Diagnosis of Autoimmune Neutropenia by Neutrophil-bound IgG and IgM Antibodies

2011 ◽  
Vol 33 (7) ◽  
pp. 552-555 ◽  
Author(s):  
Taichi Ito ◽  
Shoichiro Taniuchi ◽  
Shoji Tsuji ◽  
Anna Iharada ◽  
Masafumi Hasui ◽  
...  
Keyword(s):  
Autoimmune Neutropenia ◽  
Igm Antibodies

scholarly journals Immunoglobulin-like Domain of HsFcμR as a Capture Molecule for Detection of Crimean-Congo Hemorrhagic Fever Virus- and Zika Virus-Specific IgM Antibodies

2019 ◽  
Vol 65 (3) ◽  
pp. 451-461 ◽  
Author(s):  
Anne Rackow ◽  
Christa Ehmen ◽  
Ronald von Possel ◽  
Raquel Medialdea-Carrera ◽  
David Brown ◽  
...  
Keyword(s):  
Zika Virus ◽  
Specific Binding ◽  
Hemorrhagic Fever ◽  
Fever Virus ◽  
Size Exclusion ◽  
Animal Origin ◽  
Serum Samples ◽  
Crimean Congo Hemorrhagic Fever ◽  
Hemorrhagic Fever Virus ◽  
Igm Antibodies

Abstract BACKGROUND The cellular surface molecule HsTOSO/FAIM3/HsFcμR has been identified as an IgM-specific Fc receptor expressed on lymphocytes. Here, we show that its extracellular immunoglobulin-like domain (HsFcμR-Igl) specifically binds to IgM/antigen immune complexes (ICs) and exploit this property for the development of novel detection systems for IgM antibodies directed against Crimean-Congo hemorrhagic fever virus (CCHFV) and Zika virus (ZIKV). METHODS His-tagged HsFcμR-Igl was expressed in Escherichia coli and purified by affinity chromatography, oxidative refolding, and size-exclusion chromatography. Specific binding of HsFcμR-Igl to IgM/antigen ICs was confirmed, and 2 prototypic ELISAs for the detection of anti-CCHFV and anti-ZIKV IgM antibodies were developed. Thereby, patient sera and virus-specific recombinant antigens directly labeled with horseradish peroxidase (HRP) were coincubated on HsFcμR-Igl-coated ELISA plates. Bound ICs were quantified by measuring turnover of a chromogenic HRP substrate. RESULTS Assay validation was performed using paired serum samples from 15 Kosovar patients with a PCR-confirmed CCHFV infection and 28 Brazilian patients with a PCR-confirmed ZIKV infection, along with a panel of a priori CCHFV/ZIKV-IgM-negative serum samples. Both ELISAs were highly reproducible. Sensitivity and specificity were comparable with or even exceeded in-house gold standard testing and commercial kits. Furthermore, latex beads coated with HsFcμR-Igl aggregated upon coincubation with an IgM-positive serum and HRP-labeled antigen but not with either component alone, revealing a potential for use of HsFcμR-Igl as a capture molecule in aggregation-based rapid tests. CONCLUSIONS Recombinant HsFcμR-Igl is a versatile capture molecule for IgM/antigen ICs of human and animal origin and can be applied for the development of both plate- and bead-based serological tests.

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 ◽  
...  
Keyword(s):  
Viral Infections ◽  
Antibody Responses ◽  
Nucleocapsid Proteins ◽  
Igm Antibodies ◽  
Igm Antibody ◽  
Specificity And Sensitivity ◽  
The Us ◽  
Autoimmune Conditions ◽  
Antibody Positivity ◽  
Recombinant Nucleocapsid Protein

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.

Development of species-specific IgM antibodies and elevation of mucosal immune response in Labeo rohita using recombinant bicistronic nano DNA vaccine priming

2021 ◽  
Vol 113 ◽  
pp. 185-195
Author(s):  
Tasok Leya ◽  
Irshad Ahmad ◽  
Rajendran Kooloth Valappil ◽  
Pani Prasad Kurcheti ◽  
Gayatri Tripathi ◽  
...  
Keyword(s):  
Immune Response ◽  
Dna Vaccine ◽  
Labeo Rohita ◽  
Mucosal Immune Response ◽  
Igm Antibodies ◽  
Species Specific

Autoimmune neutropenia associated with heterozygous variant of SBDS gene mimicking Shwachman–Bodian–Diamond syndrome

2021 ◽  
pp. 1-4
Author(s):  
Conn Rother ◽  
Niklas Gebauer ◽  
Juliane Schneider ◽  
Arthur Bauer ◽  
Fabian Holzhausen ◽  
...  
Keyword(s):  
Autoimmune Neutropenia ◽  
Heterozygous Variant

scholarly journals Hematological Features in Sheep with IgG and IgM Antibodies against Borrelia burgdorferi sensu lato

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 164
Author(s):  
Labrini V. Athanasiou ◽  
Victoria M. Spanou ◽  
Eleni G. Katsogiannou ◽  
Panagiotis D. Katsoulos
Keyword(s):  
Borrelia Burgdorferi ◽  
Rural Areas ◽  
Blood Analysis ◽  
Borrelia Burgdorferi Sensu Lato ◽  
Igm Antibodies ◽  
Group A ◽  
Group B ◽  
Group D ◽  
Immunofluorescence Antibody

Exposure of sheep to Borreliaburgdorferi sensulato (s.I.) complex, the causative agent of Lyme borreliosis (LB), has been reported in tick-abundant areas worldwide, while no data have been reported in Greece. The aim of the study was to identify the hematological alterations in sheep with seropositivity against Borrelia burgdorferi (s.I.). Blood samples were obtained from 318 tick infested sheep for blood analysis and serological determination of IgG and IgM antibodies against B. burgdorferi by indirect immunofluorescence antibody (IFA) assay after exclusion of endo-ectoparasites and other tick-borne infections. A total number of 162 sheep met the inclusion criteria, allocated in four groups based on the presence or absence of IgG and/or IgM; sheep found negative for IgM and IgG (Group A), positive for IgM (Group B), positive for both IgM and IgG (Group C) and positive for IgG (Group D). Anemia, thrombocytopenia and normal or decreased leukocyte count, mainly due to lymphopenia were the main hematological features observed in seropositive sheep. The presence of these features raises the suspicion of Borrelia infection in tick infested sheep. The seropositivity of 23.58% in sheep raises concerns of Borrelia circulation, especially in rural areas and potential risk of transmission to humans.

scholarly journals Endogenously Produced SARS-CoV-2 Specific IgG Antibodies May Have a Limited Impact on Clearing Nasal Shedding of Virus during Primary Infection in Humans

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 516
Author(s):  
Shuyi Yang ◽  
Keith R. Jerome ◽  
Alexander L. Greninger ◽  
Joshua T. Schiffer ◽  
Ashish Goyal
Keyword(s):  
Production Rate ◽  
Neutralizing Antibodies ◽  
Primary Infection ◽  
Natural Infection ◽  
Viral Clearance ◽  
Clinical Severity ◽  
Igg Antibodies ◽  
Igm Antibodies ◽  
Specific Igg ◽  
Specific Igg Antibodies

While SARS-CoV-2 specific neutralizing antibodies have been developed for therapeutic purposes, the specific viral triggers that drive the generation of SARS-CoV-2 specific IgG and IgM antibodies remain only partially characterized. Moreover, it is unknown whether endogenously derived antibodies drive viral clearance that might result in mitigation of clinical severity during natural infection. We developed a series of non-linear mathematical models to investigate whether SARS-CoV-2 viral and antibody kinetics are coupled or governed by separate processes. Patients with severe disease had a higher production rate of IgG but not IgM antibodies. Maximal levels of both isotypes were governed by their production rate rather than different saturation levels between people. Our results suggest that an exponential surge in IgG levels occurs approximately 5–10 days after symptom onset with no requirement for continual antigenic stimulation. SARS-CoV-2 specific IgG antibodies appear to have limited to no effect on viral dynamics but may enhance viral clearance late during primary infection resulting from the binding effect of antibody to virus, rather than neutralization. In conclusion, SARS-CoV-2 specific IgG antibodies may play only a limited role in clearing infection from the nasal passages despite providing long-term immunity against infection following vaccination or prior infection.

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