OBJECTIVE: To assess serum antibody responses of patients with severe acute respiratory syndrome (SARS) to nucleocapsid (N) antigen of SARS-associated coronavirus. METHODS: The serum levels of IgM and IgG antibodies to N antigen were measured in 200 healthy blood donors and 13 SARS patients at different time points of acute and convalescent phases using indirect enzyme-linked immunosorbent assay (ELISA) with N fusion proteins of SARS-associated coronaviruses. RESULTS: The IgM positive critical value of 0.233 and IgG of 0.239 were selected as the threshold value for positive results that equals the product of 2.1 and the mean IgM and IgG levels of 200 healthy blood donors. In 13 patients with SARS, the antibody responses to N antigen were not detectable in the first week after the onset of symptoms. The IgM and IgG seroprotection rates were 83.3% and 66.7% respectively in the second week, both reaching 100% at the third week. IgM seroprotection rates was 61.5% in the second month, and 38.5% at third month. The IgG peaked one month after the onset and remained at high levels in the following 2 months. CONCLUSION: The antibody responses suggest that N protein of SARS is immunodominant and plays an important role in viral pathogenesis. This ELISA-based test for detecting anti- N antigen may be of significant value for SARS diagnosis.
OBJECTIVE: To assess serum antibody responses of patients with severe acute respiratory syndrome (SARS) to nucleocapsid (N) antigen of SARS-associated coronavirus. METHODS: The serum levels of IgM and IgG antibodies to N antigen were measured in 200 healthy blood donors and 13 SARSpatients at different time points of acute and convalescent phases using indirect enzyme-linked immunosorbent assay (ELISA) with N fusion proteins of SARS-associated coronaviruses. RESULTS: The IgM positive critical value of 0.233 and IgG of 0.239 were selected as the threshold value for positive results that equals the product of 2.1 and the mean IgM and IgG levels of 200 healthy blood donors. In 13 patients with SARS, the antibody responses to N antigen were not detectable in the first week after the onset of symptoms. The IgM and IgG seroprotection rates were 83.3% and 66.7% respectively in the second week, both reaching 100% at the third week. IgM seroprotection rates was 61.5% in the second month, and 38.5% at third month. The IgG peaked one month after the onset and remained at high levels in the following 2 months. CONCLUSION: The antibody responses suggest that N protein of SARS is immunodominant and plays an important role in viral pathogenesis. This ELISA-based test for detecting anti- N antigen may be of significant value for SARS diagnosis.
Authors: Heike Hofmann; Kim Hattermann; Andrea Marzi; Thomas Gramberg; Martina Geier; Mandy Krumbiegel; Seraphin Kuate; Klaus Uberla; Matthias Niedrig; Stefan Pöhlmann Journal: J Virol Date: 2004-06 Impact factor: 5.103
Authors: Ken Yan Ching Chow; Chung Chau Hon; Raymond Kin Hi Hui; Raymond Tsz Yeung Wong; Chi Wai Yip; Fanya Zeng; Frederick Chi Ching Leung Journal: Genomics Proteomics Bioinformatics Date: 2003-11 Impact factor: 7.691
Authors: Ralph A Tripp; Lia M Haynes; Deborah Moore; Barbara Anderson; Azaibi Tamin; Brian H Harcourt; Les P Jones; Mamadi Yilla; Gregory J Babcock; Thomas Greenough; Donna M Ambrosino; Rene Alvarez; Justin Callaway; Sheana Cavitt; Kurt Kamrud; Harold Alterson; Jonathan Smith; Jennifer L Harcourt; Congrong Miao; Raj Razdan; James A Comer; Pierre E Rollin; Thomas G Ksiazek; Anthony Sanchez; Paul A Rota; William J Bellini; Larry J Anderson Journal: J Virol Methods Date: 2005-09 Impact factor: 2.014
Authors: Suxiang Tong; Christina Conrardy; Susan Ruone; Ivan V Kuzmin; Xiling Guo; Ying Tao; Michael Niezgoda; Lia Haynes; Bernard Agwanda; Robert F Breiman; Larry J Anderson; Charles E Rupprecht Journal: Emerg Infect Dis Date: 2009-03 Impact factor: 6.883