Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 6 de 6
Filter
1.
Proteomics ; : e2200118, 2022 Jul 09.
Article in English | MEDLINE | ID: covidwho-1925988

ABSTRACT

The spread of coronavirus disease 2019 (COVID-19) viral pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a worldwide pandemic claiming several thousands of lives worldwide. During this pandemic, several studies reported the use of COVID-19 convalescent plasma (CCP) from recovered patients to treat severely or critically ill patients. Although this historical and empirical treatment holds immense potential as a first line of response against eventual future unforeseen viral epidemics, there are several concerns regarding the efficacy and safety of this approach. This critical review aims to pinpoint the possible role of mass spectrometry-based analysis in the identification of unique molecular component proteins, peptides, and metabolites of CCP that explains the therapeutic mechanism of action against COVID-19. Additionally, the text critically reviews the potential application of mass spectrometry approaches in the search for novel plasma biomarkers that may enable a rapid and accurate assessment of the safety and efficacy of CCP. Considering the relative low-cost value involved in the CCP therapy, this proposed line of research represents a tangible scientific challenge that will be translated into clinical practice and help save several thousand lives around the world, specifically in low- and middle-income countries.

2.
PLoS One ; 17(2): e0262442, 2022.
Article in English | MEDLINE | ID: covidwho-1854992

ABSTRACT

In late December 2019, pneumonia cases of unknown origin were reported in Wuhan, China. This virus was named SARS-CoV2 and the clinical syndrome was named coronavirus disease 19 (COVID-19). South Africa, despite strict and early lockdown has the highest infection rate in Africa. A key component of South Africa's response to SARSCoV2 was the rapid scale-up of diagnostic testing. The Abbott SARS-CoV2 assay detects IgG antibodies against the Nucleocapsid (N) protein of the SARS-CoV2 virus. This study undertook to validate and evaluate performance criteria of the Abbott assay and to establish whether this assay would show clinical utility in our population. Positive patients (n = 391) and negative controls (n = 139) were included. The Architect-i and Alinity-i systems were analyzers that were used to perform the SARS-CoV-2 IgG assay. In-house ELISA was incorporated into the study as a confirmatory serology test. A total of number of 530 participants was tested, 87% were symptomatic with infection and 13% were asymptomatic. When compared to RT-qPCR, the sensitivity of Architect and Alinity SARS-CoV2 assays was 69.5% and 64.8%, respectively. Specificity for Architect and Alinity assays was 95% and 90.3%, respectively. The Abbott assay was also compared to in house ELISA assay, with sensitivity for the Architect and Alinity assays of 94.7% and 92.5%, respectively. Specificity for Abbott Alinity assays was 91.7% higher than Abbott Architect 88.1%. Based on the current findings testing of IgG after 14 days is recommended in South Africa and supports other studies performed around the world.


Subject(s)
Antibodies, Viral/blood , COVID-19 Serological Testing/methods , COVID-19/diagnosis , Immunoglobulin G/blood , SARS-CoV-2/isolation & purification , Adult , Aged , Aged, 80 and over , Antibodies, Viral/immunology , COVID-19/blood , COVID-19/epidemiology , COVID-19/virology , Enzyme-Linked Immunosorbent Assay , Female , Follow-Up Studies , Humans , Immunoglobulin G/immunology , Male , Middle Aged , Prognosis , Retrospective Studies , South Africa/epidemiology , Young Adult
3.
Nature ; 602(7898): 654-656, 2022 02.
Article in English | MEDLINE | ID: covidwho-1616992

ABSTRACT

The emergence of the SARS-CoV-2 variant of concern Omicron (Pango lineage B.1.1.529), first identified in Botswana and South Africa, may compromise vaccine effectiveness and lead to re-infections1. Here we investigated Omicron escape from neutralization by antibodies from South African individuals vaccinated with Pfizer BNT162b2. We used blood samples taken soon after vaccination from individuals who were vaccinated and previously infected with SARS-CoV-2 or vaccinated with no evidence of previous infection. We isolated and sequence-confirmed live Omicron virus from an infected person and observed that Omicron requires the angiotensin-converting enzyme 2 (ACE2) receptor to infect cells. We compared plasma neutralization of Omicron relative to an ancestral SARS-CoV-2 strain and found that neutralization of ancestral virus was much higher in infected and vaccinated individuals compared with the vaccinated-only participants. However, both groups showed a 22-fold reduction in vaccine-elicited neutralization by the Omicron variant. Participants who were vaccinated and had previously been infected exhibited residual neutralization of Omicron similar to the level of neutralization of the ancestral virus observed in the vaccination-only group. These data support the notion that reasonable protection against Omicron may be maintained using vaccination approaches.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Immune Evasion/immunology , Neutralization Tests , SARS-CoV-2/immunology , Angiotensin-Converting Enzyme 2/metabolism , Animals , Cell Line , Chlorocebus aethiops , Humans , Mutation , SARS-CoV-2/classification , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism
4.
Clin Infect Dis ; 2021 Dec 10.
Article in English | MEDLINE | ID: covidwho-1566004

ABSTRACT

BACKGROUND: People living with HIV (PLWH) have been reported to have a higher risk of more severe Covid-19 disease and death. We assessed the ability of the Ad26.CoV2.S vaccine to elicit neutralizing activity against the Delta variant in PLWH relative to HIV-negative individuals. We also examined effects of HIV status and suppression on Delta neutralization response in SARS-CoV-2 infected unvaccinated participants. METHODS: We enrolled participants who vaccinated through the SISONKE South African clinical trial of the Ad26.CoV2.S vaccine in health care workers (HCW). PLWH in this group had well controlled HIV infection. We also enrolled unvaccinated participants previously infected with SARS-CoV-2. Neutralization capacity was assessed by a live virus neutralization assay of the Delta variant. RESULTS: Majority of Ad26.CoV2.S vaccinated HCW were previously infected with SARS-CoV-2. In this group, Delta variant neutralization was 9-fold higher compared to the infected only group and 26-fold higher relative to the vaccinated only group. No decrease in Delta variant neutralization was observed in PLWH relative to HIV-negative participants. In contrast, SARS-CoV-2 infected, unvaccinated PLWH showed 7-fold lower neutralization and a higher frequency of non-responders, with the highest frequency of non-responders in people with HIV viremia. Vaccinated only participants showed low neutralization capacity. CONCLUSIONS: The neutralization response of the Delta variant following Ad26.CoV2.S vaccination in PLWH with well controlled HIV was not inferior to HIV-negative participants, irrespective of past SARS-CoV-2 infection. In SARS-CoV-2 infected and non-vaccinated participants, HIV infection reduced the neutralization response to SARS-CoV-2, with the strongest reduction in HIV viremic individuals.

5.
PLoS One ; 16(6): e0252317, 2021.
Article in English | MEDLINE | ID: covidwho-1280618

ABSTRACT

Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2) has been identified as the causative agent for causing the clinical syndrome of COVID -19. Accurate detection of SARS-CoV-2 infection is not only important for management of infected individuals but also to break the chain of transmission. South Africa is the current epicenter of SARS-CoV-2 infection in Africa. To optimize the diagnostic algorithm for SARS-CoV-2 in the South African setting, the study aims to evaluate the diagnostic performance of the EUROIMMUN Anti-SARS-CoV-2 assays. This study reported the performance of EUROIMMUN enzyme-linked immunosorbent assay (ELISA) for semi-quantitative detection of IgA and IgG antibodies in serum and plasma samples targeting the recombinant S1 domain of the SARS-CoV-2 spike protein as antigen. Samples were collected from 391 individuals who had tested positive for SARS-CoV-2 and 139 SARS CoV-2 negative controls. Samples were stratified by number of days' post-PCR diagnosis and symptoms. The sensitivity of EUROIMMUN IgG was 64.1% (95% CI: 59.1-69.0%) and 74.3% (95% CI: 69.6-78.6%) for IgA and the specificity was lower for IgA [84.2% (95% CI: 77-89.2%)] than IgG [95.2% (95% CI: 90.8-98.4%)]. The EUROIMMUN Anti-SARS-CoV-2 ELISA Assay sensitivity was higher for IgA but low for IgG and improved for both assays in symptomatic individuals and at later timepoints post PCR diagnosis.


Subject(s)
COVID-19 Serological Testing/methods , Immunoglobulin A/blood , Immunoglobulin G/blood , Adult , Aged , Aged, 80 and over , COVID-19 Nucleic Acid Testing/methods , Enzyme-Linked Immunosorbent Assay/methods , Female , Humans , Male , Middle Aged , Point-of-Care Testing , Sensitivity and Specificity , South Africa
6.
Analyst ; 146(4): 1207-1215, 2021 Feb 21.
Article in English | MEDLINE | ID: covidwho-1137828

ABSTRACT

Tuberculosis (TB) is one of the top ten causes of death globally, despite being treatable. The eradication of TB disease requires, amongst others, diagnostic tests with high specificity and sensitivity that will work at the point of care (POC) in low-resource settings. The TB surface glycolipid antigen, mannose-capped lipoarabinomannan (ManLAM) currently serves as the only POC molecular diagnostic biomarker suitable for use in low cost immunoassays. Here, we demonstrate the high affinity and exceptional specificity of microvirin-N (MVN), a 14.3 kDa cyanobacterial lectin, toward H37Rv TB ManLAM and utilize it to develop a novel on-bead ELISA. MVN binds to ManLAM with sub-picomolar binding affinity, but does not bind to other variants of LAM expressed by non-pathogenic mycobacteria - a level of binding specificity and affinity that current commercially available anti-LAM antibodies cannot achieve. An on-bead ELISA was subsequently developed using MVN-functionalized magnetic beads which allows for the specific capture of ManLAM from human urine with a limit of detection (LOD) of 1.14 ng mL-1 and no cross-reactivity when tested with PILAM, a variant of LAM found on non-pathogenic mycobacteria.


Subject(s)
Mycobacterium tuberculosis , Tuberculosis , Diagnostic Tests, Routine , Humans , Lectins , Lipopolysaccharides , Sensitivity and Specificity , Tuberculosis/diagnosis
SELECTION OF CITATIONS
SEARCH DETAIL