Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 22
Filter
1.
J Clin Invest ; 132(12)2022 Jun 15.
Article in English | MEDLINE | ID: covidwho-1832834

ABSTRACT

BACKGROUNDPatients undergoing immune-modifying therapies demonstrate a reduced humoral response after COVID-19 vaccination, but we lack a proper evaluation of the effect of such therapies on vaccine-induced T cell responses.METHODSWe longitudinally characterized humoral and spike-specific T cell responses in patients with inflammatory bowel disease (IBD), who were on antimetabolite therapy (azathioprine or methotrexate), TNF inhibitors, and/or other biologic treatment (anti-integrin or anti-p40) for up to 6 months after completing 2-dose COVID-19 mRNA vaccination.RESULTSWe demonstrate that a spike-specific T cell response was not only induced in treated patients with IBD at levels similar to those of healthy individuals, but also sustained at higher magnitude for up to 6 months after vaccination, particularly in those treated with TNF inhibitor therapy. Furthermore, the spike-specific T cell response in these patients was mainly preserved against mutations present in SARS-CoV-2 B.1.1.529 (Omicron) and characterized by a Th1/IL-10 cytokine profile.CONCLUSIONDespite the humoral response defects, patients under immune-modifying therapies demonstrated a favorable profile of vaccine-induced T cell responses that might still provide a layer of COVID-19 protection.FUNDINGThis study was funded by the National Centre for Infectious Diseases (NCID) Catalyst Grant (FY2021ES) and the National Research Fund Competitive Research Programme (NRF-CRP25-2020-0003).


Subject(s)
COVID-19 , Inflammatory Bowel Diseases , Viral Vaccines , Antibodies, Viral , COVID-19 Vaccines , Humans , Inflammatory Bowel Diseases/therapy , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , T-Lymphocytes , Vaccination , Viral Vaccines/genetics
2.
Cell Host Microbe ; 27(6): 879-882.e2, 2020 06 10.
Article in English | MEDLINE | ID: covidwho-1719463

ABSTRACT

The inflammatory response to SARS-coronavirus-2 (SARS-CoV-2) infection is thought to underpin COVID-19 pathogenesis. We conducted daily transcriptomic profiling of three COVID-19 cases and found that the early immune response in COVID-19 patients is highly dynamic. Patient throat swabs were tested daily for SARS-CoV-2, with the virus persisting for 3 to 4 weeks in all three patients. Cytokine analyses of whole blood revealed increased cytokine expression in the single most severe case. However, most inflammatory gene expression peaked after respiratory function nadir, except expression in the IL1 pathway. Parallel analyses of CD4 and CD8 expression suggested that the pro-inflammatory response may be intertwined with T cell activation that could exacerbate disease or prolong the infection. Collectively, these findings hint at the possibility that IL1 and related pro-inflammatory pathways may be prognostic and serve as therapeutic targets for COVID-19. This work may also guide future studies to illuminate COVID-19 pathogenesis and develop host-directed therapies.


Subject(s)
Coronavirus Infections/genetics , Coronavirus Infections/immunology , Pneumonia, Viral/genetics , Pneumonia, Viral/immunology , Adult , Aged , Biological Variation, Individual , COVID-19 , Cluster Analysis , Coronavirus Infections/blood , Coronavirus Infections/pathology , Cytokines/blood , Gene Expression Regulation , Humans , Male , Pandemics , Pneumonia, Viral/blood , Pneumonia, Viral/pathology , Transcriptome , Up-Regulation
3.
NPJ Vaccines ; 7(1): 31, 2022 Mar 02.
Article in English | MEDLINE | ID: covidwho-1721525

ABSTRACT

COVID-19 vaccines are effective and important to control the ongoing pandemic, but vaccine reactogenicity may contribute to poor uptake. Analgesics or antipyretic medications are often used to alleviate vaccine side effects, but their effect on immunogenicity remains uncertain. Few studies have assessed the effect of analgesics/antipyretics on vaccine immunogenicity and reactogenicity. Some studies revealed changes in certain immune response parameters post-vaccination when analgesics/antipyretics were used either prophylactically or therapeutically. Still, there is no evidence that these changes impact vaccine efficacy. Specific data on the impact of analgesic/antipyretic medications on immunogenicity of COVID-19 vaccines are limited. However, available data from clinical trials of licensed vaccines, along with recommendations from public health bodies around the world, should provide reassurance to both healthcare professionals and vaccine recipients that short-term use of analgesics/antipyretics at non-prescription doses is unlikely to affect vaccine-induced immunity.

4.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-322457

ABSTRACT

Background: Arterial and venous thrombosis are reported to be common in critically ill COVID-19 patients.Method and Results: This is a national multicenter retrospective observational study involving all consecutive adult COVID-19 patients who required intensive care units (ICU) admission between 23 January 2020 and 30 April 2020 in Singapore. 111 patients were included and the venous and arterial thrombotic rates in ICU were 1.8% (n=2) and 9.9% (n=11), respectively. Major bleeding rate was 14.8% (n=16). Conclusions: Critically ill COVID-19 patients in Singapore have lower venous thromboembolism but higher arterial thrombosis rates and bleeding manifestations than other reported cohorts.

5.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-312783

ABSTRACT

Background: To determine the utility of chest radiography (CXR) for assessing and prognosticating COVID-19 disease with an objective radiographic scoring system. Methods: A multicenter, prospective study was conducted, forty patients were included. Seventy-eight CXR’s were performed on the first derivation cohort of twenty patients with COVID-19 (median age 47.5 years, 10 females and four with comorbidities) admitted between 22 January 2020 and 1 February 2020. Each CXR was scored by three radiologists in consensus and graded on a 72-point COVID-19 Radiographic Score (CRS). This was correlated with supplemental oxygen requirement, C-reactive protein (CRP), lactate dehydrogenase (LDH) and lymphocyte count. To validate our findings, the parameters of another validation cohort of twenty patients with 65 CXRs were analysed. Results: In the derivation cohort, seven patients needed supplemental oxygen and one was intubated for mechanical ventilation with no death. The maximum CRS was significantly different between patients on and not on supplemental oxygen (p=<.001). There was strong correlation between maximum CRS and lowest oxygen saturation (r= -.849), maximum CRP (r= .832) and maximum LDH (r= .873). These findings were consistent in the validation cohort. An increment of 2 points in CRS had an accuracy of 0.938 with 100.0% sensitivity (95% CI 100.0-100.0) and 83.3% (95% CI 65.1-100.0) specificity in predicting supplemental oxygen requirement. Conclusion: Using an objective scoring system (CRS), the degree of abnormalities on CXR correlates closely with known markers of disease severity. CRS may further be applied to predict patients who require oxygen supplementation during the course of their disease.

6.
Med (N Y) ; 3(2): 104-118.e4, 2022 Feb 11.
Article in English | MEDLINE | ID: covidwho-1628746

ABSTRACT

BACKGROUND: Protection offered by coronavirus disease 2019 (COVID-19) vaccines wanes over time, requiring an evaluation of different boosting strategies to revert such a trend and enhance the quantity and quality of Spike-specific humoral and cellular immune responses. These immunological parameters in homologous or heterologous vaccination boosts have thus far been studied for mRNA and ChAdOx1 nCoV-19 vaccines, but knowledge on individuals who received a single dose of Ad26.COV2.S is lacking. METHODS: We studied Spike-specific humoral and cellular immunity in Ad26.COV2.S-vaccinated individuals (n = 55) who were either primed with Ad26.COV2.S only (n = 13) or were boosted with a homologous (Ad26.COV2.S, n = 28) or heterologous (BNT162b2, n = 14) second dose. We compared our findings with the results found in individuals vaccinated with a single (n = 16) or double (n = 44) dose of BNT162b2. FINDINGS: We observed that a strategy of heterologous vaccination enhanced the quantity and breadth of both Spike-specific humoral and cellular immunity in Ad26.COV2.S-vaccinated individuals. In contrast, the impact of the homologous boost was quantitatively minimal in Ad26.COV2.S-vaccinated individuals, and Spike-specific antibodies and T cells were narrowly focused to the S1 region. CONCLUSIONS: Despite the small sample size of the study and the lack of well-defined correlates of protection against COVID-19, the immunological features detected support the utilization of a heterologous vaccine boost in individuals who received Ad26.COV2.S vaccination. FUNDING: This study is partially supported by the Singapore Ministry of Health's National Medical Research Council under its COVID-19 Research Fund (COVID19RF3-0060, COVID19RF-001, and COVID19RF-008), The Medical College St. Bartholomew's Hospital Trustees - Pump Priming Fund for SMD COVID-19 Research.


Subject(s)
COVID-19 , Antibodies, Neutralizing , COVID-19/prevention & control , COVID-19 Vaccines , Humans , SARS-CoV-2
7.
Mikrochim Acta ; 189(1): 14, 2021 12 06.
Article in English | MEDLINE | ID: covidwho-1556195

ABSTRACT

In the ongoing COVID-19 pandemic, simple, rapid, point-of-care tests not requiring trained personnel for primary care testing are essential. Saliva-based antigen rapid tests (ARTs) can fulfil this need, but these tests require overnight-fasted samples; without which independent studies have demonstrated sensitivities of only 11.7 to 23.1%. Herein, we report an Amplified Parallel ART (AP-ART) with sensitivity above 90%, even with non-fasted samples. The virus was captured multimodally, using both anti-spike protein antibodies and Angiotensin Converting Enzyme 2 (ACE2) protein. It also featured two parallel flow channels. The first contained spike protein binding gold nanoparticles which produced a visible red line upon encountering the virus. The second contained signal amplifying nanoparticles that complex with the former and amplify the signal without any linker. Compared to existing dual gold amplification techniques, a limit of detection of one order of magnitude lower was achieved (0.0064 ng·mL-1). AP-ART performance in detecting SARS-CoV-2 in saliva of COVID-19 patients was investigated using a case-control study (139 participants enrolled and 162 saliva samples tested). Unlike commercially available ARTs, the sensitivity of AP-ART was maintained even when non-fasting saliva was used. Compared to the gold standard reverse transcription-polymerase chain reaction testing on nasopharyngeal samples, non-fasting saliva tested on AP-ART showed a sensitivity of 97.0% (95% CI: 84.7-99.8); without amplification, the sensitivity was 72.7% (95% CI: 83.7-94.8). Thus, AP-ART has the potential to be developed for point-of-care testing, which may be particularly important in resource-limited settings, and for early diagnosis to initiate newly approved therapies to reduce COVID-19 severity.


Subject(s)
Antigens/analysis , COVID-19/diagnosis , Point-of-Care Testing , Saliva/virology , COVID-19/virology , Case-Control Studies , Gold/chemistry , Immunoassay/instrumentation , Immunoassay/methods , Metal Nanoparticles/chemistry , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism , Sensitivity and Specificity
9.
Nature ; 584(7821): 457-462, 2020 08.
Article in English | MEDLINE | ID: covidwho-1373437

ABSTRACT

Memory T cells induced by previous pathogens can shape susceptibility to, and the clinical severity of, subsequent infections1. Little is known about the presence in humans of pre-existing memory T cells that have the potential to recognize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here we studied T cell responses against the structural (nucleocapsid (N) protein) and non-structural (NSP7 and NSP13 of ORF1) regions of SARS-CoV-2 in individuals convalescing from coronavirus disease 2019 (COVID-19) (n = 36). In all of these individuals, we found CD4 and CD8 T cells that recognized multiple regions of the N protein. Next, we showed that patients (n = 23) who recovered from SARS (the disease associated with SARS-CoV infection) possess long-lasting memory T cells that are reactive to the N protein of SARS-CoV 17 years after the outbreak of SARS in 2003; these T cells displayed robust cross-reactivity to the N protein of SARS-CoV-2. We also detected SARS-CoV-2-specific T cells in individuals with no history of SARS, COVID-19 or contact with individuals who had SARS and/or COVID-19 (n = 37). SARS-CoV-2-specific T cells in uninfected donors exhibited a different pattern of immunodominance, and frequently targeted NSP7 and NSP13 as well as the N protein. Epitope characterization of NSP7-specific T cells showed the recognition of protein fragments that are conserved among animal betacoronaviruses but have low homology to 'common cold' human-associated coronaviruses. Thus, infection with betacoronaviruses induces multi-specific and long-lasting T cell immunity against the structural N protein. Understanding how pre-existing N- and ORF1-specific T cells that are present in the general population affect the susceptibility to and pathogenesis of SARS-CoV-2 infection is important for the management of the current COVID-19 pandemic.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/immunology , Pneumonia, Viral/immunology , Severe Acute Respiratory Syndrome/immunology , T-Lymphocytes/immunology , Betacoronavirus/chemistry , COVID-19 , Case-Control Studies , Coronavirus Infections/virology , Coronavirus Nucleocapsid Proteins , Cross Reactions/immunology , Humans , Immunodominant Epitopes/immunology , Nucleocapsid Proteins/chemistry , Nucleocapsid Proteins/immunology , Pandemics , Phosphoproteins , Pneumonia, Viral/virology , SARS-CoV-2
11.
Blood ; 136(Supplement 1):37-38, 2020.
Article in English | PMC | ID: covidwho-1338985

ABSTRACT

ObjectiveArterial and venous thrombosis are reported to be common in critically ill COVID-19 patients.This study aims to describe the thrombotic and bleeding rates in COVID-19 patients admitted to intensive care units (ICU) in Singapore.DesignRetrospective observational study involving all consecutive adult COVID-19 patients who required ICU admission between 23 January 2020 and 30 April 2020.SettingNational multicenter study involving all eight public hospitals in Singapore.Patients111 consecutive COVID-19 patients who required ICU admission were included.Measurements and Main ResultsPrimary outcome was any venous or arterial thrombotic events occurred in ICU. Other measures included (1) the overall, venous and arterial thrombotic events throughout the hospitalisation, (2) major and minor bleeding events. The overall thrombotic rate in ICU was 11.7% (n=13), with 1.8% (n=2) venous and 9.9% (n=11) arterial events. The overall thrombotic rates throughout hospitalisation, censored at 30 April 2020, increased to 18.0% (n=20) with 6.3% (n=7) venous and 11.7% (n=13) arterial events. Major and minor bleeding rates were 14.8% (n=16) and 3.7% (n=4), respectively. Two-third of the patients received pharmacological thromboprophylaxis in ICU.ConclusionsCritically ill COVID-19 patients in Singapore have lower VTE but higher arterial thrombosis rates with higher bleeding manifestations than other reported cohorts. Standard thromboprophylaxis may be sufficient to prevent thrombotic complications in patients with similar demographics.

12.
Blood ; 136(Supplement 1):25-26, 2020.
Article in English | PMC | ID: covidwho-1338960

ABSTRACT

IntroductionAn increasing number of evidence have reported the association of COVID-19 with increased incidence of thrombotic events. High incidences were initially reported in critically ill COVID-19 patients, but subsequently an increased incidence was also noticed in non-critically ill general ward patients. This has led to a universal recommendation of thromboprophylaxis for all COVID-19 patients by ASH and ISTH. As the data on COVID-19 and thrombosis continue to develop and evolve, we examined the data in two aspects. Firstly, other non-SARS-CoV-2 viral respiratory infections have also been reported to be associated with thrombotic events, be it arterial or venous. Thus, we aimed to compare the thrombotic rates between these two groups of patients directly to hopefully ascertain the actual thrombotic tendency in COVID-19 infections. Secondly, global hemostatic assays such as thromboelastogram and clot waveform analysis (CWA) have been used to demonstrate hypercoagulability in COVID-19 patients, albeit in a small group of patients and only in the critically ill. Incorporating these laboratory results into the management of thromboprophylaxis in COVID-19 is an attractive notion but more data and studies are definitely needed. Here, we evaluate the dynamic changes of hemostatic assays in patients with COVID-19 to better understand the overall coagulation profiles of COVID-19 infection.MethodsWe performed a single center, retrospective cohort study. All consecutive patients admitted to our hospital between 15 January and 10 April 2020 that were tested positive for COVID-19 or other non-SARS-CoV-2 respiratory viruses were included in our study. The main coagulation assays studied were prothrombin time and activated partial thromboplastin time and its associated CWA, min1, min2 and max2.FindingsWe included a total of 181 COVID-19 patients and 165 patients with non-SARS-CoV-2 respiratory viral infections. The respiratory viruses were rhinovirus (n=65), influenza A and B (n=46), adenovirus (n=13), human coronavirus 229E/NL63/OC43 (n=15), human enterovirus (n=3), metapneumovirus (n=6), parainfluenza virus 1 to 4 (n=11), respiratory syncytial virus (n=6) and human bocavirus 1 to 4 (n=0). The median age of COVID-19 patients was 37 (interquartile range [IQR], 30.5-51 years) versus 35 (IQR, 29-51.5) in the non-SAR-CoV-2 respiratory viruses group (P=0.12). Comorbidities, assessed by Charlson score, was also not statistically different between both groups (median score 0 (IQR, 0-1) in both groups, P=0.39). Majority of our patients had relatively mild infection as reflected by the low proportions of them requiring oxygen supplementation (11.0% in COVID-19 vs 4.8% in non-SARS-COV-2, P=0.035). COVID-19 patients had longer hospital stay (7 days (IQR, 5.5-13) vs 3 days (IQR, 2-3), P<0.001) and more required ICU support (5.0% vs 1.2%, P=0.04). Mortality rate was low in both groups. We reported two (1.0 event/1000-hospital-days) and one (1.8 event/1000-hospital-day) thrombotic events amongst COVID-19 group and non-SARS-COV-2 group respectively (P=0.63). All were myocardial infarction and occurred in intensive care unit. No venous thrombotic event was noted. There was no significant difference in all the coagulation parameters throughout the course of mild COVID-19 infection (Table 1). However, CWA parameters were significantly higher in severe COVID-19 infection compared with mild disease (min1: 6.48%/s vs 5.05%/s, P<0.001;min2: 0.92%/s2 vs 0.74%/s2, P=0.033), suggesting hypercoagulability in severe COVID-19 infection (Table 2 and Figure 1). We also observed that critically ill COVID-19 patients had higher absolute CWA parameters as compared to non-SARS-CoV-2 patients, albeit in small number of patients (Table 3).ConclusionThe thrombotic rates were low in both groups and did not differ significantly between COVID-19 and Non-SARS-CoV-2 patients. Nonetheless, our analysis of hemostatic parameters demonstrated hypercoagulability in COVID-19 as a dynamic process with the risk highest when the patients are critically ill. These c anges in hemostasis could be detected by CWA. With our findings, we suggest that a more individualized thromboprophylaxis approach, considering clinical and laboratory factors, is probably preferred over universal pharmacological thromboprophylaxis for all hospitalized COVID-19 patients and warrants further research.

13.
Eur J Clin Microbiol Infect Dis ; 40(12): 2489-2496, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1293388

ABSTRACT

Easy access to screening for timely identification and isolation of infectious COVID-19 patients remains crucial in sustaining the international efforts to control COVID-19 spread. A major barrier limiting broad-based screening is the lack of a simple, rapid, and cost-effective COVID-19 testing method. We evaluated the feasibility and utility of facemask sampling in a cohort of 42 COVID-19-positive and 36 COVID-19-negative patients. We used a prototype of Steri-Strips™ (3 M) applied to the inner surface of looped surgical facemasks (Assure), which was worn by patients for a minimum wear time of 3 h, then removed and sent for SARS-CoV-2 PCR testing. Baseline demographics and symptomatology were also collected. Facemask sampling positivity was highest within the first 5 days of symptomatic presentation. Patients with nasopharyngeal and/or oropharyngeal swab SARS-CoV-2 PCR Ct values < 25.09 had SARS-CoV-2 detected on facemask sampling, while patients with Ct values ≥ 25.2 had no SARS-CoV-2 detected on facemask sampling. Facemask sampling can identify patients with COVID-19 during the early symptomatic phase or those with high viral loads, hence allowing timely identification and isolation of those with the highest transmission risk. Given the widespread use of facemasks, this method can potentially be easily applied to achieve broad-based, or even continuous, population screening.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/virology , Masks/virology , SARS-CoV-2/isolation & purification , Adult , Aged , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19 Nucleic Acid Testing/instrumentation , Cohort Studies , Feasibility Studies , Female , Humans , Male , Middle Aged , Nasopharynx/virology , Oropharynx/virology , Pandemics , SARS-CoV-2/classification , SARS-CoV-2/genetics , Young Adult
16.
Thromb J ; 19(1): 14, 2021 Mar 08.
Article in English | MEDLINE | ID: covidwho-1123658

ABSTRACT

BACKGROUND: Arterial and venous thrombosis are reported to be common in critically ill COVID-19 patients. METHOD AND RESULTS: This is a national multicenter retrospective observational study involving all consecutive adult COVID-19 patients who required intensive care units (ICU) admission between 23 January 2020 and 30 April 2020 in Singapore. One hundred eleven patients were included and the venous and arterial thrombotic rates in ICU were 1.8% (n = 2) and 9.9% (n = 11), respectively. Major bleeding rate was 14.8% (n = 16). CONCLUSIONS: Critically ill COVID-19 patients in Singapore have lower venous thromboembolism but higher arterial thrombosis rates and bleeding manifestations than other reported cohorts.

17.
Nutrition ; 79-80: 111017, 2020.
Article in English | MEDLINE | ID: covidwho-1087212

ABSTRACT

OBJECTIVES: The aim of this study was to determine clinical outcomes of older patients with coronavirus (COVID-19) who received a combination of vitamin D, magnesium, and vitamin B12 (DMB) compared with those who did not. We hypothesized that fewer patients administered this combination would require oxygen therapy, intensive care support, or a combination of both than those who did not. METHODS: This was a cohort observational study of all consecutive hospitalized patients ≥50 y of age with COVID-19 in a tertiary academic hospital. Before April 6, 2020, no patients received the (DMB) combination. After this date, patients were administered 1000 IU/d oral vitamin D3, 150 mg/d oral magnesium, and 500 mcg/d oral vitamin B12 upon admission if they did not require oxygen therapy. Primary outcome was deterioration leading to any form of oxygen therapy, intensive care support, or both. RESULTS: Between January 15 and April 15, 2020, we identified 43 consecutive patients ≥50 y of age with COVID-19. Seventeen patients received DMB before onset of primary outcome and 26 patients did not. Baseline demographic characteristics between the two groups were significantly different by age. In univariate analysis, age and hypertension had a significant influence on outcome. After adjusting for age or hypertension separately in a multivariate analysis, the intervention group retained protective significance. Fewer treated patients than controls required initiation of oxygen therapy during hospitalization (17.6 vs 61.5%, P = 0.006). DMB exposure was associated with odds ratios of 0.13 (95% confidence interval [CI], 0.03-0.59) and 0.20 (95% CI, 0.04-0.93) for oxygen therapy, intensive care support, or both on univariate and multivariate analyses, respectively. CONCLUSIONS: A vitamin D / magnesium / vitamin B12 combination in older COVID-19 patients was associated with a significant reduction in the proportion of patients with clinical deterioration requiring oxygen support, intensive care support, or both. This study supports further larger randomized controlled trials to ascertain the full benefit of this combination in ameliorating the severity of COVID-19.


Subject(s)
COVID-19/drug therapy , Critical Care , Magnesium/therapeutic use , Micronutrients/therapeutic use , Oxygen Inhalation Therapy , Vitamin B 12/therapeutic use , Vitamin D/therapeutic use , Aged , COVID-19/therapy , Cohort Studies , Disease Progression , Female , Hospitalization , Humans , Male , Middle Aged , Minerals/therapeutic use , Multivariate Analysis , Pandemics , SARS-CoV-2 , Severity of Illness Index , Vitamins/therapeutic use
18.
Sci Rep ; 11(1): 1793, 2021 01 19.
Article in English | MEDLINE | ID: covidwho-1065942

ABSTRACT

COVID-19 caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) and other respiratory viral (non-CoV-2-RV) infections are associated with thrombotic complications. The differences in prothrombotic potential between SARS-CoV-2 and non-CoV-2-RV have not been well characterised. We compared the thrombotic rates between these two groups of patients directly and further delved into their coagulation profiles. In this single-center, retrospective cohort study, all consecutive COVID-19 and non-CoV-2-RV patients admitted between January 15th and April 10th 2020 were included. Coagulation parameters studied were prothrombin time and activated partial thromboplastin time and its associated clot waveform analysis (CWA) parameter, min1, min2 and max2. In the COVID-19 (n = 181) group there were two (1.0 event/1000-hospital-days) myocardial infarction events while one (1.8 event/1000-hospital-day) was reported in the non-CoV-2-RV (n = 165) group. These events occurred in patients who were severely ill. There were no venous thrombotic events. Coagulation parameters did not differ throughout the course of mild COVID-19. However, CWA parameters were significantly higher in severe COVID-19 compared with mild disease, suggesting hypercoagulability (min1: 6.48%/s vs 5.05%/s, P < 0.001; min2: 0.92%/s2 vs 0.74%/s2, P = 0.033). In conclusion, the thrombotic rates were low and did not differ between COVID-19 and non-CoV-2-RV patients. The hypercoagulability in COVID-19 is a highly dynamic process with the highest risk occurring when patients were most severely ill. Such changes in haemostasis could be detected by CWA. In our population, a more individualized thromboprophylaxis approach, considering clinical and laboratory factors, is preferred over universal pharmacological thromboprophylaxis for all hospitalized COVID-19 patients and such personalized approach warrants further research.


Subject(s)
COVID-19/pathology , Thrombophilia/diagnosis , Virus Diseases/pathology , Adult , COVID-19/complications , COVID-19/virology , Female , Humans , Male , Myocardial Infarction/complications , Myocardial Infarction/diagnosis , Partial Thromboplastin Time , Prothrombin Time , Retrospective Studies , Risk Factors , SARS-CoV-2/isolation & purification , Severity of Illness Index , Thrombophilia/complications , Virus Diseases/complications
19.
EBioMedicine ; 58: 102911, 2020 Aug.
Article in English | MEDLINE | ID: covidwho-662643

ABSTRACT

BACKGROUND: Given the unceasing worldwide surge in COVID-19 cases, there is an imperative need to develop highly specific and sensitive serology assays to define exposure to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). METHODS: Pooled plasma samples from PCR positive COVID-19 patients were used to identify linear B-cell epitopes from a SARS-CoV-2 peptide library of spike (S), envelope (E), membrane (M), and nucleocapsid (N) structural proteins by peptide-based ELISA. Hit epitopes were further validated with 79 COVID-19 patients with different disease severity status, 13 seasonal human CoV, 20 recovered SARS patients and 22 healthy donors. FINDINGS: Four immunodominant epitopes, S14P5, S20P2, S21P2 and N4P5, were identified on the S and N viral proteins. IgG responses to all identified epitopes displayed a strong detection profile, with N4P5 achieving the highest level of specificity (100%) and sensitivity (>96%) against SARS-CoV-2. Furthermore, the magnitude of IgG responses to S14P5, S21P2 and N4P5 were strongly associated with disease severity. INTERPRETATION: IgG responses to the peptide epitopes can serve as useful indicators for the degree of immunopathology in COVID-19 patients, and function as higly specific and sensitive sero-immunosurveillance tools for recent or past SARS-CoV-2 infections. The flexibility of these epitopes to be used alone or in combination will allow for the development of improved point-of-care-tests (POCTs). FUNDING: Biomedical Research Council (BMRC), the A*ccelerate GAP-funded project (ACCL/19-GAP064-R20H-H) from Agency of Science, Technology and Research (A*STAR), and National Medical Research Council (NMRC) COVID-19 Research fund (COVID19RF-001) and CCGSFPOR20002. ATR is supported by the Singapore International Graduate Award (SINGA), A*STAR.


Subject(s)
B-Lymphocytes/immunology , Coronavirus Infections/diagnosis , Epitopes/immunology , Nucleocapsid Proteins/immunology , Pneumonia, Viral/diagnosis , Spike Glycoprotein, Coronavirus/immunology , Adult , Biomarkers/blood , COVID-19 , Coronavirus Infections/blood , Coronavirus Infections/immunology , Epitopes/blood , Female , Humans , Male , Middle Aged , Pandemics , Pneumonia, Viral/blood , Pneumonia, Viral/immunology , Serologic Tests/methods
20.
Adv Cell Gene Ther ; : e101, 2020 Jul 31.
Article in English | MEDLINE | ID: covidwho-640073

ABSTRACT

OBJECTIVES: To determine whether the frequencies of SARS-CoV-2-specific T cells are sufficiently high in the blood of convalescent donors and whether it is technically feasible to manufacture clinical-grade products overnight for T-cell therapy and assessment of COVID-19 immunity. METHODS: One unit of whole blood or leukapheresis was collected from each donor following standard blood bank practices. The leukocytes were stimulated using overlapping peptides of SARS-CoV-2, covering the immunodominant sequence domains of the S protein and the complete sequence of the N and M proteins. Thereafter, functionally reactive cells were enriched overnight using an automated device capturing IFNγ-secreting cells. RESULTS: From 1 × 109 leukocytes, a median of 0.98 × 106 (range 0.56-2.95) IFNγ + T cells were produced from each of the six donors, suggesting a high frequency of SARS-CoV-2 reactive T cells in their blood, even though only one donor had severe COVID-19 requiring mechanical ventilation whereas the other five donors had minor symptoms. A median of 57% of the enriched T cells were IFNγ+ (range 20%-74%), with preferential enrichment of CD56+ T cells and effector memory T cells. TCRVß-spectratyping confirmed distinctively tall oligoclonal peaks in final products. With just six donors, the probability that a recipient would share at least one HLA allele with one of the donors is >88% among Caucasian, >95% among Chinese, >97% among Malay, and >99% among Indian populations. CONCLUSIONS: High frequencies of rapid antigen-reactive T cells were found in convalescent donors, regardless of severity of COVID-19. The feasibility of clinical-grade production of SARS-CoV-2-specific T cells overnight for therapeutics and diagnostics is revealed.

SELECTION OF CITATIONS
SEARCH DETAIL