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1.
J Clin Microbiol ; 59(9): e0098921, 2021 08 18.
Article in English | MEDLINE | ID: covidwho-1501532

ABSTRACT

With the availability of widespread SARS-CoV-2 vaccination, high-throughput quantitative anti-spike protein serological testing will likely become increasingly important. Here, we investigated the performance characteristics of the recently FDA-authorized semiquantitative anti-spike protein AdviseDx SARS-CoV-2 IgG II assay compared to the FDA-authorized anti-nucleocapsid protein Abbott Architect SARS-CoV-2 IgG, Roche Elecsys anti-SARS-CoV-2-S, EuroImmun anti-SARS-CoV-2 enzyme-linked immunosorbent assay (ELISA), and GenScript surrogate virus neutralization assays and examined the humoral response associated with vaccination, natural protection, and vaccine breakthrough infection. The AdviseDx assay had a clinical sensitivity at 14 days after symptom onset or 10 days after PCR detection of 95.6% (65/68; 95% confidence interval [CI], 87.8 to 98.8%), with two discrepant individuals seroconverting shortly thereafter. The AdviseDx assay demonstrated 100% positive percent agreement with the four other assays examined using the same symptom onset or PCR detection cutoffs. Using a recently available WHO international standard for anti-SARS-CoV-2 antibody, we provide assay unit conversion factors to international units for each of the assays examined. We performed a longitudinal survey of healthy vaccinated individuals, finding that median AdviseDx immunoglobulin levels peaked 7 weeks after first vaccine dose at approximately 4,000 IU/ml. Intriguingly, among the five assays examined, there was no significant difference in antigen binding level or neutralizing activity between two seropositive patients protected against SARS-CoV-2 infection in a previously described fishing vessel outbreak and five health care workers who experienced vaccine breakthrough of SARS-CoV-2 infection, all with variants of concern. These findings suggest that protection against SARS-CoV-2 infection cannot currently be predicted exclusively using in vitro antibody assays against wild-type SARS-CoV-2 spike. Further work is required to establish protective correlates for SARS-CoV-2 infection.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Viral , COVID-19 Vaccines , Humans , Sensitivity and Specificity
2.
PLoS One ; 16(9): e0257560, 2021.
Article in English | MEDLINE | ID: covidwho-1430541

ABSTRACT

Certain clinical indications and treatments such as the use of rasburicase in cancer therapy and 8-aminoquinolines for Plasmodium vivax malaria treatment would benefit from a point-of-care test for glucose-6-phosphate dehydrogenase (G6PD) deficiency. Three studies were conducted to evaluate the performance of one such test: the STANDARD™ G6PD Test (SD BIOSENSOR, South Korea). First, biological interference on the test performance was evaluated in specimens with common blood disorders, including high white blood cell (WBC) counts. Second, the test precision on fingerstick specimens was evaluated against five individuals of each, deficient, intermediate, and normal G6PD activity status. Third, clinical performance of the test was evaluated at three point-of-care settings in the United States. The test performed equivalently to the reference assay in specimens with common blood disorders. High WBC count blood samples resulted in overestimation of G6PD activity in both the reference assay and the STANDARD G6PD Test. The STANDARD G6PD Test showed good precision on multiple fingerstick specimens from the same individual. The same G6PD threshold values (U/g Hb) were applied for a semiquantitative interpretation for fingerstick- and venous-derived results. The sensitivity/specificity values (95% confidence intervals) for the test for G6PD deficiency were 100 (92.3-100.0)/97 (95.2-98.2) and 100 (95.7-100.0)/97.4 (95.7-98.5) for venous and capillary specimens, respectively. The same values for females with intermediate (> 30% to ≤ 70%) G6PD activity were 94.1 (71.3-99.9)/88.2 (83.9-91.7) and 82.4 (56.6-96.2)/87.6(83.3-91.2) for venous and capillary specimens, respectively. The STANDARD G6PD Test enables point-of-care testing for G6PD deficiency.


Subject(s)
Glucosephosphate Dehydrogenase Deficiency/diagnosis , Glucosephosphate Dehydrogenase/blood , Point-of-Care Systems/standards , Adolescent , Adult , Aged , Blood Specimen Collection , Child , Child, Preschool , Female , Glucosephosphate Dehydrogenase/genetics , Glucosephosphate Dehydrogenase/standards , Glucosephosphate Dehydrogenase Deficiency/complications , Hematologic Diseases/complications , Hemoglobins/analysis , Humans , Leukocyte Count , Male , Middle Aged , Reagent Kits, Diagnostic , Reference Standards , Sensitivity and Specificity , Young Adult
3.
J Clin Microbiol ; 59(9): e0098921, 2021 08 18.
Article in English | MEDLINE | ID: covidwho-1365134

ABSTRACT

With the availability of widespread SARS-CoV-2 vaccination, high-throughput quantitative anti-spike protein serological testing will likely become increasingly important. Here, we investigated the performance characteristics of the recently FDA-authorized semiquantitative anti-spike protein AdviseDx SARS-CoV-2 IgG II assay compared to the FDA-authorized anti-nucleocapsid protein Abbott Architect SARS-CoV-2 IgG, Roche Elecsys anti-SARS-CoV-2-S, EuroImmun anti-SARS-CoV-2 enzyme-linked immunosorbent assay (ELISA), and GenScript surrogate virus neutralization assays and examined the humoral response associated with vaccination, natural protection, and vaccine breakthrough infection. The AdviseDx assay had a clinical sensitivity at 14 days after symptom onset or 10 days after PCR detection of 95.6% (65/68; 95% confidence interval [CI], 87.8 to 98.8%), with two discrepant individuals seroconverting shortly thereafter. The AdviseDx assay demonstrated 100% positive percent agreement with the four other assays examined using the same symptom onset or PCR detection cutoffs. Using a recently available WHO international standard for anti-SARS-CoV-2 antibody, we provide assay unit conversion factors to international units for each of the assays examined. We performed a longitudinal survey of healthy vaccinated individuals, finding that median AdviseDx immunoglobulin levels peaked 7 weeks after first vaccine dose at approximately 4,000 IU/ml. Intriguingly, among the five assays examined, there was no significant difference in antigen binding level or neutralizing activity between two seropositive patients protected against SARS-CoV-2 infection in a previously described fishing vessel outbreak and five health care workers who experienced vaccine breakthrough of SARS-CoV-2 infection, all with variants of concern. These findings suggest that protection against SARS-CoV-2 infection cannot currently be predicted exclusively using in vitro antibody assays against wild-type SARS-CoV-2 spike. Further work is required to establish protective correlates for SARS-CoV-2 infection.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Viral , COVID-19 Vaccines , Humans , Sensitivity and Specificity
5.
J Clin Invest ; 131(3)2021 02 01.
Article in English | MEDLINE | ID: covidwho-1124908

ABSTRACT

BACKGROUNDSARS-CoV-2-specific antibodies may protect from reinfection and disease, providing rationale for administration of plasma containing SARS-CoV-2-neutralizing antibodies (nAbs) as a treatment for COVID-19. Clinical factors and laboratory assays to streamline plasma donor selection, and the durability of nAb responses, are incompletely understood.METHODSPotential convalescent plasma donors with virologically documented SARS-CoV-2 infection were tested for serum IgG against SARS-CoV-2 spike protein S1 domain and against nucleoprotein (NP), and for nAb.RESULTSAmong 250 consecutive persons, including 27 (11%) requiring hospitalization, who were studied a median of 67 days since symptom onset, 97% were seropositive on 1 or more assays. Sixty percent of donors had nAb titers ≥1:80. Correlates of higher nAb titers included older age (adjusted OR [AOR] 1.03 per year of age, 95% CI 1.00-1.06), male sex (AOR 2.08, 95% CI 1.13-3.82), fever during illness (AOR 2.73, 95% CI 1.25-5.97), and disease severity represented by hospitalization (AOR 6.59, 95% CI 1.32-32.96). Receiver operating characteristic analyses of anti-S1 and anti-NP antibody results yielded cutoffs that corresponded well with nAb titers, with the anti-S1 assay being slightly more predictive. nAb titers declined in 37 of 41 paired specimens collected a median of 98 days (range 77-120) apart (P < 0.001). Seven individuals (2.8%) were persistently seronegative and lacked T cell responses.CONCLUSIONnAb titers correlated with COVID-19 severity, age, and sex. SARS-CoV-2 IgG results can serve as useful surrogates for nAb testing. Functional nAb levels declined, and a small proportion of convalescent individuals lacked adaptive immune responses.FUNDINGThe project was supported by the Frederick National Laboratory for Cancer Research with support from the NIAID under contract number 75N91019D00024, and was supported by the Fred Hutchinson Joel Meyers Endowment, Fast-Grants, a New Investigator award from the American Society for Transplantation and Cellular Therapy, and NIH contracts 75N93019C0063, 75N91019D00024, and HHSN272201800013C, and NIH grants T32-AI118690, T32-AI007044, K08-AI119142, and K23-AI140918.


Subject(s)
Antibodies, Neutralizing , Antibodies, Viral , Blood Donors , COVID-19/therapy , Immunoglobulin G , SARS-CoV-2 , Adult , Aged , Aged, 80 and over , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/blood , COVID-19/immunology , Female , Humans , Immunization, Passive , Immunoglobulin G/blood , Immunoglobulin G/immunology , Male , Middle Aged , SARS-CoV-2/immunology , SARS-CoV-2/metabolism
6.
Clin Infect Dis ; 72(5): 869-872, 2021 03 01.
Article in English | MEDLINE | ID: covidwho-1114831

ABSTRACT

We found low prevalence of SARS-CoV-2 (2.7% [5/188]) among pregnant and postpartum patients with universal testing. Prevalence among symptomatic patients was similar under initial targeted screening (22.2% [4/18]) and universal approaches (19.1% [8/42]). Among 170 asymptomatic patients, 2 were positive or inconclusive, respectively; repeat testing at 24 hours was negative.


Subject(s)
COVID-19 , Pregnancy Complications, Infectious , COVID-19 Testing , Female , Humans , Postpartum Period , Pregnancy , Pregnancy Complications, Infectious/diagnosis , Pregnancy Complications, Infectious/epidemiology , Prevalence , SARS-CoV-2 , Washington/epidemiology
7.
J Clin Invest ; 131(3)2021 02 01.
Article in English | MEDLINE | ID: covidwho-1066998

ABSTRACT

BACKGROUNDSARS-CoV-2-specific antibodies may protect from reinfection and disease, providing rationale for administration of plasma containing SARS-CoV-2-neutralizing antibodies (nAbs) as a treatment for COVID-19. Clinical factors and laboratory assays to streamline plasma donor selection, and the durability of nAb responses, are incompletely understood.METHODSPotential convalescent plasma donors with virologically documented SARS-CoV-2 infection were tested for serum IgG against SARS-CoV-2 spike protein S1 domain and against nucleoprotein (NP), and for nAb.RESULTSAmong 250 consecutive persons, including 27 (11%) requiring hospitalization, who were studied a median of 67 days since symptom onset, 97% were seropositive on 1 or more assays. Sixty percent of donors had nAb titers ≥1:80. Correlates of higher nAb titers included older age (adjusted OR [AOR] 1.03 per year of age, 95% CI 1.00-1.06), male sex (AOR 2.08, 95% CI 1.13-3.82), fever during illness (AOR 2.73, 95% CI 1.25-5.97), and disease severity represented by hospitalization (AOR 6.59, 95% CI 1.32-32.96). Receiver operating characteristic analyses of anti-S1 and anti-NP antibody results yielded cutoffs that corresponded well with nAb titers, with the anti-S1 assay being slightly more predictive. nAb titers declined in 37 of 41 paired specimens collected a median of 98 days (range 77-120) apart (P < 0.001). Seven individuals (2.8%) were persistently seronegative and lacked T cell responses.CONCLUSIONnAb titers correlated with COVID-19 severity, age, and sex. SARS-CoV-2 IgG results can serve as useful surrogates for nAb testing. Functional nAb levels declined, and a small proportion of convalescent individuals lacked adaptive immune responses.FUNDINGThe project was supported by the Frederick National Laboratory for Cancer Research with support from the NIAID under contract number 75N91019D00024, and was supported by the Fred Hutchinson Joel Meyers Endowment, Fast-Grants, a New Investigator award from the American Society for Transplantation and Cellular Therapy, and NIH contracts 75N93019C0063, 75N91019D00024, and HHSN272201800013C, and NIH grants T32-AI118690, T32-AI007044, K08-AI119142, and K23-AI140918.


Subject(s)
Antibodies, Neutralizing , Antibodies, Viral , Blood Donors , COVID-19/therapy , Immunoglobulin G , SARS-CoV-2 , Adult , Aged , Aged, 80 and over , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/blood , COVID-19/immunology , Female , Humans , Immunization, Passive , Immunoglobulin G/blood , Immunoglobulin G/immunology , Male , Middle Aged , SARS-CoV-2/immunology , SARS-CoV-2/metabolism
8.
Clin Infect Dis ; 71(10): 2702-2707, 2020 12 17.
Article in English | MEDLINE | ID: covidwho-1059704

ABSTRACT

BACKGROUND: Healthcare workers (HCWs) who serve on the front lines of the coronavirus disease 2019 (COVID-19) pandemic have been at increased risk for infection due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in some settings. Healthcare-acquired infection has been reported in similar epidemics, but there are limited data on the prevalence of COVID-19 among HCWs and their associated clinical outcomes in the United States. METHODS: We established 2 high-throughput employee testing centers in Seattle, Washington, with drive-through and walk-through options for symptomatic employees in the University of Washington Medicine system and its affiliated organizations. Using data from these testing centers, we report the prevalence of SARS-CoV-2 infection among symptomatic employees and describe the clinical characteristics and outcomes among employees with COVID-19. RESULTS: Between 12 March 2020 and 23 April 2020, 3477 symptomatic employees were tested for COVID-19 at 2 employee testing centers; 185 (5.3%) employees tested positive for COVID-19. The prevalence of SARS-CoV-2 was similar when comparing frontline HCWs (5.2%) with nonfrontline staff (5.5%). Among 174 positive employees reached for follow-up at least 14 days after diagnosis, 6 reported COVID-related hospitalization; all recovered. CONCLUSIONS: During the study period, we observed that the prevalence of positive SARS-CoV-2 tests among symptomatic HCWs was comparable to that of symptomatic nonfrontline staff. Reliable and rapid access to testing for employees is essential to preserve the health, safety, and availability of the healthcare workforce during this pandemic and to facilitate the rapid return of SARS-CoV-2-negative employees to work.


Subject(s)
COVID-19 , COVID-19 Testing , Health Personnel , Humans , Prevalence , SARS-CoV-2 , Washington/epidemiology
9.
J Clin Microbiol ; 58(8)2020 07 23.
Article in English | MEDLINE | ID: covidwho-999205

ABSTRACT

Coronavirus disease 2019 (COVID-19), the novel respiratory illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is associated with severe morbidity and mortality. The rollout of diagnostic testing in the United States was slow, leading to numerous cases that were not tested for SARS-CoV-2 in February and March 2020 and necessitating the use of serological testing to determine past infections. Here, we evaluated the Abbott SARS-CoV-2 IgG test for detection of anti-SARS-CoV-2 IgG antibodies by testing 3 distinct patient populations. We tested 1,020 serum specimens collected prior to SARS-CoV-2 circulation in the United States and found one false positive, indicating a specificity of 99.90%. We tested 125 patients who tested reverse transcription-PCR (RT-PCR) positive for SARS-CoV-2 for whom 689 excess serum specimens were available and found that sensitivity reached 100% at day 17 after symptom onset and day 13 after PCR positivity. Alternative index value thresholds for positivity resulted in 100% sensitivity and 100% specificity in this cohort. We tested specimens from 4,856 individuals from Boise, ID, collected over 1 week in April 2020 as part of the Crush the Curve initiative and detected 87 positives for a positivity rate of 1.79%. These data demonstrate excellent analytical performance of the Abbott SARS-CoV-2 IgG test as well as the limited circulation of the virus in the western United States. We expect that the availability of high-quality serological testing will be a key tool in the fight against SARS-CoV-2.


Subject(s)
Antibodies, Viral/blood , Betacoronavirus/immunology , Clinical Laboratory Techniques/methods , Coronavirus Infections/epidemiology , Coronavirus Infections/immunology , Immunoglobulin G/blood , Pneumonia, Viral/epidemiology , Pneumonia, Viral/immunology , Adult , Aged , Aged, 80 and over , COVID-19 , COVID-19 Testing , Coronavirus Infections/diagnosis , Female , Humans , Idaho/epidemiology , Male , Middle Aged , Pandemics , SARS-CoV-2 , Sensitivity and Specificity , Seroepidemiologic Studies , Young Adult
11.
J Transl Autoimmun ; 3: 100073, 2020.
Article in English | MEDLINE | ID: covidwho-947300

ABSTRACT

Immunopathology may play a significant role in the pathogenesis of Coronavirus-Induced Disease-19 (COVID-19). Immune-mediated tissue damage could result from development of rapid autoimmune responses, characterized by production of self-reactive autoantibodies. In this study, we tested specimens from acutely ill patients hospitalized with COVID-19 for autoantibodies against nuclear, vasculitis-associated, and phospholipid antigens. Detectable autoantibodies were present in 30% of the patients in our cohort, with the majority of reactive specimens demonstrating antibodies to nuclear antigens. However, antinuclear antibodies were only weakly reactive and directed to single antigens, as is often seen during acute infection. We identified strongly reactive antibodies to nuclear antigens only in patients with a prior history of autoimmune disease. In our cohort, the prevalence of antiphospholipid antibodies was low, and we did not detect any vasculitis-associated autoantibodies. We found similar levels of inflammatory markers and total immunoglobulin levels in autoantibody positive versus negative patients, but anti-SARS-CoV-2 antibody levels were increased in autoantibody positive patients. Together, our results suggest that acute COVID-19 is not associated with a high prevalence of clinically significant autoantibody responses of the type usually associated with autoimmune rheumatic disease.

12.
Open Forum Infect Dis ; 7(12): ofaa535, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-900465

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load on admission was associated with a significantly increased 30-day mortality (odds ratio [OR], 4.20; 95% CI, 1.62-10.86), and anti-SARS-CoV-2 nucleocapisid IgG seropositivity on admission trended toward a reduced 30-day mortality (OR, 0.43; 95% CI, 0.15-1.26). Reporting of quantitative SARS-CoV-2 viral load and serologic assays may offer prognostic clinical information.

13.
Diagn Microbiol Infect Dis ; 98(3): 115161, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-776481

ABSTRACT

In a Clinical Laboratory Improvement Amendments laboratory setting, we evaluated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG detection with 4 lateral flow immunoassays [LFIAs; 2 iterations from BTNX Inc. (n = 457) and 1 each from ACON Laboratories (n = 200) and SD BIOSENSOR (n = 155)]. In a cohort of primarily hospitalized, reverse-transcription polymerase chain reaction-confirmed coronavirus disease 2019 cases, sensitivity at ≥14 days from symptom onset was: BTNX kit 1, 95%; BTNX kit 2, 91%; ACON, 95%; and SD, 92%. All assays showed good concordance with the Abbott SARS-CoV-2 IgG assay at ≥14 days from symptom onset: BTNX kit 1, 99%; BTNX kit 2, 94%; ACON, 99%; and SD, 100%. Specificity, measured using specimens collected prior to SARS-CoV-2 circulation in the United States and "cross-reactivity challenge" specimens, was 98% for BTNX kit 1 and ACON and 100% for BTNX kit 2 and SD. These results suggest that LFIAs may provide adequate results for rapid detection of SARS-CoV-2.


Subject(s)
Antibodies, Viral/blood , Betacoronavirus/immunology , Coronavirus Infections/diagnosis , Immunoassay/methods , Immunoglobulin G/blood , Pneumonia, Viral/diagnosis , COVID-19 , Humans , Pandemics , Retrospective Studies , Reverse Transcriptase Polymerase Chain Reaction/methods , SARS-CoV-2 , Sensitivity and Specificity
14.
Emerg Infect Dis ; 26(10): 2501-2503, 2020 10.
Article in English | MEDLINE | ID: covidwho-690401

ABSTRACT

Many serologic tests are now available for measuring severe acute respiratory syndrome coronavirus 2 antibodies to evaluate potential protective immunity and for seroprevalence studies. We describe an approach to standardizing positivity thresholds and quantitative values for different assays that uses z-scores to enable rapid and efficient comparison of serologic test performance.


Subject(s)
Antibodies, Viral/blood , Betacoronavirus/immunology , Clinical Laboratory Techniques/methods , Coronavirus Infections/diagnosis , Immunoglobulin G/blood , Pneumonia, Viral/diagnosis , COVID-19 , COVID-19 Testing , Coronavirus Infections/blood , Humans , Mass Screening/methods , Pandemics , Pneumonia, Viral/blood , Reproducibility of Results , SARS-CoV-2 , Serologic Tests
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