scholarly journals Longitudinal analysis of virus load, serum antibody levels and virus neutralizing activity in vitro in cases with less severe COVID-19

2020 ◽  
Author(s):  
Bertram Flehmig ◽  
Michael Schindler ◽  
Natalia Ruetalo ◽  
Ramona Businger ◽  
Manfred Bayer ◽  
...  
Keyword(s):  
Serum Antibody ◽  
Disease Onset ◽  
Igg Antibodies ◽  
Virus Load ◽  
Neutralizing Activity ◽  
N Protein ◽  
Life Threatening ◽  
Antibody Levels ◽  
The Relationship

Background: Patients infected with SARS-CoV-2 exhibit a highly variable clinical course, varying from barely discernible signs of disease, to moderate flu-like symptoms and, occasionally, with life-threatening pneumonia and/or cytokine storm. The relationship between the nasopharyngeal virus load, IgA and IgG antibodies to both the S1-RBD-protein and the N-protein as well the neutralizing activity (NAbs) against SARS-CoV-2 in the blood of moderately afflicted COVID-19 patients has not been investigated longitudinally so far. Methods: Several new serological methods to examine these parameters were developed and validated for the longitudinal investigation in three patients of a family which underwent a mild course of COVID-19. Findings: We observed that the virus load had almost completely disappeared after about four weeks, whereas serum antibodies showed a contrasting course. IgA levels to S1-RBD-protein and, to a lesser extent, to the N-protein, peaked about three weeks after clinical disease onset but declined soon thereafter. IgG levels rose continuously, reaching a plateau approximately six weeks after disease onset. NAbs in serum reached a peak about four weeks after disease onset but dropped to a lower level about six weeks later. Interpretation: Our data establishes associations of virus neutralization and a serological immune response foremost against Sars-CoV-2 S1-RDB-protein in a longitudinal manner.

scholarly journals Persisting Neutralizing Activity to SARS-CoV-2 over Months in Sera of COVID-19 Patients

Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1357
Author(s):  
Bertram Flehmig ◽  
Michael Schindler ◽  
Natalia Ruetalo ◽  
Ramona Businger ◽  
Manfred Bayer ◽  
...  
Keyword(s):  
Clinical Course ◽  
Disease Onset ◽  
Igg Antibodies ◽  
Virus Load ◽  
Neutralizing Activity ◽  
N Protein ◽  
Longitudinal Investigation ◽  
Serum Iga ◽  
The Relationship ◽  
Observation Period

The relationship between the nasopharyngeal virus load, IgA and IgG antibodies to both the S1-RBD-protein and the N-protein, as well as the neutralizing activity (NAbs) against SARS-CoV-2 in the blood of moderately afflicted COVID-19 patients, needs further longitudinal investigation. Several new serological methods to examine these parameters were developed, validated and applied in three patients of a family which underwent an ambulatory course of COVID-19 for six months. The virus load had almost completely disappeared after about four weeks. Serum IgA levels to the S1-RBD-protein and, to a lesser extent, to the N-protein, peaked about three weeks after clinical disease onset but declined soon thereafter. IgG levels rose continuously, reaching a plateau at approximately six weeks, and stayed elevated over the observation period. Virus-neutralizing activity reached a peak about 4 weeks after disease onset but dropped slowly. The longitudinal associations of virus neutralization and the serological immune response suggest immunity in patients even after a mild clinical course of COVID-19.

scholarly journals Longitudinal Analysis of Virus Load, Serum Antibody Levels and Virus Neutralizing Activity In Vitro in Cases with Less Severe COVID-19

2020 ◽  
Author(s):  
Bertram Flehmig ◽  
Michael Schindler ◽  
Natalia Ruetalo ◽  
Ramona Businger ◽  
Manfred Bayer ◽  
...  
Keyword(s):  
Longitudinal Analysis ◽  
Serum Antibody ◽  
Virus Load ◽  
Neutralizing Activity ◽  
Antibody Levels

scholarly journals Ontogenesis of the formation of secretory antibodies to respiratory syncytial (RS) virus

1988 ◽  
Vol 101 (3) ◽  
pp. 565-575 ◽  
Author(s):  
N. P Leschinskaya ◽  
E. E Pokrovskaya ◽  
E. A Kantorovitch ◽  
S.K Grigorjeva ◽  
YA. S Shvartsman
Keyword(s):  
Old Age ◽  
Serum Antibody ◽  
Close Correlation ◽  
Secretory Iga ◽  
Igg Antibodies ◽  
Virus Infections ◽  
Neutralizing Activity ◽  
Iga Antibodies ◽  
Antibody Levels ◽  
Secretory Antibodies

SUMMARYExamination of sera from 184 children aged between 0 and 12 years and 161 adults revealed a close correlation between age and the level of humoral anti-RS virus immunity. Secretory IgG antibodies were found in children in their first months of life. Evidence for their release into secretions from the serum was obtained. This might explain the positive correlation between serum antibody levels in women recently confined with the morbidity due to RS virus in children during their first months of life. Secretory IgA antibodies were found from 4 months untill old age. The secretions of children and adults contained virus-neutralizing activity which was non-immunoglobulin in nature, as well as antibodies. However, in contrast to secretory antibody this material did not prevent development of severe RS virus infections.

scholarly journals Serum anti-DIDO1, anti-CPSF2, and anti-FOXJ2 antibodies as predictive risk markers for acute ischemic stroke

BMC Medicine ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Takaki Hiwasa ◽  
Hao Wang ◽  
Ken-ichiro Goto ◽  
Seiichiro Mine ◽  
Toshio Machida ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Serum Antibody ◽  
Protein Array ◽  
Cdna Libraries ◽  
Igg Antibodies ◽  
Serum Igg ◽  
Predictive Risk ◽  
Ischemic Attack ◽  
Antibody Levels

Abstract Background Acute ischemic stroke (AIS) is a serious cause of mortality and disability. AIS is a serious cause of mortality and disability. Early diagnosis of atherosclerosis, which is the major cause of AIS, allows therapeutic intervention before the onset, leading to prevention of AIS. Methods Serological identification by cDNA expression cDNA libraries and the protein array method were used for the screening of antigens recognized by serum IgG antibodies in patients with atherosclerosis. Recombinant proteins or synthetic peptides derived from candidate antigens were used as antigens to compare serum IgG levels between healthy donors (HDs) and patients with atherosclerosis-related disease using the amplified luminescent proximity homogeneous assay-linked immunosorbent assay. Results The first screening using the protein array method identified death-inducer obliterator 1 (DIDO1), forkhead box J2 (FOXJ2), and cleavage and polyadenylation specificity factor (CPSF2) as the target antigens of serum IgG antibodies in patients with AIS. Then, we prepared various antigens including glutathione S-transferase-fused DIDO1 protein as well as peptides of the amino acids 297–311 of DIDO1, 426–440 of FOXJ2, and 607–621 of CPSF2 to examine serum antibody levels. Compared with HDs, a significant increase in antibody levels of the DIDO1 protein and peptide in patients with AIS, transient ischemic attack (TIA), and chronic kidney disease (CKD) but not in those with acute myocardial infarction and diabetes mellitus (DM). Serum anti-FOXJ2 antibody levels were elevated in most patients with atherosclerosis-related diseases, whereas serum anti-CPSF2 antibody levels were associated with AIS, TIA, and DM. Receiver operating characteristic curves showed that serum DIDO1 antibody levels were highly associated with CKD, and correlation analysis revealed that serum anti-FOXJ2 antibody levels were associated with hypertension. A prospective case–control study on ischemic stroke verified that the serum antibody levels of the DIDO1 protein and DIDO1, FOXJ2, and CPSF2 peptides showed significantly higher odds ratios with a risk of AIS in patients with the highest quartile than in those with the lowest quartile, indicating that these antibody markers are useful as risk factors for AIS. Conclusions Serum antibody levels of DIDO1, FOXJ2, and CPSF2 are useful in predicting the onset of atherosclerosis-related AIS caused by kidney failure, hypertension, and DM, respectively.

scholarly journals Seroprevalence of antibodies for pertussis and diphtheria among people leaving or entering China: a cross-sectional study

2019 ◽  
Vol 13 (05) ◽  
pp. 394-399
Author(s):  
Hui Han ◽  
Zhiqiang Fang ◽  
Xiangguang Ye ◽  
Hailei Wu ◽  
Feng Zuo ◽  
...  
Keyword(s):  
Serum Antibody ◽  
Cross Sectional Study ◽  
Igg Antibodies ◽  
Male Population ◽  
Cross Sectional ◽  
Adult Men ◽  
Population Immunity ◽  
Chinese Adult ◽  
Almost All ◽  
Antibody Levels

Introduction: Despite high population immunity, pertussis remains one of the leading causes of vaccine-preventable deaths worldwide. The aim of this study was to determine the seroprevalence of IgG antibodies to pertussis toxin (PT) and diphtheria among the adult male population leaving or entering China. Methodology: Blood samples were obtained from 240 Chinese and 207 African healthy adults that were leaving and entering China, respectively. Serum IgG antibodies against PT (anti-PT IgG) and diphtheria were determined. Results: The mean concentration of anti-PT IgG antibodies was 13.82 IU/mL and 18.11 IU/mL for the leaving and entering populations, respectively. None of the studied Chinese leaving China were seropositive for pertussis. Of the 240 subjects leaving China, 209 (87.1%) had anti-diphtheria antibody concentrations of ≥ 0.1 IU/mL and 31 (12.9%) had antibody concentrations between 0.01 and 0.099 IU/mL. Eleven (5.31%) of the studied Africans entering China had anti-PT IgG antibodies higher than 30 IU/mL and thus were considered seropositive for pertussis. Of the 207 Africans entering China, antibody concentrations of ≥ 0.1 IU/mL were found in 164 subjects (79.2%) while 43 (20.8%) had antibody concentrations between 0.01 and 0.099 IU/mL. Conclusions: Almost all Chinese adult men leaving China and most African men entering China have very low serum antibody levels of pertussis. Furthermore, the antibody level of diphtheria among these two populations was low among adults. A larger population study is needed to determine whether booster vaccinations against pertussis and diphtheria should be considered for adults in China and also for Africans entering China.

Identification and characterization of a putative agglutination/immobilization antigen on the surface ofCryptocaryon irritans

Parasitology ◽  
2007 ◽  
Vol 134 (9) ◽  
pp. 1163-1174 ◽  
Author(s):  
A. HATANAKA ◽  
N. UMEDA ◽  
S. YAMASHITA ◽  
N. HIRAZAWA
Keyword(s):  
Serum Antibody ◽  
Integral Membrane Protein ◽  
Control Fish ◽  
Booster Immunization ◽  
Immobilization Antigen ◽  
Indirect Immunofluorescence Staining ◽  
Tiger Puffer ◽  
Biochemical Analyses ◽  
Antibody Levels

SUMMARYThe ciliated protozoanCryptocaryon irritans, a parasite of seawater fishes, was found to express an antigen that elicits antibodies in rabbits and tiger puffer (Takifugu ruburipes). Serum from rabbits and fish immunized with theronts had agglutination/immobilization activity against therontsin vitro; fish serum antibody levels (measured by enzyme-linked immunosorbent assays: ELISA) correlated with this activity. Anti-theront antibody levels in fish were significantly higher in the immunized group as compared with control fish at 2 weeks after booster immunization (injection of bovine serum albumin; Student'st-test,P<0·01). Biochemical analyses indicated that a Triton X-114-soluble 32 kDa theront integral membrane protein may be the agglutination/immobilization antigen. Indirect immunofluorescence staining of theronts suggested that this 32 kDa antigen was expressed on the surface of cilia. The full-length 32 kDa antigen cDNA contained 1147 basepairs, encoding a 328-amino acid protein including hydrophobic N- and C-termini. As withTetrahymenaandParameciumspp., TAA and TAG appear to be used as glutamine codons in the 32 kDa antigen gene.

scholarly journals Lack of Humoral Immune Protection againstTreponema denticola Virulence in a Murine Model

1999 ◽  
Vol 67 (11) ◽  
pp. 5736-5746 ◽  
Author(s):  
Lakshmyya Kesavalu ◽  
Stanley C. Holt ◽  
Jeffrey L. Ebersole
Keyword(s):  
Immune Responses ◽  
Primary Infection ◽  
Serum Antibody ◽  
Active Immunization ◽  
Antigenic Specificity ◽  
Immune Protection ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Antibody Levels

ABSTRACT This study investigated the characteristics of humoral immune responses to Treponema denticola following primary infection, reinfection, and active immunization, as well as immune protection in mice. Primary infection with T. denticolainduced a significant (400-fold) serum immunoglobulin G (IgG) response compared to that in control uninfected mice. The IgG response to reinfection was 20,000-fold higher than that for control mice and 10-fold higher than that for primary infection. Mice actively immunized with formalin-killed treponemes developed serum antibody levels seven- to eightfold greater than those in animals after primary infection. Nevertheless, mice with this acquired antibody following primary infection or active immunization demonstrated no significant alterations of lesion induction or decreased size of the abscesses following a challenge infection. Mice with primary infection developed increased levels of IgG3, IgG2b, and IgG2a antibodies, with IgG1 being lower than the other subclasses. Reinfected mice developed enhanced IgG2b, IgG2a, and IgG3 and less IgG1. In contrast, immunized mice developed higher IgG1 and lower IgG3 antibody responses to infection. These IgG subclass distributions indicate a stimulation of both Th1 and Th2 activities in development of the humoral immune response to infection and immunization. Our findings also demonstrated a broad antigen reactivity of the serum antibody, which was significantly increased with reinfection and active immunization. Furthermore, serum antibody was effective in vitro in immobilizing and clumping the bacteria but did not inhibit growth or passively prevent the treponemal infection. These observations suggest that humoral immune responses, as manifested by antibody levels, isotype, and antigenic specificity, were not capable of resolving a T. denticola infection.

scholarly journals REGULATION OF ANTIBODY FORMATION BY SERUM ANTIBODY

1970 ◽  
Vol 132 (6) ◽  
pp. 1279-1287 ◽  
Author(s):  
Jean-Claude Bystryn ◽  
Martin W. Graf ◽  
Jonathan W. Uhr
Keyword(s):  
Antibody Formation ◽  
Exchange Transfusion ◽  
Serum Antibody ◽  
Igg Antibodies ◽  
Neutralization Titer ◽  
Peak Titer ◽  
Antibody Levels

Rabbits were immunized to two antigens and 18–55 days later exchange transfusion was performed using blood of rabbits immunized to one antigen only. By this means, serum antibody levels to one antigen were reduced 50–84% while maintaining serum antibody levels to the second antigen. After exchange, serum antibody levels of the removed antibody rose rapidly for 24–48 hr and then more slowly, reaching peak titers an average of 8 days later. The peak titer was 48–222% higher than the preexchange titer. The specificity of this rebound excluded as a cause nonspecific changes in Ig levels. Passive administration of antibody to a third antigen 4–7 days before the exchange indicated that re-equilibration of preformed antibody was not a major factor in the rebound. A change in the ratio of IgM to IgG antibodies as a cause of an increased neutralization titer in the postexchange sera was also excluded. It was therefore suggested that a change in the rate of antibody formation had occurred, although other changes in the quality of serum antibody were not excluded.

Prevalence and persistence of Chlamydia trachomatis-specific antibodies after occasional and recurrent infections

2019 ◽  
Vol 96 (4) ◽  
pp. 277-282 ◽  
Author(s):  
Hanna Öhman ◽  
Tiina Rantsi ◽  
Päivi Joki-Korpela ◽  
Aila Tiitinen ◽  
Heljä-Marja Surcel
Keyword(s):  
Serum Antibody ◽  
Recurrent Infection ◽  
Chlamydia Infection ◽  
Recurrent Infections ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Initial Infection ◽  
Humoral Immune ◽  
Antibody Levels

ObjectivesPopulation-based Chlamydia trachomatis seroepidemiological studies help to identify trends in chlamydia infection. However, an improved understanding of the antibody response to infection is required when using serology to estimate cumulative incidence. Thus, the objectives of this longitudinal, retrospective, biobank-based study were to assess the appearance and persistence of C. trachomatis major outer membrane protein (MOMP)-specific serum IgG antibodies after infection and to evaluate the role of antibodies in providing protective immunity against recurrent infection.MethodsData of notified C. trachomatis infections in Finland were obtained from the National Infectious Diseases Register. Serum samples were acquired from the Finnish Maternity Cohort. 411 women with single chlamydia infection and 62 women with recurrent infections, and for whom suitable paired serum samples were available, were included in the study. Antibody appearance, persistence after infection and the impact of recurrent infections were evaluated. IgG antibodies specific for MOMP were measured from serum using an ELISA method.ResultsAnti-C. trachomatis MOMP-specific IgG antibodies were detected in 65.5% (269/411) of women within 3 months of notification of infection. In the absence of recurrent infection, seroprevalence declined to 34.5% (142/411) 3–10 years after the initial infection. The serum antibody levels at baseline correlated positively with seroprevalence at follow-up. Reinfection boosted the humoral immune response by increasing seroprevalence and the serum antibody levels. Seroprevalence within 3 months after first notification of infection was 65.5% (19/29) in women who were later diagnosed with recurrent infection, comparable with women with single notification of infection (65.5%, 269/411).ConclusionsApproximately one-third of women with single notification of chlamydia infection remain seropositive 3–10 years after the initial infection. The concentration of antibodies remained stable during the follow-up. Recurrent infection boosted the humoral immune response, but reinfection occurred despite the presence of pre-existing antibodies.

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