scholarly journals IgG and IgM antibody formation to spike and nucleocapsid proteins in COVID-19 characterized by multiplex immunoblot assays

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.

1979 ◽  
Vol 9 (4) ◽  
pp. 503-506
Author(s):  
T E Minor ◽  
P B Helstrom ◽  
D B Nelson ◽  
D J D'Alessio

A counterimmunoelectrophoresis test was developed for immunoglobulin M (IgM) antibodies to group B coxsackievirus (CB) types 1 through 5. The IgM precipitin line could be identified and differentiated from the IgG line by treating sera with 2-mercaptoethanol. Antigen purity was demonstrated by single precipitin lines occurring only to the homologous antigen when tested with type-specific hyperimmune rabbit sera. Serum pairs from 19 of 22 patients with documented CB type 1,3,4, and 5 infections were positive for IgM antibody to the infecting serotype, whereas 2 of 7 pairs from CB type 2 patients were positive. Heterologous IgM antibodies were present in sera from 14 fo 29 CB patients. Of the 14 patients with heterologous IgM antibodies, 12 also had greater than or equal to 4-fold rises in whole serum neutralizing antibody to heterologous serotypes. Only three control sera from 72 patients with coxsackievirus group A, echovirus, or other viral infections had IgM antibody to CB serotypes.


2021 ◽  
pp. 113046
Author(s):  
A.M. Cook ◽  
S.E. Faustini ◽  
L.J. Williams ◽  
A.F. Cunningham ◽  
M.T. Drayson ◽  
...  

Author(s):  
Claudio R. GONSALEZ ◽  
Jorge CASSEB ◽  
Francisco G. V. MONTEIRO ◽  
João B. PAULA-NETO ◽  
Rufino B. FERNANDEZ ◽  
...  

A clinical trial pilot study, double-blinded, randomized, and controlled with a placebo to assess the effectiveness of oral doxycycline (200 mg, single dose) in preventing leptospirosis after high exposure to potentially contamined water was performed in São Paulo, SP, Brazil. Confirmed cases were defined as those with leptospira IgM antibody and symptoms; asymptomatic cases were those presenting with IgM antibodies but no symptoms; and suspected cases were individuals with symptoms but no IgM antibody. Forty subjects were given doxycycline and 42 were given placebo. In the drug-treated group there were 2 confirmed cases, 11 asymptomatic cases, and 6 suspected cases. In the placebo group there were 5 confirmed, 6 symptomatic, and 5 suspected cases. Even though we found a protective association of doxycycline for confirmed leptospirosis cases (RR = 2.3) and seroconversion only (RR = 2.0), the association was not statistically significant because of the small number of individuals enrolled in this pilot study. We observed that the 22% of the volunteers already had IgM antibodies to leptospirosis at the first sampling. Finally, the attack rate to confirmed, asymptomatic, and suspected cases of Leptospirosis was 8.5%, 22%, and 13%, respectively, in this population.


Author(s):  
Qunfeng Dong ◽  
Xiang Gao

Abstract Accurate estimations of the seroprevalence of antibodies to severe acute respiratory syndrome coronavirus 2 need to properly consider the specificity and sensitivity of the antibody tests. In addition, prior knowledge of the extent of viral infection in a population may also be important for adjusting the estimation of seroprevalence. For this purpose, we have developed a Bayesian approach that can incorporate the variabilities of specificity and sensitivity of the antibody tests, as well as the prior probability distribution of seroprevalence. We have demonstrated the utility of our approach by applying it to a recently published large-scale dataset from the US CDC, with our results providing entire probability distributions of seroprevalence instead of single-point estimates. Our Bayesian code is freely available at https://github.com/qunfengdong/AntibodyTest.


2021 ◽  
Author(s):  
Claire Cook ◽  
Naomi Patel ◽  
Kristin D'Silva ◽  
Tiffany T-Y Hsu ◽  
Michael DiIorio ◽  
...  

Objective To describe the characteristics of COVID-19 vaccine breakthrough infections among systemic autoimmune rheumatic disease (SARD) patients. Methods We identified SARDs patients in a large healthcare system with COVID-19 vaccination at least 14 days prior to a positive SARS-CoV-2 molecular test. Details of the SARD diagnosis, vaccination status, and COVID-19 infection were extracted. Results Of 340 confirmed COVID-19 infections among SARDs patients between December 11th, 2020 (date of first COVID-19 vaccine approval in the US) and July 30th, 2021, we identified 16 breakthrough infections. Seven (44%) received the Pfizer-BioNtech vaccine, five (31%) received the Moderna vaccine, and four (25%) received the Janssen/Johnson & Johnson vaccine. The most common SARDs included rheumatoid arthritis (6, 38%), inflammatory myopathy (3, 19%), and systemic lupus erythematosus (3, 19%). Rituximab (5, 31%), glucocorticoids (4, 25%), and mycophenolate mofetil (4, 25%) were the most frequent treatments. Among the breakthrough infections, 15 (93%) were symptomatic, six (38%) were hospitalized, one (6%) required mechanical ventilation, and two (13%) died. Conclusions Symptomatic, including severe, breakthrough infections were observed in SARDs patients; many were on treatments associated with attenuated antibody responses to vaccination. Further studies are needed to determine the rate of breakthrough infection associated with SARD treatments and other features.


2021 ◽  
Vol 15 (Supplement_1) ◽  
pp. S380-S381
Author(s):  
S Y Wong ◽  
R Dixon ◽  
S Gold ◽  
M Vicky ◽  
D Helmus ◽  
...  

Abstract Background Given that IBD patients were excluded from COVID-19 vaccine trials, there is a lack of vaccine efficacy data in this population. In this study, we evaluated longitudinal serological responses to SARS-CoV-2 infection as well as to COVID-19 vaccination in IBD patients. Methods We collected clinical data and sera from IBD patients enrolled in an observational SARS-CoV-2 sero-surveillance study at our large hospital center in New York City during routine infusions and clinic visits. To distinguish between infection and vaccination, sera was collected prior to vaccination where possible, and all sera was tested for both antibodies to SARS-CoV-2-specific RBD, the target of current available vaccines in the U.S., and nucleocapsid proteins. Results Our results reveal waning antibody titres in 13 of 16 (81%) patients infected with SARS-CoV-2 over a course of 6-7 months. Of 48 vaccinated patients, 16 patients completed vaccine schedules with two doses, and all 16 (100%) achieved seroconversion above the threshold required for convalescent plasma donation. Conclusion While antibody responses to infection in IBD patients have questionable stability, completion of the COVID-19 vaccine series in IBD patients results in robust serological responses. To our knowledge is the first data confirming adequate serological responses to COVID-19 vaccination in IBD patients with and without biologic medications. Studies are needed to assess adequacy of dosing schedules, medication effects, measurement of cell-mediated responses, durability of immune responses, and clinical efficacy of COVID-19 vaccines in IBD patients.


PEDIATRICS ◽  
1966 ◽  
Vol 38 (4) ◽  
pp. 564-570
Author(s):  
Hugh L. Moffet ◽  
Henry G. Cramblett

A fourfold rise in neutralizing antibodies was demonstrated for 45% of infants 1 through 6 months of age compared to 63% of older children or adults from whom an adenovirus or an enterovirus was recovered. This difference appeared to be related to severity of illness rather than to age, as there was no significant difference between young infants and older patients when only clinically severe illnesses were analyzed. The isolation of virus from more than one specimen increased the probability of a significant response in either age group. Infants with minor symptoms had a low frequency of significant fourfold antibody responses after virus isolation, but this was not significantly different from older children with minor symptoms. Failure to develop an increase in antibody titer could not be related to the presence of maternal antibodies.


2020 ◽  
Vol 9 (1) ◽  
pp. 1096-1101 ◽  
Author(s):  
Liang Shen ◽  
Chunhua Wang ◽  
Jianzhong Zhao ◽  
Xiaoyong Tang ◽  
Ying Shen ◽  
...  

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