Analysis of viral load in different specimen types and serum antibody levels of COVID-19 patients

Abstract Background COVID-19 has caused a global pandemic and the death toll is increasing. However, there is no definitive information regarding the type of clinical specimens that is the best for SARS-CoV-2 detection, the antibody levels in patients with different duration of disease, and the relationship between antibody level and viral load. Methods Nasopharyngeal swabs, anal swabs, saliva, blood, and urine specimens were collected from patients with a course of disease ranging from 7 to 69 days. Viral load in different specimen types was measured using droplet digital PCR (ddPCR). Meanwhile, anti-nucleocapsid protein (anti-N) IgM and IgG antibodies and anti-spike protein receptor-binding domain (anti-S-RBD) IgG antibody in all serum samples were tested using ELISA. Results The positive detection rate in nasopharyngeal swab was the highest (54.05%), followed by anal swab (24.32%), and the positive detection rate in saliva, blood, and urine was 16.22%, 10.81%, and 5.41%, respectively. However, some patients with negative nasopharyngeal swabs had other specimens tested positive. There was no significant correlation between antibody level and days after symptoms onset or viral load. Conclusions Other specimens could be positive in patients with negative nasopharyngeal swabs, suggesting that for patients in the recovery period, specimens other than nasopharyngeal swabs should also be tested to avoid false negative results, and anal swabs are recommended. The antibody level had no correlation with days after symptoms onset or the viral load of nasopharyngeal swabs, suggesting that the antibody level may also be affected by other factors.

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Antibody level of New Zealand children immunized with the triple vaccine DTP (diphtheria-tetanus-pertussis)

Epidemiology and Infection ◽

10.1017/s0950268800054352 ◽

1988 ◽

Vol 101 (2) ◽

pp. 405-410 ◽

Cited By ~ 2

Author(s):

R. C. H Lau

Keyword(s):

New Zealand ◽

Immunosorbent Assay ◽

Antibody Level ◽

Herd Immunity ◽

Enzyme Linked Immunosorbent Assay ◽

Igg Antibody ◽

Immunization Strategy ◽

The Mean ◽

Antibody Levels

SUMMARYEnzyme-linked immunosorbent assay (ELISA) tests were used to measure IgG antibody levels in 2638 New Zealand children who had been immunized with the triple vaccine DTP. The percentage of children immune to diphtheria decreased with age. The percentage of children immune to tetanus varied from 67.1 to 55.0%. The percentage of children with measurable antibody to pertussis increased with age. The mean percentages of children with measurable antibody or immunity to one or more DTP components were 34.2% (with 3 components), 34.4% (2 components), and 78.1% (1 component). It appears the immunization strategy for diphtheria and tetanus is satisfactory for herd immunity in New Zealand children. However, the current pertussis strategy may not be providing adequate immunity to 5-year-olds in this country.

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Serum epitope repertoire analysis enables early detection of Lyme disease with improved sensitivity in an expandable multiplex format

Journal of Clinical Microbiology ◽

10.1128/jcm.01836-20 ◽

2020 ◽

Author(s):

Jack Reifert ◽

Kathy Kamath ◽

Joel Bozekowski ◽

Ewa Lis ◽

Elizabeth J. Horn ◽

...

Keyword(s):

Lyme Disease ◽

Motif Discovery ◽

False Negative ◽

Serum Antibody ◽

High Sensitivity ◽

Bioinformatic Analysis ◽

Lyme Arthritis ◽

Igg Antibody ◽

Repertoire Analysis ◽

Validation Set

Widely employed diagnostic antibody serology for Lyme disease, known as standard two-tier testing (STTT), exhibits insufficient sensitivity in early Lyme disease yielding many thousands of false negative test results each year. Given this problem, we applied serum antibody repertoire analysis (SERA), or NGS-based serology, to discover IgG and IgM antibody epitope motifs capable of detecting Lyme disease specific antibodies with high sensitivity and specificity. Iterative motif discovery and bioinformatic analysis of epitope repertoires from subjects with Lyme disease (n = 264) and controls (n = 391) yielded a set of 28 epitope motifs representing 20 distinct IgG antibody epitopes, and set of 38 epitope motifs representing 21 distinct IgM epitopes which performed equivalently in a large validation cohort of STTT positive samples. In a second validation set from subjects with clinically-defined early Lyme disease (n=119) and controls (n = 257), the SERA Lyme IgG and IgM assay exhibited significantly improved sensitivity relative to STTT (77% vs. 62%, z-test, p = 0.013) and improved specificity (99% vs. 97%). Early Lyme disease subjects exhibited significantly fewer reactive epitopes (Mann-Whitney U-test, p < 0.0001), relative to subjects with Lyme arthritis. Thus, SERA Lyme IgG and M panels provided increased accuracy in early Lyme disease, in a readily expandable multiplex assay format.

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Antibody response induced by the boost overdose during COVID-19 heterologous prime-boost vaccination strategy: A four-case study

10.21203/rs.3.rs-885163/v1 ◽

2021 ◽

Author(s):

Francisco Raposo ◽

Giuseppe Lippi

Keyword(s):

Antibody Response ◽

Antibody Level ◽

Serum Antibody ◽

Vaccine Dose ◽

Vaccination Strategy ◽

Vaccination Schedule ◽

Boost Vaccination ◽

Boost Vaccine ◽

Antibody Levels ◽

Ig G

Abstract Objectives The main purpose of this study was to evaluate the anti-SARS-CoV-2 RBD Ig G antibody response in BNT162b2 vaccine recipients who erroneously received vaccine overdose. Methods Measurement of antibody levels at different time-points was performed to define the dynamics of immunization after a wrongly vaccination schedule. Three recipients had no previous evidence of infection and received the first shot of Oxford/AstraZeneca before the Pfizer/BioNTech vaccine. Another patient, formerly infected by SARS-CoV-2, received one shot of BNT162b2 vaccine. Results At day 6 after the second vaccine dose the serum increase of anti-SARS-CoV-2 RBD Ig G antibodies was analogous for the three SARS-CoV-2 naïve recipients. At 14 days the antibody level increased and reached a peak, though displaying a different pattern among the three recipients. At 21 days the serum antibody level started to decrease from its maximum value. The data for the previously infected recipient were in agreement with values found in COVID-19 positive receivers. Thus, after the single prime-dose of vaccine, the elicited antibody response was similar to prime-boost vaccination in naïve recipients. Conclusions This study confirms the efficiency of the BNT162b vaccine in eliciting a sustained antibody response as heterologous boost-vaccine in previously Oxford/AstraZeneca vaccinated recipients, as well as, prime-vaccine in COVID-19 infected receivers. Importantly, the humoral immunity response of recipients was not proportional to the vaccine overdose. Nonetheless, we cannot portray a univocal effect of vaccine overdose concerning anti-SARS-CoV-2 antibody response because the values found especially in the three SARS-CoV-2 naïve subjects were highly heterogeneous.

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SARS-CoV-2 Neutralizing Antibody Levels Post COVID-19 Vaccination Based on ELISA Method—A Small Real-World Sample Exploration

Vaccines ◽

10.3390/vaccines9101139 ◽

2021 ◽

Vol 9 (10) ◽

pp. 1139

Author(s):

Xiaoguang Li ◽

Chao Liang ◽

Xiumei Xiao

Keyword(s):

Neutralizing Antibodies ◽

Detection Rate ◽

Neutralizing Antibody ◽

Population Characteristics ◽

Detection Rates ◽

Positive Detection Rate ◽

Significant Difference ◽

Positive Rate ◽

Antibody Levels

This study investigated the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing antibodies following inoculation with the coronavirus disease (COVID-19) vaccine. From June to July 2021, 127 participants who had completed COVID-19 vaccination (inactivated SARS-CoV-2 vaccine, 64; CoronaVac, 61; CanSino, 2) were recruited and tested using SARS-CoV-2 neutralizing antibody kits. The positive detection rate (inhibition of neutralizing antibodies ≥ 30%) was calculated and stratified according to population characteristics and inoculation time. The positive rate of neutralizing antibody was 47.22% (17/36) in men and 53.85% (49/91) in women, and 54.55% (24/44) in BMI ≥ 24 and 50.60% (42/83) in BMI < 24. Age was stratified as 20–29, 30–39, 40–49, and ≥50; positive detection rates of SARS-CoV-2 neutralizing antibodies were observed in 60.00% (24/40), 50.00% (21/42), 48.39% (15/31), and 42.86% (6/14), respectively, but with no significant difference (x2 = 1.724, p = 0.632). Among 127 vaccinated participants, 66 (51.97%) were positive. The positive detection rate was 63.93% (39/61) with CoronaVac and 42.19% (27/64) with the inactivated SARS-CoV-2 vaccine (significance x2 = 5.927, p = 0.015). Multivariate analysis revealed a significant difference in vaccination times, with average vaccination weeks in the positive and negative groups of 11.57 ± 6.48 and 17.87 ± 9.17, respectively (t= −4.501, p < 0.001). The positive neutralizing antibody rate was 100.00%, 60.00%, 58.33%, 55.56%, 43.14%, 28.57%, and 0.00% at 2–4, 5–8, 9–12, 13–16,17–20, 21–24, and >24 weeks, respectively (x2 = 18.030, p = 0.006). Neutralizing antibodies were detected after COVID-19 inoculation, with differences relating to inoculation timing. This study provides a reference for vaccine evaluation and follow-up immunization strengthening.

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Immunologic Response to Pneumococcal Polysaccharide Vaccine in Infants

Annals of Otology Rhinology & Laryngology ◽

10.1177/00034894800890s382 ◽

1980 ◽

Vol 89 (3_suppl) ◽

pp. 351-356 ◽

Cited By ~ 8

Author(s):

John L. Sloyer ◽

Laurel J. Karr ◽

John H. Ploussard ◽

Gerald D. Schiffman

Keyword(s):

Antibody Response ◽

Otitis Media ◽

Natural Infection ◽

Young Infant ◽

Serum Antibody ◽

Capsular Polysaccharides ◽

Igg Antibody ◽

Nasopharyngeal Colonization ◽

Antibody Levels ◽

Group 1

The serum antibody response to purified pneumococcal capsular polysaccharides (PCP) was determined in four groups of infants ranging in age from 3 to 24 months. Group 1 consisted of eight infants immunized with an octavalent vaccine containing serotypes 1, 3, 6, 7, 14, 18, 19 and 23 (PCP-8). Group 1 received 25 μg of each serotype at 3–6 months of age and again at 18–24 months. The antibody response after the second immunization was compared to a group of nine patients receiving a primary immunization at 18–24 months and to a group of ten age-matched controls receiving saline placebo. There were no significant differences in mean serum antibody levels between the two groups receiving the PCP-8. A fourth group of 44 infants between 6 and 21 months of age received either PCP-7 or PCP-8 and were followed for two years, at which time simultaneous injections of both vaccines were administered. Types 2, 3, 7, and 8 were most immunogenic but levels six months after immunization were approximately the same as for unimmunized controls with the exception of serotypes 3 and 7 which persisted for about two years. The class of antibody induced either by natural infection or by immunization was preferentially IgG and it was more often induced by the former. There were no significant differences between the serotypes of pneumococci isolated from nasopharyngeal cultures regardless of which vaccine was administered. Finally, the least immunogenic serotypes include 4, 6, 14, 19, and 23 and these are the only serotypes thus far associated with otitis media after immunization. The results suggest that PCP do not induce a lasting immune tolerance at the dose administered in this study; PCP are not very immunogenic in the young infant; PCP antibody tends to rise naturally; IgG antibody is preferentially induced; nasopharyngeal colonization is not altered by PCP immunization; and an association may exist between PCP immunogenicity and subsequent onset of otitis media.

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Serum Immunoglobulin G Antibody To Periodontal Bacteria

Advances in Dental Research ◽

10.1177/08959374880020022401 ◽

1988 ◽

Vol 2 (2) ◽

pp. 339-345 ◽

Cited By ~ 77

Author(s):

Y. Murayama ◽

A. Nagai ◽

K. Okamura ◽

H. Kurihara ◽

Y. Nomura ◽

...

Keyword(s):

Periodontal Disease ◽

Serum Antibody ◽

Fusobacterium Nucleatum ◽

Periodontal Treatment ◽

Enzyme Linked Immunosorbent Assay ◽

Igg Antibody ◽

Periodontal Bacteria ◽

Serological Data ◽

Micro Organisms ◽

Antibody Levels

The purpose of this study was to assess the serum antibody levels to periodontal bacteria in patients with periodontal disease, and to explore the diagnostic uses of the serum antibody assessment and its potential as a therapeutic guide. One hundred twenty-nine patients were clinically examined for the type and extent of periodontal destruction and serum IgG antibody levels to Actinobacillus actinomycetemcomitans (Aa), Actinomyces israelii (Ai), A. viscosus (Av), Bacteroides asaccharolyticus (Ba), B. corporis (Bc), B. denticola (Bd), B. gingivalis (Bg), B. intermedius (Bi), B. loescheii (BI), Capnocytophaga gingivalis (Cg), C. ochracea (Co), and Fusobacterium nucleatum (Fn). Clinical and serological data were subjected to correlation analyses. A small group of patients was monitored during the progress of periodontal treatments. The IgG antibody levels were assessed with an enzyme-linked immunosorbent assay (ELISA). Significantly elevated IgG antibody levels were manifested to Aa, Ai, Bg, and Fn in all forms of periodontal disease, additionally to Cg and Co in juvenile periodontitis, and to Bi in adult periodontitis. There were some correlations between a few clinical parameters and the antibody levels. Successful periodontal treatment significantly decreased the antibody levels to all of the micro-organisms; however, during periodontal treatment, there were no marked differences between pre- and post-treatment levels. The antibody reactivities to the periodontopathic micro-organisms may be of diagnostic and predictive value in patients.

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Multicenter evaluation of the Panbio™ COVID-19 Rapid Antigen-Detection Test for the diagnosis of SARS-CoV-2 infection

10.1101/2020.11.18.20230375 ◽

2020 ◽

Author(s):

Paloma Merino-Amador ◽

Jesús Guinea ◽

Irene Muñoz-Gallego ◽

Patricia González-Donapetry ◽

Juan-Carlos Galán ◽

...

Keyword(s):

Viral Load ◽

Clinical Symptoms ◽

False Negative ◽

Rapid Test ◽

Antigen Detection ◽

Nasopharyngeal Swab ◽

Diagnostic Strategy ◽

Rt Pcr ◽

University Hospitals ◽

Kappa Score

AbstractThe standard RT-PCR assay for COVID-19 is laborious and time-consuming, limiting the availability of testing. Rapid antigen-detection tests are faster and less expensive; however, the reliability of these tests must be validated before they can be used widely. The objective of this study was to determine the reliability of the PanbioTM COVID-19 Ag Rapid Test Device (PanbioRT) (Abbott) for SARS-CoV-2 in nasopharyngeal swab specimens. This was a prospective multicenter study in ten Spanish university hospitals of patients from hospital units with clinical symptoms or epidemiological criteria for COVID-19. Patients whose onset of symptoms or exposure was more than 7 days earlier were excluded. Two nasopharyngeal exudate samples were taken to perform the PanbioRT and a diagnostic RT-PCR test. Among the 958 patients studied, 359 (37.5%) were positive by RT-PCR and 325 (33.9%) were also positive by the PanbioRT. Agreement was 95.7% (kappa score: 0.90). All 34 false-negative PanbioRT results were in symptomatic patients, with 23.5% of them at 6–7 days since the onset of symptoms and 58.8% presenting CT >30 values for RT-PCR, indicating a low viral load. Overall sensitivity and specificity for the PanbioRT were 90.5% and 98.8%, respectively. The PanbioRT provides good clinical performance as a point-of-care test, with even more reliable results for patients with a shorter clinical course of the disease or a higher viral load. While this study has had a direct impact on the national diagnostic strategy for COVID-19 in Spain, the results must be interpreted based on the local epidemiological context.

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Seroprevalence of Aspergillus-Specific IgG Antibody among Mozambican Tuberculosis Patients

Journal of Fungi ◽

10.3390/jof7080595 ◽

2021 ◽

Vol 7 (8) ◽

pp. 595

Author(s):

Helmut J. F. Salzer ◽

Isabel Massango ◽

Nilesh Bhatt ◽

Emelva Machonisse ◽

Maja Reimann ◽

...

Keyword(s):

Antibody Level ◽

Hiv Positive ◽

Igg Antibody ◽

Tuberculosis Patients ◽

Tb Treatment ◽

Life Threatening ◽

Specific Igg ◽

Limited Health ◽

Antibody Levels ◽

Hiv Negative

Background: Chronic pulmonary aspergillosis (CPA) is a life-threatening sequel in patients with pulmonary tuberculosis (PTB). Aspergillus-specific IgG antibody is a useful diagnostic biomarker supporting CPA diagnosis, especially in countries with limited health recourses. Methods: We conducted a prospective pilot study to assess the seroprevalence of Aspergillus-specific IgG antibodies among 61 Mozambican tuberculosis patients before, during, and after the end of TB treatment. Aspergillus-specific IgG antibody levels were measured using the ImmunoCAP®. Results: In this study, 3 out of 21 HIV-negative PTB patients had a positive Aspergillus-specific IgG antibody level before, during, and after the end of TB treatment. Antibody levels were 41.1, 45.5, and 174 mg/L at end of treatment (EOT), respectively. Additionally, two HIV-negative PTB patients with negative Aspergillus-specific IgG antibody levels at baseline became seropositive at EOT (41.9 and 158 mg/L, respectively). Interestingly, none of the HIV-positive PTB patients (40/61) had a positive Aspergillus-specific IgG antibody level at any time, neither at baseline nor at EOT. Probable CPA was diagnosed in one HIV-negative patient (5%; 1/20). Conclusion: Seroprevalence of Aspergillus-specific IgG antibody may differ between HIV-negative and HIV-positive Mozambican PTB patients. Future studies evaluating post-tuberculosis lung disease should integrate CPA as a life-threatening sequel to PTB.

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Antibody Response to Pertussis Vaccination in Pregnant and Non-Pregnant Women—The Role of Sex Hormones

Vaccines ◽

10.3390/vaccines9060637 ◽

2021 ◽

Vol 9 (6) ◽

pp. 637

Author(s):

Victoria Peer ◽

Khitam Muhsen ◽

Moshe Betser ◽

Manfred S Green

Keyword(s):

Immune Response ◽

Pregnant Women ◽

Sex Hormones ◽

Odds Ratio ◽

Geometric Mean ◽

Multiple Logistic Regression Analysis ◽

Serum Antibody ◽

Igg Antibody ◽

Antibody Levels

Pertussis containing vaccine is recommended for pregnant women to protect neonates prior to being fully immunized against the disease. The immune response during pregnancy may be impacted by changes in the hormonal status. The aim of this study was to evaluate the immune response to pertussis immunization in pregnancy and to assess the role of sex hormones. In a cross-sectional study, blood samples were drawn from 174 pregnant and 74 non-pregnant women 45–60 days following immunization. Anti-pertussis toxin (Anti-PT) IgG antibody levels, estrogen, and progestogen concentrations were compared between the two groups. Multiple logistic regression analysis was used to examine the association between serum antibody and sex hormone concentrations in each group, controlling for age, body mass index (BMI), and smoking status. The geometric mean concentration (GMC) of anti-PT IgG antibody was significantly higher in non-pregnant women compared with pregnant women (median of 2.09 and 1.86, interquartile range = 2.36–1.8 and 2.11–1.16 respectively, p < 0.0001). Among pregnant women, the anti-PT IgG antibody GMC was negatively associated with both progesterone (odds ratio = 0.300, 95% CI = 0.116, 0.772, p = 0.013) and estrogen (odds ratio = 0.071, 95% CI = 0.017, 0.292, p < 0.0001), after controlling for age, BMI, and smoking. Pregnancy was associated with lower anti-PT IgG antibody levels (odds ratio = 0.413, 95% CI = −0.190, 0.899, p = 0.026). This appears to be at least partially explained by the higher levels of hormones during pregnancy. These findings demonstrate the important role of sex hormones in the response to pertussis vaccine during pregnancy and can help to evaluate the optimum vaccination schedule.

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Serum antibody response in COVID-19-recovered patients who retested positive

Canada Communicable Disease Report ◽

10.14745/ccdr.v47i04a03 ◽

2021 ◽

Vol 47 (04) ◽

pp. 195-201

Author(s):

Nicole Atchessi ◽

Megan Striha ◽

Rojiemiahd Edjoc ◽

Christine Abalos ◽

Amanda Lien ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Antibody Response ◽

Reverse Transcription ◽

False Negative ◽

Serum Antibody ◽

Immunoglobulin M ◽

Rt Pcr ◽

Chain Reaction ◽

Polymerase Chain ◽

Antibody Levels

Background: Research studies comparing antibody response from coronavirus disease 2019 (COVID-19) cases that retested positive (RP) using reverse transcription polymerase chain reaction (RT-PCR) and those who did not retest positive (NRP) were used to investigate a possible relationship between antibody response and retesting status. Methods: Seven data bases were searched. Research criteria included cohort and case-control studies, carried out worldwide and published before September 9, 2020, that compared the serum antibody levels of hospitalized COVID-19 cases that RP after discharge to those that did NRP. Results: There is some evidence that immunoglobulin G (IgG) and immunoglobulin M (IgM) antibody levels in RP cases were lower compared with NRP cases. The hypothesis of incomplete clearance aligns with these findings. The possibility of false negative reverse transcription polymerase chain reaction (RT-PCR) test results during viral clearance is also plausible, as concentration of the viral ribonucleic acid (RNA) in nasopharyngeal and fecal swabs fluctuate below the limits of RT-PCR detection during virus clearance. The probability of reinfection was less likely to be the cause of retesting positive because of the low risk of exposure where cases observed a 14 day-quarantine after discharge. Conclusion: More studies are needed to better explain the immune response of recovered COVID-19 cases retesting positive after discharge.

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