scholarly journals Evaluation of Antibody Response in Symptomatic and Asymptomatic COVID-19 Patients and Diagnostic Assessment of New IgM/IgG ELISA Kits

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 161
Author(s):  
Hadeel T. Al-Jighefee ◽  
Hadi M. Yassine ◽  
Maryam A. Al-Nesf ◽  
Ali A. Hssain ◽  
Sara Taleb ◽  
...  
Keyword(s):  
Immune Response ◽  
Severe Acute Respiratory Syndrome ◽  
Antibody Response ◽  
Diagnostic Assessment ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Serum Samples ◽  
Time Intervals ◽  
Low Sensitivity ◽  
Pcr Test

This study aims to study the immune response and evaluate the performances of four new IgM and five IgG enzyme-linked immunosorbent assay (ELISA) kits for detecting anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies against different antigens in symptomatic and asymptomatic coronavirus disease 2019 (COVID-19) patients. A total of 291 samples collected from symptomatic and asymptomatic RT–PCR-confirmed patients were used to evaluate the ELISA kits’ performance (EDI, AnshLabs, DiaPro, NovaLisa, and Lionex). The sensitivity was measured at three different time-intervals post symptoms onset or positive SARS-CoV-2 RT–PCR test (≤14, 14–30, >30 days). The specificity was investigated using 119 pre-pandemic serum samples. The sensitivity of all IgM kits gradually decreased with time, ranging from 48.7% (EDI)–66.4% (Lionex) at ≤14 days, 29.1% (NovaLisa)–61.8% (Lionex) at 14–30 days, and 6.0% (AnshLabs)–47.9% (Lionex) at >30 days. The sensitivity of IgG kits increased with time, peaking in the latest interval (>30 days) at 96.6% (Lionex). Specificity of IgM ranged from 88.2% (Lionex)–99.2% (EDI), while IgG ranged from 75.6% (DiaPro)–98.3% (Lionex). Among all RT–PCR-positive patients, 23 samples (7.9%) were seronegative by all IgG kits, of which only seven samples (30.4%) had detectable IgM antibodies. IgM assays have variable and low sensitivity, thus considered a poor marker for COVID-19 diagnosis. IgG assays can miss at least 8% of RT–PCR-positive cases.

scholarly journals Use of Moraxella catarrhalis Lipooligosaccharide Mutants To Identify Specific Oligosaccharide Epitopes Recognized by Human Serum Antibodies

2009 ◽  
Vol 77 (10) ◽  
pp. 4548-4558 ◽  
Author(s):  
Johanna M. Schwingel ◽  
Katie J. Edwards ◽  
Andrew D. Cox ◽  
Hussein Masoud ◽  
James C. Richards ◽  
...  
Keyword(s):  
Immune Response ◽  
Antibody Response ◽  
Human Serum ◽  
Moraxella Catarrhalis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Antibody ◽  
Serum Antibodies ◽  
Serum Samples ◽  
Carbohydrate Epitopes ◽  
Tract Infections

ABSTRACT Moraxella catarrhalis is a causative agent of otitis media in children and lower respiratory tract infections in adults suffering from chronic obstructive pulmonary disease (COPD). This strict human pathogen continues to be a significant cause of disease in this broad spectrum of patients because there is no available vaccine. Although numerous putative vaccine antigens have been described, little is known about the human immune response to M. catarrhalis infection in vivo. Human serum antibodies are directed at a number of surface proteins, and lipooligosaccharides (LOS) and detoxified LOS may be an effective immunogen in mice. In this study, we used a specific LOS-based enzyme-linked immunosorbent assay (ELISA), containing the three major M. catarrhalis serotypes together with a complete series of truncated LOS mutants, to detect the development of new antibodies to specific regions of the oligosaccharide molecule. We compared serum samples from COPD patients who had recently cleared an M. catarrhalis infection to serum samples collected prior to their infection. Variability in the antibody response to LOS was observed, as some patients developed serotype-specific antibodies, others developed antibodies to the LOS of each serotype, others developed broadly cross-reactive antibodies, and some did not develop new antibodies. These newly developed human antibodies are directed at both side chains and core structures in the LOS molecule. This LOS-based ELISA can be used to dissect the human antibody response to both internal and external carbohydrate epitopes, thus providing a better understanding of the humoral immune response to M. catarrhalis LOS epitopes developed during natural infection.

scholarly journals Immunological imprinting of the antibody response in COVID-19 patients

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Teresa Aydillo ◽  
Alexander Rombauts ◽  
Daniel Stadlbauer ◽  
Sadaf Aslam ◽  
Gabriela Abelenda-Alonso ◽  
...  
Keyword(s):  
Immune Response ◽  
Severe Acute Respiratory Syndrome ◽  
Antibody Response ◽  
Humoral Immune Response ◽  
Nucleocapsid Protein ◽  
Spike Protein ◽  
Ongoing Research ◽  
Variable Regions ◽  
Humoral Immune ◽  
Human Coronaviruses

AbstractIn addition to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), humans are also susceptible to six other coronaviruses, for which consecutive exposures to antigenically related and divergent seasonal coronaviruses are frequent. Despite the prevalence of COVID-19 pandemic and ongoing research, the nature of the antibody response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear. Here we longitudinally profile the early humoral immune response against SARS-CoV-2 in hospitalized coronavirus disease 2019 (COVID-19) patients and quantify levels of pre-existing immunity to OC43, HKU1 and 229E seasonal coronaviruses, and find a strong back-boosting effect to conserved but not variable regions of OC43 and HKU1 betacoronaviruses spike protein. However, such antibody memory boost to human coronaviruses negatively correlates with the induction of IgG and IgM against SARS-CoV-2 spike and nucleocapsid protein. Our findings thus provide evidence of immunological imprinting by previous seasonal coronavirus infections that can potentially modulate the antibody profile to SARS-CoV-2 infection.

scholarly journals C-Terminal Invariable Domain of VlsE Is Immunodominant but Its Antigenicity Is Scarcely Conserved among Strains of Lyme Disease Spirochetes

2001 ◽  
Vol 69 (5) ◽  
pp. 3224-3231 ◽  
Author(s):  
Fang Ting Liang ◽  
Lisa C. Bowers ◽  
Mario T. Philipp
Keyword(s):  
Lyme Disease ◽  
Antibody Response ◽  
Human Serum ◽  
Synthetic Peptide ◽  
Species Complex ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Variable Surface ◽  
Entire Sequence ◽  
Carboxyl Terminal

ABSTRACT VlsE, the variable surface antigen of Borrelia burgdorferi, contains two invariable domains located at the amino and carboxyl terminal ends, respectively, and a central variable domain. In this study, both immunogenicity and antigenic conservation of the C-terminal invariable domain were assessed. Mouse antiserum to a 51-mer synthetic peptide (Ct) which reproduced the entire sequence of the C-terminal invariable domain of VlsE from B. burgdorferi strain B31 was reacted on immunoblots with whole-cell lysates extracted from spirochetes of 12 strains from the B. burgdorferi sensu lato species complex. The antiserum recognized only VlsE from strain B31, indicating that epitopes of this domain differed among these strains. When Ct was used as enzyme-linked immunosorbent assay (ELISA) antigen, all of the seven monkeys and six mice that were infected with B31 spirochetes produced a strong antibody response to this peptide, indicating that the C-terminal invariable domain is immunodominant. None of 12 monkeys and only 11 of 26 mice that were infected with strains other than B31 produced a detectable anti-Ct response, indicating a limited antigenic conservation of this domain among these strains. Twenty-six of 33 dogs that were experimentally infected by tick inoculation were positive by the Ct ELISA, while only 5 of 18 serum samples from dogs clinically diagnosed with Lyme disease contained detectable anti-Ct antibody. Fifty-seven of 64 serum specimens that were collected from American patients with Lyme disease were positive by the Ct ELISA, while only 12 of 21 European samples contained detectable anti-Ct antibody. In contrast, antibody to the more conserved invariable region IR6 of VlsE was present in all of these dog and human serum samples.

scholarly journals Monoclonal Antibody-Based Antigen Capture Enzyme-Linked Immunosorbent Assay Reveals High Sensitivity of the Nucleocapsid Protein in Acute-Phase Sera of Severe Acute Respiratory Syndrome Patients

2005 ◽  
Vol 12 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Biao Di ◽  
Wei Hao ◽  
Yang Gao ◽  
Ming Wang ◽  
Ya-di Wang ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Acute Phase ◽  
Detection Rate ◽  
Neutralization Test ◽  
Protein Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
N Protein ◽  
Antigen Capture ◽  
Healthy Donors

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.

scholarly journals First Report of Lolium latent virus in Ryegrass in the United States

Plant Disease ◽  
2006 ◽  
Vol 90 (4) ◽  
pp. 528-528 ◽  
Author(s):  
C. J. Maroon-Lango ◽  
J. Hammond ◽  
S. Warnke ◽  
R. Li ◽  
R. Mock
Keyword(s):  
United States ◽  
Lolium Perenne ◽  
The United States ◽  
Latent Virus ◽  
Hybrid Population ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
High Sequence Identity ◽  
Lolium Perenne L ◽  
Pcr Test

Initial reports of the presence of Lolium latent virus (LLV) in Lolium perenne L. and L. multiflorum Lam. breeding clones in Germany, the Netherlands, France (2), and recently the United Kingdom (3,4; described as Ryegrass latent virus prior to identification as LLV) prompted us to evaluate clonally propagated Lolium plants from the United States. Four genetically distinct plants (viz., MF22, MF48, MF125, and MF132) that have been maintained clonally for 5 years from a Lolium perenne × L. multiflorum hybrid population established in the United States exhibited either no symptoms or mild chlorotic flecking that coalesced to form chlorotic to necrotic streaking on the leaves. All four clonal plants tested positive using reverse transcription-polymerase chain reaction (RT-PCR) with the Potexvirus group PCR test (Agdia, Inc., Elkhart, IN), whereas all clones but MF48 tested positive using the Potyvirus group PCR test (Agdia, Inc.). No amplicons were obtained when the same plants were tested for tobamovirus, carlavirus, and closterovirus using appropriate virus group-specific primers. Cloning and sequencing of the potexviral amplicons revealed very high sequence identity with the comparable region of LLV-UK (GenBank Accession No. DQ333886), whereas those of the potyviral amplicons (GenBank Accession Nos. DQ355837 and DQ355838) were nearly identical with the comparable region of Ryegrass mosaic virus (RGMV), a rymovirus first reported from the United States in 1957 (1). Using indirect enzyme-linked immunosorbent assay (ELISA), extracts from all four Lolium clonal propagations tested positive for LLV using the antiserum raised to LLV-Germany (courtesy of Dr. Huth), whereas the potyvirus-positive results from RT-PCR of the three clones were confirmed using indirect ELISA with the broad spectrum potyvirus monoclonal antibody, PTY-1. LLV from singly or dually infected Lolium clones was transmitted to Nicotiana benthamiana Domin. but not to N. tabacum L. by mechanical inoculation. LLV was purified from infected N. benthamiana. Similar sized flexuous rods were observed using electron microscopy in leaf dip samples from Lolium clones and aliquots of the virions purified from N. benthamiana. References: (1) G. W. Bruehl et al. Phytopathology 47:517, 1957. (2) W. Huth et al. Agronomie 15:508, 1995. (3) R. Li et al. Asian Conf. Plant Pathol. 2:89, 2005. (4) C. Maroon-Lango et al. Int. Congr. Virol. 13:63, 2005.

scholarly journals West Nile Virus and Related Flavivirus in European Wild Boar (Sus scrofa), Latium Region, Italy: A Retrospective Study

Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 494
Author(s):  
Angela Petruccelli ◽  
Tiziana Zottola ◽  
Gianmarco Ferrara ◽  
Valentina Iovane ◽  
Cristina Di Russo ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Wild Boar ◽  
Specific Antibody ◽  
Central Italy ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Serum Samples ◽  
West Nile ◽  
Wild Boars ◽  
European Wild Boar

Background: A retrospective sero-survey for evidence of West Nile virus (WNV) infection in European wild boar (Sus scorfa) was conducted in the Latium region, Italy, on stored serum samples of the period November 2011 to January 2012. Methods: Sera were collected from 168 European wild boars and screened for antibodies to WNV and other Flaviviruses by competitive enzyme linked immunosorbent assay (cELISA). All sera positive for Flavivirus antibodies by cELISA were further examined by virus neutralization test (VNT). To test the presence of Flavivirus RNA in samples, an RT-PCR was performed using a pan-Flavivirus primers pair. Results: Thirteen wild boars (7.73%) were seropositive for Flaviviruses. The hemolysis of serum samples limited the interpretation of the VNT for 7 samples, confirming the presence of specific antibody against WNV in a single European wild boar serum sample. The presence of ELISA positive/VNT negative samples suggests the occurrence of non-neutralizing antibodies against WNV or other antigen-related Flaviviruses. No samples resulted positive for Flavivirus by RT-PCR assay. Conclusion: Although a moderately high percentage of animals with specific antibody for WNV has been detected in wild boar in other surveillance studies in Europe, this has not been reported previously in Italy. Together, these data indicate that European wild boar are exposed to WNV and/or other related-Flavivirus in central Italy and confirm the usefulness of wild ungulates, as suitable Flavivirus sentinels.

DETECTION OF SPECIFIC ANTIBODIES TO THE NUCLEOCAPSID PROTEIN FRAGMENTS OF SEVERE ACUTE RESPIRATORY SYNDROME-CORONAVIRUS AND SCOTOPHILUS BAT CORONAVIRUS-512 IN THREE INSECTIVOROUS BAT SPECIES

2018 ◽  
Vol 44 (04) ◽  
pp. 179-188 ◽  
Author(s):  
Yi-Ning Chen ◽  
Bo-Gang Su ◽  
Hung-Chang Chen ◽  
Cheng-Han Chou ◽  
Hsi-Chi Cheng
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Nucleocapsid Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Protein Fragments ◽  
Specific Antibodies ◽  
History Of ◽  
Polymerase Chain ◽  
Carboxyl Terminal ◽  
Bat Coronavirus

Bats are the natural reservoirs of severe acute respiratory syndrome-coronavirus (SARS-CoV). Six Alphacoronavirus and five Betacoronavirus have been detected in many bat species, including SARS-related CoV and Middle East respiratory syndrome (MERS)-related CoV. In Taiwan, SARS-related CoV, belonging to Betacoronavirus, has been detected in Rhinolophus monoceros. Scotophilus bat CoV-512, belonging to Alphacoronavirus, has been detected in Scotophilus kuhlii, Miniopterus fuliginosus, and Rhinolophus monoceros by using reverse transcription polymerase chain reaction (RT-PCR). To understand the infection history of CoV in these three insectivorous bat populations, CoV-specific antibodies were surveyed by using western blot (WB) analysis and indirect enzyme-linked immunosorbent assay (ELISA). The carboxyl terminal fragment of nucleocapsid protein (N3) of SARS-CoV and Scotophilus bat CoV-512 were used as the antigen in the assays. Of the 52 serum samples obtained from Scotophilus kuhlii, 29 samples (56%) were tested positive for Scotophilus bat CoV-512-specific antibodies through ELISA. Of the 63 serum samples obtained from Rhinolophus monoceros, 9 samples were tested positive for only SARS-CoV-specific antibodies, 7 samples were tested positive for only Scotophilus bat CoV-512-specific antibodies, and 16 samples (25.4%) were tested positive for both antibodies through WB analysis. Only 1 of 18 Miniopterus bat serum samples tested positive for Scotophilus bat CoV-512-specific antibodies through ELISA. Lactating female bats had higher positive rates of CoV-specific antibodies than non-lactating female and male bats did. Our findings were crucial for understanding CoV infection history in three insectivorous bat species and important for the control of bat-borne zoonosis diseases.

scholarly journals Performance Evaluation of Commercial Dengue Diagnostic Tests for Early Detection of Dengue in Clinical Samples

2017 ◽  
Vol 2017 ◽  
pp. 1-4 ◽  
Author(s):  
Tuan Nur Akmalina Mat Jusoh ◽  
Rafidah Hanim Shueb
Keyword(s):  
Dengue Virus ◽  
Real Time ◽  
Diagnostic Test ◽  
Rapid Diagnostic Test ◽  
Dengue Infection ◽  
Clinical Samples ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Serum Samples ◽  
Kappa Agreement

The shattering rise in dengue virus infections globally has created a need for an accurate and validated rapid diagnostic test for this virus. Rapid diagnostic test (RDT) and reverse transcription-polymerase chain reaction (RT-PCR) diagnostic detection are useful tools for diagnosis of early dengue infection. We prospectively evaluated the diagnostic performance of nonstructural 1 (NS1) RDT and real-time RT-PCR diagnostic kits in 86 patient serum samples. Thirty-six samples were positive for dengue NS1 antigen while the remaining 50 were negative when tested with enzyme-linked immunosorbent assay (ELISA). Commercially available RDTs for NS1 detection, RTK ProDetect™, and SD Bioline showed high sensitivity of 94% and 89%, respectively, compared with ELISA. GenoAmp® Trioplex Real-Time RT-PCR and RealStar® Dengue RT-PCR tests presented a comparable kappa agreement with 0.722. The result obtained from GenoAmp® Real-Time RT-PCR Dengue test showed that 14 samples harbored dengue virus type 1 (DENV-1), 8 samples harbored DENV-2, 2 samples harbored DENV-3, and 1 sample harbored DENV-4. 1 sample had a double infection with DENV-1 and DENV-2. The NS1 RDTs and real-time RT-PCR tests were found to be a useful diagnostic for early and rapid diagnosis of acute dengue and an excellent surveillance tool in our battle against dengue.

scholarly journals Antibody response and viraemia during the course of severe acute respiratory syndrome (SARS)-associated coronavirus infection

2004 ◽  
Vol 53 (5) ◽  
pp. 435-438 ◽  
Author(s):  
Weijun Chen ◽  
Zuyuan Xu ◽  
Jingsong Mu ◽  
Ling Yang ◽  
Haixue Gan ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Antibody Response ◽  
Time Course ◽  
Recovery Phase ◽  
Antibody Responses ◽  
Igg Antibodies ◽  
Rt Pcr ◽  
Blood Samples ◽  
Convalescent Phase ◽  
Coronavirus Infection

To understand the time-course of viraemia and antibody responses to severe acute respiratory syndrome-associated coronavirus (SARS-CoV), RT-PCR and ELISA were used to assay 376 blood samples from 135 SARS patients at various stages of the illness, including samples from patients who were in their early convalescent phase. The results showed that IgM antibodies decreased and became undetectable 11 weeks into the recovery phase. IgG antibodies, however, remained detectable for a period beyond 11 weeks and were found in 100 % of patients in the early convalescent phase. SARS-CoV viraemia mainly appeared 1 week after the onset of illness and then decreased over a period of 1 month, becoming undetectable in the blood samples of the convalescent patients. At the peak of viraemia, viral RNA was detectable in 75 % of blood samples from patients who were clinically diagnosed with SARS 1 or 2 weeks before the test.

scholarly journals Evaluation of Inapparent Nosocomial Severe Acute Respiratory Syndrome Coronavirus Infection in Vietnam by Use of Highly Specific Recombinant Truncated Nucleocapsid Protein-Based Enzyme-Linked Immunosorbent Assay

2005 ◽  
Vol 12 (7) ◽  
pp. 848-854 ◽  
Author(s):  
Fuxun Yu ◽  
Mai Quynh Le ◽  
Shingo Inoue ◽  
Hong Thi Cam Thai ◽  
Futoshi Hasebe ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Large Scale ◽  
Screening Method ◽  
Epidemiological Studies ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Nucleocapsid Proteins ◽  
N Protein ◽  
Care Workers ◽  
Coronavirus Infection

ABSTRACT Severe acute respiratory syndrome (SARS) is a recently emerged human disease associated with pneumonia. Inapparent infection with SARS coronavirus (CoV) is not well characterized. To develop a safe, simple, and reliable screening method for SARS diagnosis and epidemiological study, two recombinant SARS-CoV nucleocapsid proteins (N′ protein and NΔ121 protein) were expressed in Escherichia coli, purified by affinity chromatography, and used as antigens for indirect, immunoglobulin G enzyme-linked immunosorbent assays (ELISA). Serum samples collected from healthy volunteers and SARS patients in Vietnam were used to evaluate the newly developed methods. The N′ protein-based ELISA showed a highly nonspecific reaction. The NΔ121 protein-based ELISA, with a nonspecific reaction drastically reduced compared to that of the nearly-whole-length N′ protein-based ELISA, resulted in higher rates of positive reactions, higher titers, and earlier detection than the SARS-CoV-infected cell lysate-based ELISA. These results indicate that our newly developed SARS-CoV NΔ121 protein-based ELISA is not only safe but also a more specific and more sensitive method to diagnose SARS-CoV infection and hence a useful tool for large-scale epidemiological studies. To identify inapparent SARS-CoV infections, serum samples collected from health care workers (HCWs) in Vietnam were screened by the NΔ121 protein-based ELISA, and positive samples were confirmed by a virus neutralization test. Four out of 149 HCWs were identified to have inapparent SARS-CoV infection in Vietnam, indicating that subclinical SARS-CoV infection in Vietnam is rare but does exist.

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