over-time. Adapting our assay for ACE2 binding-competition, demonstrated that the presence of potentially neutralizing antibodies is corelated with IgG/IgA. Finally, analysis of the cytokine profile in COVID-19 patients revealed unique correlation of an IL-12p70/IL33 and IgG seroconversion, which correlated with disease severity. In summary, our comprehensive analysis has major implications on the understanding and monitoring of SARS-CoV-2 infections.


Subject(s)
COVID-19/immunology , Immunoglobulin G/immunology , Interleukin-12/blood , Interleukin-33/blood , Seroconversion/physiology , Antibody Formation , COVID-19/blood , COVID-19/diagnosis , Humans , Severity of Illness Index
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