scholarly journals Interpretations of SARS-CoV-2 IgM and IgG antibody titers in the seroepidemiological study of asymptomatic healthy volunteers

2021 ◽  
Author(s):  
Akihisa Mitani ◽  
Takeshi Horie ◽  
Rin Yokoyama ◽  
Yuki Nakano ◽  
Kensuke Hamada ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Igg Antibody ◽  
Antibody Titers

scholarly journals Safety and Immunogenicity of the COVID-19 Vaccine BNT162b2 in Patients Undergoing Chemotherapy for Solid Cancer

2021 ◽  
Author(s):  
Yohei Funakoshi ◽  
Kimikazu Yakushijin ◽  
Goh Ohji ◽  
Wataru Hojo ◽  
Hironori Sakai ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Cancer Patients ◽  
Solid Cancer ◽  
Igg Antibody ◽  
Serious Adverse Event ◽  
Cytokine Levels ◽  
Protection Strategies ◽  
Antibody Titers ◽  
Checkpoint Inhibitor Therapy ◽  
Antibody Levels

Background: Although COVID-19 severity in cancer patients is high, the safety and immunogenicity of the BNT162b2 mRNA COVID-19 vaccine in patients undergoing chemotherapy for solid cancers in Japan have not been reported. Methods: We investigated the safety and immunogenicity of BNT162b2 in 41 patients undergoing chemotherapy for solid cancers and in healthy volunteers who received 2 doses of BNT162b2. We evaluated serum IgG antibody titers for S1 protein by ELISA at pre-vaccination, prior to the second dose and 14 days after the second vaccination in 24 cancer patients undergoing cytotoxic chemotherapy (CC group), 17 cancer patients undergoing immune checkpoint inhibitor therapy (ICI group) and 12 age-matched healthy volunteers (HV group). Additionally, inflammatory cytokine levels were compared between the HV and ICI groups at pre and the next day of each vaccination. Results: Anti-S1 antibody levels were significantly lower in the ICI and CC groups than in the HV group after the second dose (median optimal density: 0.241 [0.063-1.205] and 0.161 [0.07-0.857] vs 0.644 [0.259-1.498], p = 0.0024 and p < 0.0001, respectively). Adverse effect profile did not differ among the three groups, and no serious adverse event occurred. There were no differences in vaccine-induced inflammatory cytokines between the HV and ICI groups. Conclusion: Although there were no significant differences in adverse events in three groups, antibody titers were significantly lower in the ICI and CC groups than in the HV group. Further protection strategies should be considered in cancer patients undergoing CC or ICI.

The Inducing Roles of the New Isolated Bursal Hexapeptide and Pentapeptide on the Immune Response of AIV Vaccine in Mice

2019 ◽  
Vol 26 (7) ◽  
pp. 542-549 ◽  
Author(s):  
Shan Shan Hao ◽  
Man Man Zong ◽  
Ze Zhang ◽  
Jia Xi Cai ◽  
Yang Zheng ◽  
...  
Keyword(s):  
Immune Response ◽  
Dendritic Cells ◽  
Amino Acid ◽  
T Cell ◽  
Antigen Presentation ◽  
Amino Acid Sequences ◽  
Cell Subpopulation ◽  
Igg Antibody ◽  
Antibody Titers ◽  
Specific Igg

Background: Bursa of Fabricius is the acknowledged central humoral immune organ. The bursal-derived peptides play the important roles on the immature B cell development and antibody production. Objective: Here we explored the functions of the new isolated bursal hexapeptide and pentapeptide on the humoral, cellular immune response and antigen presentation to Avian Influenza Virus (AIV) vaccine in mice immunization. Methods: The bursa extract samples were purified following RP HPLC method, and were analyzed with MS/MS to identify the amino acid sequences. Mice were twice subcutaneously injected with AIV inactivated vaccine plus with two new isolated bursal peptides at three dosages, respectively. On two weeks after the second immunization, sera samples were collected from the immunized mice to measure AIV-specific IgG antibody levels and HI antibody titers. Also, on 7th day after the second immunization, lymphocytes were isolated from the immunized mice to detect T cell subtype and lymphocyte viabilities, and the expressions of co-stimulatory molecule on dendritic cells in the immunized mice. Results: Two new bursal hexapeptide and pentapeptide with amino acid sequences KGNRVY and MPPTH were isolated, respectively. Our investigation proved the strong regulatory roles of bursal hexapeptide on AIV-specific IgG levels and HI antibody titers, and lymphocyte viabilities, and the significant increased T cells subpopulation and expressions of MHCII molecule on dendritic cells in the immunized mice. Moreover, our findings verified the significantly enhanced AIV-specific IgG antibody and HI titers, and the strong increased T cell subpopulation and expressions of CD40 molecule on dendritic cells in the mice immunized with AIV vaccine and bursal pentapeptide. Conclusion: We isolated and identified two new hexapeptide and pentapeptide from bursa, and proved that these two bursal peptides effectively induced the AIV-specific antibody, T cell and antigen presentation immune responses, which provided an experimental basis for the further clinical application of the bursal derived active peptide on the vaccine improvement.

scholarly journals Simultaneous Immunization with Multiple Diverse Immunogens Alters Development of Antigen-Specific Antibody-Mediated Immunity

Vaccines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 964
Author(s):  
Kelsey A. Pilewski ◽  
Kevin J. Kramer ◽  
Ivelin S. Georgiev
Keyword(s):  
Specific Antibody ◽  
Antibody Responses ◽  
Surface Proteins ◽  
Emerging Pathogens ◽  
Igg Antibody ◽  
Neisseria Meningitides ◽  
Immunization Strategies ◽  
Single Antigen ◽  
The Face ◽  
Antibody Titers

Vaccination remains one of the most successful medical interventions in history, significantly decreasing morbidity and mortality associated with, or even eradicating, numerous infectious diseases. Although traditional immunization strategies have recently proven insufficient in the face of many highly mutable and emerging pathogens, modern strategies aim to rationally engineer a single antigen or cocktail of antigens to generate a focused, protective immune response. However, the effect of cocktail vaccination (simultaneous immunization with multiple immunogens) on the antibody response to each individual antigen within the combination, remains largely unstudied. To investigate whether immunization with a cocktail of diverse antigens would result in decreased antibody titer against each unique antigen in the cocktail compared to immunization with each antigen alone, we immunized mice with surface proteins from uropathogenic Escherichia coli, Mycobacterium tuberculosis, and Neisseria meningitides, and monitored the development of antigen-specific IgG antibody responses. We found that antigen-specific endpoint antibody titers were comparable across immunization groups by study conclusion (day 70). Further, we discovered that although cocktail-immunized mice initially elicited more robust antibody responses, the rate of titer development decreases significantly over time compared to single antigen-immunized mice. Investigating the basic properties that govern the development of antigen-specific antibody responses will help inform the design of future combination immunization regimens.

scholarly journals Validation of a new automated chemiluminescent anti-SARS-CoV-2 IgM and IgG antibody assay system detecting both N and S proteins in Japan

2020 ◽  
Author(s):  
RIn Yokoyama ◽  
Makoto Kurano ◽  
Yoshifumi Morita ◽  
Takuya Shimura ◽  
Yuki Nakano ◽  
...  
Keyword(s):  
Measurement System ◽  
False Positive ◽  
Laboratory Testing ◽  
Antibody Test ◽  
Measurement Range ◽  
Antibody Assay ◽  
Serum Samples ◽  
Igg Antibody ◽  
Antibody Titers ◽  
Pcr Test

PCR methods are presently the standard for the diagnosis of Coronavirus disease 2019 (COVID-19), but additional methodologies are needed to complement PCR methods, which have some limitations. Here, we validated and investigated the usefulness of measuring serum antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the iFlash3000 CLIA analyzer. We measured IgM and IgG titers against SARS-CoV-2 in sera collected from 26 PCR-positive COVID-19 patients, 53 COVID-19-suspected but PCR-negative patients, and 20 and 100 randomly selected non-COVID-19 patients who visited our hospital in 2020 and 2017, respectively. The within-day and between-day precisions were regarded as good, since the coefficient variations were below 5%. Linearity was also considered good between 0.6 AU/mL and 112.7 AU/mL for SARS-CoV-2 IgM and between 3.2 AU/mL and 55.3 AU/mL for SARS-CoV-2 IgG, while the linearity curves plateaued above the upper measurement range. We also confirmed that the seroconversion and no-antibody titers were over the cutoff values in all 100 serum samples collected in 2017. These results indicate that this measurement system successfully detects SARS-CoV-2 IgM/IgG. We observed four false-positive cases in the IgM assay and no false-positive cases in the IgG assay when 111 serum samples known to contain autoantibodies were evaluated. The concordance rates of the antibody test with the PCR test were 98.1% for SARS-CoV-2 IgM and 100% for IgG among PCR-negative cases and 30.8% for SARS-CoV-2 IgM and 73.1% for SARS-CoV-2 IgG among PCR-positive cases. In conclusion, the performance of this measurement system is sufficient for use in laboratory testing.

scholarly journals Malaria serology: performance of six Plasmodium falciparum antigen extracts and of three ways of determining serum titers in IgG and IgM-ELISA

1993 ◽  
Vol 35 (6) ◽  
pp. 495-502 ◽  
Author(s):  
Maria Carmen Arroyo Sanchez ◽  
Sandra do Lago Moraes de Avila ◽  
Vera de Paula Quartier-Oliveira ◽  
Antonio Walter Ferreira
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Diagnosis ◽  
Sodium Deoxycholate ◽  
Epidemiological Studies ◽  
Negative Control ◽  
Igg Antibody ◽  
Direct Titration ◽  
Antibody Titers ◽  
Constant Slope ◽  
Better Than

The study evaluated six Plasmodium falciparum antigen extracts to be used in the IgG and IgM enzyme-linked immunosorbent assays (ELISA), for malaria diagnosis and epidemiological studies. Results obtained with eighteen positive and nine negative control sera indicated that there were statistically significant differences among these antigen extracts (Multifactor ANOVA, p< 0.0001). Urea, sodium deoxycholate and Zwittergent antigen extracts performed better than did the three others, their features being very similar for the detection of IgG antibodies. Urea, alkaline and sodium deoxycholate antigen extracts proved to be better than the others for the detection of IgM antibodies. A straight line relationship was found between the optical densities (or their respective log 10) and the log 10 of antibody dilutions, with a very constant slope. Thus serum titers could be determined by direct titration and by two different equations, needing only one serum dilution. For IgM antibody detections, log 10 expression gave results that better correlated with direct titration (95% Bonferroni). For IgG antibody detections, the titer differences were not significant. The reproducibility of antibody titers and antigen batches was also evaluated, giving satisfactory results.

scholarly journals Frequency of antibodies and risk factors associated with Toxoplasma gondii infection in backyard pig production in the city of Mossoró, state of Rio Grande do Norte, Brazil

2019 ◽  
Vol 28 (3) ◽  
pp. 508-513 ◽  
Author(s):  
Isabela Maria Campanelli dos Santos ◽  
Alexandro Iris Leite ◽  
Maria Eduarda Chiaradia Furquim ◽  
Diego Carlos de Souza Zanatto ◽  
Simone de Jesus Fernandes ◽  
...  
Keyword(s):  
Risk Factors ◽  
Rio Grande ◽  
Female Gender ◽  
Immunofluorescence Assay ◽  
P Value ◽  
Serum Samples ◽  
Igg Antibody ◽  
Source Of Infection ◽  
Antibody Titers ◽  
Toxoplasma Gondii Infection

Abstract Toxoplasmosis is an important zoonosis for pregnant women and immunosuppressed people. The pig population also becomes infected by this pathogen, and undercooked or raw meat is an important source of infection for humans. The aims of the present study were to evaluate the rate of exposure of pigs to T. gondii in the municipality of Mossoró, Rio Grande do Norte and seek to identify associations with possible risk factors. Blood samples were collected from 412 pigs and were analyzed using the immunofluorescence assay. Among these 412 serum samples, 40.7% were seropositive for T. gondii. The IgG antibody titers were 64 (56 specimens), 128 (32), 256 (37), 512 (23), 1024 (14), 2048 (5) and 4046 (1). Seropositivity for T. gondii was found to be related (p-value < 0.05) to the following factors: female gender, semi-confined rearing system, use of well water, dewormed animals, presence of cats, goats, sheep, mice and vultures on the farm and carcasses left on the ground. In contrast, seropositivity was not related (p-value < 0.05) to the age of the pigs, type of facility or feeding with human food remains. Preventive measures need to be adopted on the farms studied here, with the aim of decreasing the animals’ intake of sporulated oocysts.

scholarly journals Response to valganciclovir in chronic fatigue syndrome patients with human herpesvirus 6 and Epstein-Barr virus IgG antibody titers

2012 ◽  
Vol 84 (12) ◽  
pp. 1967-1974 ◽  
Author(s):  
Tessa Watt ◽  
Stephanie Oberfoell ◽  
Raymond Balise ◽  
Mitchell R. Lunn ◽  
Aroop K. Kar ◽  
...  
Keyword(s):  
Chronic Fatigue Syndrome ◽  
Epstein Barr Virus ◽  
Human Herpesvirus ◽  
Chronic Fatigue ◽  
Human Herpesvirus 6 ◽  
Igg Antibody ◽  
Barr Virus ◽  
Fatigue Syndrome ◽  
Antibody Titers ◽  
Epstein Barr

scholarly journals Pneumococcal Type 22F Polysaccharide Absorption Improves the Specificity of a Pneumococcal-Polysaccharide Enzyme-Linked Immunosorbent Assay

2001 ◽  
Vol 8 (2) ◽  
pp. 266-272 ◽  
Author(s):  
Nelydia F. Concepcion ◽  
Carl E. Frasch
Keyword(s):  
Correlation Coefficient ◽  
Immunosorbent Assay ◽  
Pneumococcal Vaccination ◽  
Correlation Coefficients ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Functional Activities ◽  
Antibody Titers ◽  
The Common ◽  
Elisa Inhibition

ABSTRACT The specificity of the immune response to the 23-valent pneumococcal-polysaccharide (PS) vaccine in healthy adults and to a pneumococcal conjugate vaccine in infants was examined by measuring immunoglobulin G (IgG) antibody titers by enzyme-linked immunosorbent assay (ELISA) and the opsonophagocytosis assay. ELISA measures total antipneumococcal IgG titers including the titers of functional and nonfunctional antibodies, while the opsonophagocytosis assay measures only functional-antibody titers. Twenty-four pairs of pre- and post-pneumococcal vaccination sera from adults were evaluated (ELISA) for levels of IgG antibodies against serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F. Twelve of the pairs were also examined (opsonophagocytosis assay) for their functional activities. The correlation coefficients between assay results for most types ranged from 0.75 to 0.90, but the correlation coefficient was only about 0.6 for serotypes 4 and 19F. The specificities of these antibodies were further examined by the use of competitive ELISA inhibition. A number of heterologous polysaccharides (types 11A, 12F, 15B, 22F, and 33A) were used as inhibitors. Most of the sera tested showed cross-reacting antibodies, in addition to those removed by pneumococcal C PS absorption. Our data suggest the presence of a common epitope that is found on most pneumococcal PS but that is not absorbed by purified C PS. Use of a heterologous pneumococcal PS (22F) to adsorb the antibodies to the common epitope increased the correlation between the IgG ELISA results and the opsonophagocytosis assay results. The correlation coefficient improve from 0.66 to 0.92 for type 4 and from 0.63 to 0.80 for type 19F. These common-epitope antibodies were largely absent in infants at 7 months of age, suggesting the carbohydrate nature of the epitope.

scholarly journals Hematological values associated to the serological and molecular diagnostic in cats suspected of Ehrlichia canisinfection

2013 ◽  
Vol 22 (4) ◽  
pp. 470-474 ◽  
Author(s):  
ísis Assis Braga ◽  
Luana Gabriela Ferreira dos Santos ◽  
Andréia Lima Tomé Melo ◽  
Felipe Wolf Jaune ◽  
Thaysa Felfili Ziliani ◽  
...  
Keyword(s):  
Molecular Diagnostic ◽  
Rrna Gene ◽  
Igg Antibody ◽  
Mato Grosso ◽  
Pcr Products ◽  
Antibody Titers ◽  
Polymerase Chain ◽  
Pcr Targeting ◽  
Veterinary Hospital ◽  
Hematological Alterations

The literature contains several studies on feline ehrlichiosis. However, information about the characteristics of Ehrlichiainfection in cats is still scanty. This study evaluated the association between Ehrlichia spp. infection and the hematologic data of 93 cats treated at the Federal University of Mato Grosso Veterinary Hospital in Cuiabá, state of Mato Grosso, Brazil. The presence of or exposure to Ehrlichia spp. infection was evaluated by Polymerase Chain Reaction (PCR) targeting the dsb and 16S rRNA gene of Ehrlichia, and by detection of anti-Ehrlichia canis IgG antibodies in Indirect Fluorescence Assay (IFA), respectively. Eight (8.6%) cats tested positive by PCR and the partial DNA sequence obtained from PCR products was a 100% match to E. canis. Forty-two (45.1%) cats showed antibody reactivity against Ehrlichia spp. Hematological alterations such as low erythrocyte count, thrombocytopenia, lymphopenia and monocytosis were observed in PCR positive cats. Among them, low erythrocyte counts were associated with IgG antibody titers of 40 to 640 and five cats also tested positive by PCR. Furthermore, PCR-positive cats showed a tendency to be lymphopenic. No correlation was found between age and sex, and no ticks were observed in any of the examined cats.

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