scholarly journals Performance of IgG avidity in an area endemic for schistosomiasis in Egypt

2002 ◽  
Vol 08 (01) ◽  
pp. 172-180
Author(s):  
L. M. Abou Basha ◽  
A. Y. Shehab ◽  
M. Abdel Fattah ◽  
A. Bassili
Keyword(s):  
Age Groups ◽  
Chronic Infections ◽  
Avidity Index ◽  
Igg Antibody ◽  
Igg Avidity ◽  
Praziquantel Treatment ◽  
Avidity Test ◽  
Treatment Support ◽  
Antibody Levels ◽  
Immunoglobulin Levels

We assessed the performance of IgG avidity in the diagnosis of acute, chronic and recent [reinfection] on top of chronic schistosomal infections in patients treated with praziquantel. Immunoglobulin levels were studied in 111 patients with Schistosoma mansoni infection and 28 partially cured patients [not responding to the first dose of praziquantel treatment and almost cured after a second one]. Before treatment all patients with schistosomiasis had elevated IgG levels, 75% of them also had increased IgM levels. Avidity index was high among all age groups. The increased IgM/IgG ratio and avidity index among children with schistosomiasis before treatment support the idea of reinfection. Treatment had no significant effect on the studied parameters. We conclude that unlike IgM and IgG antibody levels, IgG avidity test cannot be used to distinguish between recent and chronic infections.

scholarly journals Age-dependent immune response to the Biontech/Pfizer BNT162b2 COVID-19 vaccination

2021 ◽  
Author(s):  
Lisa Müller ◽  
Marcel Andrée ◽  
Wiebke Moskorz ◽  
Ingo Drexler ◽  
Lara Walotka ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Age Groups ◽  
Real Life ◽  
The Elderly ◽  
Igg Antibody ◽  
Real Life Data ◽  
Antibody Titers ◽  
Protection Against Infection ◽  
Vaccination Campaigns ◽  
Antibody Levels

AbstractBackgroundThe SARS-CoV-2 pandemic has led to the development of various vaccines. Real-life data on immune responses elicited in the most vulnerable group of vaccinees over 80 years old is still underrepresented despite the prioritization of the elderly in vaccination campaigns.MethodsWe conducted a cohort study with two age groups, young vaccinees below the age of 60 and elderly vaccinees over the age of 80, to compare their antibody responses to the first and second dose of the BNT162b2 COVID-19 vaccination.ResultsWhile the majority of participants in both groups produced specific IgG antibody titers against SARS-CoV-2 spike protein, titers were significantly lower in elderly participants. Although the increment of antibody levels after the second immunization was higher in elderly participants, the absolute mean titer of this group remained lower than the <60 group. After the second vaccination, 31.3 % of the elderly had no detectable neutralizing antibodies in contrast to the younger group, in which only 2.2% had no detectable neutralizing antibodies.ConclusionOur data suggests that lower frequencies of neutralizing antibodies after BNT162b2 vaccination in the elderly population may require earlier revaccination to ensure strong immunity and protection against infection.

scholarly journals IgG Avidity in Samples Collected on Filter Paper: Importance of The Early Diagnosis of Congenital Toxoplasmosis

2021 ◽  
Vol 43 (12) ◽  
pp. 887-893
Author(s):  
Jéssica Yonara de Souza ◽  
Taynara Cristina Gomes ◽  
Hanstter Hallison Alves Rezende ◽  
Heloisa Ribeiro Storchilo ◽  
Patrícia Giffron Rodrigues ◽  
...  
Keyword(s):  
Filter Paper ◽  
Peripheral Blood ◽  
Congenital Toxoplasmosis ◽  
Immunoglobulin M ◽  
High Avidity ◽  
Igg Antibody ◽  
Blood Samples ◽  
Prick Test ◽  
Igg Avidity ◽  
Avidity Test

Abstract Objective The purpose of the present study is to standardize and evaluate the use of the immunoglobulin G (IgG) antibody avidity test on blood samples from newborns collected on filter paper to perform the heel test aiming at its implementation in ongoing programs. Methods Blood samples from newborns were collected on filter paper simultaneously with the heel prick test. All samples were subjected to immunoglobulin M IgM and IgG enzyme-linked immunosorbent assays (ELISA). Peripheral blood was collected again in the traditional way and on filter paper from newborns with high IgG levels (33). Three types of techniques were performed, the standard for measuring IgG in serum, adapted for filter paper and the technique of IgG avidity in serum and on filter paper. The results of the avidity test were classified according to the Rahbari protocol. Results Among the 177 samples, 17 were collected in duplicate from the same child, 1 of peripheral blood and 1 on filter paper. In this analysis, 1 (5.88%) of the 17 samples collected in duplicate also exhibited low IgG avidity, suggesting congenital infection. In addition, the results obtained from serum and filter paper were in agreement, that is, 16 (94.12%) samples presented high avidity, with 100% agreement between the results obtained from serum and from filter paper. Conclusion The results of the present study indicate that the avidity test may be another valuable method for the diagnosis of congenital toxoplasmosis in newborns.

scholarly journals Assessment of an in-house ELISA and IgG avidity test based on SAG1 and GRA7 proteins for discriminating between acute and chronic toxoplasmosis in humans

2021 ◽  
Author(s):  
Aref Teimouri ◽  
Mohammad Javad Abbaszadeh Afshar ◽  
Sina Mohtasebi ◽  
Sanaz Jafarpour Azami ◽  
Rasoul Alimi ◽  
...  
Keyword(s):  
Area Under Curve ◽  
Roc Analysis ◽  
Operating Characteristic ◽  
Igg Antibodies ◽  
Chronic Infections ◽  
Igg Avidity ◽  
Avidity Test ◽  
Specific Igg ◽  
Commercial Kits ◽  
Lysate Antigens

To improve serodiagnostic methods for diagnosis of acute from chronic toxoplasmosis, an economical in-house ELISA for measuring Toxoplasma -specific IgG, IgM and IgG avidity has been developed and assessed based on use of various T. gondii antigens, including SAG1, GRA7 and a combination of SAG1 and GRA7 (SAG1+GRA7) as well as Toxoplasma lysate antigens (TLAs). Performances of in-house IgM, IgG and IgG avidity assays were compared to those of ELISA commercial kits and VIDAS Toxo IgG avidity. A set of 138 sera from patients with acquired T. gondii infection and seronegative people were assessed. Receiver operating characteristic (ROC) analysis revealed an area under curve (AUC) of 0.98, 0.97, 0.99 and 0.99 for IgM-TLAs, IgM-SAG1, IgM-GRA7, and IgM-SAG1+GRA7, respectively. Furthermore, AUC was calculated as 0.99, 0.99, 0.98 and 0.99 for IgG-TLAs, IgG-SAG1, IgG-GRA7 and IgG-SAG1+GRA7, respectively. The current study showed that GRA7 included 100% sensitivity for the detection of Toxo IgM, while SAG1 included 89.7% sensitivity. Furthermore, the highest specificity (97.2%) to detect Toxo IgM was achieved using SAG1+GRA7 antigen. For the detection of Toxo IgG, the highest sensitivity (100%) was recorded for SAG1+GRA7 followed by TLAs (97.9%). The SAG1+GRA7 showed the greatest potential for assessing avidity of IgG antibodies with 97.1% of sensitivity and 96.6% of specificity, compared to VIDAS Toxo IgG avidity. The preliminary results have promised better discriminations between acute and chronic infections using a combination of SAG1 and GRA7 recombinant antigens, compared to TLAs.

EVALUATION OF Toxoplasma gondii SEROPREVALENCE AND IGG AVIDITY TEST RESULTS AMONG CHILDBEARING-AGE WOMEN IN KARABUK PROVINCE

2021 ◽  
Vol 6 (12) ◽  
pp. 98-103
Author(s):  
Meryem COLAK ◽  
Nergis ASGIN
Keyword(s):  
Toxoplasma Gondii ◽  
Congenital Toxoplasmosis ◽  
Epidemiological Data ◽  
Test Results ◽  
Childbearing Age ◽  
Igg Antibody ◽  
Seropositivity Rate ◽  
Igg Avidity ◽  
Avidity Test ◽  
Childbearing Age Women

Toxoplasmosis is a zoonotic infectious disease that is common worldwide and caused by the Toxoplasma gondii. Congenital toxoplasmosis is one of the major complications of this infection. The present study aimed to investigate T.gondii seroprevalence and evaluate the IgG avidity test results among childbearing- age women retrospectively. A total of 9401 samples obtained from childbearing -age (15-49 years of age) women who attended Karabuk University Training and Research Hospital between February 2016- January 2020, over the four-year, were included in the study.The Toxoplasma-IgM, Toxoplasma-IgG antibody, and Toxoplasma IgG avidity tests were analyzed chemiluminescent method by using ARCHITECT I 2000 SR immunoassay device (Abbott Laboratories, USA). Toxoplasma-IgM and Toxoplasma-IgG seropositivity were detected as 0.7% (67/9401) and 15.7% (1415/9005) respectively. A high percentage of Toxoplasma-IgM and Toxoplasma-IgG seropositivity were detected among 31-35 years of age group. The Toxoplasma seropositivity increased by age, but no statistically difference was found (P >0.05).The Toxoplasma IgG avidity was high in 45 patients (69.4%), low avidity was detected in 16 patients (22.6%) and from the remaining 6 patients were borderline (8%). The Toxoplasma IgM and IgG seropositivity rate decreased 2016 to 2020. The highest Toxoplasma IgM and IgG seropositivity were in 2016 with 1.2% and 16.8%, respectively. The T. gondi seropositivity rate was decreased from 2016 to 2020; it is probably a result of increasing awareness of the disease among patients. We think our results will contribute to the epidemiological data in our province and country and raise awareness.

scholarly journals Older Adults Have a Low Capacity To Opsonize Pneumococci Due to Low IgM Antibody Response to Pneumococcal Vaccinations

2010 ◽  
Vol 79 (1) ◽  
pp. 314-320 ◽  
Author(s):  
Saeyoung Park ◽  
Moon H. Nahm
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Age Groups ◽  
Functional Difference ◽  
Igg Antibody ◽  
Igm Antibodies ◽  
Igm Antibody ◽  
Significant Difference ◽  
The Difference ◽  
Antibody Levels

ABSTRACTSince the 23-valent pneumococcal polysaccharide vaccine (PPV23) is less effective for older adults than for young adults, it is important to investigate the immunologic basis for the reduced efficacy of PPV23 among older adults. We determined the effectiveness of PPV23 among young (n= 55) and older (n= 44) adults by measuring the serum IgG, IgM, and IgA concentrations and opsonic capacities against serotypes 14, 18C, and 23F. While young and older adults showed no difference in levels of IgG antibodies against pneumococcal polysaccharide (PPS), older adults had lower IgA and IgM antibody levels than young adults for all three serotypes. In both age groups, anti-PPS IgA or IgM antibody levels were much lower than anti-PPS IgG antibody levels. Young adults showed higher opsonic capacities than older adults for serotypes 14 and 23F. In order to determine the effects of anti-PPS IgA or IgM antibodies on the functional difference between young and older adults, anti-PPS IgA or IgM antibodies were removed from immune sera by affinity chromatography. The difference in opsonic capacity between young and older adults disappeared for serotypes 14 and 23F (but not for serotype 18C) when IgM antibody was removed. However, there was no significant difference between the two age groups when IgA antibody was removed. In conclusion, even though anti-PPS IgG antibody levels are high compared with anti-PPS IgM antibody levels, the low levels of anti-PPS IgM antibody alone can explain the functional difference observed between young and older adults immunized with PPV23 with regard to some pneumococcal serotypes.

scholarly journals Seroprevalence of an antibody against diphtheria, tetanus, and pertussis among the elderly in Khon Kaen, Thailand

2019 ◽  
Vol 38 (1) ◽  
Author(s):  
Teeraporn Chinchai ◽  
Nawarat Posuwan ◽  
Viboonsak Vuthitanachot ◽  
Nasamon Wanlapakorn ◽  
Yong Poovorawan
Keyword(s):  
Infectious Diseases ◽  
Herd Immunity ◽  
Age Groups ◽  
Significant Risk ◽  
The Elderly ◽  
Diphtheria Toxoid ◽  
Serum Samples ◽  
Igg Antibody ◽  
Thai Population ◽  
Antibody Levels

Abstract Background Owing to a declining birth rate and longer lifespan, the number of elderly people (≥ 60 years) in Thailand has grown rapidly. However, the elderly are at significant risk of infectious diseases because they have never been immunized, because they have not been completely immunized, or because their immunity has waned. Immunity against infectious diseases in the elderly is an important means of controlling diseases in the community. Our objective was to evaluate the seroprotective rate against diphtheria, tetanus, and pertussis in the elderly Thai population. Methods In total, 430 healthy individuals from the northeastern region of Thailand were enrolled in this study and stratified into five age groups: 60–65, 66–70, 71–75, 76–80, and > 80 years. Serum samples were collected and quantitatively analyzed for diphtheria, tetanus, and pertussis IgG antibody by using commercial ELISA kits. For anti-diphtheria toxoid and anti-tetanus toxoid ELISA, values < 0.01 IU/ml were interpreted as seronegative, and for anti-Bordetella pertussis toxin ELISA, values < 5 IU/ml were interpreted as seronegative; these definitions were in accord with previous studies. Results For diphtheria toxoid Ab, the majority of the population had antibody levels > 0.01 IU/ml. For tetanus anti-toxoid Ab, the majority of the population had antibody levels of > 0.01 IU/ml, of which approximately 34% had durable antibody protection levels (DAPL) of ≥ 1 IU/ml. Meanwhile, nearly 45% of the population had an Ab level against pertussis lower than the protectivity level. Conclusions In total, 97.2%, 83.5%, and 55.8% of the population had a higher antibody level than the minimal protective level for diphtheria, tetanus, and pertussis, respectively. In order to prevent an outbreak of these diseases in the future, the elderly should be administered with Tdap revaccination to provide diphtheria herd immunity in the population; this will increase cocoon phenomenon for pertussis and protect the population from tetanus-prone injury.

scholarly journals SARS-CoV-2 natural antibody response persists up to 12 months in a nationwide study from the Faroe Islands

2021 ◽  
Author(s):  
Maria Skaalum Petersen ◽  
Cecilie Bo Hansen ◽  
Marnar Fridheim Kristiansen ◽  
Jogvan Pall Fjallsbak ◽  
Solrun Larsen ◽  
...  
Keyword(s):  
Disease Onset ◽  
Age Groups ◽  
Pairwise Comparison ◽  
Antibody Binding ◽  
Natural Immunity ◽  
Faroe Islands ◽  
Igg Antibody ◽  
Time Points ◽  
Humoral Immune ◽  
Antibody Levels

Only a few studies have assessed the long-term duration of the humoral immune response against severe acute respiratory syndrome coronavirus 2 (SARS–CoV–2). In this nationwide longitudinal study from the Faroe Islands with close to full participation of all individuals on the Islands with PCR confirmed COVID-19 during the two waves of infections in the spring and autumn 2020 (n=172 & n=233), samples were drawn at three longitudinal time points (3, 7 and 12 months and 1, 3 and 7 months after disease onset, respectively). Serum was analyzed with a direct quantitative IgG antibody binding ELISA to detect anti–SARS–CoV–2 spike RBD antibodies and a commercially available qualitative sandwich RBD ELISA kit measuring total antibody binding. The seropositive rate in the convalescent individuals was above 95 % at all sampling time points for both assays. There was an overall decline in IgG titers over time in both waves (p < 0.001). Pairwise comparison showed that IgG declined significantly from the first sample until approximately 7 months in both waves (p < 0.001). After that, the antibody level still declined significantly (p < 0.001), but decelerated with an altered slope remaining fairly stable from 7 months to 12 months after infection. Interestingly, the IgG titers followed a U-shaped curve with higher antibody levels among the oldest (67+) and the youngest (0–17) age groups compared to intermediate groups (p < 0.001). Our results indicate that COVID–19 convalescent individuals are likely to be protected from reinfection up to 12 months after symptom onset and maybe even longer. We believe our results can add to the understanding of natural immunity and the expected durability of SARS–CoV–2 vaccine immune responses.

scholarly journals Evolution of Anti-SARS-CoV-2 IgG Antibody and IgG Avidity Post Pfizer and Moderna mRNA Vaccinations

2021 ◽  
Author(s):  
Kevin P. Bliden ◽  
Tiancheng Liu ◽  
Deepika Sreedhar ◽  
Jessica Kost ◽  
Jessica Hsiung ◽  
...  
Keyword(s):  
Immune Responses ◽  
Messenger Rna ◽  
Point Of Care ◽  
Rapid Test ◽  
Similar Efficacy ◽  
Igg Antibody ◽  
Post Vaccination ◽  
Igg Avidity ◽  
Protein Receptor ◽  
Antibody Levels

Messenger RNA (mRNA) based vaccines (Pfizer/BioNTech and Moderna) are highly effective at providing immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, there is uncertainty about the duration of immunity, evolution of IgG antibody levels and IgG avidity (an index of antibody-antigen binding strength), and differences in the immune responses between vaccines. Here we performed a prospective pilot study of 71 previously COVID-19 free subjects upon receiving both doses of either the Pfizer (n = 54) or Moderna (n = 17) mRNA vaccine. Anti-spike protein receptor binding domain (RBD) IgG antibodies were measured longitudinally using a qualitative finger stick MidaSpot rapid test at the point-of-care for initial screening and a quantitative dry blood spot-based pGOLD laboratory test over ~ four months post-vaccination. The average anti-RBD IgG antibody levels peaked at ~ two weeks after the second dose vaccine and declined thereafter, while antibody avidity increased, suggesting antibody maturation. Moderna vaccine recipients compared to Pfizer vaccine recipients exhibited higher side effect severity, higher peak anti-RBD IgG antibody levels, and higher avidity up to the 90 days period. Differences in antibody levels diminished at ~ 120 days post-vaccination, in line with the similar efficacy observed in the two vaccines. The MidaSpot rapid test detected 100% anti-SARS-CoV-2 RBD positivity for fully vaccinated subjects in both Pfizer and Moderna cohorts post full vaccination but turned negative greater than 90 days post-vaccination for 5.4% of subjects in the Pfizer cohort, whose quantitative anti-IgG were near the minimum levels of the group. Immune responses were found to vary greatly among vaccinees. Personalized longitudinal monitoring of antibodies could be necessary to assessing the immunity duration of vaccinated individuals.

scholarly journals Effectiveness of the mRNA BNT162b2 vaccine six months after vaccination: findings from a large Israeli HMO

2021 ◽  
Author(s):  
Jennifer Kertes ◽  
Sharon Baruch Gez ◽  
Yaki Saciuk ◽  
Lia Supino-Rosin ◽  
Naama Shamir Stein ◽  
...  
Keyword(s):  
Vaccination Campaign ◽  
Age Groups ◽  
New Wave ◽  
Risk Of Infection ◽  
Infection Rates ◽  
Igg Antibody ◽  
Booster Vaccine ◽  
Using Data ◽  
Antibody Levels ◽  
The Relationship

Israel is currently experiencing a new wave of CoVid-19 infection, six months after implementing a national vaccination campaign. We carried out three discrete analyses using data from a large Israeli HMO to determine whether IgG levels of those fully vaccinated drop over time, the relationship between IgG titer and subsequent PCR-confirmed infection, and compare PCR-confirmed infection rates by period of vaccination. We found that mean IgG antibody levels steadily decreased over the six-month period in the total tested population, and in all age groups. An inverse relationship was found between IgG titer and subsequent CoVid-19 infection (PCR-positive). Those participants vaccinated in the first two months of the campaign were more likely to become infected than those subsequently vaccinated. The 60+ vaccinated had lower initial IgG levels, and were at greater risk of infection. The findings support the decision to add a booster vaccine for those aged 60 and over.

scholarly journals Evaluation of Toxoplasma, Rubella, and Cytomegalovirus serological results in women of childbearing age

2020 ◽  
Vol 66 (6) ◽  
pp. 789-793
Author(s):  
Fatma Avcioglu ◽  
Mustafa Behcet ◽  
Muhammet Guzel Kurtoglu
Keyword(s):  
Toxoplasma Gondii ◽  
Primary Infection ◽  
Women Of Childbearing Age ◽  
Childbearing Age ◽  
Igg Antibody ◽  
Congenital Infections ◽  
Igm Antibodies ◽  
Igg Avidity ◽  
Antibody Levels ◽  
University Training

SUMMARY OBJECTIVE This study aimed to determine the rates of IgG and IgM antibodies against cytomegalovirus, rubella, and Toxoplasma gondii (all of which may cause congenital infections) in women of childbearing age who were admitted to Bolu Abant İzzet Baysal University Training and Research Hospital. METHODS Between January 2015 and December 2017, Toxoplasma gondii, rubella, and cytomegalovirus IgM and IgG antibody levels were studied using the ELISA method (Architect i2000SR, Abbott, Germany) in patients aged 15 to 45 who attended the obstetrics and gynecology outpatient clinics. Toxoplasma gondii and cytomegalovirus IgG avidity levels were analyzed retrospectively. RESULTS A total of 13.470 tests were conducted in the laboratory. Seropositivity percentages of IgM antibodies were found to be 1.3%, 0.5%, and 1.6% for Toxoplasma (n = 3607), rubella (n = 3931), and cytomegalovirus (n = 3795), respectively. The seropositivity percentages of IgG antibodies were 22%, 94.2%, and 98.2% for Toxoplasma (n = 702), rubella (n = 693), and cytomegalovirus (n = 679), respectively. Primary infection (acute, recently acquired) was found in 7 (35%) patients with low Toxoplasma IgG avidity. One (3%) patient with low cytomegalovirus IgG avidity had a primary infection. CONCLUSION Toxoplasma gondii seronegativity was found to be high in the region. Therefore, screening women of childbearing age may be important for the prevention of congenital infections caused by Toxoplasma gondii.

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