Differential Sensitivities of Severe Acute Respiratory Syndrome (SARS) Coronavirus Spike Polypeptide Enzyme-Linked Immunosorbent Assay (ELISA) and SARS Coronavirus Nucleocapsid Protein ELISA for Serodiagnosis of SARS Coronavirus Pneumonia

ABSTRACT Antibody detection with a recombinant COOH portion of the severe acute respiratory syndrome (SARS) coronavirus nucleocapsid (N) protein, N13 (amino acids 221 to 422), was demonstrated to be more specific and sensitive than that with the full-length N protein, and an N13-based antigen-capturing enzyme-linked immunosorbent assay providing a convenient and specific test for serodiagnosis and epidemiological study of SARS was developed.

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Detection of Severe Acute Respiratory Syndrome (SARS) Coronavirus Nucleocapsid Protein in SARS Patients by Enzyme-Linked Immunosorbent Assay

Journal of Clinical Microbiology ◽

10.1128/jcm.42.7.2884-2889.2004 ◽

2004 ◽

Vol 42 (7) ◽

pp. 2884-2889 ◽

Cited By ~ 72

Author(s):

S. K. P. Lau ◽

P. C. Y. Woo ◽

B. H. L. Wong ◽

H.-W. Tsoi ◽

G. K. S. Woo ◽

...

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Immunosorbent Assay ◽

Nucleocapsid Protein ◽

Enzyme Linked Immunosorbent Assay ◽

Sars Coronavirus

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Diagnosis of Severe Acute Respiratory Syndrome (SARS) by Detection of SARS Coronavirus Nucleocapsid Antibodies in an Antigen-Capturing Enzyme-Linked Immunosorbent Assay

Journal of Clinical Microbiology ◽

10.1128/jcm.41.12.5781-5782.2003 ◽

2003 ◽

Vol 41 (12) ◽

pp. 5781-5782 ◽

Cited By ~ 58

Author(s):

Y. Shi ◽

Y. Yi ◽

P. Li ◽

T. Kuang ◽

L. Li ◽

...

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Immunosorbent Assay ◽

Enzyme Linked Immunosorbent Assay ◽

Sars Coronavirus

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Longitudinal Profile of Immunoglobulin G (IgG), IgM, and IgA Antibodies against the Severe Acute Respiratory Syndrome (SARS) Coronavirus Nucleocapsid Protein in Patients with Pneumonia Due to the SARS Coronavirus

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.11.4.665-668.2004 ◽

2004 ◽

Vol 11 (4) ◽

pp. 665-668 ◽

Cited By ~ 89

Author(s):

Patrick C. Y. Woo ◽

Susanna K. P. Lau ◽

Beatrice H. L. Wong ◽

Kwok-hung Chan ◽

Chung-ming Chu ◽

...

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Indirect Immunofluorescence ◽

Immunoglobulin G ◽

Nucleocapsid Protein ◽

Baseline Level ◽

Immunofluorescence Assay ◽

Indirect Immunofluorescence Assay ◽

Enzyme Linked Immunosorbent Assay ◽

Sars Coronavirus ◽

Iga Antibodies

ABSTRACT By using a recombinant severe acute respiratory syndrome coronavirus (SARS-CoV) nucleocapsid protein-based enzyme-linked immunosorbent assay (ELISA) and serum specimens serially collected (from day 0 to day 240 after symptom onset) from patients with pneumonia due to SARS-CoV, we analyzed the longitudinal profiles of immunoglobulin G (IgG), IgM, and IgA antibodies against the SARS-CoV nucleocapsid protein in patients with pneumonia due to SARS-CoV. For IgG, the median optical density at 450 nm (OD450) turned positive at day 17 and a biphasic response was observed. At day 240, all patients were still positive for anti-nucleocapsid protein IgG antibody. For IgM, the median OD450 turned positive at day 20.5, peaked at about day 80, and fell to below the baseline level at about day 180. At day 240, 36% of the patients were still positive for anti-nucleocapsid protein IgM antibody. For IgA, the median OD450 turned positive at day 17, peaked at about day 50, and fell to below the baseline level at about day 180. At day 240, 36% of the patients were still positive for anti-nucleocapsid protein IgA antibody. The time of seroconversion detected by the recombinant SARS-CoV nucleocapsid protein-based ELISA and that detected by indirect immunofluorescence assay were similar. The median times of seroconversion for IgG, IgM, and IgA detected by the indirect immunofluorescence assay were 17 days (17 days by ELISA), 16.5 days (20.5 days by ELISA), and 17.5 days (17 days by ELISA), respectively, after disease onset. One, four, and one of the six patients who died did not produce any IgG, IgM, and IgA antibodies against the nucleocapsid protein of SARS-CoV, respectively, although these antibodies were detected in all six patients by the indirect immunofluorescence assay. Further studies should be performed to see whether SARS-CoV nucleocapsid protein antibody positivity has any prognostic significance.

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Profile of Antibodies to the Nucleocapsid Protein of the Severe Acute Respiratory Syndrome (SARS)-Associated Coronavirus in Probable SARS Patients

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.11.1.227-228.2004 ◽

2004 ◽

Vol 11 (1) ◽

pp. 227-228 ◽

Cited By ~ 36

Author(s):

Xuan Liu ◽

Yulin Shi ◽

Ping Li ◽

Linhai Li ◽

Yanping Yi ◽

...

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Immunosorbent Assay ◽

Nucleocapsid Protein ◽

Healthy People ◽

Enzyme Linked Immunosorbent Assay ◽

High Antibody ◽

Antibody Titers

ABSTRACT Profiles of antibodies to the nucleocapsid protein of the severe acute respiratory syndrome (SARS)-associated coronavirus in 445 probable SARS patients and 3,749 healthy people or non-SARS patients were analyzed by antigen-capturing enzyme-linked immunosorbent assay. Antinucleocapsid antibodies were elucidated in 17.5% of the probable SARS patients 1 to 7 days after the onset of symptoms and in 80% of the patients 8 to 14 days after the onset. About 90% of the probable SARS patients were positive 15 or more days after illness. Antibody titers increased up to 70 days, and high antibody titers were maintained at least for another 3 months. Of the healthy people and non-SARS patients, only seven (0.187%) were weakly positive.

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Naturally Occurring Anti-Escherichia coli Protein Antibodies in the Sera of Healthy Humans Cause Analytical Interference in a Recombinant Nucleocapsid Protein-Based Enzyme-Linked Immunosorbent Assay for Serodiagnosis of Severe Acute Respiratory Syndrome

Clinical and Vaccine Immunology ◽

10.1128/cvi.00136-06 ◽

2006 ◽

Vol 14 (1) ◽

pp. 99-101 ◽

Cited By ~ 8

Author(s):

Chi Wai Yip ◽

Chung Chau Hon ◽

Fanya Zeng ◽

Ken Y. C. Chow ◽

Kwok Hung Chan ◽

...

Keyword(s):

Escherichia Coli ◽

Severe Acute Respiratory Syndrome ◽

Immunosorbent Assay ◽

Nucleocapsid Protein ◽

False Positives ◽

Enzyme Linked Immunosorbent Assay ◽

Healthy Humans ◽

Analytical Interference ◽

Human Sera ◽

Recombinant Nucleocapsid Protein

ABSTRACT We reported the analytical interference of anti-Escherichia coli protein (EP) antibodies in human sera and residual EP in a recombinant nucleocapsid protein-based enzyme-linked immunosorbent assay as a possible source of false positives in severe acute respiratory syndrome serodiagnosis. The rate of false positives was significantly reduced by adding mouse anti-EP antiserum in the blocking step.

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Recombinant Truncated Nucleocapsid Protein as Antigen in a Novel Immunoglobulin M Capture Enzyme-Linked Immunosorbent Assay for Diagnosis of Severe Acute Respiratory Syndrome Coronavirus Infection

Clinical and Vaccine Immunology ◽

10.1128/cvi.00360-06 ◽

2007 ◽

Vol 14 (2) ◽

pp. 146-149 ◽

Cited By ~ 12

Author(s):

Fuxun Yu ◽

Mai Quynh Le ◽

Shingo Inoue ◽

Futoshi Hasebe ◽

Maria del Carmen Parquet ◽

...

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Immunosorbent Assay ◽

Nucleocapsid Protein ◽

Seroconversion Rate ◽

Disease Onset ◽

Immunoglobulin M ◽

Antibody Detection ◽

Enzyme Linked Immunosorbent Assay ◽

Igm Antibody ◽

Specificity And Sensitivity

ABSTRACT We report the development of an immunoglobulin M (IgM) antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) for severe acute respiratory syndrome coronavirus (SARS-CoV) by using recombinant truncated SARS-CoV nucleocapsid protein as the antigen. The newly developed MAC-ELISA had a specificity and sensitivity of 100% as evaluated by using sera from healthy volunteers and patients with laboratory-confirmed SARS. Using serial serum samples collected from SARS patients, the times to seroconversion were determined by IgM antibody detection after SARS-CoV infection. The median time to seroconversion detection was 8 days (range, 5 to 17 days) after disease onset, and the seroconversion rates after the onset of illness were 33% by the first week, 97% by the second week, and 100% by the third week. Compared with the results of our previous report on the detection of IgG, the median seroconversion time by IgM detection was 3 days earlier and the seroconversion rate by the second week after the illness for IgM was significantly higher than by IgG assay. Our results indicating that the IgM response appears earlier than IgG after SARS-CoV infection in consistent with those for other pathogens. Our newly developed MAC-ELISA system offers a new alternative for the confirmation of SARS-CoV infection.

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