scholarly journals Profile of Immunoglobulin G and IgM Antibodies Against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)

2020 ◽  
Vol 71 (16) ◽  
pp. 2255-2258 ◽  
Author(s):  
Jiuxin Qu ◽  
Chi Wu ◽  
Xiaoyong Li ◽  
Guobin Zhang ◽  
Zhaofang Jiang ◽  
...  

Abstract We profiled the serological responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid (N) protein and spike (S) glycoprotein. The majority of the patients developed robust antibody responses between 17 and 23 days after illness onset. Delayed, but stronger, antibody responses were observed in critical patients.

Author(s):  
Yao Jiang ◽  
Xiuqi Wei ◽  
Hui Wang ◽  
Guiling Li

Abstract Background Little is known on the duration of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G (IgG) antibodies in patients following SARS-CoV-2 infection. Aims We aimed to determine the duration of the immunoglobulin G (IgG) and M (IgM) antibody responses following SARS-CoV-2 infection and to evaluate the risk factors for a short duration of anti-SARS-CoV-2 IgG. Methods We measured antibody responses in 94 patients who had recovered from SARS-CoV-2 infection. The chi-square test and multivariable logistic regression analysis were used to identify risk factors for a short duration (< 6 months) of anti-SARS-CoV-2 IgG. Results IgG antibodies were detectable in all patients until 4 months; 19 (21.8%) convalescent patients reverted to IgG negative 4–6 months after symptom onset. IgM antibodies decreased significantly to 5.7% at 4–6 months after symptom onset. Patient characteristics were not associated with a short duration of detectable IgG. Conclusions A substantial fraction of convalescents may exhibit a transient IgG response following SARS-CoV-2 infection. Our findings suggest that patients who have recovered from SARS-CoV-2 infection should also be vaccinated if their anti-SARS-CoV-2 IgG antibodies are undetectable.


2007 ◽  
Vol 14 (7) ◽  
pp. 839-846 ◽  
Author(s):  
Jincun Zhao ◽  
Wei Wang ◽  
Wenling Wang ◽  
Zhendong Zhao ◽  
Yan Zhang ◽  
...  

ABSTRACT Both the nucleocapsid (N) and the spike (S) proteins of severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) are able to induce strong humoral responses in humans following an infection. To compare the immunoglobulin G (IgG) responses to the S and N proteins of SARS-CoV in SARS patients during the manifestation/convalescent period with those during the postinfection period, serum samples were collected from hospitalized SARS patients within 6 weeks after the onset of illness (set 1; 57 sequential samples from 19 patients) or 2 to 3 months after their recovery (set 2; 33 postinfection samples from 33 subjects). Serum samples from 100 healthy blood donors (set 3), collected in 2002, were also included. The specific IgG response to whole virus, the fragment from positions 450 to 650 of the S protein (S450-650), and the full-length N protein of SARS-CoV were measured by enzyme-linked immunosorbent assays (ELISAs). Western blot assays were carried out to confirm the ELISA results. Fifty-one of the serum samples in set 1 (89%) bound to the N protein, a proportion similar to that which recognized whole virus (79%) and the S-protein fragment (77%). All 33 serum samples from set 2 were strongly positive for N-protein-specific IgG, while 27 (82%) were positive for anti-S450-650 IgG. Two of the serum samples from set 3 were strongly positive for anti-N-protein IgG but not anti-S450-650 IgG. Similar levels of IgG responses to the S and N proteins were observed in SARS patients during the manifestation and convalescent stages. In the postinfection period, however, a number of patients had much lower serum IgG levels against S450-650 than against the N protein.


2020 ◽  
Author(s):  
Yu Kyung Kim ◽  
Dohsik Minn ◽  
Eun-Hyung Yoo ◽  
Mikyoung Park ◽  
Jae Hee Lee ◽  
...  

Abstract Background: Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) started to spread in Daegu from the end of February 2020. IgG and IgM antibodies against SARS-CoV-2 were measured in hospitalized patients with COVID-19 with moderate to severe symptoms to improve the understanding of antibody responses.Methods: We enrolled 312 patients with COVID-19 admitted to seven hospitals located in Daegu. Using serum (or plasma) samples from patients with polymerase chain reaction (PCR)-confirmed SARS-CoV-2 infections, both IgG and IgM antibodies were measured using commercial enzyme-linked immunosorbent assay (R-FIND COVID-19 ELISA, SG medical, Seoul, Korea). Results: The median value from the initial diagnosis by confirming SARS-CoV-2 PCR to the sampling date was 24 days (day -1 to 88). The total positive rate of IgG was 93.9% and the positive IgM rate was 39.4%, without considering the elapsed period after diagnosis. Positive IgG and IgM rates were highest at 100.0% and 59.0% in 3 weeks (15–21 days), respectively. IgG showed a high positive rate of 79.3% even within 7 days after the initial diagnosis of the disease and maintained a positive rate of 97.8% until after 8 weeks. Conclusions: Among hospitalized patients with COVID-19, IgG was detected from the beginning of the diagnosis and persisted for an extended time period.


Author(s):  
Tatsuya Yoshihara ◽  
Kazuya Ito ◽  
Masayoshi Zaitsu ◽  
Eunhee Chung ◽  
Izumi Aoyagi ◽  
...  

Coronavirus disease 2019 (COVID-19) has become a serious public health problem worldwide. In general, healthcare workers are considered to be at higher risk of COVID-19 infection. However, the prevalence of COVID-19 among healthcare workers in Japan is not well characterized. In this study, we aimed to examine the seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antibodies among 2160 healthcare workers in hospitals and clinics that are not designated to treat COVID-19 patients in Japan. The prevalence of SARS-CoV-2 immunoglobulin G was 1.2% in August and October 2020 (during and after the second wave of the pandemic in Japan), which is relatively higher than that in the general population in Japan (0.03–0.91%). Because of the higher risk of COVID-19 infection, healthcare workers should be the top priority for further social support and vaccination against SARS-CoV-2.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jyotsna Shah ◽  
Song Liu ◽  
Hari-Hara Potula ◽  
Prerna Bhargava ◽  
Iris Cruz ◽  
...  

Abstract Background Rapid and simple serological assays for characterizing antibody responses are important in the current COVID-19 pandemic caused by SARS-CoV-2. Multiplex immunoblot (IB) assays termed COVID-19 IB assays were developed for detecting IgG and IgM antibodies to SARS-CoV-2 virus proteins in COVID-19 patients. Methods Recombinant nucleocapsid protein and the S1, S2 and receptor binding domain (RBD) of the spike protein of SARS-CoV-2 were used as target antigens in the COVID-19 IBs. Specificity of the IB assay was established with 231 sera from persons with allergy, unrelated viral infections, autoimmune conditions and suspected tick-borne diseases, and 32 goat antisera to human influenza proteins. IgG and IgM COVID-19 IBs assays were performed on 84 sera obtained at different times after a positive RT-qPCR test from 37 COVID-19 patients with mild symptoms. Results Criteria for determining overall IgG and IgM antibody positivity using the four SARS-CoV-2 proteins were developed by optimizing specificity and sensitivity in the COVID-19 IgG and IgM IB assays. The estimated sensitivities and specificities of the COVID-19 IgG and IgM IBs for IgG and IgM antibodies individually or for either IgG or IgM antibodies meet the US recommendations for laboratory serological diagnostic tests. The proportion of IgM-positive sera from the COVID-19 patients following an RT-qPCR positive test was maximal at 83% before 10 days and decreased to 0% after 100 days, while the proportions of IgG-positive sera tended to plateau between days 11 and 65 at 78–100% and fall to 44% after 100 days. Detection of either IgG or IgM antibodies was better than IgG or IgM alone for assessing seroconversion in COVID-19. Both IgG and IgM antibodies detected RBD less frequently than S1, S2 and N proteins. Conclusions The multiplex COVID-19 IB assays offer many advantages for simultaneously evaluating antibody responses to different SARS-CoV-2 proteins in COVID-19 patients.


Diagnostics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 78
Author(s):  
Anja Dörschug ◽  
Julian Schwanbeck ◽  
Andreas Hahn ◽  
Anke Hillebrecht ◽  
Sabine Blaschke ◽  
...  

Serological assays can contribute to the estimation of population proportions with previous immunologically relevant contact with the Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) virus. In this study, we compared five commercially available diagnostic assays for the diagnostic identification of SARS-CoV-2-specific antibodies. Depending on the assessed immunoglobulin subclass, recorded sensitivity ranged from 17.0% to 81.9% with best results for immunoglobulin G. Specificity with blood donor sera ranged from 90.2% to 100%, with sera from EBV patients it ranged from 84.3% to 100%. Agreement from fair to nearly perfect was recorded depending on the immunoglobulin class between the assays, the with best results being found for immunoglobulin G. Only for this immunoglobulin class was the association between later sample acquisition times (about three weeks after first positive PCR results) and positive serological results in COVID-19 patients confirmed. In conclusion, acceptable and comparable reliability for the assessed immunoglobulin G-specific assays could be shown, while there is still room for improvement regarding the reliability of the assays targeting the other immunoglobulin classes.


2004 ◽  
Vol 72 (6) ◽  
pp. 3331-3335 ◽  
Author(s):  
Catherine Laine ◽  
Tabitha Mwangi ◽  
Claudette M. Thompson ◽  
Jacktone Obiero ◽  
Marc Lipsitch ◽  
...  

ABSTRACT Streptococcus pneumoniae is the primary etiological agent of community-acquired pneumonia and a major cause of meningitis and bacteremia. Three conserved pneumococcal proteins—pneumolysin, pneumococcal surface adhesin A (PsaA), and pneumococcal surface protein A (PspA)—are currently being investigated as vaccine candidates. Such protein-based vaccines, if proven effective, could provide a cheaper alternative to conjugate vaccine formulae. Few data from sub-Saharan Africa exist concerning the development of natural antibody to these antigens, however. To investigate the age-specific development of antiprotein immunoglobulin G (IgG) and IgA antibody responses, the sera of 220 persons 2 weeks to 84 years of age from coastal Kenya were assayed using enzyme-linked immunosorbent assays. IgG and IgA antibody responses to each antigen were observed in all age groups. Serum concentrations of IgG and IgA antibody responses to PspA and PdB (a recombinant toxoid derivative of pneumolysin), but not to PsaA, increased significantly with age (P < 0.001). No decline was observed in the sera of the elderly. Anti-protein IgG concentrations were only weakly correlated (0.30 < r < 0.56; P < 0.0001), as were IgA concentrations (0.24 < r < 0.54; P < 0.0001).


2005 ◽  
Vol 12 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Biao Di ◽  
Wei Hao ◽  
Yang Gao ◽  
Ming Wang ◽  
Ya-di Wang ◽  
...  

ABSTRACT Accurate and timely diagnosis of severe acute respiratory syndrome coronavirus (SARS-CoV) infection is a critical step in preventing another global outbreak. In this study, 829 serum specimens were collected from 643 patients initially reported to be infected with SARS-CoV. The sera were tested for the N protein of SARS-CoV by using an antigen capture enzyme-linked immunosorbent assay (ELISA) based on monoclonal antibodies against the N protein of SARS-CoV and compared to 197 control serum samples from healthy donors and non-SARS febrile patients. The results of the N protein detection analysis were directly related to the serological analysis data. From 27 SARS patients who tested positive with the neutralization test, 100% of the 24 sera collected from 1 to 10 days after the onset of symptoms were positive for the N protein. N protein was not detected beyond day 11 in this group. The positive rates of N protein for sera collected at 1 to 5, 6 to 10, 11 to 15, and 16 to 20 days after the onset of symptoms for 414 samples from 298 serologically confirmed patients were 92.9, 69.8, 36.4, and 21.1%, respectively. For 294 sera from 248 serological test-negative patients, the rates were 25.6, 16.7, 9.3, and 0%, respectively. The N protein was not detected in 66 patients with cases of what was initially suspected to be SARS but serologically proven to be negative for SARS and in 197 serum samples from healthy donors and non-SARS febrile patients. The specificity of the assay was 100%. Furthermore, of 16 sera collected from four patients during the SARS recurrence in Guangzhou, 5 sera collected from 7 to 9 days after the onset of symptoms were positive for the N protein. N protein detection exhibited a high positive rate, 96 to 100%, between day 3 and day 5 after the onset of symptoms for 27 neutralization test-positive SARS patients and 298 serologically confirmed patients. The N protein detection rate continually decreased beginning with day 10, and N protein was not detected beyond day 19 after the onset of symptoms. In conclusion, an antigen capture ELISA reveals a high N protein detection rate in acute-phase sera of patients with SARS, which makes it useful for early diagnosis of SARS.


2021 ◽  
Author(s):  
Jira Chansaenroj ◽  
Ritthideach Yorsaeng ◽  
Nasamon Wanlapakorn ◽  
Chintana Chirathaworn ◽  
Natthinee Sudhinaraset ◽  
...  

Abstract Understanding antibody responses after natural severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can guide the coronavirus disease 2019 (COVID-19) vaccine schedule. This study aimed to assess the dynamics of SARS-CoV-2 antibodies, including anti-spike protein 1 (S1) immunoglobulin (Ig)G, anti-receptor-binding domain (RBD) total Ig, anti-S1 IgA, and neutralizing antibody against wild-type SARS-CoV-2 in a cohort of patients who were previously infected with SARS-CoV-2. Between March and May 2020, 531 individuals with virologically confirmed cases of SARS-CoV-2 infection were enrolled in our immunological study. The neutralizing titers against SARS-CoV-2 were detected in 95.2%, 86.7%, 85.0%, and 85.4% of recovered COVID-19 patients at 3, 6, 9, and 12 months after symptom onset, respectively. The seropositivity rate of anti-S1 IgG, anti-RBD total Ig, anti-S1 IgA, and neutralizing titers remained at 68.6%, 89.6%, 77.1%, and 85.4%, respectively, at 12 months after symptom onset. The half-life of neutralizing titers was estimated at 100.7 days (95% confidence interval = 44.5 – 327.4 days, R2 = 0.106). These results support that the decline in serum antibody levels over time depends on the symptom severity, and the individuals with high IgG antibody titers experienced a significantly longer persistence of SARS-CoV-2-specific antibody responses than those with lower titers.


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